基于长短期记忆神经网络的短期负荷预测

准确的电力负荷预测是电力系统安全、稳定、经济、优质运行的前提,负荷预测的本质是通过历史数据对未来负荷情况做出预先估计。电量的快速增长和用户的多元化对负荷预测提出了更高的要求。文中提出了一种基于长短期记忆网络的负荷预测方法,利用长短期网络数据驱动和对时间序列建模强的特点,对于含非线性、不确定性的系统,提取其负荷数据中的周期特征,具有较强的自适应性。以真实数据为算例,验证了方法的有效性。     

基于SAS软件的城市电力需求ARIMA模型及预测

城市年度电能消耗数据既有随机成分,又有较明显的内在规律。科学预测城市电力需求,是一项重要的基础性工作,需要有一种较为简易又有足够精度的预测方法。从紧贴实际和易于检验出发,以常州市1995~2004年度的全社会用电量作为时间序列,用求和自回归移动平均(ARIMA)乘积模型建模,并做出1年期电能消耗预测。将预测结果和2005年1~12月的实际用电量进行对比,预测结果令人满意,表明该类模型可以用于城市电力需求中期预测。     

飞机战伤抢修备件需求预测方法研究

针对飞机战伤抢修备件需求预测模型存在的强非线性,利用RBF网络的参数自调节性和能以任意精度逼近任意非线性系统的特性,提出了飞机战伤抢修备件需求的RBF网络预测方法。仿真实验结果表明,基于RBF网络的飞机战伤抢修备件需求预测模型具有较强的自适应性和较高的计算精度,将其用于预测飞机战伤抢修备件需求是完全可行和行之有效的。     

基于直觉模糊推理的态势预测方法

在作战辅助决策系统中,针对战场态势预测问题,提出一种基于直觉模糊推理的战场态势综合预测方法.分析了当前态势预测方法的特点与不足;建立了直觉模糊推理规则,设计了推理合成算法和解模糊算法,检验了推理规则的完备性,并引入态势指标的权重向量;最后通过态势预测中的一个具体仿真实例验证了该方法的有效性与合理性.     

适应频繁波动特点的移动话务量预测系统

移动通信话务量的时间序列具有较强的非线性和随机性，易受各种突发情况的影响。特别是在有频繁剧烈变动的情况下，很难用传统的预测方法进行预测。本文根据移动通信话务量的这一特点，采用分解及建模的方法，对话务量进行综合预测，经实践可以达到更好的效果。     

基于T-S模糊模型的非线性系统状态估计

现实世界中的动力系统大多是非线性的,而非线性系统的状态估计方法目前主要有扩展卡尔曼滤波,无味滤波,粒子滤波等,但它们对于非线性程度很高的系统滤波结果不是很理想。若用模糊规则模型去逼近非线性系统,基于规则理论去寻求状态的估计,则估计性能能够得到较大的改善。将模糊推理理论与Kalman滤波结合,用线性的方法逼近非线性模型,提出一种对非线性系统目标状态估计的新方法,给出了具体的处理过程,仿真实验支持理论结果     

小波去噪和神经网络在电力负荷预测中的应用研究

为了降低历史负荷数据噪声对负荷预测的影响,提高电力负荷的预测精度,提出了一种基于小波去噪和BP神经网络的电力负荷预测方法。首先,对所得电力负荷数据进行了小波变换去噪处理,有效去除了噪声,然后利用BP神经网络在非线性处理中的优异特性,对小波去噪后的电力负荷进行了BP神经网络建模训练及仿真。实验结果表明:相比于其他电力负荷模型,该方法可以有效提高电力负荷的预测精度,是一种有效的电力负荷预测方法。     

混沌信号的相空间重构和预测方法研究

基于复杂非线性系统的相空间重构理论和神经网络本质为非线性映射关系的特点,提出利用混沌时间序列重构相空间和BP神经网络构建其预测模型的方法。利用该方法对典型的Lorenz混沌时间序列进行了空间重构,研究了预测模型的预测效果,结果表明单步预测效果理想,多步预测在50步以内也能取得较小的预测误差,证明了混沌信号不同于随机噪声,具有短期可预测、长期不可预测的特征。该方法为具有混沌特性的时间序列如心电信号、电力负荷等预测模型的建立提供了理论基础。     

基于ANFIS的电气火灾预测模型

对电气火灾进行精确的预测是保证工业安全生产的重要手段。提出ANFIS(自适应神经模糊推理系统)预测模型,通过BP算法和最小二乘估计法(LSE)的混合算法来进行学习,来调整系统的前件和后件参数。以徐州特气某一办公楼层的实测数据为例进行算例分析,其中在形成初始模糊推理系统结构时,采用的算法是减法聚类,该算法有效地避免了人工设定结构法产生的组合爆炸问题。引入一阶Sugeno模糊模型,该算法有效解决了平滑地改变线性增益及非线性建模问题。最后将预测结果与真实值对比,利用MTALB仿真工具进行误差分析,结果表明鲁棒性较高,进一步说明了ANFIS预测模型的有效性。     

基于复合模型的智能化移动通信话务预测

移动通信话务量作为一种时间序列,具有较强的非线性和随机性,而且易受节假日、旅游等客户行为及天气等其它因素的影响。尤其是话务量长期的发展变化,很难用传统的预测方法进行预测。根据移动通信话务量自身特点,采用复合模型,将话务量分为平稳期趋势分量、平稳期周期分量、节假日话务量,用综合评判的分段一元线性回归及模板匹配算法分别对趋势分量、周期分量和节假日话务进行建模。最后,开发了基于复合模型的智能化预测系统,在广东省某市试运行的结果表明：基于复合模型的预测方法比传统预测方法精度高。     

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.     

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.     

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.     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks