Probability density function from experimental positron annihilation lifetime spectra

Inversion of experimental positron annihilation lifetime spectra was carried out to obtain the probability density function. Apparatus resolution together with experimental noise was taken into consideration while solving this ill posed problem. The singular value decomposition approach, moving the boundary between the subspaces was the theoretical formulation to calculate the probability density function. For the system considered, the Al(dpm)3 complex, three peaks will be presented in the inverted spectra, indicating the presence of the para-Positronium, the free positron and the ortho-Positronium. The predicted positions were, 0.1042 ns, 0.3542 ns and 1.3958 ns, respectively. Since the present approach gives the distribution of the species, it was possible also to predict the relative importance of each species in the spectra. The areas found correspond to: 13%, 32%, 55%. Both these results, position of the peaks and the areas, together with the half-life distribution can provide important information for experimentalists

Benefits and limitations of project-to-project job rotation in software organizations: A synthesis of evidence

Context Job rotation has been proposed as a managerial practice to be applied in the organizational environment to reduce job monotony, boredom, and exhaustion resulting from job simplification, specialization, and repetition. The scientific literature distinguishes between job-to-job and project-to-project rotations. Despite the potential benefits and its actual use on behalf of software companies, we do not have an accumulated body of scientific knowledge about benefits and limitations of job rotation in software engineering practice. In particular, we have no concrete empirical evidence about the use of project-to-project rotations in practice. Goal We aim to identify and discuss evidence about project-to-project (P2P) job rotation, in order to understand the potential benefits and limitations of this practice in software organizations. Method We deployed a mix-method research strategy to collect and analyze empirical evidence from the scientific literature, performing a systematic literature review, on one hand and from industrial practice, performing qualitative case studies on the other. We synthesized the evidence using techniques from meta-ethnography. Results We found eight benefits, nine limitations, and two factors classified as both benefits and limitations of P2P rotations in software engineering. Different research methods yielded confirmatory and complementary evidence, emphasizing the importance of conducting mix-method research. We found no contradictory evidence and five factors were identified in more than one study using different research methods, contributing to the strength of the evidence. Conclusion We synthesized evidence from multiple sources and used different research methods concerning the benefits and limitations of P2P rotation in software engineering practice. Our findings show that rotation tends to benefit important job outcomes, such as motivation, and to decrease job monotony. The main limitations were associated with the potential increase in intra-group social conflicts, individual cognitive effort, and workload, and a temporary decrease in productivity