用GO语言实现C语言词法分析器

词法分析器是编译器的第一阶段,其从左到右读入程序的源文件,而后分解出有意义的词法单元。大多数编译器的词法分析器都采用手工实现,所以学习、实现词法分析器在教学上有重要意义。本系统使用新的系统级程序语言gO语言,并利用其内置的字典数据类型,构建出几个查找表,简化了程序,实现了C语言的词法分析器

基于TDMA的无线传感器网络MAC协议的研究

描述了设计WSnS的MAC协议应该考虑的问题,对无线传感器网络中一些典型的以及新提出的基于Td-MA的MAC层协议进行分析和讨论,对其进行比对、分析,最后提出了对将来设计MAC协议的方向和建议

Physical layer designing and simulation for wireless sensor network based on NS-3

nS-3是一种新的网络仿真工具,它将会慢慢取代目前广泛使用的nS-2。本文着重介绍了基于nS-3的无线传感器网络的物理层仿真模块的设计,搭建了无线传感器网络仿真平台,使一个简单的例子得以在上面运行,并给出了仿真结果。该仿真平台可以用于对无线传感器网络的深入研究与探讨,有助于无线传感器网络的优化设计、缩短系统的开发周期。NS-3 is a new network simulation tool.It will gradually replace NS-2 which is popularly used now.This article focuses on the designing of the physical layer of wireless sensor network.A wireless sensor network simulation platform was set up and made a simple example run on it and also the simulation result was presented.The simulation platform can be used for further research of wireless sensor networks.And it is helpful for wireless sensor networks to optimize the design and shorten the development cycle.福建省重点科技计划(No.2008H0037

Fast Fixed Codebook Search Method

为降低固定码本搜索算法的复杂度,在脉冲取代法的基础上提出一种码矢分段优化的快速搜索方法。采用码矢分段优化的方法,在保证语音质量的前提下,降低计算复杂度。实验结果表明,与AMr-Wb采用的深度优先树算法及传统的脉冲取代算法相比,在不影响语音质量的条件下,码矢分段优化算法复杂度降低了70%--80%。In order to reduce complexity of fixed codebook search,a fast algebraic codebook search argorithm based on pulse replacement procedure is proposed in this paper.The proposed method is employed dividing candidate codevector into two sub-codevectors to optimize.It not only lowers the computational complexity sharply,but also ensures the speech quality.Experimental results show that the proposed method reduces the total computational complexity by 70%--80% with speech quality equivalent,compared with that by the depth-first tree search method adopted in AMR-WB and traditional pulse replace method.福建省科技厅重大专项基金资助项目(2009HZ0003-1

Performance Analysis Model for IEEE 802.11 Distributed Coordination Function Protocol

提出了一种改进的二维MArkOV链模型用于分析IEEE 802.11 dCf协议.该模型不仅考虑实际应用中饱和业务量和非饱和业务量的情况,而且考虑dCf协议的退避计时器的冻结状态和有限的重传次数.通过对该MArkOV链模型稳定状态的求解并结合M/M/1/k排队模型,导出了dCf系统性能的理论模型.仿真结果表明,该理论模型能够精确地预测广义IEEE 802.11 dCf协议的系统性能.This paper proposes an improved two-dimensional Markov chain model for the performance analysis of the IEEE 802.11 DCF protocol.The model is applicable to both saturated and unsaturated traffic conditions.Moreover,it extends the existing models to take into account previously-ignored MAC layer factors such as backoff freezing and limited times of retry.In addition,by deriving the stationary state of the Markov model and considering an M/M/l/K queuing model,we further derive a theoretical model for evaluating performance of the general IEEE 802.11 DCF protocols.Accuracy of the proposed theoretical model is validated with simulation results.福建省科技重大专项基金(No.2007HZ0003); 福建省自然科学基金(No.2010J01347)资

An Analysis of Ways to Develop Core Competence for Xiamen Huicheng Developments Ltd.

如何打造基业常青的房地产开发企业？这已成为许多新世纪中国房地产企业正在苦苦思考与摸索的问题。其中关键的一条就是如何在整合战略资源的同时强化企业的核心竞争力，并以此来面对日益成熟的中国房地产行业的竞争。论文以汇成建设作为研究对象，在讨论房地产企业核心竞争力的基础上,运用所学理论知识并结合企业实践，尝试给出打造汇成建设核心竞争力之路的战略。 本文共六章。第一章为前言部分，叙述了论文课题的选题缘由、论文研究的主要内容、方法以及论文结构；第二章阐述了房地产企业核心竞争力的定义，分析了研究核心竞争力与企业战略的关系，介绍了我国房地产企业探索核心竞争力的历程，引出本文的研究模型；第三章介绍汇成建设的背景...How can a real estate corporation be developed constantly and healthily? It has becoming a problem thought over and grappled for by most Chinese real estate corporations in the new century. The key of this problem lies in how a real estate corporation strengthens its core competence by conforming its resources strategically, in order to face the growing competition in the real estate industry in C...学位：工商管理硕士院系专业：管理学院工商管理教育中心_工商管理硕士(MBA)学号：X200115007

基于V.90标准的MODEM的实现

作者以CX88168单片调制解调芯片为核心，设计了一种基于V．90标准的高速MODEM。对V．90高速 MODEM的工作模型、硬件构成、设计中应注意的问题及其功能调试等进行了详细介绍

LEACH Simulation and Improvement Based on NS3

lEACH协议是无线传感器网络中经典的分簇算法,但lEACH协议中簇首是随机产生的,存在簇首分布不均、网络拓扑和能量消耗不均衡的问题.基于此提出的lEACH-Er算法采用动态的簇首选举机制,将代表簇首间地理位置的rSSI信息和节点剩余能量引入选举权值,以均衡能量消耗和优化簇首分布.仿真结果表明,与lEACH算法相比,lEACH-Er算法有效地均衡了节点能耗,提高了能量利用率,从而大大地延长了网络寿命.LEACH Protocol is a classic clustering algorithm for Wireless Sensor Networks.In this protocol,cluster heads was randomly generated,which bring about several problems such as cluster heads uneven distribution and Energy consumption imbalance.This article proposes an improved algorithm named LEACH-ER,which aims at improving the existence problems mentioned above and makes out a prioritization scheme.Dynamic and multiple Electoral mechanism are adopted,LEACH-ER combines the RSSI information between cluster heads and the sump energy of candidate cluster heads into the weighting coefficient,of which the RSSI information represents the correlation of geographical location among candidate cluster heads.Finally,a system simulation and analysis based on NS3 are given,the simulation result show that LEACH-ER effectively balance the energy of the whole network and extend the network lifetime by 8.06% compare to LEACH.福建省自然科学基金(A0710021);福建省科技计划项目(2008H0037);福建省科技重大专项(2007HZ0003

移动公话接入设备的设计与应用

作者采用WAVECOM公司的GSM移动通信模块及以PIC16C65单片机为核心的外围控制电路,设计了一种基于900MHz/1800MHz GSM数字移动网的移动公话接入设备,该文介绍了此设备的工作原理、硬件构成、软件设计及其应用