Casimir effect of an ideal Bose gas trapped in a generic power-law potential

The Casimir effect of an ideal Bose gas trapped in a generic power-law potential and confined between two slabs with Dirichlet, Neumann, and periodic boundary conditions is investigated systematically, based on the grand potential of the ideal Bose gas, the Casimir potential and force are calculated. The scaling function is obtained and discussed. The special cases of free and harmonic potentials are also discussed. It is found that when T<Tc (where Tc is the critical temperature of Bose-Einstein condensation), the Casimir force is a power-law decay function; when T>Tc, the Casimir force is an exponential decay function; and when T>>Tc, the Casimir force vanishes.Comment: 5 pages, 1 figur

Theoretical bound of the efficiency of learning

A unified thermodynamic formalism describing the efficiency of learning is proposed. First, we derive an inequality, which is more strength than Clausius's inequality, revealing the lower bound of the entropy-production rate of a subsystem. Second, the inequality is transformed to determine the general upper limit for the efficiency of learning. In particular, we exemplify the bound of the efficiency in nonequilibrium quantum-dot systems and networks of living cells. The framework provides a fundamental trade-off relationship between energy and information inheriting in stochastic thermodynamic processes

Possible canonical distributions for finite systems with nonadditive energy

It is shown that a small system in thermodynamic equilibrium with a finite thermostat can have a q-exponential probability distribution which closely depends on the energy nonextensivity and the particle number of the thermostat. The distribution function will reduce to the exponential one at the thermodynamic limit. However, the nonextensivity of the system should not be neglected.Comment: 13 pages, 4 figure

1526 The Open Automation and Control Systems Journal

Abstract: Traditional resistance measurement for DC motor commutator segment is manual. The process is complicated, the efficiency is low, and the cost is high. In order to enhance efficiency and precision of the resistance measurement, we design an automatic measurement equipment using virtual instrument technique. The equipment consists on industrial compute, stepping motor drive transmission system, low resistance measuring meter, host compute software. Making the equipment universal and automated is the core of design. We discuss working principle of the equipment, hardware design, software design, measurement experiment process and results analysis. Hardware design includes accurate position control of stepping motor, 4-wire method for resistance measurement, special fixture design for probe. Software design based on LabWindows/CVI platform includes serial communication, asynchronous timers, multi-thread, ActiveX control. The measurement experiment results indicate that the euipment can measure almost all kind of DC motor rotors accurately, also can record and save measurement results automatically

AutoShot: A Short Video Dataset and State-of-the-Art Shot Boundary Detection

The short-form videos have explosive popularity and have dominated the new social media trends. Prevailing short-video platforms,~\textit{e.g.}, Kuaishou (Kwai), TikTok, Instagram Reels, and YouTube Shorts, have changed the way we consume and create content. For video content creation and understanding, the shot boundary detection (SBD) is one of the most essential components in various scenarios. In this work, we release a new public Short video sHot bOundary deTection dataset, named SHOT, consisting of 853 complete short videos and 11,606 shot annotations, with 2,716 high quality shot boundary annotations in 200 test videos. Leveraging this new data wealth, we propose to optimize the model design for video SBD, by conducting neural architecture search in a search space encapsulating various advanced 3D ConvNets and Transformers. Our proposed approach, named AutoShot, achieves higher F1 scores than previous state-of-the-art approaches, e.g., outperforming TransNetV2 by 4.2%, when being derived and evaluated on our newly constructed SHOT dataset. Moreover, to validate the generalizability of the AutoShot architecture, we directly evaluate it on another three public datasets: ClipShots, BBC and RAI, and the F1 scores of AutoShot outperform previous state-of-the-art approaches by 1.1%, 0.9% and 1.2%, respectively. The SHOT dataset and code can be found in https://github.com/wentaozhu/AutoShot.git .Comment: 10 pages, 5 figures, 3 tables, in CVPR 2023; Top-1 solution for scene / shot boundary detection https://paperswithcode.com/paper/autoshot-a-short-video-dataset-and-state-o

Parametric analysis and optimization for exergoeconomic performance of a combined system based on solid oxide fuel cell-gas turbine and supercritical carbon dioxide Brayton cycle

Fuel cell-gas turbine hybrid system is a potential field of investigation. This study establishes a modeling and optimization framework for a novel hybrid system consisting of a solid oxide fuel cell, a gas turbine and a supercritical carbon dioxide Brayton cycle. Based on the proposed thermodynamical model, a parametric analysis is investigated to determine the impacts of several key parameters on the system exergoeconomic performance. Meanwhile, bi-objective optimization is conducted for maximizing the exergy efficiency and minimizing the levelized cost of electricity via the Epsilon-constraint approach. The Linear Programming Techniques for Multidimensional Analysis of Preference decision-making approach is further employed to select the Pareto optimum solution from Pareto frontiers. The results show that several extreme values for the exergy efficiency and the levelized cost of electricity exist in a series of sensitivity curves, respectively. The Pareto frontiers indicates that with the increase of the exergy efficiency, the levelized cost of electricity shows a moderately increasing trend at first and increases rapidly afterward. Overall, at the Pareto optimum solution, the combined system can achieve an optimal exergy efficiency and levelized cost of electricity by 68% and 0.0575 $ kWh −1 , respectively

Self-similar motion for modeling anomalous diffusion and nonextensive statistical distributions

We introduce a new universality class of one-dimensional iteration model giving rise to self-similar motion, in which the Feigenbaum constants are generalized as self-similar rates and can be predetermined. The curves of the mean-square displacement versus time generated here show that the motion is a kind of anomalous diffusion with the diffusion coefficient depending on the self-similar rates. In addition, it is found that the distribution of displacement agrees to a reliable precision with the q-Gaussian type distribution in some cases and bimodal distribution in some other cases. The results obtained show that the self-similar motion may be used to describe the anomalous diffusion and nonextensive statistical distributions.Comment: 15pages, 5figure

Thermoeconomic performance optimization of an irreversible Brayton refrigeration cycle using Gd, Gd 0.95 Dy 0.05 or Gd 0.95 Er 0.05 as the working substance

Abstract(#br)An irreversible regenerative Brayton refrigerator cycle is established, in which the nonperfect regenerator, regenerative time, heat leak, and irreversible adiabatic processes are taken into account. The mathematical expressions of the refrigeration rate, coefficient of performance, and thermoeconomic function of the refrigeration cycle are derived and the thermoeconomic function is optimized. Moreover, choosing Gd, Gd 0.95 Dy 0.05 and Gd 0.95 Er 0.05 as the working substances respectively, we discussed in detail the influences of the thermoeconomic and thermodynamic parameters on the optimal thermoeconomic and thermodynamic performances. The results show that the thermoeconomic performance of the refrigeration cycle using Gd or Gd 0.95 Dy 0.05 as the working substance is better than that using Gd 0.95 Er 0.05 and the thermoeconomic performance of the refrigeration cycle using Gd 0.95 Dy 0.05 as the working substance is better than that using Gd in the situation with the lower adiabatic magnetization