An Analytical Model to Measure the Effectiveness of Safety Management Systems: Global Safety Improve Risk Assessment (G-SIRA) Method

The ever-increasing complexity of production systems, together with the need to obtain efficient processes with limited costs, has led companies to develop custom tools for process control and management. Even for risk assessment, the traditional models often are overcome by methods that are best suited to specific needs. In this context, the aim of this paper was to propose a new model, which we call the global safety improve risk assessment (G-SIRA). This model can classify risks and identify corrective actions that allow the best risk reduction at the lowest cost. The proposed model, which is based on improvements to previous research, uses the analytic hierarchy process approach to develop a valid and simple tool for risk management. The G-SIRA method has been tested in a real-world application, i.e., it was applied to all of the processes of a textile company, and the results were compared with those obtained from the classical approach failure mode, effects, and criticality analysis. The comparison clearly showed the effectiveness of the proposed model.     

Player behavior and traffic characterization for MMORPGs: a survey

Massively Multiplayer Online Role-Playing Games (MMORPGs) are one of the most exciting and most rapidly expanding genres of online games. This survey presents state-of-the-art and current research efforts in measuring, characterizing, and modeling the player behavior and the network traffic, as well as the relationships between them. We also tabulate the measurement, modeling and analysis results regarding network traffic and player behavior found in literature, with key information regarding each dataset. Finally, we list currently confirmed claims and open research questions in the area of MMORPGs.     

A new method for computing fuzzy functional dependencies in relational database systems

In this paper, we present a new method for computing fuzzy functional dependencies between attributes in fuzzy relational database systems. The method is based on the use of fuzzy implications. A literature analysis has shown that there is no algorithm that would enable the identification of attribute relationships in fuzzy relational schemas. This fact was the motive for development a new methodology in the analysis of fuzzy functional dependencies over a given set of attributes. Solving this, not so new problem, is not only research challenge having theoretical importance, but it also has practical significance. Possible applications of the proposed methodology include GIS, data mining, information retrieval, reducing data redundancy in fuzzy relations through implementation of logical database model, estimation of missing values etc.     

Design,manufacture and geometric verification of rapid prototyped microfluidic encapsulations by computed tomography

This paper presents the dimensional verification of encapsulations used to package microfluidic devices manufactured using a 3D printer of photopolymerisable resin. This characterisation has been performed by computed tomography (CT) by comparing newly manufactured encapsulations and samples that have been subjected to test conditions. Thus, it has been possible to draw conclusions both on the deviations of the nominal geometry of the encapsulations and on how this might affect their performance. This paper presents a scheme of dimensional verification from the point clouds obtained by CT. Finally, a combined threshold and scale factor correction technique of the tomography images is shown. This method is based on the simultaneous measurement of objective and master parts with known geometry. The results reveal the improvements achievable in the accuracy, given a particular machine configuration. The conclusions facilitate the improvement of the geometric design of these devices regarding their behaviour under test conditions.     

A method for the remote sensing identification of uncontrolled landfills: formulation and validation

The identification of uncontrolled landfills is a central environmental problem in all developed and developing countries, where several illegal waste deposits exist as a result of rapid industrial growth over the past century. Remote sensing can potentially provide crucial information for the identification of contaminated sites, but surprisingly there is a marked lack of rigorously validated approaches. In this paper we introduce and validate a method that uses remotely sensed information and a geographic information system (GIS) to identify unknown landfills over large areas. The method is applied to a study area located in NE Italy (part of the Venice lagoon watershed) using IKONOS satellite data. Soil contamination effects on the radiometric properties of vegetation, calibrated using spectral signatures of stressed vegetation from known illegal landfill sites, were used to define numerous candidate sites that are most likely to host waste materials. Distributed geographical information, such as the position of the road network, the population density, and historical aerial photographs, have then been used to select the most likely contaminated sites among the candidates identified through remote sensing. The importance of the integration of GIS and remote sensing is highlighted and represents a key instrument for environmental management and for the spatially distributed characterization of possible uncontrolled landfill sites.     

Push &; Pull: autonomous deployment of mobile sensors for a complete coverage

Mobile sensor networks are important for several strategic applications devoted to monitoring critical areas. In such hostile scenarios, sensors cannot be deployed manually and are either sent from a safe location or dropped from an aircraft. Mobile devices permit a dynamic deployment reconfiguration that improves the coverage in terms of completeness and uniformity. In this paper we propose a distributed algorithm for the autonomous deployment of mobile sensors called Push & Pull. According to our proposal, movement decisions are made by each sensor on the basis of locally available information and do not require any prior knowledge of the operating conditions or any manual tuning of key parameters. We formally prove that, when a sufficient number of sensors are available, our approach guarantees a complete and uniform coverage. Furthermore, we demonstrate that the algorithm execution always terminates preventing movement oscillations. Numerous simulations show that our algorithm reaches a complete coverage within reasonable time with moderate energy consumption, even when the target area has irregular shapes. Performance comparisons between Push & Pull and one of the most acknowledged algorithms show how the former one can efficiently reach a more uniform and complete coverage under a wide range of working scenarios.     

A biochemical approach to adaptive service ecosystems

Emerging network scenarios call for innovative open service frameworks to ensure capability of self-adaptability and long-lasting evolvability. In this paper, we assess the need for such innovative service frameworks, and discuss how their engineering should get inspiration from natural ecosystems, i.e., by modelling services as autonomous individuals in an ecosystem of other services and data sources. We introduce a reference conceptual architecture with the goal of clarifying the concepts expressed and framing the several possible nature-inspired metaphors that could be adopted to realise the idea. On this basis, we go into details about one of such possible approaches, in which the rules governing the ecosystem are inspired by biochemical mechanisms. A case study is also introduced to exemplify the potentials of the presented biochemical approach and to experiment with some representative biochemistry-inspired patterns of adaptive service organisation and evolution.     

Time-Resolved Soft X-ray Diffraction Reveals Transient Structural Distortions of Ternary Liquid Crystals

Home-based soft X-ray time-resolved scattering experiments with nanosecond time resolution (10 ns) and nanometer spatial resolution were carried out at a table top soft X-ray plasma source (2.2–5.2 nm). The investigated system was the lyotropic liquid crystal C₁₆E₇/paraffin/glycerol/formamide/IR 5. Usually, major changes in physical, chemical, and/or optical properties of the sample occur as a result of structural changes and shrinking morphology. Here, these effects occur as a consequence of the energy absorption in the sample upon optical laser excitation in the IR regime. The liquid crystal shows changes in the structural response within few hundred nanoseconds showing a time decay of 182 ns. A decrease of the Bragg peak diffracted intensity of 30% and a coherent macroscopic movement of the Bragg reflection are found as a response to the optical pump. The Bragg reflection movement is established to be isotropic and diffusion controlled (1 μs). Structural processes are analyzed in the Patterson analysis framework of the time-varying diffraction peaks revealing that the inter-lamellar distance increases by 2.7 Å resulting in an elongation of the coherently expanding lamella crystallite. The present studies emphasize the possibility of applying TR-SXRD techniques for studying the mechanical dynamics of nanosystems.