煤矿监控系统主要设备的平均无故障工作时间测试与分析

介绍了平均无故障工作时间测试方法,在4个煤矿对某种煤矿监控系统的平均无故障工作时间进行了现场测试,得到了该煤矿监控系统主要设备的平均无故障工作时间,并得出结论:该系统中本质安全型电源、瓦斯传感器、CO传感器和风速传感器的平均无故障工作时间相对较短,应是今后设计改进的重点;该系统能达到AQ 6201—2006标准提出的平均无故障工作时间应不小于800h的指标;统计结果表明,煤矿井下的线路故障是一种多发故障。     

基于主成分聚类分析的煤矿安全评价模型

首先从人的行为、安全管理、装备设施、自然条件、安全技术与监管机制5个方面建立了煤矿安全评价指标体系;然后运用主成分分析和聚类分析建立了煤矿安全评价模型,通过主成分分析选取综合指标,减少了评价指标的个数,通过聚类分析对各煤矿企业的安全状态进行分类评价,分析其相似性和差异性;最后通过对某省40个煤矿企业的安全状况进行评价,介绍了该煤矿安全评价模型的应用步骤。应用结果表明,该煤矿安全评价模型得出的评价结果简单、直观地反映了煤矿的安全状态。     

矿井机电设备数据分析系统设计

针对矿井机电设备管理存在不能及时发现设备潜在故障、设备利用率低、生产效率低等问题,设计了一种矿井机电设备数据分析系统。该系统采用iHistorian服务器存储各个采集点的机电设备数据,从基础数据、可靠性、能耗、效率和预警5个方面分析数据,并将分析结果存储在SQL Server数据库中,通过Web服务器供客户端使用。实际应用表明,该系统可实时反馈矿井机电设备的运行状况,确保了矿井机电设备运行数据的实时分析和安全高效运行预警。     

计算机网络系统可靠性分析及在矿山的应用

随当前我国计算机网络技术的不断快速发展,以及全球信息化的发展趋势日渐成型,人们对于信息的需求也愈发地渴望.正是基于此时代背景,以信息作为传输载体的计算机网络系统也应势而起,并且其可靠性、安全性也更加受到让人们的关注.本文中研究了计算机网络系统可靠性,比较了存在的优劣问题,并探讨其应用于矿山计算机系统的可行性.     

基于主成分分析法的煤矿安全事故原因统计

以2001—2011年煤矿安全事故发生频次为例,应用主成分分析法得到煤矿安全事故原因的第1、第2主成分,进一步分析得出煤矿安全事故主要是由冒顶事故和机械事故引起。分析结果表明,主成分分析法对煤矿安全设施规划有一定的指导作用。     

矿井通风三维仿真系统设计与实现

为了保障地下矿山工作人员的安全,服务于矿山实际生产的需要,在数据处理和系统界定的基础上研究了矿井通风原理,并建立了通风网路、通风动力和通风控制设施等通风系统模型.结合计算机仿真和计算机网络技术,提出了一套基于网络的三维可视化仿真技术体系,设计并实现了以B/S结构为平台的矿井通风网络三维可视化仿真系统.并以某地下矿山为实例进行了通风系统建模与仿真的验证,结果能够反映矿山井巷工程的三维空间位置及拓扑关系,符合矿山通风系统正常运行状况,可为通风系统的计算机辅助设计及采矿计划的制定提供参考.     

WCDMA无线通信系统在煤矿的应用分析

针对当前煤矿对无线通信系统的要求,分析比较了现有矿用无线通信系统的特点,阐述了WCDMA矿用无线通信系统的优势,并对其关键技术进行分析;介绍了该系统的网络架构和功能特点。应用结果表明,该系统能够满足煤矿日常生产管理的通信需要。     

Computationally efficient seismic fragility analysis of geostructures

Seismic fragility analysis is considered nowadays as a very efficient computational tool for determining the structural behaviour over a range of seismic intensity levels. There are two approaches for developing fragility curves, either based on the assumption that the structural response follows the lognormal distribution or using reliability analysis techniques for calculating the probability of exceedance for various damage states for a variety of seismic hazard levels. The Monte Carlo simulation (MCS) technique is regarded as the most consistent reliability analysis method having no limitations regarding its applicability range. However, the required computational effort is the only limitation which increases substantially when implemented for calculating lower probabilities. Incorporating artificial neural networks (ANN) into the fragility analysis framework enhances the computational efficiency of MCS, since ANN require a fraction of time compared to the conventional procedure. In this work two types of ANN are implemented into a MCS-based vulnerability analysis framework of geostructures, where the randomness of material properties, geometry and of the pseudostatically imposed seismic loading is considered.     

Three dimensional modeling and finite element simulation of a generic end mill

The geometry of cutting flutes and the surfaces of end mills is one of the crucial parameters affecting the quality of the machining in the case of end milling. These are usually represented by two-dimensional models. This paper describes in detail the methodology to model the geometry of a flat end mill in terms of three-dimensional parameters. The geometric definition of the end mill is developed in terms of surface patches; flutes as helicoidal surfaces, the shank as a surface of revolution and the blending surfaces as bicubic Bezier and biparametric sweep surfaces. The proposed model defines the end mill in terms of three-dimensional rotational angles rather than the conventional two dimensional angles. To validate the methodology, the flat end milling cutter is directly rendered in OpenGL environment in terms of three-dimensional parameters. Further, an interface is developed that directly pulls the proposed three-dimensional model defined with the help of parametric equations into a commercial CAD modeling environment. This facilitates a wide range of downstream technological applications. The modeled tool is used for finite element simulations to study the cutting flutes under static and transient dynamic load conditions. The results of stress distribution (von mises stress), translational displacement and deformation are presented for static and transient dynamic analysis for the end mill cutter flute and its body. The method described in this paper offers a simple and intuitive way of generating high-quality end mill models for use in machining process simulations. It can be easily extended to generate other tools without relying on analytical or numerical formulations.     

煤矿井下作业人员管理系统人员数据分析软件的应用

提出了一种煤矿井下作业人员管理系统人员数据分析软件,介绍了该软件数据曲线分析的原理,以下井人员总数曲线为例介绍了该软件在煤矿交接班管理、人员定位管理中的应用。该软件可以曲线形式直观、定量地反映煤矿交接班状况、人员活动情况、人员定位系统运行状况等,已应用于某煤矿井下作业人员管理系统,效果良好。     

闭坑矿井矿界煤柱采动损伤及其安全性评价

闭坑矿井矿界煤柱受采动损伤后其隔水能力降低,易导致闭坑老空水破坏矿界煤柱进入相邻生产矿井,影响矿井安全生产。以淮北矿区两相邻矿井即闭坑矿井沈庄矿和生产矿井袁庄矿的矿界煤柱为研究对象,采用FLAC 3d数值模拟和理论计算方法,对沈庄矿S2Ⅱ313工作面和袁庄矿Ⅲ3142工作面矿界煤柱采动损伤区宽度进行研究,根据研究结果确定矿界煤柱采动损伤区宽度为13.1 m,表明矿界煤柱已被破坏,两相邻矿井边界煤岩层已不具备阻水能力。在此基础上对矿界煤柱安全性进行了评价,得出现有矿界煤柱存在渗水和溃水危险性,需采取布置阻水帷幕或注浆加固等措施。     

Two parallel algorithms for the convex hull problem in a two dimensional space

Two parallel algorithms for determining the convex hull of a set of data points in two dimensional space are presented. Both are suitable for MIMD parallel systems. The first is based on the strategy of divide-and-conquer, in which some simplest convex-hulls are generated first and then the final convex hull of all points is achieved by the processes of merging 2 sub-convex hulls. The second algorithm is by the process of picking up the points that are necessarily in the convex hull and discarding the points that are definitely not in the convex hull. Experimental results on a MIMD parallel system of 4 processors are analysed and presented.     

Modelling of a continuous food pressing process by dimensional analysis

This paper focuses on the development of a mathematical model of a continuous pressing operation where biscuit shape is formed. It identifies a functional relationship and predicts its parameter values using a set of observed data. Dimensional analysis was used to model biscuit thickness as a non-linear function of a number of predictor variables and multiple regression was applied for parameter estimation of the model. The results were satisfactorily tested against real data.     

煤矿救援机器人结构设计及分析

针对矿井地貌环境的非结构性和复杂性,为了提高救灾机器人的越障能力和实际救援能力,分析了轮式救援机器人行走系统的力学系统原理,提出了机器人六轮行走机构的设计方案。六轮移动机器人采用电动推杆为升降系统提供动力;采用独立悬挂系统,减小了车身的倾斜和震动;采用集中控制-分布驱动方式,有利于运动机构性能的发挥;能够根据地形特征调整自己的底座结构,有很强的越障能力和对非结构化地形的适应能力。     

煤矿事故分析与煤矿大数据和物联网

按事故类别分析了2004—2013年全国煤矿事故:顶板、瓦斯、运输、水害、机电、爆破、火灾等事故起数和死亡人数占比分别为52.7%和36.8%,11.3%和29.7%,16.9%和11.3%,3.1%和8.1%,4.1%和2.5%,2.7%和1.9%,0.4%和1.9%;顶板事故起数和死亡人数最多;瓦斯事故起数居第3位,死亡人数居第2位,但2005年和2013年死亡人数最多;运输事故起数居第2位,死亡人数居第3位;煤矿各类事故起数和死亡人数均大幅下降;瓦斯和顶板事故起数占比明显下降,但运输和机电事故起数占比有所上升,需进一步加强运输和机电事故防治。探讨了大数据在煤与瓦斯突出、冲击地压、水害、火灾等事故预警,煤矿重大关键设备故障诊断,煤炭需求和价格预测等方面的应用。探讨了物联网在矿用安全标志准用产品管控、煤矿重大关键设备管控与远程维护、煤矿设备材料管控、防碰撞、持证上岗与专人操作管控等方面的应用。     

Two dimensional coupled oscillators array with rhombus structure and its application in active antenna array

Beam scanning and forming can be achieved by coupled oscillators array without phase shifter. Active antenna array based on coupled oscillators array has the virtue of low cost, high integration, and high efficiency. Traditional two dimensional coupled oscillators array has been arranged on rectangular lattices, and phase difference of adjacent elements is limited to [-90°, 90°]. Therefore, the beam scanning range is limited to [-30°, 30°] from normal for half wavelength element spacing. A new two dimensional coupled oscillators array with rhombus structure is presented. Phase control method and phase error of the array are also provided. Stability of the array is analyzed, and stable condition is given. When this coupled oscillators array with rhombus structure is used in active antenna array, theoretical results show that phase difference of adjacent elements reach the limit of [-180°, 180°] along the horizontal and vertical directions. Therefore, it has wider beam scanning range than that of a rectangular lattice structure.     

Markovian analysis of a discrete material manufacturing system with merge operations, operation-dependent and idleness failures

This paper examines a discrete material manufacturing system consisting of three machines that are subject to breakdown and one buffer of finite capacity. It is assumed that the buffer has two immediate preceding machines performing the same operations and one immediate succeeding machine receiving material from the buffer. When the buffer reaches its own capacity, one of the two preceding machines has priority over the other to dispose its processed part into the buffer.

It is also assumed that there is a new way of the machines reaching failure, by allowing the machines to fail not only when they are operational but also when are either blocked or starved. The latter gives rise to the possibility of modeling the production of more than one part types. The model is solved analytically by developing a recursive algorithm that generates the transition matrix for any value C of the intermediate buffer capacity. Then various performance measures of the system (e.g., throughput) can be easily evaluated. Numerical results for the throughput are also given and these are compared against simulation. The proposed model may be used as a decomposition block to solve large flow lines with merge/split operations (for example, flow lines with quality inspections and rework loops) and multiple part types.     

The Failure Trace Archive: Enabling the comparison of failure measurements and models of distributed systems

With the increasing presence, scale, and complexity of distributed systems, resource failures are becoming an important and practical topic of computer science research. While numerous failure models and failure-aware algorithms exist, their comparison has been hampered by the lack of public failure data sets and data processing tools. To facilitate the design, validation, and comparison of fault-tolerant models and algorithms, we have created the Failure Trace Archive (FTA)—an online, public repository of failure traces collected from diverse parallel and distributed systems. In this work, we first describe the design of the archive, in particular of the standard FTA data format, and the design of a toolbox that facilitates automated analysis of trace data sets. We also discuss the use of the FTA for various current and future purposes. Second, after applying the toolbox to nine failure traces collected from distributed systems used in various application domains (e.g., HPC, Internet operation, and various online applications), we present a comparative analysis of failures in various distributed systems. Our analysis presents various statistical insights and typical statistical modeling results for the availability of individual resources in various distributed systems. The analysis results underline the need for public availability of trace data from different distributed systems. Last, we show how different interpretations of the meaning of failure data can result in different conclusions for failure modeling and job scheduling in distributed systems. Our results for different interpretations show evidence that there may be a need for further revisiting existing failure-aware algorithms, when applied for general rather than for domain-specific distributed systems.     

矿井通风系统三维模型的构建与应用

现有的巷道三维模型建模算法复杂,且以巷道两端端点坐标直接确定巷道的走势,不能较好地体现巷道的起伏。针对上述问题,以煤矿工程平面图为基础数据,利用巷道间的拓扑关系进行定位点采集,采用中心线加载断面的算法构建了矿井三维巷道模型。基于矿井三维巷道模型,将通风设施模型同步到三维系统中,生成了矿井通风系统三维模型及相应数据库,生成的立体图能清晰地展示矿井巷道的整体走势,结合数据库信息管理可对矿井模型进行添加、修改等智能操作。实际应用结果表明:该模型实现了矿井通风系统二维图到三维图的快速转换,可真实地展示煤矿巷道信息及工作面状况,生成的矿图数据库可实时更新,为研究矿井通风网络解算和灾变模拟提供了优良平台。     

Damage analysis and numerical simulation for failure process of a reinforced concrete arch structure

This work focuses on the implementation of damage mechanics model to explain and understand failure mechanisms of the concrete structures. A tensorial damage theory and an isotropic application to the arch ribs of a real bridge are presented. Two reinforced concrete arch ribs of a 28 year old bridge has been removed from the field to the laboratory. They were loaded up to failure in order to study the remaining strength of the structure. The damage model involves three independent parameters for simulating the damage behaviors of the concrete material. The damage theory—additional load—finite element method is developed to simulate numerically the failure process of the RC structures based on the proposed damage model. The predicted displacements, strains and failure mode of the RC arch are good agreement with the experimental results. The values of the three material parameters that describe the damage characteristics of concrete were obtained. The numerical calculations revealed the interested behaviors of concrete in a damaging process. The proposed damage model can be used effectively to describe the damage and fracture behaviors of concrete.