147 research outputs found
Optimal Robot Arm Movement using Tabu Search Algorithm
Abstract: This study presents an optimum approach to calculate the optimal robot arm movement for processing a considerable commitment of tasks using Tabu Search (TS) algorithm. In the scheduling problem, the objective is to minimize the total processing time related to tasks distances from each other. In the first step, the TS method is reviewed and we employ the proposed method in order to assign efficiently the optimal robot arm movement. In our proposed algorithm, the crossover rate is large at first and gradually it is decreased based on convergence improvement in next generations. We define an objective function including the operation times. Then, by minimizing this function using discrete TS algorithm, the optimal robot arm movement trajectory is assigned efficiently and quickly. If the resulted best cost converges to global minima, the crossover rate will be decreased in next generation. This method is studied in terms of operation time, convergence speed and quality of the results. Superior features of this algorithm are fast tuning, rapid convergence, less computational burden and capability to avoid from local minima. High promising results demonstrate that our proposed method is very efficient and can obtain higher quality solutions with better computational capability
Estimate of the Cosmological Bispectrum from the MAXIMA-1 Cosmic Microwave Background Map
We use the measurement of the cosmic microwave background taken during the
MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We
propose an estimator for the bispectrum that is appropriate in the flat sky
approximation, apply it to the MAXIMA-1 data and evaluate errors using
bootstrap methods. We compare the estimated value with what would be expected
if the sky signal were Gaussian and find that it is indeed consistent, with a
per degree of freedom of approximately unity. This measurement places
constraints on models of inflation.Comment: 5 pages, 2 figures. New version to match paper accepted for
publication in Phys. Rev. Lett. Non-diagonal terms included leading to new
limits on f_N
Determining Foreground Contamination in CMB Observations: Diffuse Galactic Emission in the MAXIMA-I Field
Observations of the CMB can be contaminated by diffuse foreground emission
from sources such as Galactic dust and synchrotron radiation. In these cases,
the morphology of the contaminating source is known from observations at
different frequencies, but not its amplitude at the frequency of interest for
the CMB. We develop a technique for accounting for the effects of such emission
in this case, and for simultaneously estimating the foreground amplitude in the
CMB observations. We apply the technique to CMB data from the MAXIMA-1
experiment, using maps of Galactic dust emission from combinations of IRAS and
DIRBE observations, as well as compilations of Galactic synchrotron emission
observations. The spectrum of the dust emission over the 150--450 GHz observed
by MAXIMA is consistent with preferred models but the effect on CMB power
spectrum observations is negligible.Comment: 19 pages, 8 figures, accepted for publication in the Astrophysical
Journal. Monor changes to match the published versio
Paragangliome non secrétant de l’organe de Zuckerkandl
Le Phéochromocytome extra-surrénalien ou paragangliome est une tumeur rare. Il dérive de la crête neurale du système neuroendocrinien et il est souvent sécrétant. La plupart de ces tumeurs sont situées dans les ganglions sympathiques abdominaux, y compris l'organe de Zuckerkandl adjacent à la bifurcation de l'aorte abdominale. Les Formes non fonctionnelles sont rares: moins de 50 cas sont rapportés dans la littérature. Nous rapportons le cas d'un paragangliome non sécrétant de l'organe de Zuckerkandl opéré au sein de notre service d'urologie ainsi qu'une revue de la littérature afin de discuter les différents aspects diagnostiques et thérapeutiques de cette entité tumorale rare
Cystadénome Papillaire de L’épididyme: Un Nouveau Cas
Le cystadénome papillaire de l’épididyme est une tumeur paratesticulaire bénigne rare. Se présentant comme une masse épididymaire uni ou bilatérale. Son association avec le syndrome de Von Hippel-Lindau est fréquente, en particulier dans les lésions bilatérales. Nous rapportons l’observation d’un patient âgé de 36 ans, qui présentait depuis un an des douleurs scrotales gauches, une grosse bourse chronique, sans fièvre ni signes fonctionnels urinaires. L’examen avait mis en évidence une masse testiculaire dure, irrégulière et indolore sans adénopathies inguinales ni masse abdominale. L’échographie scrotale avait montré une masse testiculaire gauche solide hypoéchogène bien limitée de 3 x 2,5 x 2,2 cm. Les marqueurs tumoraux étaient normaux (ßHCG : 2 UI/j, AlphaFoetoProteine : 2,94 UI/l). La masse testiculaire a été explorée à travers une incision inguinale gauche. A la palpation, c’était une tumeur testiculaire dure. Une orchidectomie gauche a été réalisée. L’examen anatomopathologique de la pièce d’exérèse avait conclu à un aspect morphologique et immunohistochimique d’un cystadénome papillaire séreux borderline paratesticulaire sans signe d’invasion. A travers notre observation et les données de la littérature, nous proposons de mieux définir le diagnostic clinique et anatomopathologique ainsi que le traitement de ces tumeurs testiculaires rares.Mots clés : épididyme, cystadénome papillaire
MAXIMA: an experiment to measure temperature anisotropy in the cosmic microwave background
We describe the MAXIMA experiment, a balloon-borne measurement designed to
map temperature anisotropy in the Cosmic Microwave Background (CMB) over a wide
range of angular scales (multipole range 80 < l < 800). The experiment consists
of a 1.3 m diameter off-axis Gregorian telescope and a receiver with a 16
element array of bolometers cooled to 100 mK. The frequency bands are centered
at 150, 240, and 410 GHz. The 10' FWHM beam sizes are well matched to the scale
of acoustic peaks expected in the angular power spectrum of the CMB. The first
flight of the experiment in its full configuration was launched in August 1998.
A 122 sq-deg map of the sky was made near the Draco constellation during the 7
hour flight in a region of extremely low galactic dust contamination. This map
covers 0.3% of the sky and has 3200 independent beamsize pixels. We describe
the MAXIMA instrument and its performance during the recent flight.Comment: To appear in proceedings of `3K Cosmology', ed. F Melchiorri,
Conference held Oct 5-10 1998, Rome, 13 pages LaTeX (using aipproc2.sty &
aipproc2.cls), Postscript with higher resolution graphics available at
http://cfpa.berkeley.edu/group/cmb/gen.htm
From the time-ordered data to the Maximum-Likelihood temperature maps of the Cosmic Microwave Backgorund anisotropy
We review selected methods of the Cosmic Microwave Background data analysis appropriate for the analysis of the largest currently available data sets. We focus on techniques of the time-ordered data manipulation and map making algorithms based on the maximum-likelihood approach. The presented methods have been applied to the MAXIMA data analysis (Hanany et al 2000) and the description of the algorithms is illustrated with the examples drawn from that experience. The more extensive presentation of the here-mentioned issues will be given in the forthcoming paper (Stompor et al 2001)
MAXIPOL: Cosmic Microwave Background Polarimetry Using a Rotating Half-Wave Plate
We discuss MAXIPOL, a bolometric balloon-borne experiment designed to measure
the E-mode polarization of the cosmic microwave background radiation (CMB).
MAXIPOL is the first bolometric CMB experiment to observe the sky using rapid
polarization modulation. To build MAXIPOL, the CMB temperature anisotropy
experiment MAXIMA was retrofitted with a rotating half-wave plate and a
stationary analyzer. We describe the instrument, the observations, the
calibration and the reduction of data collected with twelve polarimeters
operating at 140 GHz and with a FWHM beam size of 10 arcmin. We present maps of
the Q and U Stokes parameters of an 8 deg^2 region of the sky near the star
Beta Ursae Minoris. The power spectra computed from these maps give weak
evidence for an EE signal. The maximum-likelihood amplitude of
l(l+1)C^{EE}_{l}/(2 pi) is 55_{-45}^{+51} uK^2 (68%), and the likelihood
function is asymmetric and skewed positive such that with a uniform prior the
probability that the amplitude is positive is 96%. This result is consistent
with the expected concordance LCDM amplitude of 14 uK^2. The maximum likelihood
amplitudes for l(l+1)C^{BB}_{l}/(2 pi) and are
-31_{-19}^{+31} and 18_{-34}^{+27} uK^2 (68%), respectively, which are
consistent with zero. All of the results are for one bin in the range 151 < l <
693. Tests revealed no residual systematic errors in the time or map domain. A
comprehensive discussion of the analysis of the data is presented in a
companion paper.Comment: 19 pages, 11 figures, 2 tables, submitted to Ap
The Quintessential CMB, Past & Future
The past, present and future of cosmic microwave background (CMB) anisotropy
research is discussed, with emphasis on the Boomerang and Maxima balloon
experiments. These data are combined with large scale structure (LSS)
information and high redshift supernova (SN1) observations to explore the
inflation-based cosmic structure formation paradigm. Here we primarily focus on
a simplified inflation parameter set, {omega_b,omega_{cdm},Omega_{tot},
Omega_Q,w_Q, n_s,tau_C, sigma_8}. After marginalizing over the other cosmic and
experimental variables, we find the current CMB+LSS+SN1 data gives
Omega_{tot}=1.04\pm 0.05, consistent with (non-baroque) inflation theory.
Restricting to Omega_{tot}=1, we find a nearly scale invariant spectrum, n_s
=1.03 \pm 0.07. The CDM density, omega_{cdm}=0.17\pm 0.02, is in the expected
range, but the baryon density, omega_b=0.030\pm 0.004, is slightly larger than
the current nucleosynthesis estimate. Substantial dark energy is inferred,
Omega_Q\approx 0.68\pm 0.05, and CMB+LSS Omega_Q values are compatible with the
independent SN1 estimates. The dark energy equation of state, parameterized by
a quintessence-field pressure-to-density ratio w_Q, is not well determined by
CMB+LSS (w_Q<-0.3 at 95%CL), but when combined with SN1 the resulting w_Q<-0.7
limit is quite consistent with the w_Q=-1 cosmological constant case. Though
forecasts of statistical errors on parameters for current and future
experiments are rosy, rooting out systematic errors will define the true
progress.Comment: 14 pages, 3 figs., in Proc. CAPP-2000 (AIP), CITA-2000-6
- …