PEN=Paint Every Night =Party Every Night

当涂鸦文化在潮流中兴起．众多的涂鸦艺术家从地下浮出水面．越来越多关于涂鸦的服饰．玩具．书籍，影片．更多的跨领域合作．就好象当前炙手可热的日本街头潮牌BATHING APE与美国纽约的涂鸦大师KAWS在一系列T-SHIRT的设计合作上的成功．涂鸦艺术好象已经不再只是在边缘徘徊。新的一种艺术形式已经广泛被人们所接受。年轻人正在属于他们的潮流中，感受和进行着他们的文化。在中国．涂鸦已经不知不觉经历了几个耐人寻味的时期。一代代的涂鸦青年正演绎着同样有中国特色的涂鸦文化。     

SMB=价格战?

最好、最全、最实用、最便宜,要想把这四点要求全部做到,想来并不是一件容易的事     

Queries = examples + counterexamples

Database queries can be expressed as unordered collections of examples and counterexamples. The resulting languages are intuitive, first order complete, and applicable to a variety of data models including relational, object oriented, and visual models. This class of languages based on examples and counterexamples employ a minimal number of constructs with no sequencing or nesting of the constructs implied, allowing a simple and uniform theoretical analysis of their syntax, semantics, and completeness.     

Numbers Don’t Lie: 1+1=1, 1+1=2, 1+1=3

“Do you think that’s air you’re breathing?”A question posed by Morpheus to Neo in the movie The Matrix.I have a name for my pain and that name is ‘reality.’ What is real? Can you prove that its real? What constitutes proof? And if you can prove that it’s real, I may not accept your version of reality. For example, you may logically prove all foxes are green. I know some that are brunette. Take the mathematical equations in the title. Is the first one true or false? It’s true. In marriage, the union of a man and a woman makes one (social unit). Is the second equation true or false? True again. One person plus one person equals two persons. Is the third equation true or false? It’s also true. Take a man and a woman, add some pixie dust, and poof! You have a child, the third member of a social unit. No, I haven’t gone potty or gone mad trying to solve Mensa puzzles.     

System reduction by Cauer continued-fraction expansion about s = 0 and s = a alternately

A new algorithm to obtain the Cauer continued-fraction expansion (CFE) about the origin and about a general point from the time-moments and weighted time-moments of the impulse response of a linear time-invariant system is presented. Also presented is a systematic approach to deriving a similarity transformation matrix that transforms a general state-space model to a state-space model corresponding to the Cauer CFE about s = 0 and s = a alternately. The transformation matrix enables an approximate relationship to be established to relate the state vector of the original system and that of the reduced model obtained by the CFE about s = 0 and s = a alternately. The step of transformation to phase variable canonical form is thus eliminated.     

An LP-rounding 22-approximation for restricted maximum acyclic subgraph

In the classical Maximum Acyclic Subgraph problem (MAS), given a directed-edge weighted graph, we are required to find an ordering of the nodes that maximizes the total weight of forward-directed edges. MAS admits a 2-approximation, and this approximation is optimal under the Unique Game Conjecture.     

Induction=I-Axiomatization+First-Order Consistency

In the early 1980s, there was a number of papers on what should be called proofs by consistency. They describe how to perform inductive proofs, without using an explicit induction scheme, in the context of equational specifications and ground-convergent rewrite systems. The method was explicitly stated as a first-order consistency proof in the case of pure equational, constructor-based specifications. In this paper, we show how, in general, inductive proofs can be reduced to first-order consistency and hence be performed by a first-order theorem prover. Moreover, we extend previous methods, allowing nonequational specifications (even non-Horn specifications) and designing some specific strategies. Finally, we also show how to drop the ground convergence requirement (which is called Saturatedness for general clauses).     

Fuzzy logic = computing with words

As its name suggests, computing with words (CW) is a methodology in which words are used in place of numbers for computing and reasoning. The point of this note is that fuzzy logic plays a pivotal role in CW and vice-versa. Thus, as an approximation, fuzzy logic may be equated to CW. There are two major imperatives for computing with words. First, computing with words is a necessity when the available information is too imprecise to justify the use of numbers, and second, when there is a tolerance for imprecision which can be exploited to achieve tractability, robustness, low solution cost, and better rapport with reality. Exploitation of the tolerance for imprecision is an issue of central importance in CW. In CW, a word is viewed as a label of a granule; that is, a fuzzy set of points drawn together by similarity, with the fuzzy set playing the role of a fuzzy constraint on a variable. The premises are assumed to be expressed as propositions in a natural language. In coming years, computing with words is likely to evolve into a basic methodology in its own right with wide-ranging ramifications on both basic and applied levels     

A zero-one SUBEXP-dimension law for BPP

We show that BPP has either SUBEXP-dimension zero (randomness is easy) or BPP=EXP (randomness is intractable).     

Timed CSP = Closed Timed Automata

We study the expressive power of an augmented version of Timed CSP and show that it is precisely equal to that of closed timed automatatimed automata with closed invariant and enabling clock constraints. We also show that this new version of Timed CSP is expressive enough to capture the most widely used specifications on timed systems as refinements between processes, and moreover that refinement checking is amenable to digitisation analysis. As a result, we are able to verify some of the most important timed specifications, including branching-time liveness properties such as timestop-freedom and constant availability, using the model checker FDR (a commercial product of Formal Systems (Europe) Ltd.).     

Cauer continued-fraction expansion about s = 0 and s = a for biased reduced-order state-space models

A method of linear-system reduction is presented which produces biased state-space models such that combinations of retained time-moments and weighted time-moments may be varied. The method is based on the concept of representing the system transfer function in a biased Cauer form of continued-fraction expansion (CFE) about s = 0 and s = a. A new algorithm for obtaining the continued-fraction expansion of the transfer function of a linear time-invariant system from its state-space model directly, without first determining the corresponding transfer function, is derived. A realization which uses only integrators for the biased Cauer continued-fraction expansion about s = 0 and s = a is presented. The corresponding canonical state-space model is established, which allows the reduced-order state-space model to be formed by directly partitioning the system matrices. Also presented are two new similarity transformation matrices; one is used to transform a state-space model from a general form to a state-space model in the biased CFE canonical form, and the other is used to transform a state-space model from phase-variable canonical form to the biased CFE canonical form.     

无线局域网络通信安全研究

经过多年的发展,无线局域网己经成为一种比较成熟的技术,应用也越来越广泛,是计算机有线网络的一个必不可少的补充。无线局域网迅速发展的同时,对网络的安全性也提出了更高的要求。文章研究了现阶段无线局域网面临的主要安全问题,并介绍了相应的解决办法。     

Music Tempo Estimation With $k$-NN Regression

An approach for tempo estimation from musical pieces with near-constant tempo is proposed. The method consists of three main steps: measuring the degree of musical accent as a function of time, periodicity analysis, and tempo estimation. Novel accent features based on the chroma representation are proposed. The periodicity of the accent signal is measured using the generalized autocorrelation function, followed by tempo estimation using k-Nearest Neighbor regression. We propose a resampling step applied to an unknown periodicity vector before finding the nearest neighbors. This step improves the performance of the method significantly. The tempo estimate is computed as a distance-weighted median of the nearest neighbor tempi. Experimental results show that the proposed method provides significantly better tempo estimation accuracies than three reference methods.     

PSO + FL = PAASO: particle swarm optimization + federated learning = privacy-aware agent swarm optimization

International Journal of Information Security - In this paper, we present an unified framework that encompasses both particle swarm optimization (PSO) and federated learning (FL). This unified...