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自适应最小二乘格型算法在天线阵列中的应用 总被引:1,自引:0,他引:1
在天线阵列中对天线阵列信号分析的算法有LMS和RLS等,主要介绍了自适应最小二乘格型算法LSL对天线信号进行分析,并对算法过程展开介绍。 相似文献
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Laminated Strand Lumber (LSL) is a type of engineered wood product widely used as a substitute for sawn structural lumber. This is because LSL can be manufactured to have superior mechanical and physical performance to competing products, including high resistance to splitting, high strength and dimensional stability. The authors studied connections in LSL with behaviour of similar connections in sawn Spruce lumber as a benchmark. Proneness to splitting is the Achilles heel of most wood-based construction materials and especially products like sawn lumber and glued-laminated-timber. This characteristic makes it especially difficult to make connections that are mechanically efficient. However, when constructing with LSL it is possible to create connections that not only have desirable response characteristics, but also achieve labour efficiencies. The particular type of connection studied by the authors uses small diameter steel tube fasteners inserted in tight-fitting holes in conjunction with steel plate elements located in slots in ends of joined members and links them together. Tube fasteners are driven perpendicular to the axes of wood members and pass through both those members and steel link elements. Tests were conducted under static tensile loads with multiple-fastener arrangements obeying spaced and end distance rules typical for solid bolts in sawn softwood lumber. The response was highly ductile and failure occurred mainly in the fasteners. Consequently the so-called European Yield Model (EYM) for doweled timber connections yields good predictions of connection strengths. A detailed finite element analysis was also performed to assist interpretation of test results and validate predictions from the EYM beyond the range of test data. The finite element model was developed using the ABAQUS software and results from that model agreed closely with experimental findings in both qualitative and quantitative aspects. 相似文献
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自适应均衡系统用于各种类型数字通信系统,随时均衡传输信号有畸变的信道.研究一基于LSL(最小平方格型)算法的QPSK(正交相移键控)自适应均衡器,均衡效果良好.然后结合仿真实验分析研究系统采样延迟对调制自适应均衡性能的影响,实验结果表明其影响作用明显,不可忽略. 相似文献
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最小二乘格型(Least Squares Lattice,LSL)自适应均衡算法具有收敛速度快、算法复杂度低、对舍入误差不敏感等特点,适于应用在水下实时通信中。在LSL均衡算法的基础上,为增强对多普勒频移的跟踪能力,在均衡器中加入等效二阶锁相环(PLL),提出了两种算法:后置PLL的LSL算法(LSL-PLL-post)和预置PLL的LSL算法(LSL-PLL-pre)。对RLS、LSL、LSL-PLL-post和LSL-PLL-pre四种算法进行了仿真,结果表明:PLL显著增强了LSL均衡器对多普勒频移的跟踪能力;在多径和多普勒环境下,LSL-PLL-pre是四种算法中性能最好的。湖试数据分析表明,LSL-PLL-pre算法性能略优于LSL-PLL-post算法,更具实用价值。 相似文献
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The desirability of a response that increases in a linear manner from the lower specification limit to the target value and decreases in a linear manner from the target value to the upper specification limit results in a breakpoint (nondifferentiable point) at the target value of its desirability function. Thus, modified desirability functions were proposed to solve this breakpoint problem so that the generalized reduced gradient can be applied. The modified desirability functions require the fitting of a quartic polynomial in the vicinity of the target. However, the fitting of the quartic polynomial needs to satisfy five conditions and involves numerous computations. Therefore, an approach with less computations and yet that is simple to implement is proposed in this article. This approach is applicable when the lower specification limit, the target value, and the upper specification limit of a response are available. In addition, this approach also allows practitioners to assign different degrees of importance to the responses. An example from the original paper of modified desirability functions is used to illustrate this approach. 相似文献
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Active Noise Control of the Heavy Truck Interior Cab 总被引:1,自引:1,他引:0
In order to control the noise of the heavy truck interior cab effectively,the active noise control methods are employed. First,an interior noise field test for the heavy truck is performed,and frequencies of interior noise of this vehicle are analyzed. According to the spectrum analysis of acquired noise signal,it is found out that the main frequencies of interior noise are less than 800Hz. Then the least squares lattice (LSL) algorithm is used as signal processing algorithm of the controller and a closed-loop control DSP system,based on TMS 320VC5416,is developed. The residual signal at driver's ear is used as feedback signal. Lastly,the developed ANC system is loaded into the heavy truck cab,and controlling the noise at driver's ear for that truck at different driving speeds is attempted. The noise control test results indicate that the cab interior noise is reduced averagely by 0.9 dBA at different driving speeds. 相似文献
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面向用户的CIMS总体设计模型体系的一种形式化描述 总被引:1,自引:0,他引:1
总体设计作为引导企业CIMS建设的总纲和蓝图,其设计质量直接关系到CIMS建设的成败,以及未来企业的运行效率。面向用户的CIMS的总体设计模型体系(UMSCOD)为企业CIMS提供了良好的模型表现机制。文章提出了用LSL(LarchSharedLanguage)对面向用户的CIMS总体设计模型体系的静态结构进行形式化的方法,使得该模型体系既能作为与用户交流、对系统建模的工具,又能保证模型体系中各子模型的一致性,为后续的模型分析和系统设计提供坚实的理论基础。 相似文献
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LSL自适应权向量法检测弱脉冲信号方法研究 总被引:3,自引:0,他引:3
自适应权向量LMS算法用于检测弱信号具有收敛响应较慢的缺点,本文应用自适应权向量格型LSL算法检测噪声中的射频弱脉冲信号取得满意结果。仿真检验表明,本文方法用于检测快变弱信号是一种行之有效的方法。 相似文献