One of the most successful applications of textual analysis in software engineering is the use of information retrieval (IR) methods to reconstruct traceability links between software artifacts. Unfortunately, because of the limitations of both the humans developing artifacts and the IR techniques any IR-based traceability recovery method fails to retrieve some of the correct links, while on the other hand it also retrieves links that are not correct. This limitation has posed challenges for researchers that have proposed several methods to improve the accuracy of IR-based traceability recovery methods by removing the 'noise' in the textual content of software artifacts (e.g., by removing common words or increasing the importance of critical terms). In this paper, we propose a heuristic to remove the 'noise' taking into account the linguistic nature of words in the software artifacts. In particular, the language used in software documents can be classified as a technical language, where the words that provide more indication on the semantics of a document are the nouns. The results of a case study conducted on five software artifact repositories indicate that characterizing the context of software artifacts considering only nouns significantly improves the accuracy of IR-based traceability recovery methods.

BackgroundLowering mortality and hospitalization of older adults is one of the main goals of public health to improve both health systems’ sustainability and older adults’ quality of life. The aim of this study is to identify the determinants associated with mortality and the use of hospital services in the population older than 64 years of age.MethodsA randomized sample from the population of the Lazio region (Italy) above the age of 64 was enrolled in 2014 by the administration of a questionnaire to assess frailty; the rates of use of hospital services and mortality in the year following the enrolment have been retrieved by the regional database. Univariable and multivariable analyses addressed the association of health status, social and economic variables with health outcomes.ResultsOne thousand two hundred and eighty persons were recruited; 52 deaths were reported at 1 year of follow-up (robust 1.8%, frail 10.1% and very frail 19.1%, P < 0.001). The mean rate of use of hospital services was 692.2 per 1000 observation/year (robust 589.5, frail 1191.1 and very frail 848.4, P < 0.001). In the multivariate analysis, the higher rate of use of hospital services was independently associated with functional status, social support, psychological/psychiatric discomfort, availability of home care services and physical health.ConclusionsFrailty, as a multidimensional issue, is also a strong predictor of survival in the short term. The use of the hospital services by older adults is associated mainly with functional status, social resources, psycho-physical status and health service organization factors.

No abstract

The paper proposes a novel Information Retrieval technique based on numerical analysis for recovering traceability links between code and software documentation. The results of a reported case study demonstrate that the proposed approach significantly outperforms two vector-based IR models, i.e., the Vector Space Model and Latent Semantic Indexing, and it is comparable and sometimes better than a probabilistic model, i.e., the Jensen-Shannon method. The paper also discusses the influence of each method with the specific artifact type considered and the artifact language.

Charged dust particles are theoretically expected to modify the amplitude and spectrum of plasma fluctuations, and this can eventually provide novel diagnostic tools. Direct experimental evidence of the effects of dust particles on the fluctuations of a low collisionality plasma is reported, in agreement with the expectations of kinetic theory.