字符串近似匹配查询技术综述

字符串匹配是计算机科学中最经典、研究最广泛的问题之一,并且已经被应用到了众多领域当中。然而随着计算机和网络技术的飞速发展以及新问题的不断提出,人们逐渐发现在实际应用中有时更需要进行近似字符串匹配。因此,研究高效的近似字符串匹配算法具有重要的理论价值和实际意义。     

Layout Optimization for Greenhouse WSN Based on Path Loss Analysis

When wireless sensor networks (WSN) are deployed in the vegetable greenhouse with dynamic connectivity and interference environment, it is necessary to increase the node transmit power to ensure the communication quality, which leads to serious network interference. To offset the negative impact, the transmit power of other nodes must also be increased. The result is that the network becomes worse and worse, and node energy is wasted a lot. Taking into account the irregular connection range in the cucumber greenhouse WSN, we measured the transmission characteristics of wireless signals under the 2.4 Ghz operating frequency. For improving network layout in the greenhouse, a semi-empirical prediction model of signal loss is then studied based on the measured data. Compared with other models, the average relative error of this semi-empirical signal loss model is only 2.3%. Finally, by combining the improved network topology algorithm and tabu search, this paper studies a greenhouse WSN layout that can reduce path loss, save energy, and ensure communication quality. Given the limitation of node-degree constraint in traditional network layout algorithms, the improved algorithm applies the forwarding constraint to balance network energy consumption and constructs asymmetric network communication links. Experimental results show that this research can realize the energy consumption optimization of WSN layout in the greenhouse.     

Parallel optimization of three-dimensional wedge-shaped underwater acoustic propagation based on MPI+OpenMP hybrid programming model

The three-dimensional wedge-shaped underwater acoustic propagation model exists analytical solution, which provides verification for models like FOR3D propagation model under certain situation. However, the solving process of a three-dimensional complex underwater sound field problem is hindered by intensive computing and long calculation times. In this paper, we exploit a hybrid parallel programing model, such as MPI and OpenMP, to accelerate the computation, design various optimization methods to improve the overall performance, and then carry out the performance and optimization analysis on the Tianhe-2 platform. Experiments show that the optimized implementation of the three-dimensional wedge-shaped underwater acoustic propagation model achieves a 46.5 speedup compared to the original serial program, thereby illustrating a substantial performance improvement. We also carried out scalability tests and parallel optimization experiments for large-scale practical examples.

     

Segmentation by Continuous Latent Semantic Analysis for Multi-structure Model Fitting

International Journal of Computer Vision - In this paper, we propose a novel continuous latent semantic analysis fitting method, to efficiently and effectively estimate the parameters of model...     

基于SOPC的任意波形发生器人机交互系统设计

任意波形发生器是现代电子测量领域应用最为广泛的一种通用信号源;为了更好地满足人机交互,介绍了一套基于μC/GUI和SOPC技术的任意波形发生器人机交互系统设计方案;系统采用Avalon突发模式设计一个通用的LCD控制器,实现触摸屏为人机交互输入接口,分析并完成μC/GUI的移植,最后完成仪器的图形界面设计;整个系统采用SOPC技术集成到单片FPGA芯片内部,既降低开发成本,又提高系统的稳定性;实验结果表明基于μC/GUI设计的界面简洁友好,触摸屏操作方便直观,整个系统运行稳定,任务能够实时处理;该系统占用资源少,成本低,集成度高,稳定性强,具有一定的实用价值。     

车载冰箱变频控制器的开发

根据车载冰箱的功能需求,以德州仪器公司的TMS320F28035芯片为主控制芯片,设计一款能根据用户的指令及冰箱的温度控制无刷直流电机变频调速的控制器;此控制器由3个模块组成:一是开关电源模块,采用boost升压电路,将12/24V的汽车电源电压升至40V供给电机驱动模块;二是电机驱动模块,通过反电动势法检测无刷直流电机的位置,控制电机启停及变频调速;三是通信模块,采用抗干扰能力强的485通信方式实现控制器与上位机的通信;实验结果表明,控制器的可靠性高,制冷能力强,最低温度可低于-19°C,比普通车载冰箱更节能,满足了使用的要求。     

基于IPv6的无线高原冻土监测系统

设计了一种新型的高原冻土监测系统。采用ARM7内核的MCU进行控制,并基于IPv6协议利用IPv6技术和GPRS技术相结合的方式,建立了可自组网的无线传感器网络,实现了对指定区域环境参数的实时监测。系统使用了多个土壤水分传感器、温度传感器、二氧化碳传感器、氮气传感器对高原冻土环境进行全方位实时观测。各监测点将数据通过基于IPv6的无线网络传送给汇聚节点,汇聚节点再通过GPRS网络将数据传送给监控中心。监控中心可以对数据进行记录和分析,更好地指导环境保护和建设工作。     

Business process design: Process comparison and integration

This paper proposes a framework for business process design, which is based on process comparison and integration. This framework supports process stakeholders to model business processes collaboratively, which can greatly enhance the efficiency and effectiveness of business process design. By applying this framework, each process stakeholder can create his or her own model of the business process. The different models of the same business process can be automatically compared to find the conflicts between them. Based on the conflicts, process stakeholders can collaborate to improve the models. Then the models can be integrated to form a more complete model.     

Unified uncertainty analysis by the mean value first order saddlepoint approximation

Uncertainties exist in products or systems widely. In general, uncertainties are classified as epistemic uncertainty or aleatory uncertainty. This paper proposes a unified uncertainty analysis (UUA) method based on the mean value first order saddlepoint approximation (MVFOSPA), denoted as MVFOSPA-UUA, to estimate the systems probabilities of failure considering both epistemic and aleatory uncertainties simultaneously. In this method, the input parameters with epistemic uncertainty are modeled using interval variables while input parameters with aleatory uncertainty are modeled using probability distribution or random variables. In order to calculate the lower and upper bounds of system probabilities of failure, both the best case and the worst case scenarios of the system performance function need to be considered, and the proposed MVFOSPA-UUA method can handle these two cases easily. The proposed method is demonstrated to be more efficient, robust and in some situations more accurate than the existing methods such as uncertainty analysis based on the first order reliability method. The proposed method is demonstrated using several examples.     

磁流变阻尼器内部流体动能的能量采集

为了构建自供能式磁流变阻尼器内部实时状态监测传感系统,本文介绍了一种针对磁流变阻尼器内部流体能的能量采集装置。该装置被安装于磁流变阻尼器活塞顶端并为检测阻尼器内部工作参数的无线传感模块1供电。根据能量守恒定律,推导出磁流变阻尼器中磁流变液流动能的理论模型。通过实验测试分析了在不同的外界激励下能量采集装置的工作情况,证明了采集的电能随着活塞的运动频率增加而增加,而与磁流变阻尼器的磁流变特性没有明显的关系。测试表明利用此装置能较好的采集到来自于磁流变阻尼器内部流体流动产生的能量,为无线传感模块供电。