17 research outputs found
Simplified high-order Volterra series transfer function for optical transmission links
Get PDFWe develop a simplified high-order multi-span Volterra series transfer function (SHMS-
VSTF), basing our derivation on the well-known third-order Volterra series transfer function
(VSTF). We notice that when applying an approach based on a recursive method and considering
the phased-array factor, the order of the expression for the transfer function grows as 3 raised to
the number of considered spans. By imposing a frequency-flat approximation to the higher-order
terms that are usually neglected in the commonly used VSTF approach, we are able to reduce
the overall expression order to the typical third-order plus a complex correction factor. We carry
on performance comparisons between the purposed SH-MS-VSTF, the well-known split-step
Fourier method (SSFM), and the third-order VSTF. The SH-MS-VSTF exhibits a uniform
improvement of about two orders of magnitude in the normalized mean squared deviation with
respect to the other methods. This can be translated in a reduction of the overall number of steps
required to fully analyze the transmission link up to 99.75% with respect to the SSFM, and
98.75% with respect to the third-order VSTF, respectively, for the same numerical accuracy
Development of the Prevent for Work questionnaire (P4Wq) for assessment of musculoskeletal risk in the workplace: part 1-literature review and domains selection
Get PDFObjective This study aims to define appropriate domains and items for the development of a self-administered questionnaire to assess the risk of developing work-related musculoskeletal disorder (WMSD) and the risk of its progression to chronicity. Design Literature review and survey study. Setting and participants A literature review and a two-round interview with 15 experts in musculoskeletal pain were performed to identify the available domains for WMSD assessment. Interventions and outcome To ensure quality, only validated questionnaires were included for the Delphi process. A three-round Delphi method, with three round steps, was used to select the most pertinent and relevant domains and items. Results Nine questionnaires were identified through the expert discussion and literature review, comprising 38 candidate domains and 504 items. In the first round of the Delphi group, 17 domains reached more than 70% agreement and were selected. In the second round, 10 domains were rejected, while 11 were selected to complete the pool of domains. In the third and final round, 89 items belonging to 28 domains were defined as significant to develop a WMSDs risk assessment questionnaire. Conclusions No specific risk assessment questionnaires for WMSDs were identified from the literature. WMSD risk of presence and chronicity can be defined by an assessment tool based on the biopsychosocial model and the fear-avoidance components of chronic pain. The present study provides the formulation and operationalisation of the constructs in domains and items needed for developing and validating the questionnaire
[Peritoneo-jugular shunt with a Denver valve in the treatment of refractory ascites (personal experience)].
No full textThe Denver valve peritoneo-jugular shunt has proved to be a valid therapeutic procedure in the treatment of refractory ascites. After briefly outlining the indications and advantages of the Denver valve and explaining how it is applied, the authors report the results obtained in their patient population
[Echographic control of porto-systemic anastomosis (personal cases)].
No full textThe authors describe the clinical case of a patient undergoing a porto-caval shunt for portal hypertension, in which the patency of the anastomosis was checked by ultrasound examination
Perforazione di diverticolo di Meckel da corpo estraneo (Osservazione clinica).
No full textNon disponibil
L'anastomosi colangioenterica intraepatica sinistra nelle neoplasie dell'ilo epatico.
No full textNon disponibil
