Ultra-compact structure in intermediate-luminosity radio quasars: building a sample of standard cosmological rulers and improving the dark energy constraints up to z∼3z\sim 3

In this paper, we present a new compiled milliarcsecond compact radio data set of 120 intermediate-luminosity quasars in the redshift range $0.46< z <2.76$. These quasars show negligible dependence on redshifts and intrinsic luminosity, and thus represents, in the standard model of cosmology, a fixed comoving-length of standard ruler. We implement a new cosmology-independent technique to calibrate the linear size of of this standard ruler as $l_m= 11.03\pm0.25$ pc, which is the typical radius at which AGN jets become opaque at the observed frequency $\nu\sim 2$ GHz. In the framework of flat $\Lambda$CDM model, we find a high value of the matter density parameter, $\Omega_m=0.322^{+0.244}_{-0.141}$, and a low value of the Hubble constant, $H_0=67.6^{+7.8}_{-7.4}\; \rm{kms}^{-1}\rm{Mpc}^{-1}$, which is in excellent agreement with the CMB anisotropy measurements by \textit{Planck}. We obtain ${\Omega_m}=0.309^{+0.215}_{-0.151}$, $w=-0.970^{+0.500}_{-1.730}$ at 68.3% CL for the constant $w$ of a dynamical dark-energy model, which demonstrates no significant deviation from the concordance $\Lambda$CDM model. Consistent fitting results are also obtained for other cosmological models explaining the cosmic acceleration, like Ricci dark energy (RDE) or Dvali-Gabadadze-Porrati (DGP) brane-world scenario. While no significant change in $w$ with redshift is detected, there is still considerable room for evolution in $w$ and the transition redshift at which $w$ departing from -1 is located at $z\sim 2.0$. Our results demonstrate that the method extensively investigated in our work on observational radio quasar data can be used to effectively derive cosmological information. Finally, we find the combination of high-redshift quasars and low-redshift clusters may provide an important source of angular diameter distances, considering the redshift coverage of these two astrophysical probes.Comment: 36 pages, 5 tables, 16 figures, A&A, in pres

EFFECT OF ARCH SUPPORT FOOT ORTHOSIS ON LOWER WTREMIN LOADING AND KINEMATICS DURING THE REBOUND

The purpose of this study was to determine whether arch support foot orthosis was capable of altering lower extremity loading and kinematics during the rebound. Nineteen female Division I basketball players participated in this study. Utilizing a repeated measures design, participants completed two rebound tasks with and without the arch support foot orthosis. Results showed that the selected arch support foot orthosis significantly decreased the peak impact force, knee internal rotation and foot inversion angle at the initial contact of the ground compared to those of the flat insole. It suggested that the use of the arch support foot orthosis can decrease the lower extremity loading and further decrease the risk of ACL injury in female basketball players

THE INFLUENCE OF ARCH SUPPORT INSOLE ON BASKETBALL JUMP SHOT

The purpose of this investigation was to examine the effects of arch support insole on jump shot scored percentage and kinetics. Eleven females Division I basketball participated in this study. They performed the jump shots until 5 shots were scored in arch support insoles and flat insoles. Kinematic data were collected with a motion analysis system (Motion Analysis Corporation, Santa Rosa, CA, USA) at 200-Hz sampling rate. Kinetic data were collected with two AMTl force platforms (AMTI Inc., Watertown, MA, USA) at 2000-Hz sampling rate. Non-parametric Wilcoxon signed-rank test was used to compare differences between arch support insole and flat insole on variables. No difference was found on jump shot scored percentage, jump height, peak ground reaction force, time to peak force and rate of force development. Wearing arch supporting insole did not influence the jump shot scored percentage and kinetics during jump shot

Deadline Constrained Cloud Computing Resources Scheduling through an Ant Colony System Approach

Cloud computing resources scheduling is essential for executing workflows in the cloud platform because it relates to both execution time and execution cost. In this paper, we adopt a model that optimizes the execution cost while meeting deadline constraints. In solving this problem, we propose an Improved Ant Colony System (IACS) approach featuring two novel strategies. Firstly, a dynamic heuristic strategy is used to calculate a heuristic value during an evolutionary process by taking the workflow topological structure into consideration. Secondly, a double search strategy is used to initialize the pheromone and calculate the heuristic value according to the execution time at the beginning and to initialize the pheromone and calculate heuristic value according to the execution cost after a feasible solution is found. Therefore, the proposed IACS is adaptive to the search environment and to different objectives. We have conducted extensive experiments based on workflows with different scales and different cloud resources. We compare the result with a particle swarm optimization (PSO) approach and a dynamic objective genetic algorithm (DOGA) approach. Experimental results show that IACS is able to find better solutions with a lower cost than both PSO and DOGA do on various scheduling scales and deadline conditions