Hybrid analytical resolution approach based on ambiguity function for attitude determination

When satellite navigation receivers are equipped with multiple antennas, they can deliver attitude information. In previous researches, carrier phase differencing measurement equations were built in the earth-centered, earth-fixed （ECEF） coordinate, and attitude angles could be obtained through the rotation matrix between the body frame （BF） and the local level frame （LLF）. Different from the conventional methods, a hybrid algorithm is presented to resolve attitude parameters utilizing the single differencing （SD） carrier phase equations established in LLF. Assuming that the cycle integer ambiguity is known, the measurement equations have attitude analytical resolutions by using simultaneous single difference equations for two in-view satellites. In addition, the algorithm is capable of reducing the search integer space into countable 2D discrete points and the ambiguity function method （AFM） resolves the ambiguity function within the analytical solutions space. In the case of frequency division multiple access （FDMA） for the Russian Global Orbiting Navigation Satellite System （GLONASS）, a receiver clock bias estimation is employed to evaluate its carrier phase. An evaluating variable and a weighted factor are introduced to assess the integer ambiguity initialization. By static and dynamic ground experiments, the results show that the proposed approach is effective, with enough accuracy and low computation. It can satisfy attitude determination in cases of GPS alone and combined with GLONASS.     

A novel algorithm for Ethernet-passive-optical-network dynamic bandwidth allocation based on threshold

The Ethernet passive optical network (EPON) is the next generation of broad-band network technique. A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units (ONUs). This article provides a novel dynamic bandwidth allocation algorithm, i.e. threshold dynamic bandwidth allocation (TDBA), which is based on adaptive threshold, to increase resource utilization. The algorithm uses ONU data-transmitting rate to adjust optical line terminal (OLT) receiving data threshold from an ONU. Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a 10G EPON system.     

Distributed localization algorithm for wireless sensor network based on multidimensional scaling and the shortest path distance correction

Sensor localization is crucial for the configuration and applications of wireless sensor network (WSN). A novel distributed localization algorithm, MDS-DC was proposed for wireless sensor network based on multidimensional scaling (MDS) and the shortest path distance correction. In MDS-DC, several local positioning regions with reasonable distribution were firstly constructed by an adaptive search algorithm, which ensures the mergence between the local relative maps of the adjacent local position regions and can reduce the number of common nodes in the network. Then, based on the relationships between the estimated distances and actual distances of anchors, the distance estimation vectors of sensors around anchors were corrected in each local positioning region. During the computations of the local relative coordinates, an iterative process, which is the combination of classical MDS algorithm and SMACOF algorithm, was applied. Finally, the global relative positions or absolute positions of sensors were obtained through merging the relative maps of all local positioning regions. Simulation results show that MDS-DC has better performances in positioning precision, energy efficiency and robustness to range error, which can meet the requirements of applications for sensor localization in WSN.     

A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks

To extract the maximum power from a photovoltaic （PV） energy system, the real-time maximum power point （MPP） of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller （FNNC）, which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the filzzy logic control algorithm.     

A new optimization algorithm based on chaos

INTRODUCTION Chaos (Wang et al., 2002) is a common nonlin- ear phenomenon, whose action is complex and similar to that of randomness. The characteristics of chaos being highly sensitive to the initial value of chaos make a world of differences due to the ergodic prop- erty of the phase space—chaos can go through all states in certain ranges without repetition; the inher- ent randomness of the system—means that chaos behavior is similar to randomness which is disorderly; but at the same t…     

项目驱动教学在综合布线实训教学中的应用与实践

以网络技术专业综合布线实训课程为例,通过综合布线课程实训教学改革,体现＂学生为主体,教师为主导＂的教学模式,给学生一个真实的实训情境,探索如何对学生进行专业岗位技能培训,让学生尽快掌握、熟练综合布线的各项基本技能。     

基于VB语言的粒子群优化算法描述

粒子群优化算法是基于群智能的随机优化算法,目前已广泛应用于神经网络、非线性函数优化、模式分类、模糊系统控制等,特别适合工程应用。本文首先介绍传统的PSO算法原理及算法流程,最后用VB语言实现算法的伪码。     

基于自适应预测算法的APF无差拍控制方法

有源电力滤波器（active power filter, APF）补偿电流跟踪控制要求具有较高的稳态精度和较快的动态响应速度。文章将自适应预测滤波算法应用于无差拍控制,实现APF补偿电流精确控制。根据APF时域数学模型,推导滤波系统的无差拍控制离散方程;通过自适应(finite impulse response filter, FIR)预测滤波算法实现基波电流预测,消除控制系统的计算延迟,给无差拍控制提供所需的指令电流预测值。对预测算法进行MATLAB仿真,验证预测算法的稳态精度和动态跟踪快速性;实验室样机验证控制实验结果证明所提出的控制策略有效的,具有一定的实用性。     

SSABC:一种基于能力的超级节点选择算法

结合P2P和网格的特点,提出了从P2P与网格混合的分布式网络中选择超级节点的算法SSABC．算法使用网格信息监控系统（MDS）获取节点资源的动态属性信息,如可用带宽、空闲CPU、可用内存、当前连接数及在线时间等,根据以上属性计算节点的能力．当有新节点加入且超级节点均饱和时,从新节点或已加入节点中选择能力最高的作为新的超级节点．通过理论分析和仿真实验表明,基于能力选择的超级节点与随机选择的超级节点相比,提高了资源的查询成功率,缩短了平均查询跳数,并能够在超级节点饱和时均衡网络负载．当网络中节点数发生变化时,以上结论依然成立,说明了算法的可行性和稳定性．     

一种新颖的基于FGS的发射能量最小化算法

1Introduction Inamobilecommunicationsystem,themobile phoneusesabatterytosupplyenergy.Sincethebat teryenergyislimited,minimizationofenergycon sumedinprocessingandtransmission[1]inmultimedia communicationbecomesanimportantconsideration.Hereweconsidertransmissionenergy.Twofactors areconcernedwithtransmissionenergy,i.e.,trans missionpowerandtransmissiontime,theformeris basedonchannelcharacteristicandconsumerrequire ments,whilethelatterisdecidedbythenumberof bits.Researchonthesetwotopicshasreceive…     

烟草物流配送中心各部门绩效评价构建研究——基于Fuzzy-AHP的分析

烟草物流配送中心部门绩效评价是衡量烟草物流中心各部门业务实施效果,促进物流配送中心持续改进的重要手段。文章针对烟草物流配送中心绩效评价现有研究的不足,在已有的烟草行业标准的基础上,对烟草物流配送中心各部门的绩效评价体系进行构建,并引入三角模糊数概念,提出了基于Fuzzy-AHP的烟草物流配送中心部门绩效评价的评价模型。案例分析表明,该方法科学合理且操作性强。     

基于一个新核函数的半定规划的内点算法的复杂性分析

Interior-point methods （IPMs） for linear optimization （LO） and semidefinite optimization （SDO） have become a hot area in mathematical programming in the last decades. In this paper, a new kernel function with simple algebraic expression is proposed. Based on this kernel function, a primal-dual interior-point methods （IPMs） for semidefinite optimization （SDO） is designed. And the iteration complexity of the algorithm as O（n^3/4 log n/ε） with large-updates is established. The resulting bound is better than the classical kernel function, with its iteration complexity O（n log n/ε） in large-updates case.     

Science Letters:A power divider based on a new kind of composite right/left-handed transmission line (CRLH TL) unit

INTRODUCTION Wave propagation in a material with negative magnetic permeability and negative electric permit- tivity was first theoretically analyzed by Veselago (1968). In such a left-handed material (LHM), the electric field E, the magnetic field H and the wave vector k of electromagnetic wave propagation obey the left-hand rule (instead of the right-hand rule for usual materials). After Smith et al.(2000) demon- strated simultaneously negative permeability and permittivity, using cop…     

Implementing a teaching approach based on the multiple intelligence theory in a South African school: A case study

Abstract

This article reports on the implementation of a teaching approach based on Gardner's theory of multiple intelligences (MI) at a school in the Hammanskraal area in Gauteng, South Africa. The aim was to determine the impact that such an approach would have on teachers, learners and learner performance. This article discusses the implementation process and the impact thereof on learner results and conduct, as well as learners' opinion on the implementation of the MI approach in the classroom. The study showed that the implementation of a new approach should be monitored regularly and that teachers should receive ample support. An MI approach to teaching had a positive influence on learners' conduct and academic achievement. It also made learners more aware of their own strengths and weaknesses and how to overcome weaknesses. Learners indicated that they prefer an MI approach in teaching.