摘要：Based on the theory of SVPWM for three - level inverter,energy feedback based on SVPWM control algorithm for three - level inverter was proposed. Then the way to apply SVPWM for three - level into inverter was analyzed. Method to calculate the dwell time of voltage vector was given and it was demonstrated that two - level was simply used to judge the located region of three - level preference vector. Then achievement of PWM sequence was analyzed, and some PWM sequences were mended in order to reduce the total harmonics distortion of inverter output. At last, the experiment of energy feedback system based on SVPWM for three - level inverter was achieved. The effectiveness of the method was experimentally verified.%在研究三电平空间矢量调制方法的基础上,提出将该方法用于能量回馈.分析了三电平空间矢量调制方法如何运用于逆变器中,给出了电压矢量作用时间的计算方法和如何用二电平简单判断三电平参考矢量所在区域的方法,并详细分析了脉冲序列的实现方法,对一些脉冲序列进行了改进,从而再次降低输出谐波.针对能量回馈,结合三电平空间矢量调制进行了系统实验,实验结果验证了方案的正确性.
摘要：Many types of equipment do not have network interface. The goal of this thesis is to solve the access to this kind of equipment. The embedded system constructed on basis of ARM7 Coxtex- M3 MCU LM8962 and 8 -channel UART was expanded by SC28L198. The multi- serial port device through TCP/IP protocol was developed under μC/OS- Ⅱ operation system. The system can provide remote data via Ethernet for eight serial devices simultaneously,which provides conditions for the devices with the serial communication interface in the network control and realizes the capability of computer remote monitoring.%针对许多设备不具备网络接口的问题,以ARM7 Cortex-M3处理器IM8962为核心构建嵌入式系统,利用SC28L198芯片扩展8个串口,完成基于μC/OS-Ⅱ操作系统和TCP/IP协议的多串口服务器设计.该系统能够同时为8个串口设备提供以太网远程数据传输,为具有串行通信接口设备的网络控制提供了条件,实现了计算机远程监控.
摘要：An original muffler modal was analyzed by finite element method.Based on the results of the analysis, the topography of the muffler cover was optimized by OptiStruct software.The optimization was used to improve the first natural frequency of the muffler.The optimization results were combined with manufacturing processes to arrange the ribs of muffler cover,and then optimization case was validated.Results show that the first natural frequeney increases by 30％.It provides a new approach of the ribs arrangement of the muffler cover.%采用有限元方法对某消声器进行模态分析,根据分析结果,以提高消声器的第1阶固有频率为目标,在OptiStruct软件中对消声器端盖进行形貌优化.根据优化分析结果,将其与制造工艺相结合,布置消声器端盖的加强筋,并对优化方案进行验证,结果表明,所得到的消声器第1阶固有频率提高了30%,优化效果明显,为消声器端盖加强筋布置提供了新的思路.
摘要：For the test system of automobile exhaust heat power generation, a multi -point temperature measurement system was designed based on the MCU, second - order Butterworth active filter circuit, temperature measurement circuit and CAN communication circuit. Combining with the software filter algorithm, the system overcome the traditional limitations of large temperature detection range limits, low accuracy, unstable and non - digital communications. While detecting the operating automobile exhaust pipe,it was shown that the temperature detection system is not only in high accuracy,but also in high stability.%针对汽车尾气余热发电气道实验系统设计了由单片机、二阶巴特沃斯有源滤波电路、温度采集电路和CAN通信电路组成的多点温度检测系统,结合抗干扰的软件滤波算法,克服了传统温度检测范围局限性大、精度低、不稳定和无数字通信的缺点.对汽车运行时尾气管道的温度进行检测,表明该温度检测系统不仪精度高,而且稳定.
摘要：剖分变径带式无级变速器在凋速过程中存在带长变化的问题,由此会引起传动比和传动带张紧力的变化.在分析剖分变径带式无级变速器工作原理的基础上,推导了传动带带长变化和传动比波动的计算公式.通过优化变速杠杆的杠杆比可以将带长变化引起的传动比波动控制在很小的范围内,通过张紧弹簧可以补偿因带长变化引起的传动带张紧力的变化.%There is a problem of belt length change in transmission ratio regulation for split variable diameter belt CVT. The belt length change causes transmission ratio fluctuation and belt tension change. The working principle of split variable diameter belt CVT was introduced. The calculation formulas on transmission ratio fluctuation and belt length change were then derived. Transmission ratio fluctuation caused by belt length variation stays in small range through optimizing the lever ratio of regulation lever.Belt tension variation resulting from belt length variation is compensated by using tension spring.
摘要：利用Beppo-Levi定理和H(o)lder不等式,以及Minkowski不等式研究了随机级数∞∑n=1X2n的收敛性,其中{Xn}是随机变量序列,在此基础上讨论了随机级数∞∑n=1anXn的收敛性,其中{Xn}为正项同分布随机变量序列.将Paley-Zygmund定理推广到更一般的情形.%Convergence of random series ∞∑n=1 X2n was studied by Beppo - Levi theorem,Holder inequality and Minkowski inequality,where {Xn} is the random variables.And convergence of the random series ∞∑n=1anXn was then discussed,where {Xn} is the same distribution random variables.Then the Paley - Zygmund theorem was generalized.
摘要：基于均衡汇率BEER模型,采用2000年第一季度到2008年第四季度期间的数据,运用协整技术得出基本经济因素向量对均衡汇率的影响系数,估计出样本期间内人民币汇率的失调程度.结果表明,政府支出对人民币均衡汇率影响最大,贸易条件和对外净资产对均衡汇率具有正向作用;利用模型得出的人民币均衡汇率方程对当前人民币汇率进行测算,样本期间内人民币大都处在低估的状态;另外,2005年的汇改使得人民币汇率在3个季度内连续升值并接近均衡,长期内人民币仍有升值的压力.%Data of the period from the first quarter of 2000 to the last quarter of 2008 were taken as sample. Co- integration was applied to get the impact coefficient of the vectors of basic economic factors on equilibrium exchange rate. The degree of current RMB exchange rate imbalance in sample period was estimated based on equilibrium exchange rate BEER model. The results show that,government expenditure has the greatest impact on RMB equilibrium exchange rate; terms of trade and net foreign assets change in the same direction with equilibrium exchange rate;measuring current RMB exchange rate through the RMB equilibrium exchange rate equation from the model. It showed that, RMB was mostly underestimated in sample period;In addition,the exchange rate reform in 2005 made RMB exchange rate appreciate in a row in three quarters and be close to equilibrium,in long term, there is still upward pressure on the RMB exchange rate.
摘要：The remote monitoring system for the state of ship's cargo based on GPRS and Web/WAP services was designed. The schematic and circuit diagram design was completed by using the ARM data acquisition module, GPRS wireless communication module, GPS positioning module,image acquisition and image compression coding function module. At the same time, the Web/WAP network server was combined with data flows provided by these modules and the use of real - time data and historical data were presented based on the B/S architecture. The Monitoring center personnel can make a reference to these data and control the acquisition mode of remote camera from the network platforms. The monitoring system has the advantage of high reliability ,stable performance and excellent practicability.%设计了一种基于GPRS和Web/WAP服务的船载货物状态远程监控系统.利用ARM数据采集模块、GPRS无线通信模块、GPS定位模块、图像采集和图像压缩编码功能模块,实现原理图设计到电路板设计开发;同时将Web/WAP网络与这些模块所提供的数据流有机结合,利用各种现场采集的实时数据和历史数据,以网络的B/S模式呈现,可供监控中心人员参考,同时也可以利用网络平台控制远端摄像头的采集模式.实践证明,该系统可靠性高,性能稳定,具有良好的实用性.
摘要：Image restoration is a typical ill-poised problem. Total variation regularization model is one of the most successful image restoation models. However,there is a ubiquitous problem of a slow and inefficient convergence rate in its algorithm. Based on Bregman iteration regularization models,an iteration algorithm was constructed to solve total variation regulation model quickly.The experimental results show that this algorithm can solve total variatiou regularization model quickly with an obvious enhancement in the obtained restoration image in terms of PSNR and subjective visual effect.%针对全变差正则化模型求解算法普遍存在收敛速度慢的问题,基于Bregman迭代正则化方法构建了一种快速求解全变差正则化模型的迭代算法.实验结果表明,该算法能快速求解全变差正则化模型,得到的复原图像在峰值信噪比和主观视觉效果方面有着明显提高.
摘要：对几种曲轴外圆加工工艺及复合车削工艺在加工效率、加工精度和投资费用等方面进行了分析对比,结合我国曲轴的生产现状,提出了曲轴外圆复合车削工艺,试验表明它是符合我国国情的曲轴外圆加工的新加工方法,并介绍了实现新工艺的试验装置.%Several processing and compound turning technologies for the crankshaft were analyzed and compared in processing efficiency, machining accuracy and investment costs. It is concluded that compound turning technology is a new processing method which is more suitable for the market in China. And new testing equipment for the new method was introduced.
摘要：为了提高滚动轴承故障诊断的准确性,介绍了一种基于DSP和组态软件的滚动轴承在线故障诊断系统.该系统以DSP作为信号处理部分,以组态软件作为人机交互界面,通过采用轴承振动信号的时域特征参数法对滚动轴承故障进行判断.实践检验证明,该系统能准确地判断出滚动轴承故障,具有较好的应用前景.%In order to improve the accuracy of fault diagnosis of rolling bearings, an on - line fault diagnosis system was provided based on digital signal process and configuration software. DSP was used as the signal processing portion and configuration software was used as the human- machine interaction interface. The system takes advantage of the bearing vibration signals in time domain method to determine the fault characteristic. The tests show that the system can accurately identify the rolling bearing failure, which means its prospective application.
摘要：In view of the fact that many transnational enterprises and companies are actively seeking external resources to upgrade competitive strength when globalizing their production and operation,the research status and its application of overseas enterprise crowdsourcing were discussed from three respects, the concept, basic factors and application of crowdsourcing. To correctly understand the overseas crowdsourcing research trends has certain theoretical and realistic significance in promoting our open innovative research and innovation strategies of service enterprises.%针对许多跨国公司和企业在将其生产经营活动全球化的同时,积极寻求外部资源以提高自身竞争力的情况,从众包的概念、基础要素和应用3个方面概述了国外企业众包的研究和应用现状,正确认识国外众包研究的动态,对于推动我国开放式创新研究的深入开展、服务企业创新战略具有一定的理论意义和现实意义.
摘要：在面临变化的市场环境时,生产能力是制造企业在生产过程中一项重要的战略决策.考虑下游订单需求、生产成本及外包成本都为随机变量的情况下,结合数学规划(动态批量模型,Dynamic-Lot Size)和模拟仿真(Monte-Carlo模拟)两种方法,得到制造商的最优生产能力.最后给出了一个算例分析,为制造企业实际运作提供了较为实际的参考.%When the market environment is uncertain, one of the important challenging decisions of the manufacturer is to determine the production capacity. In consideration of that all the downstream demand, the unit production cost and outsourcing cost were stochastic,the optimal production capacity was searched out by integrating the dynamic -lot size model and Monte- Carlo simulation. In the end,a numerical example was given to provide the optimal production capacity. The conclusion is meaningful for the manufacturer to refer.
摘要：企业六西格玛管理成熟度评价可以有效地判定在其持续改进过程中的状态,帮助企业的管理活动从"被动反应"向"主动提升"转变.借鉴软件工程、项目管理成熟度的理念.建立了企业六西格玛管理成熟度评价体系,应用网络层次分析法确定各指标的权重,将其成熟度划分为认知级、成长级、规范级和优化级,并通过案例说明了该方法的可行性和有效性.%The maturity evaluation of six sigma management in enterprises can effectively judge the state in its process of continuous improvement,and help management activity to transform passive reaction into initiative upgrade. The ideas of software engineering and the maturity of project management were used to establish the maturity evaluation system of six sigma management in enterprises. Analytic network process was used to identify the weights of various indexes. And the maturity of six sigma management was divided into cognitive level,growth level,gause level and optimizing level. The feasibility and effectiveness of this method was verified by a case.
摘要：假设线性市场中存在不同偏好的顾客,建立了同类产品在横向差异和纵向差异同时存在条件下的双寡头企业两阶段动态博弈竞争选址模型.运用逆向归纳法求出各属性处于支配地位时的子博弈精炼纳什均衡解,并对均衡策略进行了比较分析.该模型拓广了传统决策选址模型的适用范围,弥补了决策选址模型的缺陷,使模型更具有实际意义.%Under the assumption of different consumers' preferences in the linear market, a two- stage dynamic and competition location game model for duopoly firms was proposed under horizontal and vertical property differences of a same kind product. The sub - game perfect Nash equilibrium of two - stage dynamic game was obtained by backward induction method when each property was dominant. And the strategies of equilibrium was analyzed. This model extends the scope of traditional location model and remedies its defect. It makes competition location game model more practical.
摘要：数字水印作为图像版权保护和内容认证已成为多媒体信息安全研究领域的一个热点.利用混沌序列对图像信号加密和解密的方法,给出了基于混沌特性的彩色图像数字水印算法,该算法选择彩色图像的YIQ色彩空间,将原始图像Y分量进行二级离散小波变换(DWT),水印图像进行一维Logistic置乱加密后嵌入到原始图像Y分量的低频子带中,其算法具有水印嵌入信息量大和隐蔽性好的特性.实验结果表明,算法对滤波、剪切和噪声攻击具有较强的鲁棒性.%Digital watermarking becomes a focus in the study of copyright protection and autbentication of multimedia information security.The way to encrypt and decrypt graphic signal was discussed by chaos sequence theory.A chaos - based digital watermarking embedding algorithm was proposed for color image.The original color image was transformed into the YIQ color space,its component Y was decomposed by a two - level discrete wavelet transform.The watermark image was embedded into low frequency sub - band of component Y after 1 - dimensional Logistic scrambling and encrypting.The algorithm can contain more embedding intensity and be invisible.The experimental results verify the algorithm's robustness for filtration ,crop procession and noise attacking.
摘要：Characteristic of OpenGL was introduced and a 3D model was created by OpenGL. under the environment of VC + +6.0 The fiber bundle trace of the grid component on the winding progress was analyzed. Filament winding simulation for grid component was then realized.%阐述了OpenGL的特点,介绍了在VC++6.0的环境中使用OpenGL进行三维实体建模,分析了网格构件在纤维缠绕过程中的纱线轨迹,实现了网格构件的纤维缠绕仿真.
摘要：The garment layout problem is how to find the arrangement of cloth units in a region without overlapping so that the least cloth would be wasted According to actual technical requirements ,a mathematic model of optimal layout was obtained based on hybrid combinations of rectangular parts for this problem. An optimal solution algorithm was presented based on the combination optimization method and actual garment layout experience. Einally,an example was used to verify the effectiveness of the method.%服装排料问题是指如何将样片在指定的面料内进行合理的排列,使面料利用率达到最大.根据实际技术需求,在服装样片矩形化的基础上,建立了混合组合方式下的服装最优排料的数学模型,并将最优化方法与实际服装排料经验相结合,设计了整体排料最优求解算法.最后,通过实例证明了所提出的服装排料数学模型的正确性.
摘要：The advantages and disadvantages of methods for converting Founder proofreading files to PDF ones were discussed.In the view of the needs of reproduction and retrieval for the open access of journals, a new approach was developed to convert Founder files to double -layer PDF ones by software ps22pdf and Foxit PDF Editor,etc.The PDF file created by this method can reproduce the printed journal precisely, copy and search the original texts.A new method for the open access of science and technology journals was provided.%概述了方正书版大样转PDF文件方法的优缺点.根据科技期刊开放存取以及复制、检索的需要,提出一种用ps22pdf、Foxit PDF Editor等软件实现方正大样转双层PDF文件的新方法,所生成的PDF文件具有精确重现原文、能复制原文本和全文检索等功能,为科技期刊的开放存取提供了一种新的实现手段.
摘要：The air compressor of fuel cell engine (FCE) is a nonlinear system. Aiming at the difficulty and complexity of its modeling, the nonlinear mapping and self- learning ability of neural networks was utilized to build the model. In the neural networks model,the different rotating speed and output pressure of air compressor were the inputs of neural networks,and air flow was taken as its outputs,the neural networks was trained with Levenberg - Marquardt algorithm. The validity and accuracy of the model are proved by the simulation results;the neural networks modeling makes it possible to optimize the real - time control of air supply system in FCE.%燃料电池发动机的风机系统是一个非线性系统,针对其难以建模以及建立的模型过于复杂等问题,利用神经网络的非线性映射和自学习能力建立了风机系统的辨识模型.模型以风机转速和空气压力为输入,以空气流量为输出,采用Levenberg-Marquardt优化算法进行神经网络的训练,建立了不同转速和压力条件下的空气流量模型.仿真结果表明,该模型精度较高,可为燃料电池发动机空气供给系统的优化控制奠定基础.
摘要：A systematic analysis for the status quo of high - technology industry's innovation capability in Wuhan was conducted in accordance with the connotation,from the angles of science and technology,institution and management. The evaluation index system of high - technology industry's innovation capability in Wuhan was established. Fuzzy estimation model was employed to make synthetic estimation for high- technology industry's innovation capability in Wuhan. On this basis, some suggestions on improving high- technology industry's innovation capability in Wuhan were proposed.%从高技术产业创新能力的科技、制度和管理3个维度,对武汉市高技术产业创新能力的现状进行了系统分析,建立了武汉市高技术产业创新能力评价指标体系,运用模糊评价模型,对武汉市高技术产业创新能力进行了综合评价,在此基础上提出了武汉市高技术产业创新能力提升的相关建议.
摘要：The coupling situations among human factors, equipment factors, environment factors and management factors were analyzed. These factors affect air traffic safety. By Using the N - K model, occurrence probability and the value at risk of the single factor coupling,two -factor coupling and multi -factor coupling were calculated separately with reference to the unsafe events occurred in the ATC in China over the past decade. Then the status of safety risks in air traffic control were assessed according to the value at risk. In this way,it provided new ideas and methods to ATC safety risk manasement.%对影响空中交通安全的人为因素、设备因素、环境因素和管理因素耦合的情况进行了分析,并结合我国近10年来发生的空管不安全事件,利用N-K模型,分别计算出单因素耦合、双因素耦合、多因素耦合发生的概率及风险值.根据风险值大小评估空管安全风险状态,从而为空管安全风险管理提供了新的思路和方法.
摘要：针对金融危机对深圳道路集装箱运输业的影响问题,利用灰色关联度模型分析并计算深圳道路集装箱货运量与经济相关指标的灰色关联度,并比较其关联度的大小.提出了金融危机下深圳道路集装箱运输业的发展前景及趋势,以及深圳道路集装箱运输业的对应措施及相关建议.%The impact of financial crisis on road container transportation industry was investigated. Gray relational model was used to analyze and calculate the gray relational grade between Shenzhen road container cargo and correlative economic indicators. The development prospects and trend of Shenzhen road container transportation industry were analyzed under condition of financial crisis;counter- measures and related policy measures were also proposed for Shenzhen road container transportation industry.
摘要：Fixed assets investment and economic growth in Gaochun County were investigated in 30 years period of China reforming and opening up.Relationship between fixed assets investment and economic growth of the county were analyzed by econometrics analysis methods of co - integration analysis and Granger causality test.Results show that there exists a two - way Granger causality in the relationship between fixed assets investment and secondary industry ,and the relationship between fixed assets investment and primary industry is unclear;tertiary industry is the Granger cause of investment and there exists a negative relationship between the changes of tertiary industry and fixed assets investment.%描述了改革开放30年来江苏省高淳县的固定资产投资与经济增长的状况,并运用协整分析和格兰杰因果检验等其他计量经济分析方法,对该县的固定资产投资与经济增长的长期均衡关系进行验证分析,结果表明,固定资产投资与第二产业是双向的格兰杰因果关系,与第一产业关系尚不明显,而第三产业是固定资产投资的格兰杰原因且第三产业增长变化与固定资产投资变化是负向关系.
摘要：阐述了FFT分析与阶比分析的基本理论,得出了阶比分析在旋转机械特征值获取中的优势;详细论述了基于LabVIEW语言实现阶比分析的编程方式,并插值获得转速信号,以获取等角度采样振动信号;实验验证了阶比分析的可行性和准确性.%The basic theory of FFT analysis and the order analysis were introduced. The superiority of the order analysis was investigated in obtaining the characteristic value of rotating machinery. Based on LabVIEW,the way of programming was explained in detail to implement the order analysis;and the rotating speed signal was gained by interpolation in order to obtain the angle sampling vibration signal. The feasibility and accuracy of the order analysis were verified by experiments.
摘要：The finite elements software ANSYS was applied to stability analysis on tubular steel,and the applicability of the method was defined. It provides some experience to the buckling analysis of these kinds of steel structure. The main research method was eigenvalue buckling analysis. The results were then compared with eigenvalue buckling analysis and euler formulas. It was found that eigenvalue buckling analysis is available to solve the buckling problems under the limit of certain conditions.%利用有限元软件ANSYS对圆管钢结构进行了稳定性分析,并且界定出该分析方法的适用范围,为该类钢结构稳定性的数值分析和设计提供了依据.分析主要采用特征值屈曲方法,将经ANSYS特征值屈曲分析得出的结果与经验公式和欧拉公式得出的结果相比,发现ANSYS屈曲分析方法必须在-定条件下才适用于解决稳定性分析问题.
摘要：The commodity catalogs in the e- commerce website are diversified;there is currently no uniform standard for e -catalog, so it is necessary to solve the semantic interoperability of heterogeneous e - catalog. The status of e - catalog ontology integration was analyzed. The process framework of multi - source e - catalog ontology integration was proposed; it includes 3 modes of ontology pretreatment, ontology mapping and ontology merging. The ontology mapping algorithm and ontology merging algorithm of e- catalog were proposed at last.%针对电子商务网站中的商品目录内容各异,没有统一的电子目录标准而带来的异构电子目录的语义互操作问题,对电子目录本体集成研究现状进行了分析,提出了多源电子目录本体集成的流程框架,主要包括本体预处理、本体映射和本体合并3个模块,并给出了电子目录本体映射算法和电子目录本体合并算法.
摘要：The basic theory of the emergency management process was introduced to analyze the applications of the current emergency management process that used in the fire prevention safety management. The current situation and existing problems in the fire prevention safety management system's construction were discussed on basis of the emergency management process. And construction and improvement of the fire prevention safety management system were then proposed. These provide references for the governments at various levels to enhance the construction of fire prevention safety management system and the capabilities of fire prevention.%通过引入应急管理过程论基本原理,分析了目前应急管理中过程论在消防安全应急管理中的应用,并在运用应急管理过程论分析我国消防安全应急管理体系建设现状及存在问题的基础上,提出了构建与完善基于应急管理过程论的消防安全应急管理体系建设的建议,以期为各级政府加强消防安全应急管理体系建设,增强消防安全管理能力提供参考.
摘要：The defects of two popular e - business models were analyzed and the needs of current Chinese companies were investigated. A new B2B e - business model was proposed on basis of P2P. It is a beneficial supplement to the existed models and feasible for e-business in China. The P2P- based e- business model and its characteristics,including its structure of the system,market establishment, working process and key technologies, were discussed in detail.%分析了目前常用的两种电子商务模式存在的问题,以及我国国情下企业对电子商务的特殊需求,提出了基于P2P的电子商务模型,该模型是对现有电子商务模式的补充,是我国电子商务的一种可行方案.详细论述了基于P2P的电子商务模型和性能特点,包括其体系结构、市场建立、工作过程及关键技术.
摘要：Cloud service of single form cannot meet users' increasingly complex and diverse demand,so the cloud service collaboration,integrating single ones into more powerful and better quality service, becomes an effective solution. Cloud services collaboration market transaction model was proposed from the perspective of multi - level cloud. The model allows collaboration among the different cloud providers from the same and different levels as well. The management way of the cloud service collaboration transaction and the third - party transaction was discussed. This work will offer a good reference to service collaboration in the cloud.%随着用户需求的日益复杂和多样化,单一形式的云服务无法满足其需求,将单个的云服务集成为功能更强大质量更优的服务成为必要的解决途径.从多层次云服务角度出发,提出了云服务组合交易模型,实现了同一层次不同云服务提供商之间、不同层次服务提供商之间的服务组合,并探讨了云服务组合交易和第三方服务组合交易管理方法,为云服务组合的研究提供参考.
