远程测振系统在群楼拆除爆破振动监测中的应用

为了探索数字爆破测振系统在工程爆破危害效应实时监测中的应用效果,以汉口滨江商务区拆除爆破19栋群楼的工程为例,按照公安主管部门在审批拆除爆破方案时的要求,该工程必须采用控制爆破的方法,同时加强拆除爆破产生危害效应的实时监测。为此,本次群楼拆除爆破采用的是广州中爆数字公司研发的远程测振系统,对群楼拆除爆破过程中产生的爆破振动及塌落振动进行了全程、在线监测。通过远程测振系统,能够实现爆破测振数据的自动记录、远程传输和精细处理,进而推动爆破行业的快速发展,同时作为爆破安全监管的数字化、信息化手段,可对拆除爆破危害效应进行实时在线监测,可有效提升公安主管部门对复杂环境下爆破工程项目作业安全的远程监管能力。应用结果表明,远程测振系统可对爆破振动进行实时有效监测。     

雷达状态监测系统设计

为降低雷达维修成本、提高雷达保障效率,针对雷达的不同信号分别设计不同的采集方式,完成雷达实时状态监测系统,确保采集监测信息的准确性。该设计增加了数据实时处理终端系统,能够实时处理雷达状态信息,对雷达出现的故障能够做到早发现、早报警、早维修,满足保障需求。     

Data acquisition system for photovoltaic systems performancemonitoring

In order to analyze the performance of photovoltaic (PV) systems, we have developed a real-time expert system based on a central microcomputer used as a microserver and can be easily consulted from different automatic stations. The developed system is able to ensure the monitoring, supervision, and control of PV systems installed over a wide area, on one hand, and to create a general PV systems database, on the other. This paper presents a design of a universal data acquisition system with available components and which is easily accessible through a server. The hardware and software configuration of the expert system are described. Performance of this system are also presented when applied on PV systems     

基于物联网的电梯实时监测系统设计

针对目前电梯监测方法繁杂、工作效率低等问题,引入惯性捷联系统,并介绍了基于物联网的电梯实时监测系统的硬件结构和软件流程。运用惯性捷联原理,提出判断电梯运行状态的算法;引入物联网,实时获取、保存、查询及分析电梯运行状态,及时实现电梯与人的信息交互;引入无线射频系统,准确获取电梯特殊标志信息;选用MC52I无线模块,远程语音安抚被困人员情绪。现场调试证明系统工作稳定可靠,各项指标均达到设计要求。     

Flood hazard and management: a UK perspective

This paper discusses whether flood hazard in the UK is increasing and considers issues of flood risk management. Urban development is known to increase fluvial flood frequency, hence design measures are routinely implemented to minimize the impact. Studies suggest that historical effects, while potentially large at small scale, are not significant for large river basins. Storm water flooding within the urban environment is an area where flood hazard is inadequately defined; new methods are needed to assess and manage flood risk. Development on flood plains has led to major capital expenditure on flood protection, but government is attempting to strengthen the planning role of the environmental regulator to prevent this. Rural land use management has intensified significantly over the past 30 years, leading to concerns that flood risk has increased, at least at local scale; the implications for catchment-scale flooding are unclear. New research is addressing this issue, and more broadly, the role of land management in reducing flood risk. Climate change impacts on flooding and current guidelines for UK practice are reviewed. Large uncertainties remain, not least for the occurrence of extreme precipitation, but precautionary guidance is in place. Finally, current levels of flood protection are discussed. Reassessment of flood hazard has led to targets for increased flood protection, but despite important developments to communicate flood risk to the public, much remains to be done to increase public awareness of flood hazard.     

一种嵌入式移动机器人控制系统

为克服传统移动机器人控制系统的性能与功耗的矛盾,提出了一种高性能、低功耗的嵌入式控制系统.该系统以微处理器ARM9作为上位机处理器,配上基于数字信号处理器(DSP)、现场可编程门阵列((FPGA)的视觉模块、传感器模块和伺服模块,构成一种主从分布式、多CPU的控制系统,实现了基于实时Linux的机器人控制软件体系结构.整个系统具有处理能力强,实时性高,稳定性好等特点.通过对比实验证实,该移动机器人控制系统真正具有高性能、低功耗以及软件实时性高等优点.     

Redundancy index of lifelines for mitigation measures against seismic risk

Basic consideration is made on how comprehensively we can evaluate potential seismic risk of lifeline systems and gain an insight into the safety by way of information entropy, which transmits information of various kinds under uncertainties. It is clarified that a redundancy index R_E defined via Shannon's information entropy can be an index to represent redundancy of a system and whose value plays a role to choose the best alternative for designing a system or for finding the best damage mitigation measure against earthquake hazard. The redundancy index R_E takes a value between zero and unity with zero for no redundancy, and unity for maximum redundancy. After the validity of R_E is justified to represent a redundancy measure, a case study is conducted for a Kobe water supply system to evaluate a mitigation measure against earthquake risk where the 1995 Hyogoken-Nanbu earthquake is used as the input hazard.     

Effectiveness of mitigation measures against natural hazards

We describe a general procedure to assess the effectiveness of mitigation measures against the following natural hazards: snow avalanches, rockfall, landslides, debris flows and floods. First the basic principles necessary for considering mitigation measures related to hazard maps are defined. These principles ensure that a minimal level of quality, safety and sustainability is met and that mitigation measures are tested not only with respect to regular design events but also to extreme events. Once the basic standards are met, the effectiveness of a mitigation measure is analyzed in more detail. This approach is subdivided into three main steps. In the first step, the question of whether the mitigation measures may be relevant in any way to the hazard assessment or not is investigated. In the second step, the mitigation measures are assessed technically by determining their reliability, defined in terms of structural safety, serviceability and durability. The third step involves the quantification of the effectiveness, taking into account the mitigation measures with respect to their reliability. Finally, the adaptation of hazard zones can be elaborated based on this information.     

A field-portable plasma source monitor for real-time air particulate monitoring

In this research, a novel portable instrument for on-site, real-time air particulate monitoring was developed. It is highly desirable to use microwave plasmas for on-site, real-time environmental and occupational hazard monitoring because they can be sustained with various gases at relatively low power and possess excellent detection capabilities for both metal and nonmetal air pollutants. In the new instrument design, a microwave plasma was selected as an excitation source and was used in conjunction with atomic emission spectrometry. A small, integrated spectrometer with a charge-coupled detector (CCD) was used for optical signal detection. An efficient, in situ air-sampling system was developed for direct sampling of air particles into the plasma. Characterization and calibration of the new instrument were achieved with an in-house-fabricated high-efficiency nebulization-desolvation system. Tolerance of the microwave argon plasma source to air introduction was tested, and the operational parameters were optimized. Analytical performance and the feasibility of the newly developed portable instrument for aerosol particle analysis were evaluated. Some advantages and possible applications of the new instrument are discussed. The instrument provides an innovative tool for rapid environmental and occupational hazard monitoring.     

A contaminant detection system for early warning in water distribution networks

Water distribution systems are spatially diverse. As such, they are inherently vulnerable to accidental or deliberate physical, chemical, or biological threats. Efficient water quality monitoring is one of the most important tools to guarantee a reliable potable water supply. A methodology and two example applications for finding the optimal layout of a detection system, taking explicitly into account the dilution and decay properties of the water quality constituents as distributed with flow, as well as the ability of the monitoring equipment to detect contaminant concentrations, are formulated and demonstrated. The detection system outcome is aimed at capturing contaminant entries within a pre-specified level of service (LOS) defined as the maximum volume of polluted water exposure to the public at a concentration higher than a minimum hazard level. The proposed methodology couples hydraulic simulations with graph theory techniques to identify a minimum set of monitoring stations that ‘covers’ the entire network for a given LOS, at a maximum degree of system invulnerability. The model developed extends a previous work of the authors through explicitly considering the deterioration and dilution of water quality as distributed with flow, and by taking into account the monitoring equipment capabilities to detect pollutant concentrations. The methodology is demonstrated using two example applications.     

道路施工机群智能化管理系统的设计及开发

以高等级公路施工机群管理为背景,研究和开发了智能化公路工程机械机群管理系统,描述了系统的体系结构设计,组成系统的各级中心站的设计以及功能,以及监控系统的核心功能,包括资源配置功能、监控调度功能及故障诊断功能等。本文所描述的系统是计算机智能化信息采集及控制在一个新的行业领域的应用,并针对问题的特殊性,设计并实现了实时监控及动态优化调度的功能和算法。     

Design and implementation of an identification system in construction site safety for proactive accident prevention

Identifying accident precursors using real-time identity information has great potential to improve safety performance in construction industry, which is still suffering from day to day records of accident fatality and injury. Based on the requirements analysis for identifying precursor and the discussion of enabling technology solutions for acquiring and sharing real-time automatic identification information on construction site, this paper proposes an identification system design for proactive accident prevention to improve construction site safety. Firstly, a case study is conducted to analyze the automatic identification requirements for identifying accident precursors in construction site. Results show that it mainly consists of three aspects, namely access control, training and inspection information and operation authority. The system is then designed to fulfill these requirements based on ZigBee enabled wireless sensor network (WSN), radio frequency identification (RFID) technology and an integrated ZigBee RFID sensor network structure. At the same time, an information database is also designed and implemented, which includes 15 tables, 54 queries and several reports and forms. In the end, a demonstration system based on the proposed system design is developed as a proof of concept prototype. The contributions of this study include the requirement analysis and technical design of a real-time identity information tracking solution for proactive accident prevention on construction sites. The technical solution proposed in this paper has a significant importance in improving safety performance on construction sites. Moreover, this study can serve as a reference design for future system integrations where more functions, such as environment monitoring and location tracking, can be added.     

Development and Evaluation of a Seismic Monitoring System for Building Interiors—Part II: Image Data Analysis and Results

Previous experiences during earthquake events emphasize the need for new technologies for real-time monitoring and assessment of facilities with high-value nonstructural contents. Moreover, there is a substantial limitation in our ability to rapidly evaluate and identify potential hazard zones within a structure, exposing rescue workers, society, and the environment to unnecessary risks. A real-time image-based monitoring system, which is integrated with warning systems, would allow for improved channeling of resources and informed decision making for rescue workers and building owners. In recognition of these issues, in this paper, we describe a methodology for image-based tracking of seismically induced motions. The methodology includes the acquisition, calibration, and processing of image sequences to detect and track object features under seismic-event conditions. We address the issue of providing a reliable feature/object-detection and object-tracking methodology for an image sequence from a single camera view. In addition, we introduce an extension to the 2-D tracking approach by providing a 3-D feature tracking methodology when the camera array itself is affected by the seismic event. The methods presented are demonstrated using the data collected during the full-scale field vibration tests conducted on a vacant building that was damaged during the 1994 Northridge earthquake (presented in a companion paper). We present experimental tracking results of the implemented algorithms for a variety of objects and discuss additional challenges that emerge when image-based systems are used under these extreme conditions.     

Design of an irradiation facility with a real-time radiation effects monitoring capability

An in-core irradiation facility for radiation effects testing with a real-time monitoring capability has been designed for the 1.1 MW TRIGA Mark II research reactor at The University of Texas at Austin. The facility is larger than any currently available non-central location in a TRIGA, supporting testing of larger electronic components as well as other in-core irradiation applications requiring significant volume such as isotope production or neutron transmutation doping of silicon. This article presents the layout and characterization of the large in-core irradiation facility and the real-time electronics performance monitoring capability it is designed to support. To demonstrate this capability, an experimental campaign was conducted where the real-time current transfer ratio for 4N25 general-purpose optocouplers was obtained from in-situ voltage measurements. The resultant radiation effects data - current transfer ratio as a function of neutron and gamma dose - was seen to be repeatable and exceptionally finely resolved. Therefore, the real-time capability at UT TRIGA appears competitive with other effects characterization facilities in terms of number and size of testable samples while additionally offering a novel real-time, in-core monitoring capability.     

A data acquisition system for machine tool condition monitoring

A flexible, generically applicable and inexpensive data acquisition system (DAS), for machine tool condition monitoring, has been designed, constructed and installed as part of a European Union sponsored project. The DAS is more than just a data logger and an array of sensors. It also consists of a methodology for analysing data logging requirements and a relational database that supports this methodology. The database is held on a central ‘maintenance management’ computer. The monitoring to be carried out by the DAS is specified through this database, which contains detailed information about the DAS's facilities. This feature makes it simple to reconfigure the DAS to implement new monitoring requirements and to customize its operation to meet the needs of different machines. The information in the database is transformed into a look-up table that is read by the software that sets up and controls the data logging processes.     

Enhancement of seismic sustainability of critical facilities through system analysis

Proper functioning of critical facilities such as acute care hospitals and fire stations are essential in the aftermath of a severe earthquake. For these facilities to remain operational, not only their building structures must remain safe for continued occupancy, but also their nonstructural components/systems must remain functional. Motivated by a previous study by the second author, this paper demonstrates a probabilistic system analysis for enhancing the sustainability of deficient critical facilities. The analysis, in principle, utilizes event and fault tree procedures to evaluate the system fragility defined by the probability that the system will not perform its intended purpose. Enhancement of sustainability is demonstrated by using a representative numerical model of an existing facility. The study shows that by selecting the most vulnerable components, utilizing the concept of annual sensitivity index, the annual probability of failure can be reduced significantly in a cost-effective way.     

激光冲击强化设备控制系统

针对复杂曲面类零件,研发一种新型表面激光冲击强化的控制系统,该系统是一套全自动可控操作系统,通过工控机/PLC集成控制,实现自动化、数字化控制,并完成实时在线监控和信息交互反馈,属于开放式分布系统。该系统用于激光冲击强化核心设备(包括激光器、机器人、辅助控制、质量检测装置与辅助系统等),实现各环节的信息交互和系统的协同工作,通过实时监控系统,远程观察加工状态,有效避免重大事故的发生。同时,该控制系统添加激光冲击强化工艺试验数据记录功能,可根据实际需求调用后台工艺参数数据库,实现高效工艺参数优化。除此之外,该系统还能够实现激光冲击强化模型建立、加工过程有限元模拟、复杂曲面加工轨迹自动规划、加工策略制定等功能,从而实现激光冲击强化自动化生产,目前已经处于工程应用阶段。     

Real-time assessment of fog-related crashes using airport weather data: A feasibility analysis

The effect of reduction of visibility on crash occurrence has recently been a major concern. Although visibility detection systems can help to mitigate the increased hazard of limited-visibility, such systems are not widely implemented and many locations with no systems are experiencing considerable number of fatal crashes due to reduction in visibility caused by fog and inclement weather. On the other hand, airports’ weather stations continuously monitor all climate parameters in real-time, and the gathered data may be utilized to mitigate the increased risk for the adjacent roadways. This study aims to examine the viability of using airport weather information in real-time road crash risk assessment in locations with recurrent fog problems. Bayesian logistic regression was utilized to link six years (2005–2010) of historical crash data to real-time weather information collected from eight airports in the State of Florida, roadway characteristics and aggregate traffic parameters. The results from this research indicate that real-time weather data collected from adjacent airports are good predictors to assess increased risk on highways.     

Deriving origin destination data from a mobile phone network

Acquiring high-quality origin-destination (OD) information for traffic in a geographic area is both time consuming and expensive while using conventional methods such as household surveys or roadside monitoring. These methods generally present only a snapshot of traffic situation at a certain point in time, and they are updated in time intervals of up to several years. A technique was developed that makes use of the global system for mobile communications (GSM) mobile phone network. Instead of monitoring the flow of vehicles in a transportation network, the flow of mobile phones in a cell-phone network is measured and correlated to traffic flow. This methodology is based on the fact that a mobile phone moving on a specific route always tends to change the base station nearly at the same position. For a first pilot study, a GSM network simulator has been designed, where network data can be simulated, which is then extracted from the phone network, correlated, processed mathematically and converted into an OD matrix. Primary results show that the method has great potential, and the results inferred are much more cost-effective than those generated with traditional techniques. This is due to the fact that no change has to be made in the GSM network, because the information that is needed can readily be extracted from the base station database, that is the entire infrastructure needed is already in place     

A real-time remote control architecture using mobile communication

This paper presents a new development of mobile communication for application to remote data transmission and control. The concept of G/sup 3/, including global positioning system, global system for mobile (GSM), and geographic information system, is proposed. In this paper, a GSM real-time control system for data uplink and downlink remote terminals is considered. The proposed system can be implemented on a PC-based or a /spl mu/P-based to integrate into G/sup 3/ configuration. This paper presents the system design and implementation with practical data verification. The proposed GSM real-time control system has accomplished a very reliable two-way point-to-point uplink and downlink data transmission within a 0.6-s time delay.