Entropy2016, 18(6), 205; doi:10.3390/e18060205 - published 25 May 2016 Show/Hide Abstract
Abstract: The difference between quantum isoenergetic process and quantum isothermal process comes from the violation of the law of equipartition of energy in the quantum regime. To reveal an important physical meaning of this fact, here we study a special type of quantum heat engine consisting of three processes: isoenergetic, isothermal and adiabatic processes. Therefore, this engine works between the energy and heat baths. Combining two engines of this kind, it is possible to realize the quantum Carnot engine. Furthermore, considering finite velocity of change of the potential shape, here an infinite square well with moving walls, the power output of the engine is discussed. It is found that the efficiency and power output are both closely dependent on the initial and final states of the quantum isothermal process. The performance of the engine cycle is shown to be optimized by control of the occupation probability of the ground state, which is determined by the temperature and the potential width. The relation between the efficiency and power output is also discussed.
Entropy2016, 18(6), 206; doi:10.3390/e18060206 - published 25 May 2016 Show/Hide Abstract
Abstract: The pivotal proposal of this work is to present a reliable algorithm based on the local fractional homotopy perturbation Sumudu transform technique for solving a local fractional Tricomi equation occurring in fractal transonic flow. The proposed technique provides the results without any transformation of the equation into discrete counterparts or imposing restrictive assumptions and is completely free of round-off errors. The results of the scheme show that the approach is straightforward to apply and computationally very user-friendly and accurate.
Entropy2016, 18(6), 203; doi:10.3390/e18060203 - published 24 May 2016 Show/Hide Abstract
Abstract: Numerical and analytical investigation of the effects of thermal radiation and viscous heating on a convective flow of a non-Newtonian, incompressible fluid in an axisymmetric stretching sheet with constant temperature wall is performed. The power law model of the blood is used for the non-Newtonian model of the fluid and the Rosseland model for the thermal radiative heat transfer in an absorbing medium and viscous heating are considered as the heat sources. The non-dimensional governing equations are transformed to similarity form and solved numerically. A parameter study on entropy generation in medium is presented based on the Second Law of Thermodynamics by considering various parameters such as the thermal radiation parameter, the Brinkman number, Prandtl number, Eckert number.
Entropy2016, 18(6), 204; doi:10.3390/e18060204 - published 24 May 2016 Show/Hide Abstract
Abstract: Relation extraction has benefited from distant supervision in recent years with the development of natural language processing techniques and data explosion. However, distant supervision is still greatly limited by the quality of training data, due to its natural motivation for greatly reducing the heavy cost of data annotation. In this paper, we construct an architecture called MIML-sort (Multi-instance Multi-label Learning with Sorting Strategies), which is built on the famous MIML framework. Based on MIML-sort, we propose three ranking-based methods for sample selection with which we identify relation extractors from a subset of the training data. Experiments are set up on the KBP (Knowledge Base Propagation) corpus, one of the benchmark datasets for distant supervision, which is large and noisy. Compared with previous work, the proposed methods produce considerably better results. Furthermore, the three methods together achieve the best F1 on the official testing set, with an optimal enhancement of F1 from 27.3% to 29.98%.
Entropy2016, 18(6), 202; doi:10.3390/e18060202 - published 24 May 2016 Show/Hide Abstract
Abstract: We articulate and apply the generalized Onsager principle to derive transport equations for active liquid crystals in a fixed domain as well as in a free surface domain adjacent to a passive fluid matrix. The Onsager principle ensures fundamental variational structure of the models as well as dissipative properties of the passive component in the models, irrespective of the choice of scale (kinetic to continuum) and of the physical potentials. Many popular models for passive and active liquid crystals in a fixed domain subject to consistent boundary conditions at solid walls, as well as active liquid crystals in a free surface domain with consistent transport equations along the free boundaries, can be systematically derived from the generalized Onsager principle. The dynamical boundary conditions are shown to reduce to the static boundary conditions for passive liquid crystals used previously.
Entropy2016, 18(6), 200; doi:10.3390/e18060200 - published 24 May 2016 Show/Hide Abstract
Abstract: In this article, entropy generation with radiation on non-Newtonian Carreau nanofluid towards a shrinking sheet is investigated numerically. The effects of magnetohydrodynamics (MHD) are also taken into account. Firstly, the governing flow problem is simplified into ordinary differential equations from partial differential equations with the help of similarity variables. The solution of the resulting nonlinear differential equations is solved numerically with the help of the successive linearization method and Chebyshev spectral collocation method. The influence of all the emerging parameters is discussed with the help of graphs and tables. It is observed that the influence of magnetic field and fluid parameters oppose the flow. It is also analyzed that thermal radiation effects and the Prandtl number show opposite behavior on temperature profile. Furthermore, it is also observed that entropy profile increases for all the physical parameters.