变参数QPSO算法优化神经网络的短期电力负荷预测

为了提高电力负荷预测精度,提出了一种变参数量子粒子群(VPQPSO)算法优化RBF神经网络的短期负荷预测模型(VPQPSO-RBFNN)。首先利用电力负荷的混沌性,对短期负荷时间序列进行相空间重构;然后采用变参数QPSO算法优化RBF神经网络参数对重构后的短期负荷时间序列进行学习,建立短期电力负荷最优预测模型;最后采用对某地区短期电力负荷进行预测。VPQPSO-RBFNN可以准确描述复杂多变的电力负荷变化趋势,提高了电力负荷的预测精度,仿真结果验证了VPQPSO-RBFNN可以用于电力系统负荷预测。     

基于联想神经网络算法的电力系统负荷预测

基于神经网络可以模仿人脑进行智能化信息处理,对大量非结构性、非确定性规律具有自适应功能,将人工神经网络的预测原理应用于电力系统负荷预测中。分析了负荷预测的基本概念,以及基于神经网络的预测原理中正向和逆向建模的基本结构,研究了联想神经网络优化算法。设计了电力系统负荷预测模型,并对系统进行仿真测试,试验结果表明,基于联想神经网络优化算法的电力系统负荷预测具有提高预测精度的效果。     

基于粒子群优化方法的短期电力负荷组合预测

短期电力负荷预测是实现电力系统安全、经济运行的基础,其准确性对电力系统运行的可靠性、经济性都有重要意义。本文在灰色模型、ARIMA模型以及指数平滑族模型的基础上,提出了一种基于以上三种模型的组合预测模型,并用粒子群优化算法对其组合权重系数进行了优化。对澳大利亚新南威尔士州2011年9月实际电力负荷数据进行实例分析,其结果表明本文提出的组合模型确实能够提高短期电力负荷预测的精度。     

电网负荷预测中组合预测模型运用

在电力系统规划设计中,电力系统负荷预测是进行规划设计工作的基础。负荷预测的准确性和负荷分布情况,对电源规划和电网规划具有很大的影响。在电力市场化的发展过程中,产业结构的变化和技术进步使得电力消耗发生了变化,因此在对电网负荷进行预测的过程中,使用单项预测模型已经不足以满足要求。本文主要阐述了组合预测模型在实际运用过程中其主要的结构特点,同时结合四川某城市以及对我国社会用电量电网负荷预测过程中对组合预测模型的实际使用案例,对组合预测模型能够很大的提高负荷预测精度进行验证。望能够为电网的负荷预测积攒有效参考资料。     

基于支持向量机的负荷非线性组合预测研究

短期负荷预测是电力系统调度管理部门制定开停机计划及在线安全分析的基础,为了提高电力行业经济效益和社会效益,精确的负荷预测是最重要的工作内容。近年来的研究表明,组合预测比单项预测具有更高的精度。为了提高短期负荷的预测精度,提出一种基于支持向量机的负荷非线性组合预测方法,并与BP神经网络组合预测相比较,测试结果表明了该方法的有效性与优越性。     

天气因素在短期电力负荷预测中的应用

为了更有效地提高地区电网短期负荷预测的精度,提出基于BP人工神经网络原理,利用神经网络高度非线性建模能力,根据电力系统短期负荷变化的特性,建立了既反映电力系统负荷连续性、周期性及其负荷变化趋势,又包含天气因素变化对系统负荷影响的天气因素敏感模型,并对岳阳地区短期负荷进行预测,预测结果表明天气因素应用于电力系统短期负荷预测后使预测精度明显提高,故这种方法是可行和有效的。     

基于SFO-GRU模型的短期负荷预测

为提高短期负荷预测精度,提出一种基于旗鱼优化算法(SFO)和GRU神经网络的短期负荷预测模型.通过使用负荷、气象等真实数据对GRU神经网络的权重参数进行训练并建立GRU预测模型,同时采用旗鱼优化算法(SFO)优化GRU模型的迭代次数、学习率和隐藏层神经元数量,仿真实验结果表明,与BP、LSTM等经典预测模型相比,SFO...     

基于生物免疫优化支持向量机算法的居民区负荷预测

针对居民区用电负荷随机性强、稳定性差等问题,综合考虑各因素对居民用电负荷的影响,提出一种免疫支持向量机(support vector machine,SVM)算法负荷预测模型。以居民区历史用电量及相关气候数据为处理对象,使用PCA(principal component analysis)算法对电网历史数据进行处理,并结合免疫算法对电网历史数据进行预处理,形成数据簇并划定标签提供给预测模型进行训练。为提高模型精度,采用生物免疫优化算法对SVM模型参数进行优化,并在负荷预测环节,将预测误差作为调优依据,对预测模型进行反馈调优。将预测效果与常用于负荷预测的BP(back propagation)神经网络、SVM算法模型进行对比,免疫SVM算法负荷预测模型的短期、中期预测精准度均在98%以上,具有较好的精度与鲁棒性。     

基于CEEMD-ITSA-BiLSTM组合模型的短期负荷预测

准确预测电力系统短期负荷有助于灵活规划系统资源、合理安排机组工作调度以及提高系统运行效率。针对负荷预测精度问题,文中提出了一种基于CEEMD-ITSA-BiLSTM(Complete Ensemble Empirical Mode Decomposition-Improved Tunicate Swarm Algorithm-Bidirectional Long Short-Term Memory)的短期负荷预测模型。对时序性负荷数据进行CEEMD分解,得到若干个平稳的IMF(Intrinsic Mode Function),并对每个IMF进行BiLSTM建模预测。为了提高BiLSTM的精度,采用ITSA算法对BiLSTM的隐含层节点数、学习率和训练次数等超参数进行参数寻优,建立CEEMD-ITSA-BiLSTM负荷预测模型。文中以实际负荷数据进行仿真实验,对比了单一BiLSTM和不同算法优化的BiLSTM模型,结果表明CEEMD-ITSA-BiLSTM模型的RMSE(Root Mean Square Error)、MAE(Mean Absolute Error)和MAPE(Mean ...     

基于灰色神经网络的厦门市商品房需求量研究

介绍了灰色预测模型GM（1,1）的结构和模型检验,以及BP神经网络预测模型的原理,对灰色预测模型进行改良,将此改良模型与BP神经网络模型进行组合,建立了新的组合灰色神经网络模型。以厦门市商品房成交量为例,以MATLAB为工具,进行2012年的成交量对比以及2013年成交量的预测,结果证明组合灰色神经网络的预测精度较高,可以为房地产价格指数预测研究提供参考依据。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.