补白

煤矿井下图像型早期火灾探测研究王媛彬,马宪民(西安科技大学电控学院,陕西西安?710054)摘要:针对煤矿井下传统火灾探测方法的不足,提出了一种基于图像型的火灾探测方法,阐述了对所获取的红外图像进行预处理、特征提取和火灾识别的过程。根据早期火灾的特点,通过提取图像序列中多个参数的火灾信     

LVQ神经网络的红外光谱火灾早期预警算法

对前期大量试验采集的火灾气体数据进行特征提取,找出能够代表火灾整体特征的过程特征信息.通过体积分数曲线拟合分析,提取出体积分数、速度和加速度估值等火灾特征信息参量,建立适合于火灾早期探测的学习向量量化(LVQ)神经网络算法.通过对比分析证明,该算法比传统火灾探测器报警时间提前3～21 min,且对于真假火灾可进行准确识...     

神经网络与模糊逻辑在火灾探测报警系统中的应用

为了精确高效地识别、分析、处理火灾,将神经网络、模糊逻辑、分级报警技术综合应用在火灾探测报警系统中,建立了一种神经网络与模糊逻辑相组合的火灾探测分级报警模型。通过编制MATLAB仿真模型,利用归一化处理后的NIST两组实验数据作为仿真试验数据,进行了一系列仿真试验。结果表明:火灾探测分级报警模型不仅能够识别有无火灾,还能进一步识别火灾类型、规模和发展过程。     

基于方次火灾模型的感温探测器设计的研究

火灾探测和报警系统是建筑防防火策略的关键组成部分,通过研究建筑物内火灾发展和烟气流动的规律,消防工程师获得了大量有价值的信息和工具,所有这些信息使消防工程师和设计人员设计满足特定安全目标的火灾探测和报警系统成为可能.方次火灾模型是最常见的室内火灾发展的模型,而t2火是最常见的模型.根据其火灾增长模型确定不同情况下的热释放速率,进而确定探测器对特定火灾场景发生响应时的安全距离.     

火灾早期特性分析及影像特征研究

火灾早期是整个火灾过程的开始阶段,也是火灾研究的重点与难点之一,火灾早期的研究对火灾早期探测和扑救具有重要意义.对火灾早期特性进行了初步分析,利用火灾早期特性用实验台对其进行了实验研究;利用CCD(ChargeCoupledDevice)摄像机获取火焰影像,研究表明火灾早期的影像面积持续增长,其增长规律可以用几何函数来描述.     

洁净空调系统对初期火灾探测的影响分析

运用FDS(Fire Dynamic Simulator)软件对采用上送下回式空调系统的洁净室火灾烟气运动进行了数值模拟.通过对速度场及温度场的分析,研究了上送下回式气流组织模式对烟气运动和早期火灾烟气探测的影响.模拟研究结果表明,天花板附近的温度场和浓度场均受到较大影响,与没有洁净空调作用情况下相比,火灾探测响应时间将延迟数十秒.     

基于Dignet无监督学习聚类算法的智能火灾探测

介绍了一种基于Dignet ANN无监督学习聚类算法和自适应模糊控制算法的智能火灾探测算法模型.详细阐述了算法模型的思想和实现,给出了环境模式阈值自适应的方法和简单的多类型火灾探测器探测数据融合的方法,较好地解决了环境阈值的自适应问题.在实验室条件下利用欧洲标准火对算法进行了检测,结果表明该智能算法可以有效地对火灾进行探测.     

一种新型的图像型火灾识别算法的研究

图像型火灾探测技术是一种新型的探测技术,可以有效地克服传统火灾探测技术的缺陷.针对背景复杂的火灾图像,首先利用差分技术、RGB颜色分割技术和形态特征分割技术建立3层复合分割模型,排除大部分干扰,得到火焰疑似区域;然后分析火焰疑似区域的相似性测度、面积变化值、致密度、偏心率和质心点偏移距离等特征,这些特征可以较全面地表征火灾信息;最后利用RBF神经网络建立火灾识别模型,将提取出的火焰特征作为输入量,对火灾图像进行分类识别.仿真结果表明,该算法对不同场景的火灾识别具有较高的准确率.     

早期火灾火焰识别的滑动平均计数模型

针对大空间环境下的早期火灾的探测问题,提出一种基于滑动平均计数模型的视频火灾火焰探测方法.使用自适应背景减除法提取前景中的运动目标,通过滑动平均计数模型度量运动目标的闪烁特性,结合运动目标的圆度变化和面积变化,实现早期火灾火焰的识别.实验结果表明:方法能够适应室外环境变化,快速检测火灾火焰.     

基于无线传感器网络的森林火灾模型参数估计

针对森林火灾形势复杂不利于搜救的特点,提出将无线传感器网络应用于森林火灾检测,建立准确的火灾模型,对森林火灾位置和强度进行估计预测.研究了利用无线传感器网络节点进行自适应采样数据的方法和建立高斯空间多峰火灾模型理论方法,并将最大期望算法(EM)和多分辨率搜索算法(MR)相结合,提出用EM-MR算法对火灾模型进行参数估计.通过仿真实验比较,结果表明该模型能较准确地描述森林火灾现场,EM-MR算法在保证估计精度的基础上降低了计算复杂度,证明了方法的有效性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has