WSN环境监测系统节点功耗与能量预警研究

良好的核心机房环境条件对于各类园区网络的正常运行至关重要,因此配备环境监测系统已经成为核心机房的一项必备措施。针对传统监测系统布线的灵活性差等问题,本文提出了一种具有能量感知的节能无线传感器网环境监测系统。节点设计采用Jennic公司的JN5139 SOC芯片,集成编译环境采用开源软件Code::Blocks,其内部运行由简单任务调度器BOS来统一管理。最后结合本单位核心机房实际情况,经过实际测试,给出了恰当的节点布置方案、节点节能发射功率值,实现了能量监测预警功能。此方法不仅可以用于机房环境监测,对于其他环境监测,如现代化养殖场的环境监测同样适用。

基于能量预警和分簇的ZigBee网络路由协议研究

针对传统ZigBee路由算法存在RREQ分组洪泛、能耗过高和通信效率低等问题,本文引入能量预警机制,设计一种优化的分簇路由算法。算法吸取Cluster-Tree和AODVjr的优点,设置节点能量预警等级,优化路由选择机制,适时启动备用节点,有效避免关键节点过早死亡,降低网络分割风险。仿真结果表明,该算法可提高网络通信效率,均衡网络能量,延长网络运行周期。

不同卸压措施下“双能量”指标协同预警及调控机制分析

现有的煤矿冲击地压防治措施实施均与卸压工程息息相关。基于广泛认可的冲击地压能量理论,提出利用不同卸压措施,降低冲击危险区域岩体高应力集中程度,有效规避众多冲击地压的产生,但即使在现场卸压工作较为充分的情况下,其仍然发生冲击地压,此外冲击地压防治和巷道支护本身作为一对矛盾体,更加剧理论研究工作的复杂程度。为进一步细化卸压措施的合理性,从工程尺度将卸压措施转化为实验室尺度的卸压手段。通过,单轴压缩方式施加静载,在室内尺度下分别得出2种常用卸压手段承载煤样的损伤演化规律,分析“双能量”指标一致性,并构建协同预警机制。试验结果表明:注水卸压措施可以很好的降低整体煤样的冲击倾向性,而钻孔卸压措施,虽然增大了煤样的冲击倾向性,其主要目的是人为引导能量释放,因此需要结合实际情况确定自适应卸压措施;此外单纯通过能量理论的“计算能量”具有一定的单一性,通过引入声发射破坏全过程的“监测能量”指标,数据统计发现两者具有跨尺度一致性。因此,基于上述理念,将承载煤样破坏过程“双能量”指标尝试引入到承载煤样破坏前兆判别思路,最终形成协同预警机制。其中,注水卸压过程中水-孔隙-裂隙耦合介质与完整煤基质形成较为稳定的弹性体,表现为稳定储存弹性应变能和耗散应变能缓慢增加,此外由于高孔隙水压力的存在以及水对煤基质的润滑等多种协同作用,促进孔隙-裂隙均快速扩展,出现耗散应变能短时间迅速回弹上升,快速破坏。而钻孔卸压措施均对承载煤样起到了应力转移作用,且大小孔径呈现出明显差异性,这对工程尺度上合理提出钻孔参数提出要求,进而确保达到合理有效卸压效果。

Experimental investigation on synergetic prediction of granite rockburst using rock failure time and acoustic emission energy

The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering.In this work,laboratory experiments on rockburst under true triaxial conditions were carried out with granite samples.Combined with the deformation characteristics of granite,acoustic emission(AE)technology was well applied in revealing the evolution law of micro-cracks in the process of rockburst.Based on the comprehensive analysis of acoustic emission parameters such as impact,ringing and energy,the phased characteristics of crack propagation and damage evolution in granite were obtained,which were consistent with the stages of rock deformation and failure.Subsequently,based on the critical point theory,the accelerated release characteristics of acoustic emission energy during rockburst were analyzed.Based on the damage theory,the damage evolution model of rock under different loading conditions was proposed,and the prediction interval of rock failure time was ascertained concurrently.Finally,regarding damage as an intermediate variable,the synergetic prediction model of rock failure time was constructed.The feasibility and validity of model were verified.

Research about Online Security Warning and Risk Assessment of Power Grid Based on Energy Management System

In this paper, online security warning and risk assessment of power grid are proposed, based on data from EMS （Energy Management System）, combined with information of real-time operation state, component status and external operating environment. It combines the two factors, contingency likelihood and severity, that determine system reliability, into risk indices on different loads and operation modes, which provide precise evaluation of the power grid＇s security performance. According to these indices, it can know the vulnerable area of the system and whether the normal operating mode or repair mode is over-limited or not, and provide decision-making support for dispatchers. Common cause outages and equipment-aging are considered in terms of the establishment of outage model. Multiple risk indices are defined in order to reflect the risk level of the power grid more comprehensively.

大型民机进近着陆段异常能量风险判据

根据大型民机事故统计,进近着陆阶段事故率最高,而其中大部分事故首先表现出异常能量状态,并演变成失控、重着陆、擦尾、冲出跑道等事故类型,或者呈现复飞失败。在归纳上述五类终端事故类型作为重点关注对象基础上,建立典型大型民机飞行数值仿真平台,使用随机模拟和相关性分析方法研究能量状态参数偏离导致进近着陆风险的影响规律。在此基础上,根据仿真结果给出了由关键能量参数确定的能量状态安全边界,可建立不同风场条件及可能的复飞油门下由空速-下滑角参数构成的异常能量预警判据,对于异常能量导致的进近着陆风险预警具有准确性和非保守性。研究结果可为大型民机进近着陆过程的风险预警以及相关飞行控制功能设计提供方法基础。