109 research outputs found

    Effective factors on adoption technology among trout fish farms in Guilan Province

    Get PDF
    The main purpose of this study was to investigate effective factors on adopting technologies among trout fish farmers in Guilan province by Unified Theory of Acceptance and Use of Technology (UTAUT). Statistical population of this research contained of all managers of trout fish farms of Guilan province (N=170) that base on limitation of structural equation modelling in determining sample size, 97 of them were chosen as a sample. Study tool was contained Vankatesh and et al. information technology questionnaire in six items. To obtain validity of questionnaire; content, face, convergent and discriminant validity were used. As well, to obtain reliability of questionnaire; principal component analysis, Cronbachs alpha, Dillon-Goldstein’s ʃ and reagent stability were used. To accomplish analysis of data, SPSSV19 and SmartPLSV2 software were used in descriptive and inferential statistics. For testing hypothesis, structural equation model (SEM) and partial least squares (PLS) that focus on reagent variance were used. The results showed that there was significant relationship between performance expectancy and behavioral intention. Also there was significant relationship between intention to use and use behavior of aquaculture technologies. Model explains 28.8 percent of behavioral intention variance and 7.9 percent of use behavior of aquaculture technologies variance among trout fish farmers. To increase willingness to accept the technology among trout fish farms in Guilan province, it is suggested that extension-education courses for raising knowledge and awareness of aquaculture technology to be held by organizations. Providing financial resources and adequate knowledge will enable trout fish farms to equip with the aquaculture technologies

    Investigation of robust stability for fractional-order LTI systems with multilinear structure of ellipsoidal parametric uncertainty

    Get PDF
    The contribution focuses on the investigation of robust stability for fractional-order linear time-invariant (LTI) systems with the multilinear structure of ellipsoidal parametric uncertainty, i.e., the analyzed family of fractional-order polynomials has the multilinear uncertainty structure and an ellipsoid-shaped uncertainty bounding set. The robust stability test is based on the numerical calculation and subsequent plot of the value sets, and the application of the zero exclusion condition. Unlike the previously published works, this contribution shows that, contrary to the case of a two-dimensional ellipse of parameters, the internal points of a three-dimensional ellipsoid of parameters cannot create the boundary of the value set in the complex plane even under more complicated uncertainty structures, such as the multilinear one. © 2020, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

    Psychometric properties of Persian version of midwives' attitudes and beliefs questionnaire toward physiological childbirth

    Get PDF
    Introduction: Since attitudes and beliefs can predict behavior, policy, and performance of an individual, so the midwives' attitudes and beliefs toward labor and delivery can also affect their caring behavior and performance, and the prenatal consequences of the mother and neonate. And the baby is effective. There was no suitable Persian tool to measure the attitude and belief of midwives toward physiological delivery, so this present study was performed with aim of translating and psychometric evaluation of the Persian version of the questionnaire of attitude and belief of midwives toward physiological delivery. Methods: This methodological study was performed on 200 midwives working in the selected hospitals of Tehran University of Medical Sciences in 2018. The midwives were asked to complete a demographic questionnaire and midwives' attitudes and beliefs questionnaire toward physiological childbirth. At first, the face and content validity of the questionnaire was performed qualitatively. Then, construct validity was performed by confirmatory factor analysis. The reliability of the questionnaire was confirmed by stability reliability method and internal consistency. Results: The face validity and qualitative content of the questionnaire of midwives' attitudes and beliefs toward physiological childbirth were confirmed. Also, confirmatory factor analysis by estimating weight Partial Least Squares showed that the Persian version of this questionnaire has a suitable structure. In order to determine the reliability, the Cronbach's alpha coefficient was estimated as 0.68 to 0.733 for domains of the tools and the Intra-class correlation coefficient was 0.78; both of which indicated good reliability of the Persian version of the questionnaire. Conclusion: Persian version of the questionnaire of midwives' attitude and belief toward physiological childbirth is valid and reliable and can be used as an appropriate instrument for assessing the attitude and belief of midwives toward physiological childbirth in Iran. © 2020, Mashhad University of Medical Sciences. All rights reserved

    Promotion of GM-PHD Filtering Approach for Single-Target Tracking in Raw Data of Synthetic Aperture Radar in Spotlight Imaging Mode

    Get PDF
    So far multi-antenna techniques have been used in Synthetic Aperture Radar (SAR) to track moving targets. These techniques carry out the tracking of moving targets in an imaging area, using a combination of the data received by two or several antennas. The aim of this paper is single-target tracking in SAR Spotlight imaging mode based on the promoted PHD filter. In most applications, target tracking in densely cluttered environment using radar system demands robust filtering so as to increase the tracking efficiency. Therefore, tracking of moving targets in the presence of high density clutters in environment, as the particular capability of the PHD filter, has turned it into a robust approach in SAR to track moving targets. Also as the simulation results show, using Range Cell Migration Compensation (RCMC) on SAR raw data before tracking, makes it possible to track a moving target with high quality

    Metastability in spin polarised Fermi gases and quasiparticle decays

    No full text
    We investigate the metastability associated with the first order transition from normal to superfluid phases in the phase diagram of two-component polarised Fermi gases.We begin by detailing the dominant decay processes of single quasiparticles.Having determined the momentum thresholds of each process and calculated their rates, we apply this understanding to a Fermi sea of polarons by linking its metastability to the stability of individual polarons, and predicting a region of metastability for the normal partially polarised phase. In the limit of a single impurity, this region extends from the interaction strength at which a polarised phase of molecules becomes the groundstate, to the one at which the single quasiparticle groundstate changes character from polaronic to molecular. Our argument in terms of a Fermi sea of polarons naturally suggests their use as an experimental probe. We propose experiments to observe the threshold of the predicted region of metastability, the interaction strength at which the quasiparticle groundstate changes character, and the decay rate of polarons

    The Effect of Probiotics on Childhood Constipation: A Randomized Controlled Double Blind Clinical Trial

    Get PDF
    Background. Inconsistent data exist about the role of probiotics in the treatment of constipated children. The aim of this study was to investigate the effectiveness of probiotics in childhood constipation. Materials and Methods. In this placebo controlled trial, fifty-six children aged 4–12 years with constipation received randomly lactulose plus Protexin or lactulose plus placebo daily for four weeks. Stool frequency and consistency, abdominal pain, fecal incontinence, and weight gain were studied at the beginning, after the first week, and at the end of the 4th week in both groups. Results. Forty-eight patients completed the study. At the end of the fourth week, the frequency and consistency of defecation improved significantly (P=0.042 and P=0.049, resp.). At the end of the first week, fecal incontinence and abdominal pain improved significantly in intervention group (P=0.030 and P=0.017, resp.) but, at the end of the fourth week, this difference was not significant (P=0.125 and P=0.161, resp.). A significant weight gain was observed at the end of the 1st week in the treatment group. Conclusion. This study showed that probiotics had a positive role in increasing the frequency and improving the consistency at the end of 4th week

    Strongly Correlated Quantum Fluids: Ultracold Quantum Gases, Quantum Chromodynamic Plasmas, and Holographic Duality

    Get PDF
    Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical, and that do not have a simple description in terms of weakly interacting quasi-particles. Two systems that have recently attracted a great deal of interest are the quark-gluon plasma, a plasma of strongly interacting quarks and gluons produced in relativistic heavy ion collisions, and ultracold atomic Fermi gases, very dilute clouds of atomic gases confined in optical or magnetic traps. These systems differ by more than 20 orders of magnitude in temperature, but they were shown to exhibit very similar hydrodynamic flow. In particular, both fluids exhibit a robustly low shear viscosity to entropy density ratio which is characteristic of quantum fluids described by holographic duality, a mapping from strongly correlated quantum field theories to weakly curved higher dimensional classical gravity. This review explores the connection between these fields, and it also serves as an introduction to the Focus Issue of New Journal of Physics on Strongly Correlated Quantum Fluids: from Ultracold Quantum Gases to QCD Plasmas. The presentation is made accessible to the general physics reader and includes discussions of the latest research developments in all three areas.Comment: 138 pages, 25 figures, review associated with New Journal of Physics special issue "Focus on Strongly Correlated Quantum Fluids: from Ultracold Quantum Gases to QCD Plasmas" (http://iopscience.iop.org/1367-2630/focus/Focus%20on%20Strongly%20Correlated%20Quantum%20Fluids%20-%20from%20Ultracold%20Quantum%20Gases%20to%20QCD%20Plasmas

    Repulsive polarons and itinerant ferromagnetism in strongly polarized Fermi gases

    Full text link
    We analyze the properties of a single impurity immersed in a Fermi sea. At positive energy and scattering lengths, we show that the system possesses a well-defined but metastable excitation, the repulsive polaron, and we calculate its energy, quasiparticle residue and effective mass. From a thermodynamic argument we obtain the number of particles in the dressing cloud, illustrating the repulsive character of the polaron. Identifying the important 2- and 3-body decay channels, we furthermore calculate the lifetime of the repulsive polaron. The stability conditions for the formation of fully spin polarized (ferromagnetic) domains are then examined for a binary mixture of atoms with a general mass ratio. Our results indicate that mass imbalance lowers the critical interaction strength for phase-separation, but that very short quasiparticle decay times will complicate the experimental observation of itinerant ferromagnetism. Finally, we present the spectral function of the impurity for various coupling strengths and momenta.Comment: Substantial improvements to the section describing quasiparticle decays (included a discussion of two-body and three-body processes), and to the criteria for the stability of the itinerant ferromagnetic phas

    Metastability and Coherence of Repulsive Polarons in a Strongly Interacting Fermi Mixture

    Full text link
    Ultracold Fermi gases with tuneable interactions represent a unique test bed to explore the many-body physics of strongly interacting quantum systems. In the past decade, experiments have investigated a wealth of intriguing phenomena, and precise measurements of ground-state properties have provided exquisite benchmarks for the development of elaborate theoretical descriptions. Metastable states in Fermi gases with strong repulsive interactions represent an exciting new frontier in the field. The realization of such systems constitutes a major challenge since a strong repulsive interaction in an atomic quantum gas implies the existence of a weakly bound molecular state, which makes the system intrinsically unstable against decay. Here, we exploit radio-frequency spectroscopy to measure the complete excitation spectrum of fermionic 40K impurities resonantly interacting with a Fermi sea of 6Li atoms. In particular, we show that a well-defined quasiparticle exists for strongly repulsive interactions. For this "repulsive polaron" we measure its energy and its lifetime against decay. We also probe its coherence properties by measuring the quasiparticle residue. The results are well described by a theoretical approach that takes into account the finite effective range of the interaction in our system. We find that a non-zero range of the order of the interparticle spacing results in a substantial lifetime increase. This major benefit for the stability of the repulsive branch opens up new perspectives for investigating novel phenomena in metastable, repulsively interacting fermion systems.Comment: 11 pages, 9 figure
    corecore