Flexible diagnosis of discrete-event systems by similarity-based reasoning techniques

Diagnosis of discrete-event systems (DESs) may be improved by knowledge-compilation techniques, where a large amount of model-based reasoning is anticipated off-line, by simulating the behavior of the system and generating suitable data structures (compiled knowledge) embedding diagnostic information. This knowledge is exploited on-line, based on the observation of the system behavior, so as to generate the set of candidate diagnoses (problem solution). This paper makes a step forward: the solution of a diagnostic problem is supported by the solution of another problem, provided the two problems are somewhat similar. Reuse of model-based reasoning is thus achieved by exploiting the diagnostic knowledge yielded for solving previous problems. The technique still works when the available knowledge does not fit the extent of the system, but only a partition of it, that is, when solutions are available for subsystems only. In this case, the fragmented knowledge is exploited in a modular way, where redundant computation is avoided. Similarity-based diagnosis is meant for large-scale DESs, where the degree of similarity among subsystems is high and stringent time constraints on the diagnosis response is a first-class requirement.     

The saturation algorithm for symbolic state-space exploration

We present various algorithms for generating the state space of an asynchronous system based on the use of multiway decision diagrams to encode sets and Kronecker operators on boolean matrices to encode the next-state function. The Kronecker encoding allows us to recognize and exploit the “locality of effect” that events might have on state variables. In turn, locality information suggests better iteration strategies aimed at minimizing peak memory consumption. In particular, we focus on the saturation strategy, which is completely different from traditional breadth-first symbolic approaches, and extend its applicability to models where the possible values of the state variables are not known a priori. The resulting algorithm merges “on-the-fly” explicit state-space generation of each submodel with symbolic state-space generation of the overall model. Each algorithm we present is implemented in our tool SmArT. This allows us to run fair and detailed comparisons between them on a suite of representative models. Saturation, in particular, is shown to be many orders of magnitude more efficient in terms of memory and time with respect to traditional methods.     

Age-related changes in the human thymus studied with scanning electron microscopy

This investigation describes some morphological, age-related changes in different compartments and cells of the human thymus. Scanning electron microscopic observations were done on human thymus samples obtained from four young and eight elderly patients during thoracic surgery and/or diagnostic biopsy of the thymus, after receiving authorization from the Ethical Committee of our university. The morphological data were submitted to quantitative image analysis so as to obtain quantitative results. Subsequently, the related values were used for statistical analysis. Our findings demonstrate that (1) all thymus compartments (subcapsular spaces, cortical, medullar, thymus microenvironment) contain numerous thymocytes even after the thymus has aged. (2) In older humans, residual thymus lymphoid islets contain, in addition to fatty cells and/or fibrous cells, also the same types of resident and nonresident cells (permanent and moving cells) that are found in young and adult subjects. (3) Endothelial cells of thymus microvessels contain numerous gaps. These gaps are tight in young subjects and become loose with age. (4) Thymocytes, in older subjects, are always found near these loose endothelial gaps of thymus microvessels. (5) While thymus cortical microvessels are provided with pericytes and/or periarteriolar spaces, microvessels of the thymus medullar are free of such spaces. Our morphological and quantitative results lead us to consider the possibility that the thymus fraction of resident and permanent cells (including thymocytes and reticular epithelial cells) is larger in younger subjects compared with older ones. The endothelial loose gaps of thymus microvessels, in older subjects, can allow the bidirectional transit of thymocytes through the wall of the said microvessels.     

Water flow measurement in large bore pipes: an experimental comparison between two different types of insertion flowmeters

In this paper the metrological behavior of two different insertion flowmeters (magnetic and turbine types) in large water pipes is described. A master-slave calibration was carried out in order to estimate the overall uncertainty of the tested meters. The experimental results show that (i) the magnetic insertion tested flowmeter performs the claimed accuracy (+/- 2%) within all the flow range (20:1); (ii) the insertion turbine tested meter, instead, reaches the claimed accuracy just in the upper zone of the flow range.     

Potential applications of negative tone development in advanced lithography

Advanced lithography requires resolution enhancement techniques (customized illumination mode, litho friendly design), and alternative process flow schemes (double exposure, double patterning) in order to meet the requirements of the ITRS technology roadmap and to extend the applications of a full-field scanner with a 1.35 numerical aperture (NA) that represents the physical limit of water-based immersion ArF lithography.Today, one of the most interesting alternative processes uses the patterning inversion through a negative tone development (NTD) process step. Traditionally, the patterning (contacts or trenches) is done by using a dark field mask in combination with positive tone resist and positive tone development (PTD). By using a solvent-based developer (NTD) and a bright field mask, the same features can be transferred into a positive resist with the benefit of better image contrast and, consequently, better line width roughness (LWR) and resolution.In this work we have explored the potential applications of NTD for trenches and contact holes for the 45 nm technology node requirements and beyond. The NTD process is a promising option considering the impact on process window, LWR, CD uniformity and defectivity. The experimental result of this alternative approach to print critical dark field levels in an advanced lithography boundary has been explored.     

Raw milk from vending machines: Effects of boiling,microwave treatment,and refrigeration on microbiological quality

In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4°C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application.     

Use of acacia barrique barrels – Influence on the quality of Malvazija from Istria wines

In order to improve Malvazija from Istria wine quality, we used two types of barrels: oak (of French and Croatian origin) and acacia (of Croatian origin). After 12 months ageing period all of the wines were analysed chemically and sensorially. Results showed marked differences between oak and acacia aged wines, especially in simple volatile phenol and oak lactones concentrations. During the ageing period a significant increase in furfural, 5-methylfurfural, guaiacol, eugenol and trans-eugenol was noticed. Results pointed out the importance of choosing the right barrels (oak or acacia) and time of leaving the wine in the barrels to achieve the desired goal. The highest rated wines were made in acacia barrels.     

Improved Synthesis of Pyrroles and Indoles via Lewis Acid‐Catalyzed Mukaiyama–Michael‐Type Addition/Heterocyclization of Enolsilyl Derivatives on 1,2‐Diaza‐1,3‐Butadienes. Role of the Catalyst in the Reaction Mechanism

The Mukaiyama–Michael‐type addition of various silyl ketene acetals or silyl enol ethers on some 1,2‐diaza‐1,3‐butadienes proceeds at room temperature in the presence of catalytic amounts of Lewis acid affording by heterocyclization 1‐aminopyrrol‐2‐ones and 1‐aminopyrroles, respectively. 1‐Aminoindoles have been also obtained by the same addition of 2‐(trimethylsilyloxy)‐1,3‐cyclohexadiene on some 1,2‐diaza‐1,3‐butadienes and subsequent aromatization. Mechanistic investigations indicate the coordination by Lewis acid of the enolsilyl derivative and its 1,4‐addition on the azo‐ene system of 1,2‐diaza‐1,3‐butadienes. The migration of the silyl group from a hydrazonic to an amidic nitrogen, its acidic cleavage and the final internal heterocyclization give the final products. Based on NMR studies and ab initio calculations, a plausible explanation for the migration of the silyl protecting group is presented.