基于BWAS的无线传感器网络静态分簇路由算法

为提高路径搜索效率,避免动态分簇较多的能量消耗,提出了基于最优-最差蚂蚁系统(BWAS)的无线传感器网络静态分簇路由算法。BWAS是对蚁群算法的改进,在路径搜寻过程中评价出最优最差蚂蚁,引入奖惩机制,加快了路径搜索速度。通过无线传感器网络静态分簇、簇内动态选举簇头,在簇头节点间运用BWAS算法搜寻从簇头节点到汇聚节点的多跳最优路径,能减少路径寻优能量消耗,实现均衡能量管理,延长网络寿命,且具有较强的鲁棒性。通过与基于BWAS的动态分簇和基于蚁群算法的动态分簇路由的仿真实验相比较,证实了本算法的有效性。

大规模无线传感器网络中近似静态分簇的高效概率覆盖协议

为在大规模无线传感器网络中获得较好的网络性能,提出一种基于近似静态分簇的高效概率覆盖协议EPCSC.该协议通过近似静态分簇节省网络资源,保持网络连通性.根据网络QoS期望值选择必需节点数目来保证网络服务质量,实行簇头轮换机制,并在簇头间构建近似Prim最小生成树来有效延长网络生命期.仿真结果表明,EPCSC协议能有效降低控制开销,显著延长网络生命期,提供满足应用期望的网络服务质量.

配弹簧机构SF_6断路器静态分闸速度计算与分析

本文第一个提出了配弹簧机构SF_6断路器静态分闸速度计算公式,并与实测值进行比较,二者基本吻合。因而表明所提出的公式具有普遍意义和工程实用价值。本文对配优化改进的CT6—XG弹簧机构的126kV级户外高压SF_6断路器的设计原则,结构简介,型式试验等全过程作了较为详细的阐述。

静态分簇下的大规模分布式天线系统用户调度算法

在大规模分布式天线系统中,静态分簇和用户调度带来的簇间干扰问题会导致系统和速率下降。针对这个问题,提出了一种两阶段贪婪用户调度算法。首先,每个簇内并行实施贪婪用户调度;然后,从全局上再次利用贪婪算法来剔除簇间干扰较大、服务质量较差的用户,使得系统和速率进一步提升。仿真结果表明,随着不同系统参数的改变,两阶段贪婪用户调度算法可有效提高系统和速率。

基于静态分簇的LEACH算法改进研究

LEACH算法是为满足高效节能需要而提出的一种典型的分簇协议。在此基础上,提出了一种改进算法:主要体现在在网络开始工作时使用静态分簇,以簇为单位进行簇内节点轮换当选为簇首,簇间以及簇与基站间的通讯采用单跳与多跳结合的方式。最后使用NS2对LEACH算法和改进的算法进行仿真对比,证实了改进后的算法在与LEACH算法相比性能有了很大的提高。

一种抗干扰半静态分簇路由算法

针对无线传感器网络(WSNs)分簇路由算法中的能量洞、热点和抗干扰问题,设计一种抗干扰半静态分簇(AISSC)路由算法,给无线传感器网络提供能量多、距离短、链路质量好的路径来传输数据。该算法利用节点定位获取节点地理位置,综合考虑传感器节点剩余能量和干扰信噪比,通过节点距离度量、节点聚簇、簇间融合、簇头选举和簇头轮换五个步骤进行无线传感器网络节点的分簇。仿真结果表明:这种路由算法可以提高无线传感器网络通信链路质量,均衡网络能量消耗。

基于簇间干扰消除的静态基站协作策略

在分析了上行链路静态分簇基站协作策略及动态分簇基站协作策略的基础上，提出了一种基于簇间干扰消除的静态基站协作策略。运用此策略时，协作基站采用线性波束成型或连续干扰消除技术，对邻簇的边缘用户进行干扰抑制，有效地消除簇间干扰；对簇内用户采用线性波束成型，抑制簇内多用户间的干扰。仿真表明，此策略性能优于单小区处理策略和静态分簇策略，在某些情况下甚至超出动态分簇策略，有效地消除了小区间干扰，改善了用户公平性，提高了频谱效率，同时减少了动态分簇策略所需的算法复杂度。

认知无线电对电磁频谱管理的挑战

认知无线电技术使得动态频谱管理成为可能,动态频谱管理是对以往静态频谱管理策略的根本改变。基于认知无线电技术的动态频谱管理虽然短期内仍无法大规模实现,但是有步骤、有计划地开放部分频段进行动态频谱接入试验,仍然是行业发展的大势所趋。电磁频谱管理部门是空中电波秩序的维护者,同时参与电磁频谱规划、电磁频谱规则制定,更是新兴技术的引路人与监管者。当认知无线电技术促使电磁频谱管理从静态分配向动态管理过渡时。

Static and dynamic collaborative optimization of ship hull structure

The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-level optimization model, a new objective function was advised, integrating all the subsystem-levels＇ objective functions, so as to eliminate the effects of dimensions and magnitude order. The proposed CO architecture enabled multi-objectives of the system and subsystem-level to be considered at both levels during optimization. A bi-level optimization strategy was advised, using the multi-island genetic algorithm. The proposed model was demonstrated with a deck optimization problem of container ship stern. The analysis progress and results of example show that the CO strategy is not only feasible and reliable, but also well suited for use in actual optimization problems of ship design.

无线传感器网络中低速移动的单目标数据融合研究

为了提高数据融合效率,减少无线传感器网络节点能量消耗,提出一种静、动态分簇技术相结合的网络策略。它克服了传统单独静态分簇、动态分簇的不足,通过对簇头选举及检测目标坏境等参数进行分析比较,可以减小网络跳数、减少数据传输量,同时也实现了能量均衡利用,延长网络生命周期。在单目标低速移动状态下,其网络数据融合性能达到最佳。

Total Dose Radiation Hardened PDSOI CMOS 64k SRAMs

The first domestic 1×10^6rad（Si） total dose hardened 1.2μm partially depleted silicon-on-insulator （PDSOI） 64k SRAM fabricated in SIMOX is demonstrated.The address access time is independent of temperature from -55 to 125℃ and independent of radiation up to 1×10^6rad（Si） for the supply voltage VDD.The standby current is 0.65μA before the total dose of radiation and is only 0.80mA after radiation exposure,which is much better than the specified 10mA.The operating power supply current is 33.0mA before and only 38.1mA afterward,which is much better than the specified 100mA.

Design of Stubble-breaking Ditching Colter Based on SolidWorks and Its Strength Analysis

Stubble-breaking device is a key working part of no-tillage seeder in stub land,and directly affects planting quality of seeder.Based on the current domestic used stubble-breaking device,a new kind of stubble-breaking ditching colter was designed.To study its strength property and reduce trouble in work,the three-dimensional model of stubble-breaking ditching colter was established based on SolidWorks.By using Cosmos,it was carried out the finite element analysis.The distortion and stress of stubble-breaking ditching colter in work were obtained,and the weak link of strength was found.The result showed that the maximum stress of stubble-breaking ditching colter was 5.862×108 N/m2,and the maximum twisted displacement was 2.648 mm.The stubble-breaking ditching colter was carried out improved design.Based on Cosmos,the static analysis was carried out.It showed that the strength and rigidity of improved stubble-breaking ditching colter were obviously improved.The research provided reference basis for optimal design of the stubble-breaking ditching colter.

Effects of static magnetic fields on melt flow in detached solidification

A series of three-dimensional numerical computations were conducted to understand the effects of different static magnetic fields on thermal fluctuation and melt flow during the detached solidification of CdZnTe. Numerical calculations were carried out by three different configurations of magnetic field: without magnetic field, with an axial magnetic field (AMF) and with a cusp-shaped magnetic field (CMF). The results reveal that the magnetic fields can effectively suppress the melt flow and thermal fluctuation and the suppression effect of the AMF is stronger than that of the CMF. Besides, the physical mechanism of thermocapillary?buoyancy convection instability was discussed and the effects of magnetic field on the critical Marangoni number were also obtained.

Traffic-aware static channel assignment algorithm in wireless mesh networks

A channel assignment algorithm with awareness of link traffic is proposed in multi-radio multi-channel wireless mesh networks. First, the physical interference model based on the signal-to-interference-plus-noise ratio and successful transmission condition is described. The model is more suitable for a wireless communication environment than other existing models. Secondly, a pure integer quadratic programming （PIQP） model is used to solve the channel assignment problem and improve the capacity of wireless mesh networks. Consequently, a traffic- aware static channel assignment algorithm（TASC） is designed. The algorithm adopts some network parameters, including the network connectivity, the limitation of the number of radios and the successful transmission conditions in wireless communications. The TASC algorithm can diminish network interference and increase the efficiency of channel assignment while keeping the connectivity of the network. Finally, the feasibility and effectivity of the channel assignment solution are illustrated by the simulation results. Compared witb similar algorithms, the proposed algorithm can increase the capacity of WMNs.

分月静态调节响应K系数对华东电网CPS指标影响及应用前景

通过分月静态调节响应K系数对华东电网用年K系数CPS考核指标影响的对比分析,得出使用分月K系数既能体现电网运行的经济性,同时又能更公平、合理地反映和评价省市的联络线控制策略的结论,应用前景广阔。

Static analysis of synchronism deployable antenna

A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This an-tenna consists of tetrahedral elements from central element. Because there are springs at the ends of some of the rods, spider joints are applied. For analysis purpose, the structure is simplified and modelled by using 2D beam elements that have no bending stiffness. Displacement vectors are defined to include two translational displacements and one torsional displacement. The stiff-ness matrix derived by this method is relatively simple and well defined. The analysis results generated by using software de-veloped by our research group agreed very well with available test data.

Pseudo-static analysis of cantilever retaining walls using upper bound limit analysis approach

Given the extensive utilization of cantilever retaining walls in construction and development projects,their optimal design and analysis with proper attention to seismic loads is a typical engineering problem.This research presents a new algorithm for pseudo-static analysis of retaining walls employing upper bound method.The algorithm can be utilized to design and check the external and internal stability of the wall based on the proposed mechanism.One of the main features of this algorithm is its ability to determine the critical condition of failure wedges,the minimum safety factor and maximum force acting on the wall,as well as the minimum weight of the wall,simultaneously,by effectively using the multi-objective optimization.The results obtained by the proposed failure mechanisms show that,while using the upper bound limit analysis approach,the active force should be maximized concurrent with optimizing the direction of the plane passing through the back of the heel.The present study also applies the proposed algorithm to determine the critical direction of the earthquake acceleration coefficient.The critical direction of earthquake acceleration coefficient is defined as the direction that maximizes the active force exerted on the wall and minimizes the safety factor for wall stability.The results obtained in this study are in good agreement with those of similar studies carried out based on the limit equilibrium method and finite element analysis.The critical failure mechanisms were determined via optimization with genetic algorithm.

Kineto-static analysis of a novel high-speed parallel manipulator with rigid-flexible coupled links

A novel high-speed parallel kinematic machine （PKM） named Delta-S parallel manipulator is proposed, which consists of a fixed base connected to a moving platform through three limbs with identical topology. Each limb is composed of one driving ann and one follower arm, herein, the latter includes two strings and one middle rod, all located in a same plane. Compared with similar manipulators with uniform parameters, the novel and unique topology as well as the addition of two strings of Delta-S manipulator can remove the clearance of the spherical joints, reduce the inertial load of components further, improve the positioning accuracy and dynamic performance, and so on. In order to formulate the kineto-static model of Delta-S manipulator, the kineto-static analyses and models of the driving arm, the generalized follower and the moving platform can be carried out by the D＇ALEMBERT principle. For the sake of obtaining the force analytic results of strings, the deformation compatibility condition of strings and the middle rod are determined. Furthermore, in virtue of the assumption of small deformation and the linear superposition principle, the minimal pre-tightening force of the strings is calculated. The main results include that the loads of the strings and the middle rod must be larger than ＂zero＂ and the pre-tightening force over the workspace must be larger than the minimal pre-tightening force at any time within the workspace, which lay the foundation for the dynamic analysis and the prototype manufacture of the Delta-S manipulator.

Elastic-plastic study on high building with SRC transferring story

A new type of transferring structure for steel reinforced concrete (SRC) beams is used in high building. The pushover analysis method was used to study the failure mechanism and ductility of SRC transferring structure through consulting pseudo-static test results for the structure. And, the occurrence order and position of the plastic hinge, the weak story and seismic capacity of high building with SRC transferring story were also studied through consulting shaking table test results for the high building, showing that the seismic behavior of high building with SRC transferring story is good.

Dynamic-static coupling analysis on rockburst mechanism in jointed rock mass

A numerical code called RFPA-Dynamics was used to study the rockburst mechanism under dynamic load based on coupled static-dynamic analysis.The results show that dynamic disturbance has a very distinct triggering effect on rockburst.Under the dynamic load,rockburst is motivated by tensile stress formed by the overlapping of dynamic waves in the form of instantaneous open and cutting through of cracks in weak planes and pre-damaged areas.Meanwhile,the orientation of joint sets has an obvious leading effect on rockburst locations.Finally,a higher initial static stress state before dynamic loading can cause more pre-damaged area,thus leading to a larger rockburst scope.