Local noncuppability in R/M

Given any [c],[a],[d]∈R/M such that [d]≤[a]≤[c], [a] is locally noncuppable between [c] and [d] if [d]<[a]≤[c]and [a] ∨ [b] < [c] for any [b]∈R/M such that [d]≤ [ b ] < [ c ]. It will be shown that given any nonzero [ c ] ∈ R/M, there are [ a ], [ d ] ∈R/M such that [d]<[a]≤[c] and[a] is locally noncuppable between [c] and[d].     

From liveness to promptness

Liveness temporal properties state that something “good” eventually happens, e.g., every request is eventually granted. In Linear Temporal Logic (LTL), there is no a priori bound on the “wait time” for an eventuality to be fulfilled. That is, F θ asserts that θ holds eventually, but there is no bound on the time when θ will hold. This is troubling, as designers tend to interpret an eventuality F θ as an abstraction of a bounded eventuality F ^≤k θ, for an unknown k, and satisfaction of a liveness property is often not acceptable unless we can bound its wait time. We introduce here prompt-LTL, an extension of LTL with the prompt-eventually operator F _p . A system S satisfies a prompt-LTL formula φ if there is some bound k on the wait time for all prompt-eventually subformulas of φ in all computations of S. We study various problems related to prompt-LTL, including realizability, model checking, and assume-guarantee model checking, and show that they can be solved by techniques that are quite close to the standard techniques for LTL.     

Buoyant surface jet analysis of the Yukon River

Abstract

Thermal infrared satellite imagery of the discharge from the Yukon River obtained on 5 July 1985 was compared with hydraulic theory for the dilution of buoyant surface jets. In a crossflow, the theory predicts that the plume will follow an x ^1/3 trajectory where x is distance alongshore, and that the plume temperature will decay according to x ^–1/6 due to mixing with the receiving water. Measurements of the Yukon River discharge indicate very good agreement with the predicted trajectory, and less, but acceptable, agreement with the predicted dilution. Large scale thermal fronts are also observable in the thermal imagery; the fronts may be associated with excursions of the plume due to tidal currents.     

Automatic training of a min-max neural network for function approximation by using a second feed forward network

This research is concerned with a gradient descent training algorithm of a min-max network which we will refer to as the target network. Training makes use of a helper feed-forward network (FFN) to represent the performance function used in training the target network. A helper FFN is trained because the mathematical form of the performance function for the target network in terms of its trainable parameters, p, is not differentiable. Values for the parameter vector, p, of the target network are generated randomly and performance values are determined to produce the data for training the helper FFN with its own connection matrices. Thus we find an approximation to the mathematical relationship between performance values and p by training an FFN. The input to this FFN is a value for p and the output is a performance measure. The transfer function of the helper FFN provides a differentiable function for the performance function of the parameter vector, p, for the target network allowing gradient search methods for finding the optimum p for the target network. The method is successfully tried in approximating a given function and also on training data produced by a randomly selected min-max network.     

Data Encryption

Abstract

The Generally Accepted System Security Principles (GASSP) Committee has approved this release of the GASSP for public comment. The introductory materials and the sections through and including Section 2.1 Pervasive Principles are included for the reader's information only. Pervasive Principles have previously had a public comment period. The GASSPC asks the profession to review and comment on Section 2.2 Broad Functional Principles (the majority of the document). Section 2.3 Detailed Security Principles remains a work in progress that will be built on theBroad Functional Principles. We welcome your comments on all aspects of the document; however, we ask that you concentrate on substantive matters rather than editorial.     

Summary and prospects: occupational health and safety

Abstract

This summary covers three conference sessions on occupational health and safety, of which six papers are included in this issue of Ergonomics. Based on these sessions we will comment on the role of ergonomics programmes in occupational health and safety in industry. The summary is divided into the following topics: goal, international aspects, epidemiology, team consideration, problem analysis, development of solutions, implementation and evaluation.     

Quantum models of cognition and decision

Abstract

The purpose of this article is to discuss principle ideas of quantum cognition research program, which comprise elements of the formalism of quantum mechanics (mainly Hilbert space theory and quantum probability theory) for modeling human cognition and decision processes. In the opinion of authors of this program, paradox empirical findings in psychological literature may be explained based on concepts of quantum mechanics. Formally, there is described a discrete-time random chain χ which is defined on a finite interval [0, T] and χ(t) can assume only finite number of values. The space H of such processes will be finite-dimensioned. Then some properties and applications of the quantum probability space on H are studied.     

On a gauntlet thrown by David Gries

Summary It is requested to design a program that will generate the N! permutations of the values from 0 through N — 1 in such an order that the transition from one permutation to the next is always performed by exactly one swap of two neighbours.     

Globalization of Services: GATT,NAFTA, and the Threat to Information Security

Abstract

The security spending survey by Information Security(http://www.infosecuritymag.com/2003/may/coverstory.pdf) and recent research by Forrester indicate that deployment rates of many security technologies will soar in the next three years. According to some estimates, security budgets (and thus technology purchases) will double by 2006.     

The Complexity of Flood Filling Games

We study the complexity of the popular one player combinatorial game known as Flood-It. In this game the player is given an n×n board of tiles where each tile is allocated one of c colours. The goal is to make the colours of all tiles equal via the shortest possible sequence of flooding operations. In the standard version, a flooding operation consists of the player choosing a colour k, which then changes the colour of all the tiles in the monochromatic region connected to the top left tile to k. After this operation has been performed, neighbouring regions which are already of the chosen colour k will then also become connected, thereby extending the monochromatic region of the board. We show that finding the minimum number of flooding operations is NP-hard for c≥3 and that this even holds when the player can perform flooding operations from any position on the board. However, we show that this ‘free’ variant is in P for c=2. We also prove that for an unbounded number of colours, Flood-It remains NP-hard for boards of height at least 3, but is in P for boards of height 2. Next we show how a (c−1) approximation and a randomised 2c/3 approximation algorithm can be derived, and that no polynomial time constant factor, independent of c, approximation algorithm exists unless P=NP. We then investigate how many moves are required for the ‘most demanding’ n×n boards (those requiring the most moves) and show that the number grows as fast as Q(?c n)\Theta(\sqrt{c}\, n). Finally, we consider boards where the colours of the tiles are chosen at random and show that for c≥2, the number of moves required to flood the whole board is Ω(n) with high probability.     

Generation of robust root loci for linear systems with parametric uncertainties in an ellipsoid

Given a parametric polynomial family p(s; Q) := {ⁿ _k=0 a_k (q)s^k : q ] Q}, Q R ^m , the robust root locus of p(s; Q) is defined as the two-dimensional zero set _p,Q := {s ] C:p(s; q) = 0 for some q ] Q}. In this paper we are concerned with the problem of generating robust root loci for the parametric polynomial family p(s; E) whose polynomial coefficients depend polynomially on elements of the parameter vector q ] E which lies in an m-dimensional ellipsoid E. More precisely, we present a computational technique for testing the zero inclusion/exclusion of the value set p(z; E) for a fixed point z in C, and then apply an integer-labelled pivoting procedure to generate the boundary of each subregion of the robust root locus _p,E . The proposed zero inclusion/exclusion test algorithm is based on using some simple sufficient conditions for the zero inclusion and exclusion of the value set p(z,E) and subdividing the domain E iteratively. Furthermore, an interval method is incorporated in the algorithm to speed up the process of zero inclusion/exclusion test by reducing the number of zero inclusion test operations. To illustrate the effectiveness of the proposed algorithm for the generation of robust root locus, an example is provided.     

正交约束多头自注意力的场景文本识别

目的 场景文本识别（scene text recognition，STR）是计算机视觉中的一个热门研究领域。最近，基于多头自注意力机制的视觉Transformer （vision Transformer，ViT）模型被提出用于STR，以实现精度、速度和计算负载的平衡。然而，没有机制可以保证不同的自注意力头确实捕捉到多样性的特征，这将导致使用多头自注意力机制的ViT模型在多样性极强的场景文本识别任务中表现不佳。针对这个问题，提出了一种新颖的正交约束来显式增强多个自注意力头之间的多样性，提高多头自注意力对不同子空间信息的捕获能力，在保证速度和计算效率的同时进一步提高网络的精度。方法 首先提出了针对不同自注意力头上Q （query）、K （key）和V （value）特征的正交约束，这可以使不同的自注意力头能够关注到不同的查询子空间、键子空间、值子空间的特征，关注不同子空间的特征可以显式地使不同的自注意力头捕捉到更具差异的特征。还提出了针对不同自注意力头上Q 、K 和V 特征线性变换权重的正交约束，这将为Q、K和V特征的学习提供正交权重空间的解决方案，并在网络训练中带来隐式正则化的效果。结果 实验在7个数据集上与基准方法进行比较，在规则数据集Street View Text （SVT）上精度提高了0.5%；在不规则数据集CUTE80 （CT）上精度提高了1.1%；在7个公共数据集上的整体精度提升了0.5%。结论 提出的即插即用的正交约束能够提高多头自注意力机制在STR任务中的特征捕获能力，使ViT模型在STR任务上的识别精度得到提高。本文代码已公开： https：//github.com/lexiaoyuan/XViTSTR。     

Moments With Jacques Rancière: Sketches From a Lived Pedagogical Experiment in an Elementary Science Classroom

Abstract:

The work of Jacques Rancière has become rather popular of late, with a series of high-profile advocates. In this article, we reflect on an elementary classroom and an experiment with pedagogy inspired by Rancière's (1991) text, The Ignorant Schoolmaster. The authors discuss the text, outline a 20-lesson response that emerged from the study (focusing on reading-as-inquiry), and highlighting some of the possibilities, tensions, and ambiguities involved. The article concludes with discussion of how we sought to make sense of, and redistribute, our roles as science teacher-researchers by embracing teaching, will, and instability. We suggest becoming ignorant schoolmasters, wandering beyond the domain of the sensible, as we struggle to come to different terms with our political work.     

Using Personal Traces in Context Space: Towards Context Trace Technology

Wearables are often described with a focus on providing the user with wearable information access and communication means. The contextual information retrieval aspect is, however, an essential feature of such systems, as in, for example, the Remembrance Agent [1] where manually entered search-terms are used for presenting relevant situational information, or as in different location-based systems [2]. In this position paper we outline a general framework of contextually aware wearable systems, and suggest how such mechanisms, collecting massive traces of the user context, may lead to several other interesting uses in what we will call context trace technology.     

Computing the Treewidth and the Minimum Fill-In with the Modular Decomposition

Abstract. Using the notion of modular decomposition we extend the class of graphs on which both the treewidth and the minimum fill-in can be solved in polynomial time. We show that if C is a class of graphs that are modularly decomposable into graphs that have a polynomial number of minimal separators, or graphs formed by adding a matching between two cliques, then both the treewidth and the minimum fill-in on C can be solved in polynomial time. For the graphs that are modular decomposable into cycles we give algorithms that use respectively O(n) and O(n ³ ) time for treewidth and minimum fill-in.     

Finite volume discretization and multilevel methods in flow problems

This article is intended as a preliminary report on the implementation of a finite volume multilevel scheme for the discretization of the incompressible Navier-Stokes equations. As is well known the use of staggered grids (e.g. MAC grids, Perićet al. Comput. Fluids,16(4), 389–403, (1988)) is a serious impediment for the implementation of multilevel schemes in the context of finite differences. This difficulty is circumvented here by the use of a colocated finite volume discretization (Faureet al. (2004a) Submitted, Perićet al. Comput. Fluids,16(4), 389–403, (1988)), for which the algebra of multilevel methods is much simpler than in the context of MAC type finite differences. The general ideas and the numerical simulations are presented in this article in the simplified context of a two-dimensional Burgers equations; the two-, and three-dimensional Navier-Stokes equations introducing new difficulties related to the incompressibility condition and the time discretization, will be considered elsewhere (see Faureet al. (2004a) Submitted and Faureet al. (2004b), in preparation).     

The Temporal Precedence Problem

In this paper we analyze the complexity of the Temporal Precedence Problem on pointer machines. The problem is to support efficiently two operations: insert and precedes. The operation insert (a) introduces a new element a , while precedes (a,b) returns true iff element a was temporally inserted before element b . We provide a solution to the problem with worst-case time complexity O( lg lg n) per operation, where n is the number of elements inserted. We also demonstrate that the problem has a lower bound of Ω( lg lg n) on pointer machines. Thus the proposed scheme is optimal on pointer machines. Received February 5, 1998; revised October 21, 1998.     

On solving a special class of weakly nonlinear finite-difference systems

In this paper, we consider the Newton-iterative method for solving weakly nonlinear finite-difference systems of the form F ( u )=A u + G ( u )=0, where the jacobian matrix G′( u ) satisfies an affine invariant Lipschitz condition. We also consider a modification of the method for which we can improve the likelihood of convergence from initial approximations that may be outside the attraction ball of the Newton-iterative method. We analyse the convergence of this damped method in the framework of the line search strategy. Numerical experiments on a diffusion–convection problem show the effectiveness of the method.     

Reduction of the size of L-fuzzy contexts. A tool for differential diagnoses of diseases

ABSTRACT

Information extraction from an L-fuzzy context becomes a hard problem when we work with a large set of objects and/or attributes. The goal of this paper is to present two different and complementary techniques to reduce the size of the context. First, using overlap indexes, we will establish rankings among the elements of the context that will allow us to determine those that do not provide relevant information and eliminate them. Second, by means of Choquet integrals, we will aggregate some objects or attributes of the context in order to jointly use the provided information. One interesting application of the developed theory consists on helping in the differential diagnoses of diseases that share a large number of symptoms and, therefore, that are difficult of distinguish.     

The Difference between Polynomial-Time Many-One and Truth-Table Reducibilities on Distributional Problems

In this paper we separate many-one reducibility from truth-table reducibility for distributional problems in DistNP under the hypothesis that P ≠ NP . As a first example we consider the 3-Satisfiability problem (3SAT) with two different distributions on 3CNF formulas. We show that 3SAT with a version of the standard distribution is truth-table reducible but not many-one reducible to 3SAT with a less redundant distribution unless P = NP . We extend this separation result and define a distributional complexity class C with the following properties: (1) C is a subclass of DistNP, this relation is proper unless P = NP. (2) C contains DistP, but it is not contained in AveP unless DistNP \subseteq AveZPP. (3) C has a ≤ ^p _m -complete set. (4) C has a ≤ ^p _tt -complete set that is not ≤ ^p _m -complete unless P = NP. This shows that under the assumption that P ≠ NP, the two completeness notions differ on some nontrivial subclass of DistNP.