具有OLTC的混杂电力系统模型与切换稳定分析

提出了利用可编程赋时 Petri网 ( PTPN)建立混杂电力系统模型的方法 ,分析了有载调压变压器 ( OLTC)的离散调节与连续动态负荷的相互作用。提出了分析混杂电力系统切换稳定的多Lyapunov函数方法 ,并运用多 Lyapunov函数分析了混杂电力系统切换的稳定性。针对一个实例进行仿真分析 ,给出了多 Lyapunov函数法分析的仿真结果。仿真结果表明所建立的模型是可行的     

Almost rotation-minimizing rational parametrization of canal surfaces

Almost rotation minimizing parametrization of the canal surface is given. The basic building block of our approach is the curve approximation scheme that enables us to construct a curve, called the parameter curve, on the canal surface that produces, when projected and rescaled, an almost parallel normal vector field on the spine curve. Its construction relies on our earlier methods and results on relating the geometry of the canal surface to the Lorentzian geometry of the Minkowski geometry via the Clifford algebra formalism. We then iteratively construct patches out of the parameter curves via suitable interpolation procedure. Furthermore, its rotational deviation, i.e., the angle deviation from the parallel (no rotation) frame along the spine curve, can be controlled with the use of the rotation deviation estimate of the parameter curves. Our numerical experiment shows that the rotation deviation is minuscule. When compared with other earlier results including our earlier one, our result fares extremely favorably. To facilitate the implement, a practitioners' summary is given in the appendix.     

Capturing Attention When Attention "Blinks".

Four experiments addressed the question of whether attention may be captured when the visual system is in the midst of an attentional blink (AB). Participants identified 2 target letters embedded among distractor letters in a rapid serial visual presentation sequence. In some trials, a square frame was inserted between the targets; as the only geometric object in the sequence, it constituted a singleton. Capture effects obtained when the AB was most severe and when it was over were compared. There were 3 main results. First, capture occurred even when the AB was crippling, suggesting that a singleton exogenously engaged attention even when processing of a previous target was continuing apace. Second, when the singleton contained the key target feature, capture effects were clearly manifest. Third, even when the singleton did not possess the key target feature, it still succeeded in capturing attention, although the effects were both feeble and fleeting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Image signal-to-noise ratio estimation using Shape-Preserving Piecewise Cubic Hermite Autoregressive Moving Average model

We propose to cascade the Shape-Preserving Piecewise Cubic Hermite model with the Autoregressive Moving Average (ARMA) interpolator; we call this technique the Shape-Preserving Piecewise Cubic Hermite Autoregressive Moving Average (SP2CHARMA) model. In a few test cases involving different images, this model is found to deliver an optimum solution for signal to noise ratio (SNR) estimation problems under different noise environments. The performance of the proposed estimator is compared with two existing methods: the autoregressive-based and autoregressive moving average estimators. Being more robust with noise, the SP2CHARMA estimator has efficiency that is significantly greater than those of the two methods.     

A network prototype for integrated production-distribution planning with non-multi-functional plants

This paper proposes a two-echelon network prototype for integrated production and distribution planning where non-multi-functional plants supply multiple types of products with limited quantities to the customers via capacitated warehouses. Four variations of the prototype, formulated as individual mixed integer programming models, are solved using the branch and bound algorithms by numerical experiments to examine the cost implications of production-distribution strategies involving single-sourcing constraints on different levels of the supply chain. Further discussions on the practicality and versatility of the proposed prototype (i.e. its ability to consider different facility locations, specialised capabilities of individual plants, safety stock levels and demand characteristics) illustrate the usefulness of the prototype to industry practitioners when making strategic and/or tactical decisions.     

Renewable energy supply chains,performance, application barriers,and strategies for further development

Due to the depletion of traditional energy resources, such as crude oil, coal, and natural gas, many initiatives all over the world have addressed the efficient use or replacement of these resources. Several renewable energy sources have been introduced as alternatives to traditional sources to protect environmental resources and to improve the quality of life. This study assesses renewable energy sources from a supply chain perspective and presents an investigation of renewable energies focusing on four main components: renewable energy supply chain, renewable energy performance, and barriers and strategies to its development. The study provides managerial insights to governments, researchers, and stakeholders for the initiation of renewable energy use, and suggestions for overcoming the barriers to its development.     

基于双端量的串联补偿线路单相接地故障测距算法

针对串联补偿装置位于线路中间的情况,给出了一种基于双端量的串联补偿线路单相接地故障测距方法。该算法计及了故障过程中金属氧化物变阻器(MOV)的动作情况对线路实际阻抗值的影响,在无需知道串联补偿装置的相关参数和其具体工作状态条件下,就能准确地实现串联补偿线路的故障测距。利用EMTDC/PSCAD和MATLAB软件进行了仿真实验,实验结果验证了算法的有效性。     

Augmented reality assisted facility layout digitization and planning

Journal of Mechanical Science and Technology - Facility layout planning (FLP) has an important role in manufacturing industries. There are few approaches to solve FLP such as procedural,...