A procedure to construct exact solutions of nonlinear evolution equations

In this paper, we implemented the functional variable method for the exact solutions of the Zakharov?CKuznetsov-modified equal-width (ZK-MEW), the modified Benjamin?CBona?CMahony (mBBM) and the modified KdV?CKadomtsev?CPetviashvili (KdV?CKP) equations. By using this scheme, we found some exact solutions of the above-mentioned equations. The obtained solutions include solitary wave solutions, periodic wave solutions and combined formal solutions. The functional variable method presents a wider applicability for handling nonlinear wave equations.     

不同[Cu]/[In]比例的CuInS2薄膜的特性

采用连续离子层吸附与反应方法在玻璃基板上按照不同[Cu]/[In]的比例制备了CuInS₂薄膜,并在400 °C退火30 min. 对薄膜的晶体结构和晶粒尺寸用X射线衍射方法进行了表征,原子力显微镜测定薄膜的表面形貌. 研究不同的[Cu]/[In]比例对薄膜光学和电学性能的影响. 采用直流两探针法在300～470 °C测定CuInS₂薄膜的电阻率,随着[Cu]/[In]比例的增加,电阻率值越来越低. 溶液中[Cu]/[In]的比例明显影响CuInS₂薄膜的结构、电学和光学特性.     

Spin bath decoherence of quantum entanglement

We study an analytically solvable model for decoherence of a two spin system embedded in a large spin environment. As a measure of entanglement, we evaluate the concurrence for the Bell states (Einstein-Podolsky-Rosen pairs). We find that while for two separate spin baths all four Bell states lose their coherence with the same time dependence, for a common spin bath, two of the states decay faster than the others. We explain this difference by the relative orientation of the individual spins in the pair. We also examine how the Bell inequality is violated in the coherent regime. Both for one bath and two bath cases, we find that while two of the Bell states always obey the inequality, the other two violate the inequality at early times.     

用2.5D TSV实现多处理器SiP功能

本项目由Open-Silicon,GLOBALFOUNDRI ES和Amkor三家公司合作完成。两颗28nm的ARM处理器芯片,通过2.5D硅转接板实现集成。芯片的高性能集成通常由晶体管制程提高来实现,应用2.5D技术的Si P正成为传统芯片系统集成的有效替代。Open-Silicon负责芯片和硅转接板的设计,重点在于性能优化和成本降低。GLOBALFOUNDRI ES采用28nm超低能耗芯片工艺制造处理器芯片,而用65nm技术制造2.5D硅转接板。包括功耗优化和功能界面有效管理等概念得到验证。硅基板的高密度布线提供大量平行I/O,以实现高性能存储,并保持较低功耗。所开发的EDA设计参考流程可以用于优化2.5D设计。本文展示了如何将大颗芯片重新设计成较小的几颗芯片,通过2.5D硅转接板实现Si P系统集成,以降低成本,提高良率,增加设计灵活性和重复使用性,并减少开发风险。     

Dynamic modeling of a horizontal washing machine and optimization of vibration characteristics using Genetic Algorithms

In this work, a 2D dynamic model of a horizontal axis washing machine is derived regarding the rotation plane in order to examine the vibration characteristics of the spin-cycle and improve the design proposing a new optimization scheme based on Genetic Algorithms (GA). The dynamic model is numerically simulated and the outputs are validated using experimental vibration data acquired from a test-rig including the drum and the motor of a horizontal-axis washing machine. The measurements are performed using piezo-transducers and a novel measurement scheme is used to obtain displacement values from acceleration data as well as estimating the instantaneous frequency of the rotation with appropriate signal processing. This study has two main contributions: (i) a new method for design improvement applying GA to optimization of vibration characteristics for the horizontal-axis washing machines, and (ii) a novel measurement method yielding the displacement in 2D and instantaneous frequency of vibration from acceleration data. While the GA is contributing to passive improvement methods in the field, the novel measurement method opens the way for low-cost diagnosis and active-vibration control of washing machines.     

On the Diophantine equation x 2 − kxy + y 2 − 2 n = 0

In this study, we determine when the Diophantine equation x ²?kxy+y ²?2 ⁿ = 0 has an infinite number of positive integer solutions x and y for 0 ? n ? 10. Moreover, we give all positive integer solutions of the same equation for 0 ? n ? 10 in terms of generalized Fibonacci sequence. Lastly, we formulate a conjecture related to the Diophantine equation x ² ? kxy + y ² ? 2 ⁿ = 0.     

Oscillation of even order nonlinear delay dynamic equations on time scales

One of the important methods for studying the oscillation of higher order differential equations is to make a comparison with second order differential equations. The method involves using Taylor’s Formula. In this paper we show how such a method can be used for a class of even order delay dynamic equations on time scales via comparison with second order dynamic inequalities. In particular, it is shown that nonexistence of an eventually positive solution of a certain second order delay dynamic inequality is sufficient for oscillation of even order dynamic equations on time scales. The arguments are based on Taylor monomials on time scales.     

Trajectory-tracking of 6-RSS Stewart-Gough manipulator by feedback-linearization control using a novel inverse dynamic model based on the force distribution algorithm

ABSTRACT

6-RSS Stewart-Gough parallel manipulator contains six crank-rod limbs connecting the base and moving platforms to each other, forming a 6DOF manipulator. In this paper, we introduce a novel decoupled inverse dynamic model for this manipulator based on the Force Distribution Algorithm. The performance of the proposed model was evaluated in tracking a complex trajectory (of multiple segments with simultaneous translational and rotational motions) using feedback-linearization control in the joint space and compared with that of the Lagrangian inverse dynamic model. Results showed that this model leads to a better performance in feedback-linearization control, especially when the reference trajectory is quantized, and with less calculation burden in comparison with the Lagrangian model. The control system employing both models showed robustness against payload uncertainty on the moving platform (150% of the moving platform’s mass). The performance assessment and the robustness approval were performed in simulation using a Simscape model specifically built for this purpose in the Simulink environment.