Fast spectral solutions of the double-gyre problem in a turbulent flow regime

Several semi-analytical models are considered for a double-gyre problem in a turbulent flow regime for which a reference fully numerical eddy-resolving solution is obtained. The semi-analytical models correspond to solving the depth-averaged Navier–Stokes equations using the spectral Galerkin approach. The robustness of the linear and Smagorinsky eddy-viscosity models for turbulent diffusion approximation is investigated. To capture essential properties of the double-gyre configuration, such as the integral kinetic energy, the integral angular momentum, and the jet mean-flow distribution, an improved semi-analytical model is suggested that is inspired by the idea of scale decomposition between the jet and the surrounding flow

Excitation of the Earth's Chandler wobble by a turbulent oceanic double-gyre

We develop a layer-averaged, multiple-scale spectral ocean model and show how an oceanic double-gyre can communicate with the Earth's Chandler wobble. The overall transfers of energy and angular momentum from the double-gyre to the Chandler wobble are used to calibrate the turbulence parameters of the layer-averaged model. Our model is tested against a multilayer quasi-geostrophic ocean model in turbulent regime, and base states used in parameter identification are obtained from mesoscale eddy resolving numerical simulations. The Chandler wobble excitation function obtained from the model predicts a small role of North Atlantic ocean region on the wobble dynamics as compared to all oceans, in agreement with the existing observations

Analytical assessment process of e-learning domain research between 1980 and 2014

Applying some methods to reduce the time and expenditures of training is inevitable in existing circumstances. Many educational organizations have realized the importance of Electronic Learning (E-learning) and tried to use this approach in leveraging their academic classes. As research in E-learning domain has become one of the most important and interesting subjects, observation in emerging and fading trends of E-learning is a need for the scholars and industry professionals who are interested to study and work in the field. This paper has triggered the investigation and depicting of scientific trends in E-learning by using two scientometric methods named burst detection and clustering analysis. By applying two mentioned methods, the hot topics were identified in the field of E-learning.info:eu-repo/semantics/acceptedVersio

Assessing payment instrument alternatives using cognitive mapping and the choquet integral

Technological advances have increased the diversity of payment instruments and transaction channels, heightening consumers' expectations for services in this regard. Coupled with an increasing competitiveness of the banking industry, this has emphasized the great importance of understanding consumers' choices of payment instruments. In order to meet their customers' expectations, banks have to understand what determines their choices of payment instruments. This study aims to uncover these determinants of payment instrument choice, through the use of cognitive mapping to structure the decision problem, and its combination with the Choquet integral to identify the overall preferred payment instrument from the user perspective. The results show that direct debits and electronic cards constitute the preferred payment instruments, and automated teller machines (ATMs) and point-of-sale (POS) the overall preferred transaction channels. Understanding consumers' choices of payment instrument, the factors underlying them and their interactions can contribute to better planning by banks at the distribution channel level. Strengths, limitations and managerial implications of our proposal are also discussed.info:eu-repo/semantics/publishedVersio

A cognition-driven risk evaluation framework for consumer loans

Credit to personal consumption is an important activity of the financial system and crucial to the socio-economic development of a country. It is important, therefore, that the methods and techniques used to evaluate consumer credit risk be as efficient and informative as possible, in order to strengthen decisions to approve or reject credit and promote sustainable economic growth. This study aims to create a multiple criteria expert system which integrates cognitive maps and the measuring attractiveness by a categorical based evaluation technique (MACBETH) to create a complementary framework for consumer credit risk assessment. The results show that this integrated approach allows the evaluation process of consumer credit risk to be more informed and transparent, providing value for the evaluation processes of this type of credit application as a result of the privileged contact established with a panel of credit analysts. Limitations and managerial implications are also discussed.info:eu-repo/semantics/publishedVersio

Studying the influence of emotional intelligence on the organizational innovation

In the last decades, large organizations have paid more attention to the topics such as creativity and innovation in organizational level because of changes and evolutions in the increasing competition field and unreliable environmental conditions. This research investigates the influence of emotional intelligence on the organizational innovation. This research is considered application-oriented and descriptive regarding the objectives and data collection method, respectively. Statistical population of the research included 300 employees from whom 169 employees were selected as statistical sample applying simple random sampling method and Cochran`s formula. Data collection was performed on the basis of standard questionnaires of emotional intelligence and organizational innovation. Questionnaire`s stability was calculated as 0.88 applying a Cronbach`s alpha coefficient. The obtained data were analyzed by applying regression and correlation coefficients in software SPSS. Research results showed that emotional intelligence and it`sdimensions had a significant positive influence on the organizational innovation in the employee

SOMAR-LES: A framework for multi-scale modeling of turbulent stratified oceanic flows

A new multi-scale modeling technique, SOMAR-LES, is presented in this paper. Localized grid refinement gives SOMAR (the Stratified Ocean Model with Adaptive Resolution) access to small scales of the flow which are normally inaccessible to general circulation models (GCMs). SOMAR-LES drives a LES (Large Eddy Simulation) on SOMAR's finest grids, forced with large scale forcing from the coarser grids. Three-dimensional simulations of internal tide generation, propagation and scattering are performed to demonstrate this multi-scale modeling technique. In the case of internal tide generation at a two-dimensional bathymetry, SOMAR-LES is able to balance the baroclinic energy budget and accurately model turbulence losses at only 10% of the computational cost required by a non-adaptive solver running at SOMAR-LES's fine grid resolution. This relative cost is significantly reduced in situations with intermittent turbulence or where the location of the turbulence is not known a priori because SOMAR-LES does not require persistent, global, high resolution. To illustrate this point, we consider a three-dimensional bathymetry with grids adaptively refined along the tidally generated internal waves to capture remote mixing in regions of wave focusing. The computational cost in this case is found to be nearly 25 times smaller than that of a non-adaptive solver at comparable resolution. In the final test case, we consider the scattering of a mode-1 internal wave at an isolated two-dimensional and three-dimensional topography, and we compare the results with Legg (2014) numerical experiments. We find good agreement with theoretical estimates. SOMAR-LES is less dissipative than the closure scheme employed by Legg (2014) near the bathymetry. Depending on the flow configuration and resolution employed, a reduction of more than an order of magnitude in computational costs is expected, relative to traditional existing solvers

First record of Cladius (Priophorus) rufipes (Hym.: Tenthredinidae) from Iran

در بررسی آفات درختان نارون در شهر رشت، در اواسط اردیبهشت 1390، لاروهای زنبور مشاهده و جمع‌آوری شد. جهت دست‌یابی به حشرات کامل، لاروهای آفت در آزمایشگاه پرورش داده شدند. این زنبور توسط نگارنده آخر با نام علمی Cladius (Priophorus) rufipes Serville مورد شناسایی قرار گرفت. گونه مذکور گزارش جدیدی برای فون ایران محسوب می‌شود

Abelian Higgs Hair for a Static Charged Black String

We study the problem of vortex solutions in the background of an electrically charged black string. We show numerically that the Abelian Higgs field equations in the background of a four-dimensional black string have vortex solutions. These solutions which have axial symmetry, show that the black string can support the Abelian Higgs field as hair. This situation holds also in the case of the extremal black string. We also consider the self-gravity of the Abelian Higgs field and show that the effect of the vortex is to induce a deficit angle in the metric under consideration.Comment: REVTEX4, 12 pages, 6 figures, The version to be appeared in Phys. Rev.