385 research outputs found

    The Ceramic Tile District, its Evolution and Possible Future Alternatives - a Comparison of Italy and Spain

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    Territorial agglomerations have been paradigmatic examples of localised knowledge and endogenous development that are capable of containing the whole value chain of the respective production processes [1, 2]. Nevertheless, it is a widely acknowledged fact that they are currently going through a period of uncertainty and at the same time are undergoing important changes. In order to further our understanding of what may happen in the near future and bearing in mind the context in which industrial districts currently find themselves, we conducted an analysis and comparison of two industrial districts in Spain and Italy with the aim of establishing exactly how they have evolved in recent years and the kinds of relations they have developed. Our aim is to prove that the development of one cannot be explained without taking the other into account. Therefore, any attempt to understand the future of the districts should be based on this consideration

    Impact of converter losses on the optimal power flow solution of hybrid networks based on VSC-MTDC

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    This paper studies the impact of voltage source converter (VSC) losses on the solution of the optimal power flow (OPF) of hybrid AC/DC systems with a multi-terminal configuration. The motivation of this analysis is that the expected development of high voltage direct current (HVDC) systems will entail an increase of the number of converter stations, and consequently, converter losses might not be negligible when compared with conventional transmission losses of AC and DC lines. Towards this end, an extended OPF model is proposed considering a combination of VSC based multi-terminal HVDC grids (VSC-MTDC) and AC systems. The OPF model represents converter losses according to the state-of-the art modeling where different expressions are used when the converter functions as an inverter or as a rectifier. Three simpler alternative approaches are also implemented and the obtained OPF solutions are assessed. In order to compare the OPF solutions, a comparison metric is proposed. Obtained results show that modeling the converter losses in a simplified way could lead to very different power flow solutions, especially for the DC branches.Postprint (author's final draft

    Control of a utility connected microgrid

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    This paper describes the control algorithm of a utility connected microgrid, based on independent control of active and reactive power (PQ control) and working in centralized operation mode. The microgrid under investigation is composed of three configurable units: a generation unit, a storage unit and a load. These units are interfaced with the microgrid through a Voltage Source Converter (VSC) and are controlled by the nodes of the communication system by means of IEC 61850. A set of tests have been conducted to evaluate the microgrid behavior.Postprint (published version

    Impact of adverse events, treatment modifications, and dose intensity on survival among patients with advanced renal cell carcinoma treated with first‐line sunitinib: a medical chart review across ten centers in five European countries

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    Angiogenesis inhibitors have become standard of care for advanced and/or metastatic renal cell carcinoma (RCC), but data on the impact of adverse events (AEs) and treatment modifications associated with these agents are limited. Medical records were abstracted at 10 tertiary oncology centers in Europe for 291 patients ≥18 years old treated with sunitinib as first-line treatment for advanced RCC (no prior systemic treatment for advanced disease). Logistic regression models were estimated to compare dose intensity among patients who did and did not experience AEs during the landmark periods (18, 24, and 30 weeks). Cox proportional hazard models were used to explore the possible relationship of low-dose intensity (defined using thresholds of 0.7, 0.8, and 0.9) and treatment modifications during the landmark periods to survival. 64.4% to 67.9% of patients treated with sunitinib reported at least one AE of any grade, and approximately 10% of patients experienced at least one severe (grade 3 or 4) AE. Patients reporting severe AEs were statistically significantly more likely to have dose intensities below either 0.8 or 0.9. Dose intensity below 0.7 and dose discontinuation during all landmark periods were statistically significantly associated with shorter survival time. This study of advanced RCC patients treated with sunitinib in Europe found a significant relationship between AEs and dose intensity. It also found correlations between dose intensity and shorter survival, and between dose discontinuation and shorter survival. These results confirm the importance of tolerable treatment and maintaining dose intensity

    Reexamining treatment of high-grade T1 bladder cancer according to depth of lamina propria invasion: a prospective trial of 200 patients

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    BACKGROUND: Management of high-grade T1 (HGT1) bladder cancer represents a major challenge. We studied a treatment strategy according to substaging by depth of lamina propria invasion. METHODS: In this prospective observational cohort study, patients received initial transurethral resection (TUR), mitomycin-C, and BCG. Subjects with shallower lamina propria invasion (HGT1a) were followed without further surgery, whereas subjects with HGT1b received a second TUR. Association of clinical and histological features with outcomes (primary: progression; secondary: recurrence and cancer-specific survival) was assessed using Cox regression. RESULTS: Median age was 71 years; 89.5% were males, with 89 (44.5%) cases T1a and 111 (55.5%) T1b. At median follow-up of 71 months, disease progression was observed in 31 (15.5%) and in univariate analysis, substaging, carcinoma in situ, tumour size, and tumour pattern predicted progression. On multivariate analysis only substaging, associated carcinoma in situ, and tumour size remained significant for progression. CONCLUSIONS: In HGT1 bladder cancer, the strategy of performing a second TUR only in T1b cases results in a global low progression rate of 15.5%. Tumours deeply invading the lamina propria (HGT1b) showed a three-fold increase in risk of progression. Substaging should be routinely evaluated, with HGT1b cases being thoroughly evaluated for cystectomy. Inclusion in the TNM system should also be carefully considered

    System identification of a class of Wiener systems with hysteretic nonlinearities

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    Existing works on Wiener system identification have essentially been focused on the case where the output nonlinearity is memoryless. When memory nonlinearities have been considered, the focus has been restricted to backlash like nonlinearities. In this paper, we are considering Wiener systems where the output nonlinearity is a general hysteresis operator captured by the well-known Bouc-Wen model. The Wiener system identification problem is addressed by making use of a steady-state property, obtained in periodic regime, referred to as hysteretic loop assumption'. The complexity of this problem comes from the system nonlinearity as well as its unknown parameters that enter in a non-affine way in the model. It is shown that the linear part of the system is accurately identified using a frequency method. Then, the nonlinear hysteretic subsystem is identified, on the basis of a parameterized representation, using a prediction-error approach.Postprint (author's final draft
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