The Calculation of the Bending Moment Response of a Typical Launch Vehicle Using Generalized Power Spectral Techniques

Bending moment response calculation of launch vehicle using generalized power spectral technique

Sending multiple RTP streams in a single RTP session

This memo expands and clarifies the behavior of Real-time Transport Protocol (RTP) endpoints that use multiple synchronization sources (SSRCs). This occurs, for example, when an endpoint sends multiple RTP streams in a single RTP session. This memo updates RFC 3550 with regard to handling multiple SSRCs per endpoint in RTP sessions, with a particular focus on RTP Control Protocol (RTCP) behavior. It also updates RFC 4585 to change and clarify the calculation of the timeout of SSRCs and the inclusion of feedback messages

Local Large-Scale Structure and the Assumption of Homogeneity

Our recent estimates of galaxy counts and the luminosity density in the near-infrared (Keenan et al. 2010, 2012) indicated that the local universe may be under-dense on radial scales of several hundred megaparsecs (Mpc). Such a large-scale local under-density could introduce significant biases in the measurement and interpretation of cosmological observables, such as the inferred effects of dark energy on the rate of expansion. In Keenan et al. (2013), we measured the K-band luminosity density as a function of distance from us to test for such a local under-density. We made this measurement over the redshift range 0.01 < z < 0.2 (radial distances D ~ 50-800 Mpc). We found that the shape of the K-band luminosity function is relatively constant as a function of distance and environment. We derive a local (z < 0.07, D < 300 Mpc) K-band luminosity density that agrees well with previously published studies. At z > 0.07, we measure an increasing luminosity density that by z~ 0.1 rises to a value of ~1.5 times higher than that measured locally. This implies that the stellar mass density follows a similar trend. Assuming that the underlying dark matter distribution is traced by this luminous matter, this suggests that the local mass density may be lower than the global mass density of the universe at an amplitude and on a scale that is sufficient to introduce significant biases into the measurement of basic cosmological observables. At least one study has shown that an under-density of roughly this amplitude and scale could resolve the apparent tension between direct local measurements of the Hubble constant and those inferred by Planck team. Other theoretical studies have concluded that such an under-density could account for what looks like an accelerating expansion, even when no dark energy is present.Comment: Proceedings of IAU Symposium 308 "The Zeldovich Universe: Genesis and Growth of the Cosmic Web", 23-28 June 2014, Tallinn, Estoni

Comprehensive health assessments during de-institutionalization: An observational study

Background: People with intellectual disability (ID) leaving institutions pass through a transition stage that makes them vulnerable to inadequate health care. They enter into community care under general practitioners (GPs) who are often untrained and inexperienced in their needs. Specifically designed health reviews may be of assistance to both them and their new GPs as they go through that phase

Identifying the challenges and facilitators of implementing a COPD care bundle.

BACKGROUND: Care bundles have been shown to improve outcomes, reduce hospital readmissions and reduce length of hospital stay; therefore increasing the speed of uptake and delivery of care bundles should be a priority in order to deliver more timely improvements and consistent high-quality care. Previous studies have detailed the difficulties of obtaining full compliance to bundle elements but few have described the underlying reasons for this. In order to improve future implementation this paper investigates the challenges encountered by clinical teams implementing a chronic obstructive pulmonary disease (COPD) care bundle and describes actions taken to overcome these challenges. METHODS: An initial retrospective documentary analysis of data from seven clinical implementation teams was undertaken to review the challenges faced by the clinical teams. Three focus groups with healthcare professionals and managers explored solutions to these challenges developed during the project. RESULTS: Documentary analysis identified 28 challenges which directly impacted implementation of the COPD care bundle within five themes; staffing, infrastructure, process, use of improvement methodology and patient and public involvement. Focus groups revealed that the five most significant challenges for all groups were: staff too busy, staff shortages, lack of staff engagement, added workload of the bundle and patient coding issues. The participants shared facilitating factors used to overcome issues including: shifting perceptions to improve engagement, further education sessions to increase staff participation and gaining buy-in from managers through payment frameworks. CONCLUSIONS: Maximising the impact of a care bundle relies on its successful and timely implementation. Teams implementing the COPD care bundle encountered challenges that were common to all teams and sites. Understanding and learning from the challenges faced by previous endeavours and identifying the facilitators to overcoming these barriers provides an opportunity to mitigate issues that waste time and resources, and ensures that training can be tailored to the anticipated challenges

Evaluating the articulation of programme theory in practice as observed in Quality Improvement initiatives

Background: The Action-Effect Method(AEM) was co-developed by NIHR CLAHRC Northwest London (CLAHRC NWL) researchers and QI practitioners, building on Driver Diagrams(DD). This study aimed to determine AEM effectiveness in terms of technical aspects (how diagrams produced in practice compared with theoretical ideals) and social aspects (how engagement with the method related to social benefits). Methods Diagrams were scored on criteria developed on theoretical ideals of programme theory. 65 programme theory diagrams were reviewed (21 published Driver Diagrams (External DDs), 22 CLAHRC NWL Driver Diagrams (Internal DDs), and 21 CLAHRC NWL Action-Effect Diagrams(AEDs)). Social functions were studied through ethnographic observation of frontline QI teams in AEM sessions facilitated by QI experts. Qualitative analysis used inductive and deductive coding. Results ANOVA indicated the AEM significantly improved the quality of programme theory diagrams over Internal and External DDs on an average of 5 criteria from an 8-point assessment. Articulated aims were more likely to be patient-focused and high-level in AEDs than DDs. The cause/effect relationships from intervention to overall aim also tended to be clearer and were more likely than DDs to contain appropriate measure concepts. Using the AEM also served several social functions such as facilitating dialogue among multidisciplinary teams, and encouraging teams to act scientifically and pragmatically about planning and measuring QI interventions. Implications: The Action-Effect Method developed by CLAHRC NWL resulted in improvements over Driver Diagrams in articulating programme theory, which has wide-ranging benefits to quality improvement, including encouraging broad multi-disciplinary buy-in to clear aims and pre-planning a rigorous evaluation strategy

Determination of the survival probability of a launch vehicle rising through a random wind field

Survival probability of rising launch vehicle subjected to wind shear loads - statistical load survey method, and wind profile analyses for design consideration

Locally soluble groups with all nontrivial normal subgroups isomorphic

Let $G$ be an infinite, locally soluble group which is isomorphic to all its nontrivial normal subgroups. If $G/G'$ has finite $p$-rank for $p=0$ and for all primes $p$, then $G$ is cyclic