Phonetic Alignment and Similarity

The computation of the optimal phonetic alignment andthe phonetic similarity between wordsis an important step in many applications in computational phonology,including dialectometry.After discussing several related algorithms,I present a novel approach to the problem that employsa scoring scheme for computing phonetic similarity between phonetic segmentson the basis of multivalued articulatory phonetic features.The scheme incorporates the key concept of feature salience,which is necessary to properly balance the importance of various features.The new algorithm combines several techniquesdeveloped for sequence comparison:an extended set of edit operations,local and semiglobal modes of alignment,and the capability of retrieving a set of near-optimal alignments.On a set of 82 cognate pairs,it performs better than comparable algorithms reported in the literature.     

Probabilistic Algorithms for the Wake-Up Problem in Single-Hop Radio Networks

We consider the problem of waking up n processors in a completely broadcast system. We analyze this problem in both globally and locally synchronous models, with or without n being known to the processors and with or without labeling of the processors. The main question we answer is: how fast we can wake up all the processors with probability 1 - ε in each of these eight models? In [12] a logarithmic waking algorithm for the strongest set of assumptions is described, while for weaker models only linear and quadratic algorithms were obtained. We prove that in the weakest model (local synchronization, no knowledge of n or labeling) the best waking time is O(n/log n). We also show logarithmic or polylogarithmic probabilistic waking algorithms for all stronger models, which in some cases gives an exponential improvement over previous results.     

Spatial averages for linear elements for two-parameter random field

The paper deals with the modelling of the soil medium as a random field. The necessity of using local random averages in numerical and analytical stochastic calculations are the main interest. The paper concentrates on linear elements and on the calculation of the variances and covariances of local random variables averaged over these elements. Several equations are derived by analytical integration, both for isotropic and anisotropic random fields. These should be useful for calculation, analysis and a better understanding of the influence of the geometry of elements and the value of parameters of random fields on the covariances of local averages.     

On the Structure of Mizar Types

The aim of this paper is to develop a formal theory of Mizar types. The examples are extracted from Mizar Mathematical Library (MML), some of them are simplified or presented in a bit different way. The presented theory is an approach to the structure of Mizar types as a sup-semilattice with widening (subtyping) relation as the order. It is an abstraction from the existing implementation of the Mizar verifier by Andrzej Trybulec and Czesław Byliński. The theory describes the structure of types of the base fragment of Mizar language.     

Toward Maximizing the Quality of Results of Dependent Tasks Computed Unreliably

This paper studies the problem of maximizing the number of correct results of dependent tasks computed unreliably. We consider a distributed system composed of a reliable server that coordinates the computation of a massive number of unreliable workers. Any worker computes correctly with probability p < 1. Any incorrectly computed task corrupts all dependent tasks. The goal is to determine which tasks should be computed by the (reliable) server and which by the (unreliable) workers, and when, so as to maximize the expected number of correct results, under a constraint d on the computation time. This problem is motivated by distributed computing applications that persist partial results of computations for future use in other computations and that want to ensure that the persisted results are of high quality. We show that this optimization problem is NP-hard. Then we study optimal scheduling solutions for the mesh with the tightest deadline. We present combinatorial arguments that describe all optimal solutions for two ranges of values of worker reliability p, when p is close to zero and when p is close to one.     

The Feasibility of Launching Rogue Transmitter Attacks in Indoor Visible Light Communication Networks

One of the areas in which wireless networks based on visible light communication (VLC) are considered superior to traditional radio-based communication is security. The common slogan summarizing VLC security features is: WYSIWYS—”What You See Is What You Send”. However, especially in the case of infrastructure downlink communication, security with respect to data snooping, jamming and modification must be carefully provided for. This paper examines the physical layer aspects of VLC networks with respect to possible disruptions caused by rogue transmitters. We present the theoretical system model that we use in simulations to evaluate various rogue transmission scenarios in a typical indoor environment. We use estimated bit error rate as a measure of the effectiveness of jamming and rogue data transmission. We find that it is quite easy to disrupt, and in some cases to even hijack legitimate transmission.

     

Optimization-based method for calculating water networks with user specified characteristics

This paper addresses problem of designing water usage network that consists of fixed flow rate water using processes. A design method is founded on the solution of mixed-integer linear programming (MILP) model of network superstructure. The application of optimization to solve basic formulation of network synthesis has been reported in some works. However, this approach applies certain extensions of the standard formulation that allow accounting for several industrial scenarios. In particular, it is possible to apply various performance indices and imposing conditions on continuous variables as well as on network topology. Multiple contaminant case is easily accounted for. At least but not at last, the method is able to generate several solutions of identical values of major performance indices but of different structure and other features. All these possibilities are available within single optimization framework. Several examples are given to illustrate advantages of the approach.     

Water network design with stochastic optimization approach

Water network (called also water allocation) problem has been addressed in more than 200 papers to date – see recent reviews by Je?owski (2010) and Foo (2009). Though various solution methods have been developed they all have some limitations. This paper addresses water usage network with regeneration processes. Multiple contaminants and two types of water using processes are taken into regard. Simultaneous one stage optimization method was developed to synthesize the network. In order to solve complex MINLP formulation we propose to apply meta-heuristic optimization – adaptive random search method.The paper contains detailed solution algorithm. Several examples with specific features are solved to show efficiency and flexibility of the approach.