Uncertainty representation in software models: a survey

This paper provides a comprehensive overview and analysis of research work on how uncertainty is currently represented in software models. The survey presents the definitions and current research status of different proposals for addressing uncertainty modeling and introduces a classification framework that allows to compare and classify existing proposals, analyze their current status and identify new trends. In addition, we discuss possible future research directions, opportunities and challenges.This work is partially supported by the European Commission (FEDER) and the Spanish Government under projects APOLO (US1264651), HORATIO (RTI2018-101204-B-C21), EKIPMENT-PLUS (P18-FR-2895) and COSCA (PGC2018-094905-B-I00)

Local and regional components of aerosol in a heavily trafficked street canyon in central London derived from PMF and cluster analysis of single-particle ATOFMS spectra.

Positive matrix factorization (PMF) has been applied to single particle ATOFMS spectra collected on a six lane heavily trafficked road in central London (Marylebone Road), which well represents an urban street canyon. PMF analysis successfully extracted 11 factors from mass spectra of about 700,000 particles as a complement to information on particle types (from K-means cluster analysis). The factors were associated with specific sources and represent the contribution of different traffic related components (i.e., lubricating oils, fresh elemental carbon, organonitrogen and aromatic compounds), secondary aerosol locally produced (i.e., nitrate, oxidized organic aerosol and oxidized organonitrogen compounds), urban background together with regional transport (aged elemental carbon and ammonium) and fresh sea spray. An important result from this study is the evidence that rapid chemical processes occur in the street canyon with production of secondary particles from road traffic emissions. These locally generated particles, together with aging processes, dramatically affected aerosol composition producing internally mixed particles. These processes may become important with stagnant air conditions and in countries where gasoline vehicles are predominant and need to be considered when quantifying the impact of traffic emissions.This is the author accepted manuscript. The final version is available via ACS at http://pubs.acs.org/doi/abs/10.1021/es506249z

Quality Attributes for COTS Components

As Component-based Software Development (CBSD) starts to be e#ectively used, some software vendors have commenced to successfully sell and licence commercial o#-the-shelf (COTS) components. One of the most critical processes in CBSD is the selection of the COTS components that meet the user's requirements. Current proposals have shown how to deal with the functional aspects of this evaluation process. However, there is a lack of appropriate quality models that allow an e#ective assessment of COTS components. Besides, the international standards that address the software products' quality issues (in particular, those from ISO and IEEE) have shown to be too general for dealing with the specific characteristics of software components. In this paper we propose a quality model for CBSD based on ISO 9126, that defines a set of quality attributes and their associated metrics for the e#ective evaluation of COTS components

A Survey on the Quality Information Provided by

The last decade marked the first real attempt to turn software development into engineering through the concepts of ComponentBased Software Development (CBSD) and Commercial Off-The-Shelf (COTS) components. The idea is to create high-quality parts and join them together to form a functioning system. One of the most critical processes in CBSD is the selection of the COTS components from a repository that meet the user requirements. Current approaches try to propose appropriate quality models for the effective assessment of such components. These proposals define quality characteristics, attributes, and metrics, which are specific to the particular nature of COTS components and CBSD. However, we have found that the information required evaluating those components using those quality models and metrics is not usually available in the existing commercial software repositories. This paper presents a survey we have conducted on the most popular COTS component vendor sites, trying to evaluate how much of the information required to assess COTS components is actually available. Our goal was to estimate the current gap between the "required" and the "provided" information, since there is no point in defining theoretical measures for COTS components if the data they rest upon is not available. Analyzing this gap is the first step towards successfully bridging it, by both refining the component quality models so their metrics are more realistic, and by improving the information currently provided by software component vendors