Situational awareness architecture for smart grids developed in accordance with dispatcher’s thought process: a review

The operational environment of today’s smart grids is becoming more complicated than ever before. A number of factors, including renewable penetration, marketization, cyber security, and hazards of nature, bring challenges and even threats to control centers. New techniques are anticipated to help dispatchers become aware of the accurate situations as they manipulate and navigate the situations as quickly as possible. To address the issues, we first introduce the background for this topic as well as the emerging technical demands of situational awareness in the dispatcher’s environment. The general concepts and technical requirements of situational awareness are then summarized, aimed at offering an overview for readers to understand the state-of-the-art progress in this area. In addition, we discuss the importance of integrating the architecture of support tools in accordance with the dispatcher’s thought process, which in fact guides correct and swift reactions in real-time operations. Finally, the prospects for situational awareness architecture are investigated with the goal of presenting situational awareness modules in an advanced and visualized manner.     

Physical properties of transition to chaos in RF-driven Josephson junction analog

An analog circuit is used to investigate the behavior of the transition to chaos in the rf-driven Josephson junction under the variation of excitation amplitude and frequency with McCumber parameter >1. A series of transitions is observed, including a hysteretic jump, symmetry breaking, period doubling, and intermittency prior to chaos, and the transition boundaries are given in a state diagram in the vs. parameter space. Thus, the sequence of transitions to chaos can be inferred from this diagram. Based on these results, the harmonic balance method and Floquet theory are applied to study the instability of the transition series. It is suggested that all these transitions to chaos can be explained as parametric excitations. In addition, the transition boundaries in the state diagram can be satisfactorily computed from the conditions with a Floquet multiplier =±1.     

USB2.0接口芯片CY7C68013的固件程序开发

USB2．0接口技术为外设与主机之间提供了一种灵活高效的双向数据通道。可广泛地应用于数据采集、工业控制和消费数码等方面。本文简要介绍了支持USB2．0协议的接口芯片CY7C68013的结构。分析了CY7C68013芯片的固件程序框架的结构。给出了如何在该固件程序框架下使用C语言进行固件程序开发的方法。     

硅压阻式气压高度计的设计与实现

采用硅压阻式压力传感器,以ATmega88PA为控制器设计了气压高度计。内嵌全温度范围的曲面拟合算法进行温度补偿及线性化处理,解决了压力传感器的温漂和非线性问题,并用海拔高度与气压的关系计算高度。测量结果通过RS-485接口发送给上位机。测试结果表明,该气压高度计压力测量误差优于0.50‰,分辨率为0.01 h Pa,线性度为0.999 9;标准大气环境下高度测量误差为0.16 m,线性度为0.999 8。该气压高度计具有质量小、功耗低、精度高、工作可靠等优点。     

Adaptive picking of microseismic event arrival using a power spectrum envelope

An automatic, adaptive, spectrogram-based algorithm for picking the arrival time of microseismic data is proposed. The algorithm provides a significant improvement in the ratio of detected events to false triggers and in the resolution of the microseismic structure. It mainly addresses the problem of automatic picking when the signal-to-noise ratio (S/N) is low and so false and missed triggers frequently occur. It combines the short time average/long time average (STA/LTA) algorithm with an envelope algorithm. It also constructs an envelope from a time-frequency representation of the signal. The threshold is set dynamically, according to the existing noise level and the S/N ratio. The algorithm also uses the fixed LTA value to represent the noise level for a seismic record. It is applied to pick the arrival times of P-waves of local events recorded at eight stations.     

一种自适应IP语音缓冲算法的研究与应用

当IP语音包的网络时延抖动较小时,一般的语音缓冲算法可以得到较好的语音质量．当网络中存在突发大时延时,就会出现极大丢包率或极大端到端时延,从而难以获得好的语音质量．为此,提出针对突发大时延下的自适应语音缓冲算法．通过估算网络平均时延和学习语音包经过的网络路径上的状态,来确定需要控制端到端时延大小和语音包的丢包率,动态调整Jitter Buffer队列的最小深度和最大深度,从而可以尽量减小语音裂缝（gap）的出现．通过基于听觉模型的客观音质评价（PESQ）仿真计算以及在实际语音网关设备中的应用表明算法对语音通信质量有一定的改善作用．     

两层复杂网络的特性及其抗毁性分析

构建并分析两层复杂网络的特性及其抗毁性.试图寻找两层复杂网络中具有较优抗毁性网络模型的层间链接方式和层内链接方式.基于不同的层内(层间)链接算法构建三类两层复杂网络模型并对其拓扑指标进行分析;基于最大剩余连通分支粒度分析三类复杂网络的抗毁性;通过数值仿真刻画出了具有较优抗毁性的网络拓扑结构及其特性.结果显示:当层间链接概率pn趋于10-3时,三类两层复杂网络的度分布特性均保持单层复杂网络的特性;层间链接概率pn趋于10-1时,无标度算法生成的两层复杂网络逐渐失去无标度性;蓄意攻击和随机攻击策略之下,随机算法构建的两层复杂网络具有较优抗毁性;蓄意攻击策略之下,通过无标度算法和小世界算法构建的两层复杂网络的抗毁性与层间链接概率成正比.     

并行测试技术在自动测试系统中的应用

并行测试拥有减少测试时间、降低测试成本的强大优势,正成为研究热点之一。首先详细分析了并行测试的基本概念,介绍了目前实现并行测试可以采用的两大类4种结构,对这4种结构各自的优缺点进行了比较。接着以多线程并行测试程序为例描述了并行测试程序中同步、异步和单线程的三种模型,最后重点对多线程并行测试实现中几个值得注意的重要问题进行了讨论。     

Response of radiation dosimeters based on in situ oxygen plasma post-treated CVD-diamond thin films to X-ray

Radiation dosimeters based on in situ oxygen plasma post-treated diamond thin films were fabricated in a simple sandwich configuration. Effects of deposition process, methane concentration, and in situ oxygen plasma post-treatment on the sensitivity of the devices to X-ray irradiation were investigated. X-ray response demonstrates that the cyclic deposition process could improve response sensitivity. The increase in methane concentration in the deposition gas mixture will worsen the irradiation response of the devices mainly resulted from the change of the orientation and purity of the films. X-ray photoelectron spectroscopy, photoluminescence, and Raman measurements suggest that in situ oxygen plasma post-treatment can effectively etch non-diamond phases and passivate the silicon-vacancy and nitrogen-vacancy defects of the diamond films, resulting in an increase in the sensitivity of the device by a factor of about 2. Time-dependent response to X-ray indicates that the extended period to achieve photocurrent signals stability for the devices is a limitation for promising applications in radiation dosimetry.     

Supply chain models with corporate social responsibility

Currently, corporate social responsibility (CSR) has become a critical issue because more than 88% of consumers think companies should try to achieve their business goals while improving society and the environment. This paper focuses on a CSR supply chain where an Original Equipment Manufacturer’s (OEM’s) sales can be significantly reduced because of its oversea supplier’s social misconduct. Specifically, as in a conventional wholesale price contract the supplier determines its wholesale price and the OEM decides its order quantity, but in a CSR supply chain, the supplier can autonomously change its CSR cost once a minimum requirement is satisfied. A higher CSR cost means that the supplier invests more in its corporate social responsibility and the OEM’s sales will be less likely to be influenced by negative CSR events. The equilibrium solutions show an important dilemma – although the supplier’s profit increases in the basic CSR requirement, the supplier will always use the minimum CSR cost under the conventional wholesale price contract, which eventually leads to a low supply chain profit. Thus, we introduce two different contracts to handle this problem: the flexible quantity contract and the wholesale price incentive contract, which are, respectively, a ‘tough’ way and a ‘beneficent’ way for the OEM to solve the problem. Although the two ways cannot (always) coordinate the supply chain, we show that they both will significantly improve the supply chain performance. Our results also show that in some conditions, one strategy will dominate, whereas in different conditions the other strategy dominates.