A hybrid CMA-ES and HDE optimisation algorithm with application to solar energy potential

This paper describes the results of initial experiments to apply computational algorithms to explore a large parameter space containing many variables in the search for an optimal solution for the sustainable design of an urban development using a potentially complicated fitness function. This initial work concentrates on varying the placement of buildings to optimise solar irradiation availability. For this we propose a hybrid of the covariance matrix adaptation evolution strategy (CMA-ES) and hybrid differential evolution (HDE) algorithms coupled with an efficient backwards ray tracing technique. In this paper we concentrate on the formulation of the new hybrid algorithm and its testing using standard benchmarks as well as a solar optimisation problem. The new algorithm outperforms both the standalone CMA-ES and HDE algorithms in benchmark tests and an alternative multi-objective optimisation tool in the case of the solar optimisation problem.     

The effect of extended‐hours hemodialysis on outcomes: A systematic review and meta‐analysis

Extended‐hours hemodialysis is associated with improvements in quality of life (QoL) and mortality, but it may accelerate the loss of residual kidney function (RKF) and increase vascular access complications. Multiple established databases were systematically searched; randomized and non‐randomized studies were pooled separately. QoL outcomes were assessed using standardized mean difference (SMD), vascular access adverse events and mortality were assessed with relative risk ratios (RR). Four hundred seventy‐six patients from six trials were eligible. Data from randomized controlled trials (RCTs) could only be synthesized for vascular access adverse events and mortality, which demonstrated no significant change in vascular access adverse events (RR 1.25, 95% CI 0.88 to 1.77) or mortality (RR 2.29, 95% CI 0.60 to 8.71). Pooled data from non‐randomized trials demonstrated no significant difference in QoL (SF‐36 Physical Component Summary SMD 0.61, 95% CI ?0.10 to 1.31, SF‐36 Mental Component Summary SMD ?0.04, 95% CI ?0.61 to 0.54). RKF was assessed in one report which demonstrated a potential reduction over 12 months with extended‐hours hemodialysis. The majority of trials had high risk of bias. Extended‐hours hemodialysis was not associated with improved QoL or mortality, or increased vascular access events. Adequately powered RCTs are needed to fully assess extended‐hours hemodialysis.     

xCCL: A Survey of Industry-Led Collective Communication Libraries for Deep Learning

Journal of Computer Science and Technology - Machine learning techniques have become ubiquitous both in industry and academic applications. Increasing model sizes and training data volumes...     

Nonlinear control techniques for an atomic force microscope system

Two nonlinear control techniques are proposed for an atomic force microscope system.Initially,a learning-based control algorithm is developed for the microcantilever-sample system that achieves asymptotic cantilever tip tracking for periodic trajectories.Specifically,the control approach utilizes a learning-based feedforward term to compensate for periodic dynamics and high-gain terms to account for non-periodic dynamics.An adaptive control algorithm is then developed to achieve asymptotic cantilever tip tracking for bounded tip trajectories despite uncertainty throughout the system parameters.Simulation results are provided to illustrate the efficacy and performance of the control strategies.     

Design and Implementation of the Robotic Platform

The diversity of robotic research areas along with the complex requirements of hardware and software for robotic systems have always presented a challenge for system developers. Many past robot control platforms were complex, expensive, and not very user friendly. Even though several of the previous platforms were designed to provide an open architecture system, very few of the previous platforms have been reused. To address previous disadvantages, this paper describes the design and implementation of the Robotic Platform, an object-oriented development platform for robotic applications. The Robotic Platform includes hardware interfacing, servo control, trajectory generation, 3D simulation, a graphical user interface, and a math library. As opposed to distributed solutions, the Robotic Platform implements all these components in a homogenous architecture that utilizes a single hardware platform (a standard PC), a single programming language (C++), and a single operating system (the QNX Real-Time Platform) while guaranteeing deterministic real-time performance. This design leads to an open architecture that is less complex, easier to use, and easier to extend. Particularly, the area of multiple cooperating robots benefits from this kind of architecture, since the Robotic Platform achieves a high integration of its components and provides a simple and flexible means of communication. The architecture of the Robotic Platform builds on the following state-of-the-art technologies and general purpose components to further increase simplicity and reliability: (i) PC technology, (ii) the QNX Real-Time Platform, (iii) the Open Inventor library, (iv) object-oriented design, and (v) the QMotor control environment.     

Effect of processing conditions on porosity formation in cold gas dynamic spraying of copper

The cold gas dynamics process is a promising low-temperature spray process in which particles are accelerated in a supersonic flow before impacting with substrate to be coated. In this study the effect of spray temperature, spray pressure, and particle size on porosity formation in cold spray coatings are investigated. Results show that an increase in spray temperature and a decrease in particle size lead to a decline in volume fraction of porosity. Furthermore, particle velocity and particle temperature are determined to be the significant parameters for elimination of porosity. A model is proposed for estimation of the volume fraction of porosity for alloy of this study.     

The effect of average soft segment length on morphology and properties of a series of polyurethane elastomers. II. SAXS-DSC annealing study

A series of eight thermoplastic polyurethane elastomers were synthesized from 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) chain extender, with poly(hexamethylene oxide) (PHMO) macrodiol soft segments. The PHMO molecular weights employed ranged from 433 g/mol to 1180 g/mol. All materials contained 60% (w/w) of the macrodiol. The materials were characterized by differential scanning calorimetry (DSC) following up to nine different thermal treatments. In addition, three of the materials were selected for characterization by small-angle x-ray scattering (SAXS) following similar thermal treatments. The DSC experiments showed the existence of five hard segment melting regions (labelled T1-T5), which were postulated to result from the disordering or melting of sequences containing one to five MDI-derived units, respectively. Evidence for urethane linkage dissociation and reassociation during annealing at temperatures above 150°C is presented. This process aids in the formation of higher melting structures. Annealing temperatures of 80–100°C provided the maximum SAXS scattering intensity values. Materials containing longer soft segments (and, therefore, longer hard segments) were observed to develop and sustain higher melting hard domain structures and also develop maximum average interdomain spacing values at higher annealing temperatures. Another additional series of three PHMO-based polyurethanes having narrower hard segment length distributions, was synthesized and characterized by DSC in the as-synthesized and annealed states. The resulting DSC endotherms provided further evidence to suggest that the T1-T5 endotherms were possibly due to melting of various hard segment length populations. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 803–817, 1997     

无线频谱分析仪的选择

无线设备在工作时可能会出现周期性地挂起,干扰其他消费电子产品的工作（例如电台）,或者无法完全发挥应有的功能,这些问题都会使消费者对它的技术水平和相应的产品供应商丧失信心。为了避免这种糟糕的情况,选择一种能够满足当今无线产品设计与调试需求的高性能频谱分析仪是至关重要的,这种频谱分析仪不仅要能够检验产品的真实性能,也要能够检测高度集成的无线发射器的功能。