Deployment strategies for distributed complex event processing

Several complex event processing (CEP) middleware solutions have been proposed in the past. They act by processing primitive events generated by sources, extracting new knowledge in the form of composite events, and delivering them to interested sinks. Event-based applications often involve a large number of sources and sinks, possibly dispersed over a wide geographical area. To better support these scenarios, the CEP middleware can be internally built around several, distributed processors, which cooperate to provide the processing and routing service. This paper introduces and compares different deployment strategies for a CEP middleware, which define (i) how the processing load is distributed over different processors and (ii) how these processors interact to produce the required results and to deliver them to sinks. Our evaluation compares the presented solutions and shows their benefits with respect to a centralized deployment, both in terms of network traffic and in terms of forwarding delay.     

Thermo-mechanical response of poly(methyl methacrylate) (PMMA) large volumes exposed to time-dependent environmental conditions

Low thermal conductivity and elevated absorbance of large bulky volumes of poly(methyl methacrylate) (PMMA) exposed to moderately aggressive environmental conditions may cooperate to determine critical mechanical conditions, kindling unexpected high thermal stresses values which lead the material to failure. From the engineering point of view, this can be explained as the result of two concomitant phenomena which activate a cascade of events: very sharp thermal gradients engendered by transient thermal processes induced by cyclic environmental conditions, combined with significant bulk heat generation due to the high thermal inertia of massive PMMA volumes, in turn aggravating the steepness of the thermal gradients, may in fact ingenerate severe stress regimes, potentially undermining the structural stability of the material. Moving from these considerations, the present study is aimed to investigate possible rupture of PMMA blocks experiencing heating processes as a consequence of their exposure to outdoor cyclic environmental conditions. The problem is approached by means of both rigorous analytical arguments and the Finite Element based numerical methods, finally exploiting the theoretical outcomes to formulate a hypothesis which might explain the still unclear phenomenon of the sudden breaking of the PMMA structure, named Huge Wine Glass and designed by the world famous Japanese architect Toyo Ito, which occurred in Pescara (Italy) in 2009.     

Airbrush spray-coating of polymer bulk-heterojunction solar cells

We report on the fabrication of efficient polymer solar cells via airbrush coating as a promising method for low cost and large area production. We used a dual action airbrush for deposition of the active layer from a poly(3-hexylthiophene):[6,6]-Phenyl C61 butyric acid methyl-ester (P3HT:PCBM) blend dissolved in a co-solvent mixture. The resulting devices were measured under AM1.5G conditions and compared with spin-coated ones in air and nitrogen atmosphere. High power conversion efficiencies (η=4.1%) were obtained by optimizing the parameters of the spray system (i.e. film thickness, time of spray, distance between sample and airbrush, substrate temperature, etc.). The measurements also showed good repeatability and uniformity despite a relatively rougher surface.     

Mast Cell Cytokines IL-1, IL-33, and IL-36 Mediate Skin Inflammation in Psoriasis: A Novel Therapeutic Approach with the Anti-Inflammatory Cytokines IL-37, IL-38, and IL-1Ra

Psoriasis (PS) is a skin disease with autoimmune features mediated by immune cells, which typically presents inflammatory erythematous plaques, and is associated with many comorbidities. PS exhibits excessive keratinocyte proliferation, and a high number of immune cells, including macrophages, neutrophils, Th1 and Th17 lymphocytes, and mast cells (MCs). MCs are of hematopoietic origin, derived from bone marrow cells, which migrate, mature, and reside in vascularized tissues. They can be activated by antigen-provoking overexpression of proinflammatory cytokines, and release a number of mediators including interleukin (IL)-1 and IL-33. IL-1, released by activated keratinocytes and MCs, stimulates skin macrophages to release IL-36—a powerful proinflammatory IL-1 family member. IL-36 mediates both innate and adaptive immunity, including chronic proinflammatory diseases such as psoriasis. Suppression of IL-36 could result in a dramatic improvement in the treatment of psoriasis. IL-36 is inhibited by IL-36Ra, which binds to IL-36 receptor ligands, but suppression can also occur by binding IL-38 to the IL-36 receptor (IL-36R). IL-38 specifically binds only to IL-36R, and inhibits human mononuclear cells stimulated with IL-36 in vitro, sharing the effect with IL-36Ra. Here, we report that inflammation in psoriasis is mediated by IL-1 generated by MCs—a process that activates macrophages to secrete proinflammatory IL-36 inhibited by IL-38. IL-37 belongs to the IL-1 family, and broadly suppresses innate inflammation via IL-1 inhibition. IL-37, in murine models of inflammatory arthritis, causes the suppression of joint inflammation through the inhibition of IL-1. Therefore, it is pertinent to think that IL-37 can play an inhibitory role in inflammatory psoriasis. In this article, we confirm that IL-38 and IL-37 cytokines emerge as inhibitors of inflammation in psoriasis, and hold promise as an innovative therapeutic tool.     

Effects of controlled atmosphere on the storage of new apricot cultivars

The storage in refrigerated (0-0.5°C) and controlled atmospheres (5% O₂ and 0-7.5% CO₂) of fruit belonging to two new late-ripening cultivars of apricots (ICAPI-17-COL and ICAPI-30-COL) has been studied to determine their storability and to examine the effect of the CO₂ level on weight decrease, firmness, total titratable acidity (TTA), pH, refractometric degree (RD) and physiological and pathological changes. Both cultivars, but particularly ICAPI-30-COL, proved suitable to store for up to 3 weeks under controlled conditions. Only for ICAPI-30-COL did the development during storage of some ripening parameters (firmness, TTA, pH and RD) seem to be related to CO₂ concentration, showing the importance of varietal influence.     

A constructive heuristic for the Undirected Rural Postman Problem

This paper describes a constructive heuristic for the well-known Undirected Rural Postman Problem. At each iteration, the procedure inserts a connected component of the required edges and performs a local postoptimization. Computational results on a set of benchmark instances with up to 350 vertices show that the proposed procedure is competitive with the classical Frederickson procedure. Its use is recommended when a high-quality solution is needed in a short amount of time (e.g., in laser plotter applications).     

Bayesian reliability assessment of repairable systems during multi-stage development programs

New repairable systems are generally subjected to development programs in order to improve system reliability before starting mass production. This paper proposes a Bayesian approach to analyze failure data from repairable systems undergoing a Test-Find-Test program. The system failure process in each testing stage is modeled using a Power-Law Process (PLP). Information on the effect of design modifications introduced into the system before starting a new testing stage is used, together with the posterior density of the PLP parameters at the current stage, to formalize the prior density at the beginning of the new stage. Contrary to the usual assumption, in this paper the PLP parameters are assumed to be dependent random variables. The system reliability is measured in terms of the number of failures that will occur in a batch of new units in a given time interval, for example the warranty period. A numerical example is presented to illustrate the proposed procedure.     

Modeling Discrete Bivariate Data with Applications to Failure and Count Data

In this study, we propose a new class of flexible bivariate distributions for discrete random variables. The proposed class of distribution is based on the notion of conditional failure rate for a discrete‐type random variable. We derive general formulae for the joint distributions belonging to the proposed class that, unlike other discrete bivariate models already proposed in the literature such as the well‐known and most popular Holgate's bivariate Poisson distribution, can model both positive and negative dependence. We discuss general statistical properties of the proposed class as well. Specific families of bivariate distributions can be generated from the general class proposed in this paper just by specifying the ‘baseline distributions’. Furthermore, specific discrete bivariate distributions belonging to the proposed class are applied to analyze three real data sets, and the results are compared with those obtained from conventional models. Copyright © 2017 John Wiley & Sons, Ltd.