684 research outputs found
Learning Curves and p-charts for a preliminary estimation of asymptotic performances of a manufacturing process
This paper presents a method for a preliminary estimation of asymptotic performances of a manufacturing process based on the knowledge of its learning curve estimated during the setting up of p-chart. The main novelties of the method are the possibility of estimating the asymptotic variability of a process and providing a simple approach for evaluating the period of revision of process control limits. An application of the method to a real example taken from the literature is also provided
Ecologies of Hope: environment, technology and habitation - case studies from the intervenient middle
This paper is an introduction to a special issue of the Journal of Political Ecology on "Ecologies of Hope." The authors argue that discrete, specific, and often, local actions can create spaces that are bettering human lives and livelihoods. The five papers identify actions and movements that are situated in the "middle" between the individual and larger social and economic formations, and inbetween social and economic status- quo and revolution. They are everyday initiatives that do not make revolutionary claims, but which in small but significant ways, help transform the lives of people and communities. These "ecologies of hope" resonate with the work of Karl Polanyi, and his identification of the modern disembedding of the economy and the environment from its societal and cultural context. Polanyi argued that processes that result in a loss of cultural "habitation" engender movements by societies to protect their social solidarity, and distortions of their relationship with the natural environment. Creating and carving out "ecologies of hope" may not mitigate catastrophic global change or miraculously transform the unjust into the just, but does make life and livelihoods a bit more habitable. For people whose lives are affected, this matters. Political ecology should recognize the importance of creating spaces for "habitation" that are not necessarily structural and scalable.
Key words: Karl Polanyi, ecologies of hope, habitation, self-organized communities
Fractional plateaus in the Coulomb blockade of coupled quantum dots
Ground-state properties of a double-large-dot sample connected to a reservoir
via a single-mode point contact are investigated. When the interdot
transmission is perfect and the dots controlled by the same dimensionless gate
voltage, we find that for any finite backscattering from the barrier between
the lead and the left dot, the average dot charge exhibits a Coulomb-staircase
behavior with steps of size e/2 and the capacitance peak period is halved. The
interdot electrostatic coupling here is weak. For strong tunneling between the
left dot and the lead, we report a conspicuous intermediate phase in which the
fractional plateaus get substantially altered by an increasing slope.Comment: 6 pages, 4 figures, final versio
The older volcanic complexes of Sao Miguel, Azores: Nordeste and Povoacao
The oldest part of S. Miguel is to the east of Furnas. Previous research argued that these volcanics belong to a construct called the Nordeste Volcano, a heavily eroded shield which not only extends to the east coast of the island but also underlies Furnas Volcano in the west. On the basis of geomorphological mapping, we argue that Nordeste comprises two volcanic systems: an older Nordeste construct (the Nordeste Volcanic System); and the younger Povoação Volcano which straddles the Nordeste shield on its western margin. The Nordeste Volcanic System consists of the Lower Basalts which constitute the overwhelming majority of its subaerial products which are exposed in coastal cliff sections. Above the Lower Basalts is a surficial drape of Ankaramites and the Upper Basalts. There is no evidence of large explosive trachytic eruptions from Nordeste Volcanic System. Povoação Volcano comprises an early shield construct, after which the volcano experienced caldera collapse. Post-caldera deposits are poorly exposed, but include basaltic, mugearitic and trachytic lavas intercalated by cut and fill sequences. Radiometric dating has yet to resolve fully the absolute ages of the Nordeste and Povoação volcanic systems, but morphology indicates that the former is much older than the latter
Probing the Nature of Short Swift Bursts via Deep INTEGRAL Monitoring of GRB 050925
We present results from Swift, XMM-Newton, and deep INTEGRAL monitoring in
the region of GRB 050925. This short Swift burst is a candidate for a newly
discovered soft gamma-ray repeater (SGR) with the following observational burst
properties: 1) galactic plane (b=-0.1 deg) localization, 2) 150 msec duration,
and 3) a blackbody rather than a simple power-law spectral shape (with a
significance level of 97%). We found two possible X-ray counterparts of GRB
050925 by comparing the X-ray images from Swift XRT and XMM-Newton. Both X-ray
sources show the transient behavior with a power-law decay index shallower than
-1. We found no hard X-ray emission nor any additional burst from the location
of GRB 050925 in ~5 Ms of INTEGRAL data. We discuss about the three BATSE short
bursts which might be associated with GRB 050925, based on their location and
the duration. Assuming GRB 050925 is associated with the H II regions (W 58) at
the galactic longitude of l=70 deg, we also discuss the source frame properties
of GRB 050925.Comment: 13 pages, 13 figures, accepted for publication in ASR special issue
on Neutron Stars and Gamma Ray Bursts, full resolution of Fig 5 is available
at
http://asd.gsfc.nasa.gov/Takanori.Sakamoto/GRB050925/integral_ibis_images.ep
Growing old : Do women and men age differently?
Aging of the head and especially the face has been studied intensively, yet questions remain about the timing and rates of aging throughout adulthood and about the extent to which aging differs between men and women. Here we address these issues by developing statistical models of craniofacial aging to describe and compare aging through the life course in both sexes. We selected cranial surface meshes from 254 females and 252 males, aged from 20 to 90 years from the Headspace project, Liverpool, UK. Sixteen anatomical landmarks and 59 semilandmarks on curves and surfaces were used to parameterize these. Modes and degrees of aging throughout adulthood were assessed and compared among sexes using Procrustes-based geometric morphometric methods. Regression analyses of form through the whole age range indicate that age accounts for a small proportion of total variance in both sexes, but form is significantly related to age and males and females age in significantly different ways. Further analyses indicate that aging differs in character, timing, and rates in both sexes between early and later phases of adulthood. Sexual differences in aging are evident in the early and later phases of adulthood. The study adds to knowledge of the aging of adult craniofacial form and sexual dimorphism. It is based on a local population and so the findings are directly applicable to that population. Further studies are needed to assess generalizability and provide better data on population differences to facilitate clinical assessment and treatment planning
Skilled Nursing and Inpatient Rehabilitation Facility Use by Medicare Fee-for-Service Beneficiaries Discharged Home After a Stroke: Findings From the COMPASS Trial
Objectives: To examine the effect of a comprehensive transitional care model on the use of skilled nursing facility (SNF) and inpatient rehabilitation facility (IRF) care in the 12 months after acute care discharge home following stroke; and to identify predictors of experiencing a SNF or IRF admission following discharge home after stroke. Design: Cluster randomized pragmatic trial Setting: Forty-one acute care hospitals in North Carolina. Participants: 2262 Medicare fee-for-service beneficiaries with transient ischemic attack or stroke discharged home. The sample was 80.3% White and 52.1% female, with a mean (SD) age of 74.9 (10.2) years and a mean ± SD National Institutes of Health stroke scale score of 2.3 (3.7). Intervention: Comprehensive transitional care model (COMPASS-TC), which consisted of a 2-day follow-up phone call from the postacute care coordinator and 14-day in-person visit with the postacute care coordinator and advanced practice provider. Main Outcome Measures: Time to first SNF or IRF and SNF or IRF admission (yes/no) in the 12 months following discharge home. All analyses utilized multivariable mixed models including a hospital-specific random effect to account for the non-independence of measures within hospital. Intent to treat analyses using Cox proportional hazards regression assessed the effect of COMPASS-TC on time to SNF/IRF admission. Logistic regression was used to identify clinical and non-clinical predictors of SNF/IRF admission. Results: Only 34% of patients in the intervention arm received COMPASS-TC per protocol. COMPASS-TC was not associated with a reduced hazard of a SNF/ IRF admission in the 12 months post-discharge (hazard ratio, 1.20, with a range of 0.95-1.52) compared to usual care. This estimate was robust to additional covariate adjustment (hazard ratio, 1.23) (0.93-1.64). Both clinical and non-clinical factors (ie, insurance, geography) were predictors of SNF/IRF use. Conclusions: COMPASS-TC was not consistently incorporated into real-world clinical practice. The use of a comprehensive transitional care model for patients discharged home after stroke was not associated with SNF or IRF admissions in a 12-month follow-up period. Non-clinical factors predictive of SNF/IRF use suggest potential issues with access to this type of care
Emergency department utilization after hospitalization discharge for acute stroke: The COMprehensive Post-Acute Stroke Services (COMPASS) study
Each year nearly 800,000 people in the United States experience a stroke. Those that survive are at high risk for complications after hospital discharge. Providing appropriate care during the recovery from this complex condition is a challenge for patients, caregivers, and health care providers. Understanding emergency department (ED) utilization after a stroke may provide insights into long-term management of stroke, inform interventions, improve patient outcomes, and reduce medical costs. A comprehensive transitional care model for post-acute stroke care may influence the need to seek ED care for downstream events after a stroke. To date, most transitional care trials exploring post-stroke healthcare utilization were conducted outside of the U.S. health-care system. We examined data from the Comprehensive Post-Acute Stroke Services (COMPASS) study, a cluster-randomized pragmatic trial of a post-discharge transitional care model for stroke survivors and their caregivers compared with usual care
Cold gas in elliptical galaxies
We explore the evolution of the cold gas (molecular and neutral hydrogen) of
elliptical galaxies and merger remnants ordered into a time sequence on the
basis of spectroscopic age estimates. We find that the fraction of cold gas in
early merger remnants decreases significantly for ~1-2 Gyr, but subsequent
evolution toward evolved elliptical systems sees very little change. This trend
can be attributed to an initial gas depletion by strong star-formation which
subsequently declines to quiescent rates. This explanation is consistent with
the merger picture for the formation of elliptical galaxies. We also explore
the relation between HI-to-H2 mass ratio and spectroscopic galaxy age, but find
no evidence for a statistically significant trend. This suggests little net HI
to H2 conversion for the systems in the present sample.Comment: 11 pages, 6 figures, accepted for publication by MNRA
Short Gamma Ray Bursts as possible electromagnetic counterpart of coalescing binary systems
Coalescing binary systems, consisting of two collapsed objects, are among the
most promising sources of high frequency gravitational waves signals
detectable, in principle, by ground-based interferometers. Binary systems of
Neutron Star or Black Hole/Neutron Star mergers should also give rise to short
Gamma Ray Bursts, a subclass of Gamma Ray Bursts. Short-hard-Gamma Ray Bursts
might thus provide a powerful way to infer the merger rate of two-collapsed
object binaries. Under the hypothesis that most short Gamma Ray Bursts
originate from binaries of Neutron Star or Black Hole/Neutron Star mergers, we
outline here the possibility to associate short Gamma Ray Bursts as
electromagnetic counterpart of coalescing binary systems.Comment: 4 pages, 1 figur
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