127 research outputs found

    Structural Analysis Using NX Nastran 9.0

    Get PDF
    NX Nastran is a powerful Finite Element Analysis (FEA) software package used to solve linear and non-linear models for structural and thermal systems. The software, which consists of both a solver and user interface, breaks down analysis into four files, each of which are important to the end results of the analysis. The software offers capabilities for a variety of types of analysis, and also contains a respectable modeling program. Over the course of ten weeks, I was trained to effectively implement NX Nastran into structural analysis and refinement for parts of two missions at NASA's Kennedy Space Center, the Restore mission and the Orion mission

    Youth violence intervention programme for vulnerable young people attending emergency departments in London: a rapid evaluation

    Get PDF
    BACKGROUND: Youth violence intervention programmes involving the embedding of youth workers in NHS emergency departments to help young people (broadly aged between 11 and 24 years) improve the quality of their lives following their attendance at an emergency department as a result of violent assault or associated trauma are increasing across the NHS. This study evaluates one such initiative run by the charity Redthread in partnership with a NHS trust. OBJECTIVES: To evaluate the implementation and impact of a new youth violence intervention programme at University College London Hospital NHS Trust and delivered by the charity Redthread: (1) literature review of studies of hospital-based violent crime interventions; (2) evaluation of local implementation and of University College London Hospital staff and relevant local stakeholders concerning the intervention and its impact; (3) assessment of the feasibility of using routine secondary care data to evaluate the impact of the Redthread intervention; and (4) cost-effectiveness analysis of the Redthread intervention from the perspective of the NHS. METHODS: The evaluation was designed as a mixed-methods multiphased study, including an in-depth process evaluation case study and quantitative and economic analyses. The project was undertaken in different stages over two years, starting with desk-based research and an exploratory phase suitable for remote working while COVID-19 was affecting NHS services. A total of 22 semistructured interviews were conducted with staff at Redthread and University College London Hospital and others (e.g. a senior stakeholder involved in NHS youth violence prevention policy). We analysed Redthread documents, engaged with experts and conducted observations of staff meetings to gather more in-depth insights about the effectiveness of the intervention, the processes of implementation, staff perceptions and cost. We also undertook quantitative analyses to ascertain suitable measures of impact to inform stakeholders and future evaluations. RESULTS: Redthread's service was viewed as a necessary intervention, which complemented clinical and other statutory services. It was well embedded in the paediatric emergency department and adolescent services but less so in the adult emergency department. The diverse reasons for individual referrals, the various routes by which young people were identified, and the mix of specific support interventions provided, together emphasised the complexity of this intervention, with consequent challenges in implementation and evaluation. Given the relative unit costs of Redthread and University College London Hospital's inpatient services, it is estimated that the service would break even if around one-third of Redthread interventions resulted in at least one avoided emergency inpatient admission. This evaluation was unable to determine a feasible approach to measuring the quantitative impact of Redthread's youth violence intervention programme but has reflected on data describing the service, including costs, and make recommendations to support future evaluation. LIMITATIONS: The COVID-19 pandemic severely hampered the implementation of the Redthread service and the ability to evaluate it. The strongest options for analysis of effects and costs were not possible due to constraints of the consent process, problems in linking Redthread and University College London Hospital patient data and the relatively small numbers of young people having been engaged for longer-term support over the evaluation period. CONCLUSIONS: We have been able to contribute to the qualitative evidence on the implementation of the youth violence intervention programme at University College London Hospital, showing, for example, that NHS staff viewed the service as an important and needed intervention. In the light of problems with routine patient data systems and linkages, we have also been able to reflect on data describing the service, including costs, and made recommendations to support future evaluation. FUTURE WORK: No future work is planned. FUNDING: National Institute for Health and Care Research Health Services and Delivery Research programme (RSET: 16/138/17)

    Geometric properties and continuity of the pre-duality mapping in Banach space

    Full text link
    We use the preduality mapping in proving characterizations of some geometric properties of Banach spaces. In particular, those include nearly strongly convexity, nearly uniform convexity-a property introduced by K. Goebel and T. Sekowski-, and nearly very convexity.We thank a referee for the careful reading of the manuscript. His/her observations substantially improved the overall aspect of the present work, detected several misprints and made some convenient changes. This work was supported by: (1) The National Natural Science Foundation of China (Grant no. 11271248). (2) Specific Academic Discipline Project of Shanghai Municipal Education Commission (Grant no. B-8932-13-0136). (3) Project MTM2011-22417, Ministerio de Ciencia e Innovacion, Spain (V. Montesinos).Zhang, ZH.; Montesinos Santalucia, V.; Liu, CY.; Gong, WZ. (2015). Geometric properties and continuity of the pre-duality mapping in Banach space. Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales. Serie A. Matematicas. 109(2):407-416. https://doi.org/10.1007/s13398-014-0190-6S4074161092Bandyopadhyay, P., Huang, D., Lin, B.L., Troyanski, S.L.: Some generalizations of local uniform rotundity. J. Math. Anal. Appl. 252, 906–916 (2000)Bandyopadhyay, P., Li, Y., Lin, B., Narayana, D.: Proximinality in Banach spaces. J. Math. Anal. Appl. 341, 309–317 (2008)Diestel, J.: Geometry of Banach Spaces. Selected Topics, LNM, vol. 485. Springer, Berlin (1975)Fabian, M., Habala, P., Hájek, P., Montesinos, V., Zizler, V.: Banach Space Theory. The Basis for Linear and Nonlinear Analysis, CMS Books in Mathematics. Springer, Berlin (2011)Giles, J.R., Gregory, D.A., Sims, B.: Geometrical implications of upper semi-continuity of the duality mapping on a Banach space. Pacific J. Math. 79(1), 99–109 (1978)Goebel, K., Sekowski, T.: The modulus of non-compact convexity. Ann. Univ. M. Curie-Sklodowska, Sect. A 38, 41–48 (1984)Guirao, A.J., Montesinos, V.: A note in approximative compactness and continuity of metric projections in Banach spaces. J. Convex Anal. 18, 397–401 (2011)Huff, R.: Banach spaces which are nearly uniformly convex. Rocky Mountain J. Math. 10(4), 743–749 (1980)Kutzarova, D., Rolewicz, S.: On nearly uniformly convex sets. Arch. Math. 57, 385–394 (1991)Kutzarova, D., Lin, B.L., Zhang, W.: Some geometrical properties of Banach spaces related to nearly uniform convexity. Contemp. Math. 144, 165–171 (1993)Kutzarova, D., Prus, S.: Operators which factor through nearly uniformly convex spaces. Boll. Un. Mat. Ital. B (7) 9, 2, 479–494 (1995)Montesinos, V.: Drop property equals reflexivity. Studia Math. 87, 93–100 (1987)Phelps, R.R.: Convex Functions, Monotone Operators and Differentiability, LNM, vol. 1364, 2nd edn. Springer, Berlin (1993)Rolewicz, S.: On drop property. Studia Math. 85, 27–37 (1986)Rolewicz, S.: On Δ\Delta Δ -uniform convexity and drop property. Studia Math. 87, 181–191 (1987)Wu, C.X., Li, Y.J.: Strong convexity in Banach spaces. J. Math. Wuhan Univ. 13(1), 105–108 (1993)Wang, J.H., Nan, C.X.: The continuity of subdifferential mapping. J. Math. Anal. Appl. 210, 206–214 (1997)Wang, J.H., Zhang, Z.H.: Characterization of the property (C-K). Acta Math. Sci. Ser. A Chin. Ed. 17(A)(3), 280–284 (1997)Zhang, Z.H., Liu, C.Y.: Some generalization of locally and weakly locally uniformly convex space. Nonlinear Anal. 74(12), 3896–3902 (2011)Zhang, Z.H., Liu, C.Y.: Convexity and proximinality in Banach spaces. J. Funct. Spaces Appl. 2012, 11 (2012). doi: 10.1155/2012/724120 . Article ID 724120Zhang, Z.H., Liu, C.Y.: Convexity and existence of the farthest point. Abstract Appl. Anal. 2011, 9 (2011). doi: 10.1155/2011/139597 . Article ID 139597Zhang, Z.H., Shi, Z.R.: Convexities and approximative compactness and continuity of the metric projection in Banach spaces. J. Approx. Theory 161(2), 802–812 (2009)Zhang, Z.H., Zhang, C.J.: On very rotund Banach spaces. Appl. Math. Mech. (English Ed.) 21(8), 965–970 (2000

    Rapid Evaluation of the Special Measures for Quality and Challenged Provider Regimes: A Mixed-Methods Study

    Get PDF
    Background: Healthcare organisations in England rated as inadequate for leadership and one other domain enter Special Measures for Quality (SMQ) to receive support and oversight. A ‘watch list’ of challenged providers (CPs) at risk of entering SMQ also receive support. Knowledge is limited about whether the support interventions drive improvements in quality, their costs, and whether they strike the right balance between support and scrutiny. Objective: Analyse trust responses to the implementation of a) interventions for SMQ trusts and b) interventions for CP trusts to determine their impact on these organisations' capacity to achieve and sustain quality improvements. Design: Rapid research comprising five inter-related workstreams: 1. Literature review using systematic methods. 2. Analysis of policy documents and interviews at national level. 3. Eight multi-site, mixed method trust case studies. 4. Analysis of national performance and workforce indicators. 5. Economic analysis. Results: SMQ/CP were intended to be “support” programmes. SMQ/CP had an emotional impact on staff. Perceptions of NHSI interventions were mixed overall. Senior leadership teams were a key driver of change, with strong clinical input vital. Local systems have a role in improvement. Trusts focus efforts to improve across multiple domains. Internal and external factors contribute to positive performance trajectories. Nationally, only 15.8% of SMQ trusts exited within 24 months. Relative to national trends, entry into SMQ/CP corresponded to positive changes in 4-hour waits in Emergency Departments, mortality and delayed transfers of care. Trends in staff sickness and absence improved after trusts left SMQ/CP. There was some evidence that staff survey results improve. No association was found between SMQ/CP and referral to treatment times or cancer waiting times. The largest components of NHSI spending in case studies were interventions directed at 'training on cultural change' (33.6%), 'workforce quality and safety' (21.7%) and 'governance and assurance' (18.4%). Impact of SMQ on financial stability was equivocal; most trusts exiting SMQ experienced the same financial stability before and after exiting. Limitations: The rapid research design and one-year timeframe precludes longitudinal observations of trusts and local systems. The small number of indicators limited the quantitative analysis of impact. Measuring workforce effects was limited by data availability. Conclusions: Empirical evidence of positive impacts from SMQ/CP were identified, however, perceptions were mixed. Key lessons: • Time is needed to implement and embed changes. • Ways to mitigate emotional costs and stigma are needed. • Support strategies should be more trust specific. • Poor organisational performance needs to be addressed within local systems. • Senior leadership teams with stability, strong clinical input and previous SMQ experience helped enact change. • Organisation-wide quality improvement strategies and capabilities are needed. • Staff engagement and an open listening culture promote continuous learning and a quality improvement ‘mindset’, critical for sustainable improvement. • Need to consider level of sustainable funds required to improve patients’ outcomes. Future work: Evaluating recent changes to the regimes; role of local systems; longitudinal approaches. Study registration: Review protocol registered with PROSPERO (CRD: 42019131024). Funding: The National Institute for Health Research Health Services and Delivery Research programme (16/138/17 – Rapid Service Evaluation Research Team)

    Linear Operator Inequality and Null Controllability with Vanishing Energy for unbounded control systems

    Get PDF
    We consider linear systems on a separable Hilbert space HH, which are null controllable at some time T0>0T_0>0 under the action of a point or boundary control. Parabolic and hyperbolic control systems usually studied in applications are special cases. To every initial state y0H y_0 \in H we associate the minimal "energy" needed to transfer y0 y_0 to 0 0 in a time TT0 T \ge T_0 ("energy" of a control being the square of its L2 L^2 norm). We give both necessary and sufficient conditions under which the minimal energy converges to 0 0 for T+ T\to+\infty . This extends to boundary control systems the concept of null controllability with vanishing energy introduced by Priola and Zabczyk (Siam J. Control Optim. 42 (2003)) for distributed systems. The proofs in Priola-Zabczyk paper depend on properties of the associated Riccati equation, which are not available in the present, general setting. Here we base our results on new properties of the quadratic regulator problem with stability and the Linear Operator Inequality.Comment: In this version we have also added a section on examples and applications of our main results. This version is similar to the one which will be published on "SIAM Journal on Control and Optimization" (SIAM

    Commutators on power series spaces

    Get PDF

    Local Hardy Spaces of Musielak-Orlicz Type and Their Applications

    Full text link
    Let \phi: \mathbb{R}^n\times[0,\fz)\rightarrow[0,\fz) be a function such that ϕ(x,)\phi(x,\cdot) is an Orlicz function and ϕ(,t)Aloc(Rn)\phi(\cdot,t)\in A^{\mathop\mathrm{loc}}_{\infty}(\mathbb{R}^n) (the class of local weights introduced by V. S. Rychkov). In this paper, the authors introduce a local Hardy space hϕ(Rn)h_{\phi}(\mathbb{R}^n) of Musielak-Orlicz type by the local grand maximal function, and a local BMO\mathop\mathrm{BMO}-type space bmoϕ(Rn)\mathop\mathrm{bmo}_{\phi}(\mathbb{R}^n) which is further proved to be the dual space of hϕ(Rn)h_{\phi}(\mathbb{R}^n). As an application, the authors prove that the class of pointwise multipliers for the local BMO\mathop\mathrm{BMO}-type space bmoϕ(Rn)\mathop\mathrm{bmo}^{\phi}(\mathbb{R}^n), characterized by E. Nakai and K. Yabuta, is just the dual of L^1(\rn)+h_{\Phi_0}(\mathbb{R}^n), where ϕ\phi is an increasing function on (0,)(0,\infty) satisfying some additional growth conditions and Φ0\Phi_0 a Musielak-Orlicz function induced by ϕ\phi. Characterizations of hϕ(Rn)h_{\phi}(\mathbb{R}^n), including the atoms, the local vertical and the local nontangential maximal functions, are presented. Using the atomic characterization, the authors prove the existence of finite atomic decompositions achieving the norm in some dense subspaces of hϕ(Rn)h_{\phi}(\mathbb{R}^n), from which, the authors further deduce some criterions for the boundedness on hϕ(Rn)h_{\phi}(\mathbb{R}^n) of some sublinear operators. Finally, the authors show that the local Riesz transforms and some pseudo-differential operators are bounded on hϕ(Rn)h_{\phi}(\mathbb{R}^n).Comment: Sci. China Math. (to appear
    corecore