企业税务安排初探

企业税务安排初探厦门大学肖建林，龚光明随着社会主义市场经济体制的确立和经济体制改革的深化，税收对企业的影响越来越大。因此，企业如何通过合理、有效的税务安排，以便减轻、延缓企业的税收负担，是企业管理部门、特别是财务部门的一项重大课题。本文拟对企业税务安..

Techniques and Applications in Wireless Mesh Networks

无线网状网(WMNs)由网状路由器节点和客户机节点组成,其中的网状路由器节点组成了无线网状网的网络骨干,其移动性很小。他们一起为无线网状网和其他常规无线网络的客户机节点提供网络的无线接入。WMNs技术结合了中心式控制的蜂窝网与分布式控制的无线自组织网的优点,可有效克服这两种技术的缺陷并显著提高无线网络的性能,已经成为下一代无线通信网络的研究热点之一。WMNs可为无线个域网、局域网、校园网、城域网的一系列应用提供高速无线宽带接入服务。虽然目前WMNs技术发展很快,但其协议栈各层仍存在许多有待研究的课题。首先简要介绍了无线网状网的结构与特点;随后重点分析了其主要的几个应用领域;最后探讨了WMNs各协议层的研究现状与关键技术,并分析了该技术存在的问题及未来的研究方向。Wireless Mesh Networks(WMN) consist of mesh routers and mesh clients,where mesh routers have minimal mobility and form the backbone of WMNs.They provide network access for both mesh and conventional clients.WMNs are anticipated to resolve the limitations and to significantly improve the performance of wireless Ad Hoc networks and mobile cellular networks.They are undergoing rapid progress and inspiring numerous deployments.WMNs will deliver wireless broadband services access for a large variety of applications in personal,local,campus,and metropolitan areas.Despite recent advances in WMNs,many research challenges remain in all protocol layers.This paper presents a detailed study on recent advances and application scenarios in WMNs,followed by discussing the system architectures and characteristics briefly.Finally,recent research and advanced techniques of each protocol layer are described,and some open issues are analyzed

Modified Power Control Approach Based on CSMA/CA of Wireless Ad hoc Network

基于CSMA/CA机制,提出了一个改进的功率控制算法,用于解决传统的bASIC方案中,由于功率控制的引入而产生的非对称链路对节点传输的碰撞问题,它通过简单地修改802.11MAC层协议,采用变长的rTS/CTS来使载波侦听环中的节点获得关于dATA/ACk传输的分组大小及功率强度信息,从而有效地避免碰撞与重传。仿真结果说明,该方法不仅可以节省能量,而且可以提高网络性能。Based on CSMA/CA scheme,an improved power control algorithm was proposed to solve the Asymmetric Link Problem introduced by power control of BASIC in Ad Hoc networks,which modified 802.11 MAC protocol by using variable size of RTS/CTS to gain the information of data size and power level in the area of carrier sense ring to avoid more collisions and retransmissions.Simulation result shows that the approach can not only save network energy,but also improve network performance.福建省青年创新基金资助项目(2006F3097);福建省自然科学基金资助项目(A0710022);集美大学优秀青年骨干教师基金资助项目(2008B002

Design of cross-layer security for wireless sensor network's

无线传感器网络(WSNs)发展迅速,可广泛应用于军事、工业及科学等领域。传感器网络在无线信道中工作,其节点有限的能源、计算能力、存储能力使得其面临着严重的安全问题。已提出的许多安全方法都基于分层设计的概念。分析了分层安全设计的局限性,回顾了现存的W SNs的安全设计方案,提出了一些新的跨层解决办法,并指出了传感器网络中跨层安全的研究方向。Wireless sensor networks(WSNs) are developing rapidly,it will be employed in a wide variety of applications ranging from military,industrial and social.Due to their constraints in computation,memory,and power resources,security is a challenge in these networks.Many security methods of WSNs based on the concept of layered-design have the limit,the state of art security design method of WSNs is overviewed,several new cross-layer solve methods are proposed,and the research direction of cross-layer design for the security of WSNs is point out.福建省自然科学基金资助项目(A00440004

Energy Saving Route Finding Mechanism in Underwater Acoustic Sensor Networks

提出了水声传感网中能量有效的路由方案.结合水声信道的特点对水下传感网中的能耗因素进行分析,得出给定源宿节点之间的距离时路径消耗总能量与中继节点数的关系.对定向扩散协议进行改进,在初始化阶段根据汇聚节点和邻居节点的地理信息,求出源节点到目的节点的理想的最优能量路径.仿真结果证明,该方案能减少洪泛,只需选择1条较优路径,有效地节省了能量.An energy-efficient routing scheme is presented for underwater acoustic sensor networks(UW-ASN).Firstly,the factors affecting energy consumption in UW-ASN are analyzed in light of underwater channels,the relationship between numbers of relay nodes and energy consumption is obtained for given source-destination distance.The directed diffusion routing scheme is modified in the initial diffusion phase to find the optimal route based on the geographic information between a sink node and its neighboring nodes.Simulation shows that the proposed scheme can reduce the flooding cost,select an energy-efficient route,and save more energy.国家自然科学基金项目(60672046);集美大学优秀青年骨干教师基金项目(2008B002

A Congestion-aware Cross-layer Routing Scheme of Ad Hoc Networks with Multi-rate Mechanism

利用跨层设计的思想,论文提出了一种自适应多速率机制下,基于节点信息的AdHoc路由算法。根据物理层SNR的测量,结合MAC层的信息进行延迟估计,引入一种新的路由度量来选择路径,避开拥塞,减少延迟,提高网络吞吐量,从而能改善网络的整体性能。This paper proposes a cross-layer routing scheme based on information monitored by nodes for Ad Hoc networks supporting multi-rate mechanism.A new routing metric is introduced to take SNR measure on physical layer and delay estimate on MAC layer into account.With this metric,the routing algorithm tends to choose routes with wider bandwidth,lower delay,and less congestion.It demonstrates that the proposed scheme improves the performance of Ad Hoc work.清华-高通无线通信研究中心资助项

基于颗粒阻尼的矿用自卸车振动舒适性

采用颗粒阻尼技术对驾驶室座椅进行减振,提高其振动舒适性;选择与驾驶室底板和座椅连接的基座作为颗粒阻尼器,建立了基座阻尼器的离散元模型;模拟整车在发动机最高转速下的振动环境,针对不同阻尼器方案（颗粒材质、阻尼器分层数、颗粒粒径和颗粒填充率）,通过离散元仿真计算逐一进行耗能分析,得到了最优方案;对实物模型进行试验,对比原结构与增加阻尼颗粒后基座的加速度均方根,确认减振效果,将试验与仿真计算结果进行趋势对比,验证了离散元模型的可行性;在实际样车试验中应用最优方案,采集了座椅在发动机不同转速下的响应,进行了数据分析;针对最高转速的工况,进行了人体振动暴露的舒适性分析。研究结果表明:从频域图的单峰最大值来看,减振前座椅最大加速度响应出现在425 Hz处的0.643 4 m·s-2,安装颗粒阻尼器后最大值为25 Hz处的0.087 5 m·s-2;从时域图来看,当发动机转速分别为750、1 110、1 470、1 830、2 200 r·min-1时,安装颗粒阻尼器后座椅加速度均方根综合减幅分别达到24.2%、29.6%、34.7%、39.2%、46.0%,发动机转速越高,颗粒阻尼器的减振效果越好;安装颗粒阻尼器后各频段舒适性界限时长均有大幅度增加,频段为3.1和4.0 Hz时,安装颗粒阻尼器后舒适性界限时长均提升了1.50倍,为20 Hz时,安装颗粒阻尼器后舒适性界限时长提升了1.57倍。国家自然科学基金项目(51875490)厦门市科技计划项目(3202Z20173021)厦门市交通基础设施智能管养工程技术研究中心开放基金项目(TCIMI201813)中央高校基本科研业务费专项资金项目(20720180063

Cross-layer scheme in wireless sensor networks based on power control

无线传感器网络(W SNs)协议设计中既要考虑网络性能,又要考虑能量消耗。由于考虑的因素众多,传统的分层方法通常不能满足多个目标。提出一种基于功率控制的跨层路由方案,基于微经济学中效用的概念,通过对每个链路的功率进行控制,减少不必要发送功率,减少节点之间相互干扰,节省能耗。通过基于效用的路由度量,均衡网络性能,延长网络生存期。When designing wireless sensor networks(WSNs)protocol,not only network performance is considered,but also energy consumption is considered.Tradition layered design method can not satisfy several object parameters in the same time.A cross-layer scheme based on power control is proposed.It can reduce unnecessary energy and the interference between nodes by control power of every links.It can avoid selection of the route of lower battery capacity,which can improve overall network performance.福建省青年创新基金资助项目(2006F3097

一种简易直饮水杀菌装置

本实用新型是一种简易直饮水杀菌装置，属水的杀菌技术设备。它由进、出水管、加压泵、阀门、药容器进、出水口管、药容器壳体及盖、三通结头、中心进水管、流量控制阀门、药剂输出管、射流器共同安装连接构成，其位置关系为：加压泵通过进水管与阀门连通，药容器通过其进、出水口管分别与阀门、射流器连通，药容器进、出水口管固接于药容器壳体两侧，三通结头分别与药容器进、出水口管、中心进水管相连通，药容器盖与壳体旋接，流量控制阀门装于壳体上部并通过药剂输出管与射流器相连通，射流器通过接头分别与药容器出水口管、出水管连通，另一阀门通过水管与射流器并接。本装置体积小、耗电少、投资少、运行费低、易实现无人操作、使用安全、方便

大气细粒子连续液化采集传输装置

本实用新型是一种大气细粒子连续液化采集传输装置，它由汽粒混合腔、细粒子增长腔、细粒子撞击收集腔、气泵、恒温汽化供气腔、蠕动泵和溶液瓶相互连接组成，其中，汽粒混合腔的一端分别与细粒子增长腔、恒温汽化供气腔相连通，另一端通过气体吸收管连接有进气口，细粒子增长腔还与细粒子撞击收集腔相连通，细粒子撞击收集腔通过抽气孔与气泵相连通，蠕动泵通过管道分别与细粒子撞击收集腔、恒温汽化供气腔、溶液瓶相连通。本实用新型在把大气细粒子液化收集的同时，实现了连续采样，由于是连续采样和传输大气细粒子样品，可与其他具备连续分析测试功能的仪器连接，实现大气细粒子的连续在线分析。本实用新型结构简单，安装操作方便，实用性强