2,841 research outputs found

    Decimation in Time and Space of Finite-Difference Time-Domain Schemes: Standard Isotropic Lossless Model

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    Finite-difference time-domain (FDTD) schemes permit changes in the grid density on selected regions of the wave propagation domain, which can reduce the computational load of the simulations. One possible alternative to varying the spatial density is to change the simulation temporal rate. This idea looks attractive when the wave signals exhibit pronounced bandwidth fluctuations across time. This is particularly true in sound synthesis, where a physically based acoustic resonator can be conveniently modeled using such schemes. To overcome the computational constraints that must be met by real-time distributed resonator models, this paper deals with the decimation in time and space of isotropic lossless finite-difference time-domain schemes holding conventional Nyquist-Shannon limits on the bandwidth of the wave signals. Formulas for the reconstruction of these signals at runtime over the interpolated grid are provided for both the 1D and 2D orthogonal case, depending on the ideal boundary conditions (either Neumann or Dirichlet) holding at each side of the grid in connection with the domain side lengths (either even or odd). Together, the boundaries and size determine the type of Discrete Cosine Transform used in the corresponding interpolation formula. Numerical artifacts arising as a consequence of decimating in space in 2D are discussed in terms of dispersion error and aliasing. Considerations concerning the temporal reconstruction of components lying at the decimated Nyquist frequency are addressed in the conclusion

    Last Upgrades of Roman Pot Electronics

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    This article presents the recent (2017-2018) electronics modifications for the upgrade of the TOTEM roman pot detectors at the CERN LHC. To improve the timing accuracy and reliability the new Roman Pot detector configuration utilizes both DSDD (Double Side Diamond Detector) and silicon (UFSD, Ultra Fast Silicon Detector) mounted on hybrid boards. The electronics described was designed, built and tested by the authors in Faculty of Electrical Engineering in Pilsen, Department of Applied Electronics and Telecommunications, University of West Bohemia and by the TOTEM experiment at CERN. With the new detector setup, timing measurements with resolution down to tens of picoseconds are possible.Peer reviewe

    Chapter L’equilibrio di potenza nella storiografia fiorentina

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    Although Francesco Guicciardini is usually credited with the idea of balance of power, other Florentine historians prior to him had had similar insights. The essay presents the evolution of the notion of balance of power in Florentine historiography from the 14th-century chronicles of Giovanni and Matteo Villani to Guicciardini himself. Florentine historians put forward two basic meanings of balance of power, first as aggregation of forces against the most powerful state, second as an arrangement of the international system as a whole. The former is based on the elementary idea that those who fear the strongest state create alliances with those who share similar concerns, and it amounts to an ad hoc security tool; the latter entails the awareness of the existence of a system of states, which gradually came up from the beginning of the 15th century onwards

    Measuring the effectiveness of risk assessment in project portfolio management

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    In increasingly complex and competitive markets, effective Risk Management practices are considered of upmost importance to deliver value in Project Portfolio Management systems. However, there is little literature and methodologies available to evaluate the effectiveness of Risk Management at the Project Portfolio level. This precursory study contributes to filling this gap through the definition of a set of indicators to measure the effectiveness, performance and ability of Risk Management processes to create value in Project Portfolio management. Based on the analysis of real project data from a large Project Portfolio of a major project-based company working in the automation industry, this study proposes a framework of six different Risk Management Key Performance Indicators. With reference to logs of both closed and open risks, the framework allows to measure at any point in time during the project execution the effectiveness of the Risk Assessment process to help project managers respond to threats, seize opportunities, and forecast future risks. Validation of the proposed framework has been achieved both through empirical analysis and expert interviews. The set of indicators is proposed as a valuable metrics to help Project Portfolio Managers improve their risk analysis and decision making standards and methodologie

    Elastic characterization of nanometer-thick polymeric film for astrophysics application with an experimental-numerical method

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    The x-ray detectors on board astrophysics space missions require optical blocking filters that are highly transparent to x-rays. The filter design typically consists of a polymeric film that is a few tens of nanometers thick coated with aluminium. Due to the large size of the filter membrane (from a few tens to a few hundred square centimeters) and the extreme aspect ratio, together with severe loading conditions during launch and different stoichiometries of the polymer that could change its mechanical properties, a characterization study of the employed material is needed. The plane strain bulge test is a well-accepted methodology for the mechanical testing of structures that are less than a micrometer thick, and especially for freestanding membranes. Unfortunately, testing such ultra-thin films is not a simple task due to residual stress and experimental uncertainty at very low pressure. In this work, the elastic properties of an extremely thin (between 45 and 415 nm) membrane made of bare polyimide and coated with aluminium were derived through adopting a combined experimental-numerical methodology based on the bulge test and numerical simulations

    Case Report: A Peculiar Case of Inflammatory Colitis After SARS-CoV-2 Infection

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    open14noWe report a case of inflammatory colitis after SARS-CoV-2 infection in a patient with no additional co-morbidity who died within three weeks of hospitalization. As it is becoming increasingly clear that SARS-CoV-2 infection can cause immunological alterations, we investigated the expression of the inhibitory checkpoint PD-1 and its ligand PD-L1 to explore the potential role of this axis in the break of self-tolerance. The presence of the SARS-CoV-2 virus in colon tissue was demonstrated by qRT-PCR and immunohistochemical localization of the nucleocapsid protein. Expression of lymphocyte markers, PD-1, and PD-L1 in colon tissue was investigated by IHC. SARSCoV- 2-immunoreactive cells were detected both in the ulcerated and non-ulcerated mucosal areas. Compared to healthy tissue, where PD-1 is weakly expressed and PD-L1 is absent, PD-1 and PD-L1 expression appears in the inflamed mucosal tissue, as expected, but was mainly confined to non-ulcerative areas. At the same time, these markers were virtually undetectable in areas of mucosal ulceration. Our data show an alteration of the PD-1/PD-L1 axis and suggest a link between SARS-CoV-2 infection and an aberrant autoinflammatory response due to concomitant breakdown of the PD-1/ PD-L1 interaction leading to early death of the patient.openRutigliani, Mariangela; Bozzo, Matteo; Barberis, Andrea; Greppi, Marco; Anelli, Emanuela; Castellaro, Luca; Bonsignore, Alessandro; Azzinnaro, Antonio; Pesce, Silvia; Filauro, Marco; Rollandi, Gian Andrea; Castagnola, Patrizio; Candiani, Simona; Marcenaro, EmanuelaRutigliani, Mariangela; Bozzo, Matteo; Barberis, Andrea; Greppi, Marco; Anelli, Emanuela; Castellaro, Luca; Bonsignore, Alessandro; Azzinnaro, Antonio; Pesce, Silvia; Filauro, Marco; Rollandi, Gian Andrea; Castagnola, Patrizio; Candiani, Simona; Marcenaro, Emanuel

    X-IFU Filter Wheel Optical Blocking Filters Technology Demonstration Plan

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    The main purpose of the present plan is to provide a clear path to demonstrate the TRL5 by the Mission Adoption for the three OBFs on the X-IFU Filter Wheel (FW). An effort has been performed in trying to identify what shall be considered technology, for which the maturity has to be demonstrated, and what is design that can still contribute to improve the performances of the FW filters along phases B and C of development. The X-IFU FW filters conceptual design is similar to that defined (during phase A) and described in the "X-IFU Filter Wheel Mechanism and Electronics Design Description", and the "X-IFU Thermal Filters (THFs) Description" documents presented at the I-PRR. The preliminary design of the X-IFU FW Filters rely on heritage from previous missions and characterization tests performed in phase-A on breadboards manufactured by LUXEL Corporation (Friday Harbor, WA, USA). The adoption of a design similar to that of the X-IFU THFs for frame shape and materials, and to that of the WFI FW filters for film and coating thicknesses, as well as for overall dimensions, allow migrating part of the achievements reached by the X-IFU THFs and WFI FW filters to the X-IFU FW filters. For this reason, the TDP for the X-IFU FW filters will be mainly focused on the vibro-acoustic performances. With this respect, minor effort will be dedicated to the thick and very robust meshless filter (25 μm PI + 100 nm Al) designed to observe very bright x-ray sources. The goal of this activity is to demonstrate TRL5 before MAR for the baseline technology of filters manufactured by LUXEL (PI/Al on BeCu mesh). However, in parallel to verify also the maturity of other filter technologies and to mitigate the risks of having only one manufacturer, we will procure and test filter samples and bare meshes of other European manufacturers (OXFORD instruments, XRNanotech). The identified TECHNOLOGY development elements that we consider critical in the X-IFU FW OBFs are described in this document. In section 7 we list the breadboards (BBs) we have identified to perform the necessary characterization tests aimed at demonstrating their maturity

    Post-Transplant Nivolumab Plus Unselected Autologous Lymphocytes in Refractory Hodgkin Lymphoma: A Feasible and Promising Salvage Therapy Associated With Expansion and Maturation of NK Cells

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    Immune checkpoint inhibitors (CI) have demonstrated clinical activity in Hodgkin Lymphoma (HL) patients relapsing after autologous stem cell transplantation (ASCT), although only 20% complete response (CR) rate was observed. The efficacy of CI is strictly related to the host immune competence, which is impaired in heavily pre-treated HL patients. Here, we aimed to enhance the activity of early post-ASCT CI (nivolumab) administration with the infusion of autologous lymphocytes (ALI). Twelve patients with relapse/refractory (R/R) HL (median age 28.5 years; range 18-65), underwent lymphocyte apheresis after first line chemotherapy and then proceeded to salvage therapy. Subsequently, 9 patients with progressive disease at ASCT received early post-transplant CI supported with four ALI, whereas 3 responding patients received ALI alone, as a control cohort. No severe adverse events were recorded. HL-treated patients achieved negative PET scan CR and 8 are alive and disease-free after a median follow-up of 28 months. Four patients underwent subsequent allogeneic SCT. Phenotypic analysis of circulating cells showed a faster expansion of highly differentiated NK cells in ALI plus nivolumab-treated patients as compared to control patients. Our data show anti-tumor activity with good tolerability of ALI + CI for R/R HL and suggest that this setting may accelerate NK cell development/maturation and favor the expansion of the "adaptive" NK cell compartment in patients with HCMV seropositivity, in the absence of HCMV reactivation

    A Comment on the Implementation of the Strategy of Reinvigorating our Country through trained personnel in terms of Strategic Management

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    当今世界,以知识为主导、以高新技术及其产业为基础和支撑的知识经济已经悄然来临,世界范围内综合国力的竞争日趋激烈。这种竞争,说到底是人才的竞争,实质上就是人才战略的竞争。中国作为世界上最大的发展中国家,人口多,底子薄,人均资源相对不足,这一基本国情决定了中国的发展必须坚持“以人为本”,走人才强国之路。在2003年全国人才工作会议上,把实施人才强国战略作为科学发展观的有机组成部分,作为党和国家一项重大而紧迫的任务,作为新世纪新阶段国家人才工作的根本任务。“十一五”规划进一步提出了加快推进人才强国战略,为我国政治、经济、社会的发展提供智力支持。因此,在现阶段研究人才强国战略的实施具有重大的战略意义。...In our times, the knowledge economy that took knowledge as the leading factor, is based on new and high technology and industry. It has already come quietly. The competition of the comprehensive national strength is becoming fiercer and fiercer in the whole world. This kind of competition is talents' competition after all. It is a competition of the talents strategy in fact. As the largest develop...学位:管理学硕士院系专业:公共事务学院公共管理系_行政管理学号:20030603
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