分体空调冷凝水回收利用实验研究

针对分体空调冷凝水的浪费和无规律排放,回收冷凝水用于预冷冷凝器进风具有实际的节能潜力,笔者通过制作的一套冷凝水回收预冷装置,将该装置应用于某实验室单体空调,并进行了3种工况下的试验测试,分别为未装预冷装置、提供足够冷水预冷装置,以及空调器提供自身冷凝水预冷装置。计算和分析结果表明装有预冷装置前后,无论提供足够冷水还是自身产生的冷凝水,其性能系数COP分别提高了12.94%和9.52%。同时发现冷凝水产生量与需水量具有一定的差距,仅为需水量的56.26%。最后,结合试验现状和结果,对该预冷装置的应用和推广给出了相应的建议。     

泥石流泥沙输移比的概念与计算方法探讨

通过泥石流SDR,可将泥石流流域侵蚀产沙、泥沙输移及泥石流沟道和入汇处主河河床演化有机地联系起来,用于推求流域的土壤侵蚀量,泥石流沟道的冲刷与淤积状况,泥石流所输送的泥沙进入主河的数量,以及对下游河道演变、水库使用年限的影响程度等方面。但目前泥石流SDR的研究还没有开始,在分析泥石流输沙特征的基础上,将SDR引入泥石流输沙的研究中,并将泥石流SDR分解为反映泥石流沟输沙能力的沟道泥石流SDR和反映主河输移泥石流泥沙能力的汇口泥石流SDR两个环节。给出了根据定义使用实际的监测数据计算两类泥石流SDR的具体方法,并在蒋家沟中实施,计算出蒋家沟2007年的一场泥石流过程中沟道SDR为0.14,入汇主河后的悬移质汇口泥石流SDR为0.36。泥石流SDR的模型计算法方面也根据定性分析列出了可能的影响因子,在总结河流SDR的研究成果和分析泥石流输沙特性的基础上进行了模型建立方法的初步探讨。     

模糊四元联系数在土质边坡稳定性评价中的应用

针对影响土质高边坡稳定性因素的复杂性和模糊性这一问题,将模糊四元联数与边坡稳定性评价相结合,提出了一种新的边坡稳定性计算方法,并利用该方法对燕麦沟边坡进行稳定性评价.分析结果表明,该方法能较全面地考虑边坡多参数的影响,能使边坡稳定性评价更全面、更符合实际,是一种适用于土质高边坡稳定性分析的合理算法.     

一种480MHz无线数传模块的设计

针对中国智能电网开放的免费无线计量频段,设计了一种可工作在470 MHz～510 MHz、中心频率为480 MHz、输出功率可调的无线数传模块。模块采用MSP430F2274单片机和射频芯片CC1100E设计,利用EDA软件ADS2008仿真优化了射频电路的输出匹配网络。最后对无线模块输出功率、通信距离等参数进行了测试和验证。     

Alternative mixed integer linear programming models for identifying the most efficient decision making unit in data envelopment analysis

A mixed integer linear model for selecting the best decision making unit (DMU) in data envelopment analysis (DEA) has recently been proposed by Foroughi [Foroughi, A. A. (2011a). A new mixed integer linear model for selecting the best decision making units in data envelopment analysis. Computers and Industrial Engineering, 60(4), 550–554], which involves many unnecessary constraints and requires specifying an assurance region (AR) for input weights and output weights, respectively. Its selection of the best DMU is easy to be affected by outliers and may sometimes be incorrect. To avoid these drawbacks, this paper proposes three alternative mixed integer linear programming (MILP) models for identifying the most efficient DMU under different returns to scales, which contain only essential constraints and decision variables and are much simpler and more succinct than Foroughi’s. The proposed alternative MILP models can make full use of input and output information without the need of specifying any assurance regions for input and output weights to avoid zero weights, can make correct selections without being affected by outliers, and are of significant importance to the decision makers whose concerns are not DMU ranking, but the correct selection of the most efficient DMU. The potential applications of the proposed alternative MILP models and their effectiveness are illustrated with four numerical examples.     

Stochastic Bounded Consensus Tracking of Second-Order Multi-Agent Systems with Measurement Noises and Sampled-Data

This paper investigates the stochastic bounded consensus tracking problems of second-order multi-agent systems, where the control input of an agent can only use the information measured at the sampling instants from its neighbors or the virtual leader with a time-varying reference state, and the measurements are corrupted by random noises. The probability limit theory, the algebra graph theory, and some other techniques are employed to derive the necessary and sufficient condition guaranteeing the mean square bounded consensus tracking. It turns out that the maximum allowable sampling period depends on not only the network topology but also the constant feedback gains. Furthermore, the effects of the sampling period on tracking performance, including the tracking speed and the static tracking error, are also analyzed. The results show that reducing the sampling period can accelerate the tracking speed and decrease the static tracking error. Simulations are provided to demonstrate the effectiveness of the theoretical results.     

Research on development of embedded uninterruptable power supply system for IOT-based mobile service

Under the banner of Internet of Things (IOT), mobile service is an important hot research topic. As a part of IOT, embedded systems can offer access to the devices on Internet. For supporting mobile service, one design and implementation solution of embedded Uninterruptable Power Supply (UPS) system is brought forward for long-distance monitoring and controlling UPS based on IOT. The key insight of our development is that we adopt new idea to realize new application based on new technology of IOT. The target is for mobile service to support pervasive computing paradigm. Our new idea is involved in the developed system which is based on new Arm chips, a set of new ATmega products (such as ATmega 161, ATmega 162), new Network Interface Controller, TCP/IP protocol suite and other software components. In our designed UPS system, an enhanced embedded file system is designed and implemented which saves the data and index information on the chip (such as a serial EEPROM) in structured way and communicates with MCU through I²C bus. The new file system is embedded in the UPS system. Mobile users can access and manipulate local or remote data on the client side based on IOT. Embedded file system on the chips plays a major role in the growth of IP networking. Based on our experiments, mobile users can easily monitor and control UPS in different places of long-distance. By our experiments and applications, the performance of this kind of new embedded UPS system is satisfied the requirements of all kinds of IOT-based mobile services.