基于PSO-LSSVM的网络流量预测模型

为了提高网络流量的预测精度,考虑到网络流量的长相关、非线性等特性,提出一种粒子群算法优化最小二乘支持向量机参数的网络流量预测模型（PSO-LSSVM）．首先将最小二乘支持向量机参数作为粒子的位置向量,然后利用粒子群算法找到模型的最优参数,最后采用最优参数最小二乘支持向量机建立网络流量预测模型．仿真结果表明,相对于参比模型,PSO-LSSVM能够获得更高的网络流量预测精度,更能准确描述网络流量变化规律．     

混沌理论和LSSVM相结合的网络流量预测

为提高网络流量的预测精度,提出一种基于混沌理论和最小二乘支持向量机相结合的网络流量预测方法。采用相空间重构对网络流量时间序列进行重构,恢复网络流量的演化轨迹,采用非线性预测能力强的最小二乘支持向量机对网络流量时间序列进行训练建模,采用混沌粒子群算法对最小二乘支持向量机参数进行优化,从而获得最优网络流量预测模型。用实际网络流量数据对该算法有效性进行验证,结果表明该方法能够很好刻画网络流量的变化趋势,提高了网络流量的预测精度,预测性能优于传统的预测方法。     

基于粒子群最小二乘支持向量机的水文预测

支持向量机理论为研究中长期水文预测提供了新的方法。针对最小二乘支持向量机模型参数选择费时且效果差这一问题,给出基于粒子群算法的最小二乘支持向量机水文预测模型(PSO-LSSVM)。该模型运用最小二乘支持向量机回归原理建立,参数选取采用具有全局搜索能力的粒子群算法进行寻优。用此模型对南桠河冶勒水电站月径流进行预测,仿真计算结果表明,该算法可提高预测效率与预测精度。     

基于粒子群算法的煤气化过程LS_SVM预测模型

针对最小二乘支持向量机参数选择对模型性能的重要影响,并且以往的参数优选方法效果差且耗时长这一问题,提出基于粒子群算法优化最小二乘支持向量机预测模型.该模型用最小二乘支持向量机理论建立,用粒子群算法优化模型参数.论文将此模型用于预测评价固定床煤气化气化效果的三个主要性能指标(气体热值、气化效率、气体产率),通过现场实际数据仿真结果表明,该算法有效地提高了模型预测精度,验证了此模型的可靠性和可用性.     

基于改进PSO优化LSSVM的MEMS陀螺随机漂移预测

提出一种基于改进粒子群算法（PSO）优化最小二乘支持向量机（LSSVM）的MEMS陀螺随机漂移的预测模型建立方法。该方法首先应用最小二乘支持向量机对MEMS陀螺随机漂移建立预测模型,然后应用改进粒子群算法对该模型进行优化,最后应用参数优化后的LSSVM预测模型对随机漂移进行预测。该方法不仅解决了支持向量机训练速度慢和所需计算资源多的问题,而且文中提出的改进的惯性权值递减策略使PSO算法在全局或局部搜索能力上的侧重具有更好的适应度。实验结果表明,该预测模型可以有效地进行陀螺随机漂移的预测,且预测效果优于基本PSO优化的最小二乘支持向量机。     

高斯-柯西变异算子优化的LSSVM模型研究

论文针对标准量子粒子群算法易陷入局部极值的问题,提出一种改进的量子粒子优化最小二乘支持向量机的方法。利用高斯变异数的局部开发能力以及柯西变异数的全局搜索能力,在量子粒子群优化算法中,引入高斯-柯西变异算子,帮助算法跳出局部极值。并利用该优化模型进行光伏发电量预测实验,对优化的最小二乘支持向量机模型的预测结果与其他模型预测结果进行比较,结果表明:基于高斯-柯西变异算子的量子粒子群优化的最小二乘支持向量机对光伏发电量的预测具备较好的收敛速度和跳出局部收敛困境的能力。     

基于改进PSO优化LSSVM的传感器补偿研究

针对最小二乘支持向量机在对传感器进行补偿时,正则化参数和核函数参数对补偿精度影响较大的问题,提出一种利用改进的粒子群优化算法优化最小二乘支持向量机模型参数的传感器补偿方法。该方法利用改进的粒子群优化算法优化最小二乘支持向量机模型的正则化参数和核函数参数,避免了人工选择参数的盲目性,提高了最小二乘支持向量机模型的预测精度。仿真实验表明,在传感器的补偿时,该方法比最小二乘支持向量机模型的补偿精度更高。     

多元宇宙优化算法优化WLSSVM的网络流量预测

高精度网络流量预测可以帮助管理人员了解网络流量变化态势,提高网络系统的稳定性,为了降低网络流量预测的误差,提出了基于多元宇宙优化算法优化加权最小二乘支持向量机的网络流量预测模型。首先采用网络流量历史数据,将其作为加权最小二乘支持向量机的输入向量,然后利用多元宇宙优化算法对加权最小二乘支持向量机参数寻优,从而得到最优的网络流量预测模型,最后采用具体网络流量预测应用实例对模型性能进行测试与分析,结果表明本模型可以准确描述网络流量的变化规律,预测误差很小,完全能够满足网络管理实际要求,相对于其他预测模型,本模型的网络流量预测精度得到了有效提高。     

基于粒子群优化的最小二乘支持向量机税收预测模型研究

针对税收收入预测存在着非线性、不稳定性和多经济因素影响的复杂性,提出用最小二乘支持向量回归机的方法对广东省从化市的税收收入进行预测,并建立数学模型。由于模型中的参数C和σ²直接影响支持向量机的预测效果,因此巧妙地融合了粒子群优化算法的思想,采用粒子群算法对参数进行寻优来确保预测模型的精确性和稳定性。仿真实验结果表明,相对于各参比模型,用粒子群算法对参数进行寻优的最小二乘支持向量回归机的预测精度有了显著提高,从而说明了该模型的有效性和实用性。     

基于改进PSO算法和LS-SVM的短期电力负荷预测

针对电力负荷的小样本、非线性、高维数和局部极小点等问题,提出采用最小二乘支持向量机方法建模,以历史负荷、温度、湿度等数据作为输入量,对短期电力负荷进行预测;针对最小二乘支持向量机在建模中存在的参数选取问题,采用一种根据种群多样性信息来指导初始种群选取和避免粒子早熟收敛现象的改进粒子群优化算法来优化最小二乘支持向量机的惩罚因子和核参数。仿真结果表明,基于改进粒子群优化算法和最小二乘支持向量机的短期电力负荷预测方法较最小二乘支持向量机预测方法、基于基本粒子群优化算法和最小二乘向量机的预测方法具有更好的预测精确度。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate