A Modular Solder System with Hierarchical Morphology and Backward Compatibility

A modular solder system with hierarchical morphology and micro/nanofeatures in which solder nanoparticles are distributed on the surface of template micropowders is reported. A core–shell structure of subsidiary nanostructures, which improved the intended properties of the modular solder is also presented. In addition, polymer additives can be used not only as an adhesive (like epoxy resin) but also to impart other functions. By combining all of these, it is determined that the modular solder system is able to increase reflowability on a heat‐sensitive plastic substrate, oxidation resistance, and electrical conductivity. In this respect, the system could be readily modified by changing the structure and composition of each constituent and adopting backward compatibility with which the knowledge and information attained from a previously designed solder can offer feedback toward further improving the properties of a newly designed one. In practice, In–Sn–Bi nanoparticles engineered on the surface of Sn–Zn micropowders result in pronounced reflowing on a flexible Au‐coated polyethylene terephthalate (PET) substrate even at the low temperature of 110 °C. Depending on their respective concentrations, the incorporation of CuO@CeO₂ nanostructures and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymers increases oxidation resistance and electrical conductivity of the modular solder.     

Compact see‐through near‐eye display with depth adaption

Based on the recent development of Pancharatnam–Berry deflectors and lenses, we propose a compact and lightweight near‐eye display system with depth adaption. The compact design results from the polarization selectivity of Pancharatnam–Berry deflector waveguide coupler, and the fast‐switching Pancharatnam–Berry lenses can be exploited for generating correct light fields.     

A New Approach for Vehicle Lateral Velocity and Yaw Rate Control with Uncertainty

In order to attain excellent stability and maneuverability to ensure safety and ride‐comfort, the lateral velocity and yaw rate of a vehicle are expected to be controlled at any desired values simultaneously. A basic manipulation model of a vehicle with two degrees of freedom which requires two independent control inputs (front and rear steering angle) is constructed. In this model, we consider the mass and the moment of inertia of the vehicle are the uncertain parameters which are (possibly) fast‐varying. However, no further information, except that the uncertainties are bounded, is assumed. Furthermore, the bound is unknown. An adaptive robust control methodology based on the Udwadia and Kalaba approach which guarantees uniform boundedness and uniform ultimate boundedness is proposed to drive the system to follow the pre‐specified constraints approximately. The adaptive law is of leakage type which can adjust itself based on the tracking error. The numerical simulation results conducted by MATLAB demonstrate the ease and effectiveness of implementation.     

Numerical analysis of history-dependent hemivariational inequalities and applications to viscoelastic contact problems with normal penetration

In this paper numerical approximation of history-dependent hemivariational inequalities with constraint is considered, and corresponding Céa’s type inequality is derived for error estimate. For a viscoelastic contact problem with normal penetration, an optimal order error estimate is obtained for the linear element method. A numerical experiment for the contact problem is reported which provides numerical evidence of the convergence order predicted by the theoretical analysis.     

A stochastic reward net-based assessment of reliability,availability and operational cost for a software-defined network infrastructure

The Journal of Supercomputing - The networking infrastructure of a software-defined network (SDN) requires further study to achieve continuity and high availability of data transactions for cloud...     

Route tracking for self-propelled ship model

Multimedia Tools and Applications - To ensure the safety of the navigation, self-propelled ship model test is widely used in navigable administer engineering to visually and really reflect...     

The latent learning model to derive semantic relations of words from unstructured text data in social media

Multimedia Tools and Applications - Unstructured text data is very important in many applications because it reflects the thought of the people who create this data. However, it is difficult to...     

Video highlight extraction via content-aware deep transfer

Multimedia Tools and Applications - In this paper, we focus on detecting highlights in online videos. Given the explosive growth of online videos, it is becoming increasingly important to single...     

An admittance controller based on assistive torque estimation for a rehabilitation leg exoskeleton

Intelligent Service Robotics - A rehabilitation exoskeleton leg was constructed for gait training, and a method for exoskeleton leg swing control based on admittance model was studied. The...     

0.5—7.5MeV高能磷离子注入硅中剖面分布及剖面迭加

本文对磷离子能量在0.5—7.5MeV、剂量在2.0×10~(12)—1.0×10~(13)/cm~2范围内注入硅中的载流子剖面进行了研究,发现在此条件下,n型磷载流子剖面是由两个只有不同偏差σ_(tront)(σ前)和σ_(back)(σ后)的高斯分布相连接组成的。根据实验所得剖面特性,提出了多次迭加形成平坦剖面的方法。用这种方法结合SiO_2膜屏蔽和调整注入离子能量、剂量,能够获得各种有特殊要求的载流子浓度剖面。为了得到好的可控性和可重复性,采用了瞬态退火技术。透射电镜分析表明:在我们所用退火条件下,剩余缺陷并未出现。这种迭加注入已应用于特种器件研制中,试制出的产品获得令人满意的结果。