Ultrasonographic and Biochemical Markers of Preterm Labor

> At present preterm delivery is the leading cause of perinatal morbidity and mortality and its incidence is remained stable during the past 10 years. Conventional methods of identifying patients at risk of preterm delivery such as obstetrics history, demographic factors or evaluation of uterine contractions and cervix by digital examination show disappointintly low sensitivity and positive predictive value. In this review we describe new ultrasonographic and biochemical approaches that have been recently proposed to screen for preterm labor both in patients with intact and with premature rupture of the membranes. The ultrasonographic detection of a short uterine cervix and/or of a dilation of the internal os, expression of weakening of the lower uterine segment or cervical ripening, seems to efficiently predict patients at risk of preterm delivery. The efficiency of this marker may be improved by the association with the assay of fetal fibronectin or pro inflammatory cytokines (interleukin-6 and interleukin-8) in cervical secretions. Further by the concentrations of interleukin-6 and interleukin-8 in cervical secretions seems to be possible to predict among patients in preterm labor those secondary to subclinical endoamniotic infection or chorioamnionitis. The use of these new markers in the future may allow a better identification of patients at risk of preterm labor and a proper selection of the treatment (medical or surgical) required for such patients.     

On-line fault detection in discrete event systems by Petri nets and integer linear programming

The paper addresses the fault detection problem for discrete event systems in a Petri Net (PN) framework. Assuming that the structure of the PN model and the initial marking are known, faults are modelled by unobservable transitions. Moreover, we assume that there may be additional unobservable transitions associated with the system legal behaviour and that the marking reached after the firing of any transition is unknown. The proposed diagnoser works on-line: it waits for the firing of an observable transition and employs an algorithm based on the definition and solution of some integer linear programming problems to decide whether the system behaviour is normal or exhibits some possible faults. The results characterize the properties that the PN modelling the system fault behaviour has to fulfill in order to reduce the on-line computational effort.     

A hierarchical optimization technique for the strategic design of distribution networks

The paper addresses the optimal design of the last supply chain branch, i.e., the Distribution Network (DN), starting from manufacturers till the retailers. It considers a distributed system composed of different stages connected by material links labeled with suitable performance indices. A hierarchical procedure employing direct graph (digraph) modeling, mixed integer linear programming, and the Analytic Hierarchy Process (AHP) is presented to select the optimal DN configuration. More in detail, a first-level DN optimization problem taking into account the definition and evaluation of the distribution chain performance provides a set of Pareto optimal solutions defined by digraph modeling. A second level DN optimization using the AHP method selects, on the basis of further criteria, the DN configuration from the Pareto face alternatives. To show the method effectiveness, the optimization model is applied to a case study describing an Italian regional healthcare drug DN. The problem solution by the proposed design method allows improving the DN flexibility and performance.     

Analysing industrial district performances: A structured approach

The goals of an organization of data and information collected from the European industrial systems and concerning networks of enterprises, mainly small-mid enterprises (SMEs), are many:

(a)

to offer an intelligent support system (ISS) to industrial analysers when they try to understand if a SME network, either cluster or industrial district, could be enforced by proper financing, or it cannot give sufficient assurance for a new development;

(b)

to offer to political people a support in understanding the dynamics of these SME networks, in order to be able to take decisions about public politics;

(c)

to give tools for analysing the performance of these industrial bodies to industrial people, mainly technicians and managers, such to be able to apply new strategies for their improvement;

(d)

to give information and data to researchers operating in university and RTD centers, such to be able to improve their knowledge about these so important industrial bodies.

To reach this goal, the aim of the EU-funded CODESNET (COllaborative DEmand & Supply NETwork) project is to give new ideas and concepts sufficient to drive the attention of the above-mentioned different types of people towards the SME networks and districts. To this aim, a crucial problem must be approached and solved: which model of a SME network should be stated and used as the basis for developing a clear and useful ISS, that is, able to collect information and data from existing SME networks and transfer such data into standard formats, easy to be read by both industrial people and scientific researchers. The present paper describes the theoretical methodology on which the data organization and interpretation adopted in the CODESNET project is based. The application of an original meta-model of SME network, developed in the mentioned project, is detailed according to the following steps. After the meta-model formulation (in Section 2), it is shown how the variables to be measured (such to have a clear understanding of the network status), have to be selected, and how the main issues concerning the design and management of the network has to be classified (Section 3). Then, it will be shown how the archive of both data/information from existing SME networks (for purpose of comparison-based analysis) and the catalogue of technical/scientific reports (for purpose of justifying the analysis considerations) has been organized in an integrated form. The scope is to give at disposal of industrial people the mentioned ISS which allow them to approach some main issues concerning the network design and management (Section 4). An example of ISS application in an Italian industrial district will be presented, such to illustrate the CODESNET results’ usefulness.     

Scour on Alluvial Bed Downstream of Grade-Control Structures

This paper describes an approach for predicting local scour downstream of grade control structures. The developed analysis applies the incomplete self-similarity (ISS) theory for deducing some physically based dimensionless groups controlling the geometrical pattern of the scour profile. The scour measurements available in the literature in conjunction with numerous unpublished data allow a multiregressive calibration of the ISS relationships. The experimental sample includes different bed grain-size distributions and scales of the erosive phenomenon. The results prove that the ratio between the upstream water head and the weir height is able to explain the measurements of scour depth carried out in both small- and large-scale installations. This estimation of maximum scour depth was improved, introducing variables representative of both the jet contraction and the bed particle grain-size distribution. Variables related to the longitudinal sizes of the scour profile tend to be predicted with more accuracy than those related to the scour depth and appear more influenced by the coarsest component of the alluvial bed.     

Non-repudiation analysis using LySa with annotations

This work introduces a formal analysis of the non-repudiation property for security protocols. Protocols are modelled in the process calculus LySa, using an extended syntax with annotations. Non-repudiation is verified using a Control Flow Analysis, following the same approach of Buchholtz and Gao for authentication and freshness analyses.The result is an analysis that can statically check the protocols to predict if they are secure during their execution and which can be fully automated.     

Flow-sensitive Leakage Analysis in Mobile Ambients

In this paper, we present a refinement of a Control Flow Analysis aimed at studying information flow security in the the calculus of Mobile Ambients. The improvements are achieved by making the analysis be flow-sensitive: the analysis is able to keep track of temporal dependencies of capabilities application when computing a safe approximation of the run-time topology of Mobile Ambient processes.     

Design and Modelling of Photonic Band-Gap Resonance Cavity

An optimal design of Photonic Band-Gap (PBG) based resonance cavities has been carried out and optimal design rules have been drawn by a very fast and accurate computer code, developed by the authors, implementing a new model of one-dimensional finite-size PBG materials. The model also takes into account the presence of defects; it allows to accurately determine the mode propagation constants, electromagnetic harmonics and total field distribution, transmission and reflection coefficients, forward and backward power flow, guided and radiated power and total losses due to radiation, Bragg scattering and out of plane scattering. The design of resonance cavities advancing the state of the art of commercial Dense Wavelength Division Multiplexing (DWDM) filters is performed. A great number of optical cavities have been designed and quickly simulated thanks to the fastness of the code, allowing optimal design rules to be drawn.     

Preface by the section editors

The papers in this special section present a sample of recent approaches to modeling and verification of software-based systems. This research was initially presented at the 4th International Conference on Verification, Model Checking, and Abstract Interpretation (VMCAI 03). The choice of papers for the issue was based on their merit as well as on the fact that, as a group, they represent the main current research areas in the field of software-based systems.