On the number of core coverable switching functions

Summary The results of an experimental determination of the number of switching functions covered by essential prime implicants are reported. Switching functions of 5, 6, 7, 8, 9 variables have been investigated.     

Films made from polyethylene‐co‐acrylic acid and soluble biopolymers sourced from agricultural and municipal biowaste

Blends were obtained from polyethylene‐co‐acrylic acid (PEAA) with 248 kDa molecular weight and two water soluble biopolymers isolated from the hydrolysate of postharvest tomato plant and urban biowaste compost. The two hydrolysates were constituted respectively from a polysaccharide (SP) with 27 kDa molecular weight and a lignin‐like polymer (LP) with 75 kDa molecular weight containing aliphatic and aromatic C moieties substituted by carboxyl, hydroxyl, and amino groups. Evidence was obtained for reactions occurring between the biopolymers and the synthetic polymer leading to new polymers with 151 to 1243 kDa molecular weights. The thermal and mechanical properties of the blends were studied. Compared with neat PEAA, the PEAA‐LP blends containing 5 to 10% LP exhibited 2 to 5× higher molecular weights, 10 to 50% lower crystallinity, 2 to 6× higher Young's modulus, over 3× higher stress at yield point and somewhat lower strain at break (55–280% vs. over 300%). On the contrary the PEAA‐SP blends exhibited 6 to 13% lower crystallinity and the same mechanical properties as neat PEAA. The results offer scope for investigating biopolymers sourced from other biowastes to understand more the reasons of the observed effects and exploit their full potential to modify or to replace synthetic polymers. Perspectives of economic and environmental benefits are discussed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41909.     

Advantages of continuous hyperpolarized arrest with pinacidil over St. Thomas'' Hospital solution during prolonged ischemia

vlf-1 is a baculovirus gene that regulates very late gene expression (J. R. McLachlin and L. K. Miller, J. Virol., 68, 7746-7756, 1994) and also plays a crucial role in the replication of the budded form of Autographa californica nuclear polyhedrosis virus (AcMNPV) (S. Yang and L. K. Miller, "Expression and mutational analysis of the baculovirus very late factor 1 (vlf-1) gene." Virology, 245, 99-109, 1998). To examine the influence of vlf-1 expression on baculovirus infection, we constructed recombinant viruses that expressed only low levels of VLF-1 and recombinants with vlf-1 under the control of different promoters. Viruses with mutant alleles of vlf-1 that produced low levels of VLF-1 replicated the budded form of the virus normally but produced no occlusion bodies. Thus, a higher concentration of VLF-1 was needed to activate very late gene expression than was needed to support budded virus production. By altering the level and/or timing of vlf-1 expression, the timing of polyhedrin gene (polh) expression, which normally occurs very late in infection, could be advanced or delayed. Early overexpression of vlf-1 increased the level of expression from the polh promoter but caused premature cellular disintegration. The data indicate that VLF-1 is the limiting factor in very late gene expression and that the level of VLF-1 controls the onset of occlusion.     

Using Bounded Model Checking for Coverage Analysis of Safety-Critical Software in an Industrial Setting

Testing and Bounded Model Checking (BMC) are two techniques used in Software Verification for bug-hunting. They are expression of two different philosophies: testing is used on the compiled code and it is more suited to find errors in common behaviors, while BMC is used on the source code to find errors in uncommon behaviors of the system. Nowadays, testing is by far the most used technique for software verification in industry: it is easy to use and even when no error is found, it can release a set of tests certifying the (partial) correctness of the compiled system. In the case of safety critical software, in order to increase the confidence of the correctness of the compiled system, it is often required that the provided set of tests covers 100% of the code. This requirement, however, substantially increases the costs associated to the testing phase, since it often involves the manual generation of tests. In this paper we show how BMC can be productively applied to the Software Verification process in industry. In particular, we show how to productively use a Bounded Model Checker for C programs (CBMC) as an automatic test generator for the Coverage Analysis of Safety Critical Software. In particular, we experimented CBMC on a subset of the modules of the European Train Control System (ETCS) of the European Rail Traffic Management System (ERTMS) source code, an industrial system for the control of the traffic railway, provided by Ansaldo STS. The Code of the ERTMS/ETCS, with thousands of lines, has been used as trial application with CBMC obtaining a set of tests satisfying the target 100% code coverage, requested by the CENELEC EN50128 guidelines for software development of safety critical systems. The use of CBMC for test generation led to a dramatic increase in the productivity of the entire Software Development process by substantially reducing the costs of the testing phase. To the best of our knowledge, this is the first time that BMC techniques have been used in an industrial setting for automatically generating tests achieving full coverage of Safety-Critical Software. The positive results demonstrate the maturity of Bounded Model Checking techniques for automatic test generation in industry.     

An approach and an Eclipse-based environment for enhancing the navigation structure of Web sites

This paper presents an approach based on information retrieval and clustering techniques for automatically enhancing the navigation structure of a Web site for improving navigability. The approach increments the set of navigation links provided in each page of the site with a semantic navigation map, i.e., a set of links enabling navigating from a given page to other pages of the site showing similar or related content. The approach uses Latent Semantic Indexing to compute a dissimilarity measure between the pages of the site and a graph-theoretic clustering algorithm to group pages showing similar or related content according to the calculated dissimilarity measure. AJAX code is finally used to extend each Web page with an associated semantic navigation map. The paper also presents a prototype of a tool developed to support the approach and the results from a case study conducted to assess the validity and feasibility of the proposal.     

Epidemicity of cholera spread and the fate of infection control measures

The fate of ongoing infectious disease outbreaks is predicted through reproduction numbers, defining the long-term establishment of the infection, and epidemicity indices, tackling the reactivity of the infectious pool to new contagions. Prognostic metrics of unfolding outbreaks are of particular importance when designing adaptive emergency interventions facing real-time assimilation of epidemiological evidence. Our aim here is twofold. First, we propose a novel form of the epidemicity index for the characterization of cholera epidemics in spatial models of disease spread. Second, we examine in hindsight the survey of infections, treatments and containment measures carried out for the now extinct 2010–2019 Haiti cholera outbreak, to suggest that magnitude and timing of non-pharmaceutical and vaccination interventions imply epidemiological responses recapped by the evolution of epidemicity indices. Achieving negative epidemicity greatly accelerates fading of infections and thus proves a worthwhile target of containment measures. We also show that, in our model, effective reproduction numbers and epidemicity indices are explicitly related. Therefore, providing an upper bound to the effective reproduction number (significantly lower than the unit threshold) warrants negative epidemicity and, in turn, a rapidly fading outbreak preventing coalescence of sparse local sub-threshold flare-ups.     

Geothermal contribution to greenhouse heating

Plant freezing and plant-growth inhibition are among the major problems in greenhouse cultivation in the central part of Argentina. The possibility of using a constant temperature underground geothermal water source, which flows naturally, has been studied as an economic option to solve these problems. A system of heating by means of geothermal energy, with energy-conservation measures, was designed and evaluated for typical production greenhouses in the southern part of Córdoba, Argentina. The results of tests carried out during 3 years are presented. These results are really promising, taking into account the high benefit/cost relation of the design and the availability of similar geothermal resources in many farms of this region.     

Penalized factor mixture analysis for variable selection in clustered data

A model-based clustering approach which contextually performs dimension reduction and variable selection is presented. Dimension reduction is achieved by assuming that the data have been generated by a linear factor model with latent variables modeled as Gaussian mixtures. Variable selection is performed by shrinking the factor loadings though a penalized likelihood method with an L1 penalty. A maximum likelihood estimation procedure via the EM algorithm is developed and a modified BIC criterion to select the penalization parameter is illustrated. The effectiveness of the proposed model is explored in a Monte Carlo simulation study and in a real example.     

Benchmarking parallel processing platforms: an applicationsperspective

Given the increased availability of general purpose parallel computers two issues arise: One needs to compare the performance of the different available platforms using realistic examples, and it is necessary to write application software that can be ported easily in order to take advantage of different platforms. The authors address these issues from an applications point of view. They are interested in the use of general purpose parallel computers for simulation tasks needed during the design of very large scale integrated (VLSI) circuits. They characterize the simulation task as a useful benchmark and introduce a high level process view of parallel simulation that is helpful for deriving portable parallel programs. Details of the partitioning strategy and the simulation algorithm used in the application are given. They discuss their implementation on different parallel machines and give statistics of various experiments     

A novel approach to speed and parameters estimation in inductionmotor drives

With reference to speed controlled induction motor drives, an algorithm which allows the on-line estimation either of the speed and one motor parameter or, alternatively, of two motor parameters, is presented in the paper. The results obtained by simulation fully confirm the validity of the proposed algorithm. Finally, the problems arising from the implementation of the proposed algorithm on a DSP-based control hardware are analysed