98 research outputs found
Automatic Sequential to Parallel Code Conversion
The way software programs are being written has been redefined since the introduction of multicore processors. Software developers have started writing parallel programs that are robust and scalable. This would ensure use of processor power being made available in the form of multiple cores. Though this trend is increasing, there are legacy applications that have been developed over the past few decades. Most of these applications are inherently sequential making no use of multithreading or parallel programming. If such applications are ported to execute on the multicore hardware as they are then optimal usage of all cores is not guaranteed. Such applications would ideally utilize only one core and the other cores would remain idle, unless the operating system supports some parallelism while scheduling. Hence there is a need to convert such legacy sequential codes to their parallel versions so that multicore hardware is exploited to the fullest. In this paper we present a tool that we have developed to automatically convert a sequential C code to parallel code. This Sequential to Parallel (S2P) tool is still in the development phase. We also discuss other parallelization tools available today, compare such tools with S2P tool and present our performance analysis results on different kind of multicore hardware
Community resource centres to improve the health of women and children in Mumbai slums: study protocol for a cluster randomized controlled trial
Background: The trial addresses the general question of whether community resource centers run by a non-government organization improve the health of women and children in slums. The resource centers will be run by the Society for Nutrition, Education and Health Action, and the trial will evaluate their effects on a series of public health indicators. Each resource center will be located in a vulnerable Mumbai slum area and will serve as a base for salaried community workers, supervised by officers and coordinators, to organize the collection and dissemination of health information, provision of services, home visits to identify and counsel families at risk, referral of individuals and families to appropriate services and support for their access, meetings of community members and providers, and events and campaigns on health issues.
Methods/design: A cluster randomized controlled trial in which 20 urban slum areas with resource centers are compared with 20 control areas. Each cluster will contain approximately 600 households and randomized allocation will be in three blocked phases, of 12, 12 and 16 clusters. Any resident of an intervention cluster will be able to participate in the intervention, but the resource centers will target women and children, particularly women of reproductive age and children under 5.
The outcomes will be assessed through a household census after 2 years of resource center operations. The primary outcomes are unmet need for family planning in women aged 15 to 49 years, proportion of children under 5 years of age not fully immunized for their ages, and proportion of children under 5 years of age with weight for height less than 2 standard deviations below the median for age and sex. Secondary outcomes describe adolescent pregnancies, home deliveries, receipt of conditional cash transfers for institutional delivery, other childhood anthropometric indices, use of public sector health and nutrition services, indices of infant and young child feeding, and consultation for violence against women and children
Characterization of the Millimeter-Wave Polarization of Centaurus A with QUaD
Centaurus (Cen) A represents one of the best candidates for an isolated,
compact, highly polarized source that is bright at typical cosmic microwave
background (CMB) experiment frequencies. We present measurements of the 4
degree by 2 degree region centered on Cen A with QUaD, a CMB polarimeter whose
absolute polarization angle is known to 0.5 degrees. Simulations are performed
to assess the effect of misestimation of the instrumental parameters on the
final measurement and systematic errors due to the field's background structure
and temporal variability from Cen A's nuclear region are determined. The total
(Q, U) of the inner lobe region is (1.00 +/- 0.07 (stat.) +/- 0.04 (sys.),
-1.72 +/- 0.06 +/- 0.05) Jy at 100 GHz and (0.80 +/- 0.06 +/- 0.06, -1.40 +/-
0.07 +/- 0.08) Jy at 150 GHz, leading to polarization angles and total errors
of -30.0 +/- 1.1 degrees and -29.1 +/- 1.7 degrees. These measurements will
allow the use of Cen A as a polarized calibration source for future millimeter
experiments.Comment: 9 pages, 8 figures, v2 matches version published in Ap
First season QUaD CMB temperature and polarization power spectra
QUaD is a bolometric CMB polarimeter sited at the South Pole, operating at frequencies of 100 and 150 GHz. In this paper we report preliminary results from the first season of operation (austral winter 2005). All six CMB power spectra are presented derived as cross spectra between the 100 and 150 GHz maps using 67 days of observation in a low foreground region of approximately 60 deg^2. These data are a small fraction of the data acquired to date. The measured spectra are consistent with the ΛCDM cosmological model. We perform jackknife tests that indicate that the observed signal has negligible contamination from instrumental systematics. In addition, by using a frequency jackknife we find no evidence for foreground contamination
Cosmological parameter estimation using Very Small Array data out to ℓ= 1500
We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat Λ cold dark matter (ΛCDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by the Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible with their estimates. We find that Ωbh2= 0.0234+0.0012−0.0014, Ωdmh2= 0.111+0.014−0.016, h= 0.73+0.09−0.05, nS= 0.97+0.06−0.03, 1010AS= 23+7−3 and τ= 0.14+0.14−0.07 for WMAP and VSA when no external prior is included. On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95 per cent confidence ( nrun=−0.069 ± 0.032 ), something that is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ωm. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that fν < 0.087 at 95 per cent confidence, which corresponds to mν < 0.32 eV when all neutrino masses are equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for nrun < 0 is only marginal within this model
A Comparative Rugoscopic Study of the Dentate and Edentulous Individuals in the South Indian Population
This study analyzes the rugae pattern in dentulous and edentulous patients and also evaluates the association of rugae pattern between males and females. Aims and Objectives. This study aims to investigate rugae patterns in dentulous and edentulous patients of both sexes in South Indian population and to find whether palatoscopy is a useful tool in human identification. Materials and Methods. Four hundred outpatients from Sree Balaji Dental College and Hospital, Chennai, were included in the study. The study group was equally divided between the sexes, which was further categorized into 100 dentulous and edentulous patients, respectively. Results. The edentulous male showed the highest mean of wavy pattern and total absence of circular pattern while the edentulous female group showed the highest mean of curved pattern and total absence of nonspecific pattern, while dentate population showed similar value as that of the overall population such as straight, wavy, and curved patterns. Conclusion. The present study concludes that there is similar rugae pattern of distribution between male and female dentate population while there is varied pattern between the sexes of edentulous population. However, the most predominant patterns were straight, wavy, and circular patterns
Second and third season QUaD CMB temperature and polarization power spectra
We report results from the second and third seasons of observation with the
QUaD experiment. Angular power spectra of the Cosmic Microwave Background are
derived for both temperature and polarization at both 100 GHz and 150 GHz, and
as cross frequency spectra. All spectra are subjected to an extensive set of
jackknife tests to probe for possible systematic contamination. For the
implemented data cuts and processing technique such contamination is
undetectable. We analyze the difference map formed between the 100 and 150 GHz
bands and find no evidence of foreground contamination in polarization. The
spectra are then combined to form a single set of results which are shown to be
consistent with the prevailing LCDM model. The sensitivity of the polarization
results is considerably better than that of any previous experiment -- for the
first time multiple acoustic peaks are detected in the E-mode power spectrum at
high significance.Comment: 24 pages, 23 figures, updated to reflect published versio
QUaD: A High-Resolution Cosmic Microwave Background Polarimeter
We describe the QUaD experiment, a millimeter-wavelength polarimeter designed
to observe the Cosmic Microwave Background (CMB) from a site at the South Pole.
The experiment comprises a 2.64 m Cassegrain telescope equipped with a
cryogenically cooled receiver containing an array of 62 polarization-sensitive
bolometers. The focal plane contains pixels at two different frequency bands,
100 GHz and 150 GHz, with angular resolutions of 5 arcmin and 3.5 arcmin,
respectively. The high angular resolution allows observation of CMB temperature
and polarization anisotropies over a wide range of scales. The instrument
commenced operation in early 2005 and collected science data during three
successive Austral winter seasons of observation.Comment: 23 pages, author list and text updated to reflect published versio
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The QUaD Galactic Plane Survey. II. A Compact Source Catalog
We present a catalog of compact sources derived from the QUaD Galactic Plane Survey. The survey covers ~800 deg2 of the inner galaxy (|b| < 4°) in Stokes I, Q, and U parameters at 100 and 150 GHz, with angular resolutions of 5 and 3.5 arcmin, respectively. Five hundred and twenty-six unique sources are identified in I, of which 239 are spatially matched between frequency bands, with 53 (234) detected at 100 (150) GHz alone; 170 sources are identified as ultracompact H ii regions. Approximating the distribution of total intensity source fluxes as a power law, we find a slope of γS, 100 = −1.8 ± 0.4 at 100 GHz and γS, 150 = −2.2 ± 0.4 at 150 GHz. Similarly, the power-law index of the source two-point angular correlation function is γθ, 100 = −1.21 ± 0.04 and γθ, 150 = −1.25 ± 0.04. The total intensity spectral index distribution peaks at αI ~ 0.25, indicating that dust emission is not the only source of radiation produced by these objects between 100 and 150 GHz; free–free radiation is likely significant in the 100 GHz band. Four sources are detected in polarized intensity P, of which three have matching counterparts in I. Three of the polarized sources lie close to the Galactic center, Sagittarius A*, Sagittarius B2, and the Galactic Radio Arc, while the fourth is RCW 49, a bright H ii region. An extended polarized source, undetected by the source extraction algorithm on account of its ~0fdg5 size, is identified visually, and is an isolated example of large-scale polarized emission oriented distinctly from the bulk Galactic dust polarization.Astronom
The QUAD Galactic Plane Survey 1: Maps and Analysis of Diffuse Emission
We present a survey of ~ 800 square degrees of the galactic plane observed with the QUaD telescope. The
primary product of the survey are maps of Stokes I, Q and U parameters at 100 and 150 GHz, with spatial
resolution 5 and 3.5 arcminutes respectively. Two regions are covered, spanning approximately 245 - 295°
and 315 - 5° in galactic longitude l, and -4 < b < +4° in galactic latitude b. At 0:02° square pixel size, the
median sensitivity is 74 and 107 kJy/sr at 100 GHz and 150 GHz respectively in I, and 98 and 120 kJy/sr for
Q and U. In total intensity, we find an average spectral index of α = 2:35+-0:01(stat)+-0:02(sys) for |b| ≤1°,
indicative of emission components other than thermal dust. A comparison to published dust, synchrotron
and free-free models implies an excess of emission in the 100 GHz QUaD band, while better agreement is
found at 150 GHz. A smaller excess is observed when comparing QUaD 100 GHz data to WMAP 5-year
W band; in this case the excess is likely due to the wider bandwidth of QUaD. Combining the QUaD and
WMAP data, a two-component spectral fit to the inner galactic plane (|b| ≤1°) yields mean spectral indices
of αs = -0:32+-0:03 and αd = 2:84+-0:03; the former is interpreted as a combination of the spectral indices
of synchrotron, free-free and dust, while the second is attributed largely to the thermal dust continuum. In
the same galactic latitude range, the polarization data show a high degree of alignment perpendicular to the
expected galactic magnetic field direction, and exhibit mean polarization fraction 1:38+-0:08(stat)+-0:1(sys)%
at 100 GHz and 1:70+-0:06(stat)+-0:1(sys)% at 150 GHz. We find agreement in polarization fraction between
QUaD 100 GHz and WMAP W band, the latter giving 1:1+-0:4%
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