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1.
针对聚类分析实现跳频网台分选时,分选结果对初始聚类中心敏感且某些样本点“既可以属于类A也可以属于类B”的问题,提出了一种基于模糊K调和均值(KHM)聚类的跳频网台分选方法。首先利用搜索统计直方图位置法预估聚类数目和聚类中心,减少了算法的迭代次数;然后根据跳频信号的各项参数,应用模糊KHM聚类算法对跳频网台进行分选,有效解决了样本点的隶属度问题;最后通过类内类间距法估计得到准确的聚类数目K、聚类中心位置,大幅提升了聚类算法准确度。仿真结果表明,该算法聚类中心接近实际类中心,分选正确率高,迭代次数少。  相似文献   

2.
为了抑制空时分组编码系统中的共道用户多址干扰,对低复杂度的多用户检测算法进行了研究,提出了基于概率数据辅助(Probabilistic Data Association,PDA)算法的大容量多用户检测技术。通过充分利用干扰信号的相关性进行有效干扰抑制,从增加共道用户的角度来提高系统容量。仿真表明,该检测技术能进一步提高系统性能,尤其是增大了通信系统容量。  相似文献   

3.
为了从用户地理空间分布数据中挖掘用户间关联关系,提出了一种基于谱聚类的关联关系挖掘算法。首先定义了关联度,用以衡量用户之间空间分布的相似性,基于关联度构造相似矩阵,再利用谱聚类方法对用户进行聚类分析,聚类结果表征了用户的关联关系。采用Silhouette指标和聚类准确率来衡量用户关系挖掘质量,同时与传统的K-Means方法进行了比较,通过真实数据集实验,结果表明该算法在实验数据集上能达到90%以上的聚类准确率,证明方法有效、可行。  相似文献   

4.
提出了一种新的基于OFDM多用户通信系统的资源分配算法。该算法在总功率限制和用户数据率要求下,通过以下两步实现子载波、比特和功率的动态分配:第一步,基于用户的平均信道增益和数据率要求进行资源初分配(每个用户分配多少个子载波、功率);第二步,对步骤1中的结果进行调整,最终决定每个用户分配到的子载波、功率以及比特载入方式。相比于Hujun Yjn等人提出的另一种基于用户需求的算法,新算法的基站发射功率略有增加,但复杂度大为降低,在实际运用中更有利用价值。  相似文献   

5.
针对雷达信号分选中常见的聚类数目难确定、数据簇形状识别、异常数据敏感等问题,提出了基于NeiMu(Neighboring Mutually)的雷达信号聚类分选算法。该算法首先以信号脉冲为点、各点间的欧氏距离为线构建距离矩阵,然后在进行干扰数据剔除的情况下选定合适k值完成聚类矩阵的构建,最后采取遍历聚类矩阵的方法输出聚类结果,在删除无效的聚类后实现了雷达信号的聚类分选。通过仿真可知该算法在选取合适k值的情况下具有极高的正确率,证明了其有效性和可靠性。  相似文献   

6.
根据跳频高密度异步网台信号的主要特征,通过建立分选模型,确定分选参数,将跳频信号的网络信息参数用于跳频高密度异步网台信号的分选,并与跳频信号的频率统计特性相结合,提出了一种基于多接收机分频段侦收的跳频高密度异步网台信号分选算法,并对其进行了仿真验证。  相似文献   

7.
针对复杂电磁环境下北约新型Mark XIIA模式5信号分选难度大的问题,提出了一种基于空域、时域特征的信号分选方法。通过方位角对脉冲序列进行聚类,研究前导脉冲偏移量生成规则,提出了基于通信安全有效性间隔与交错索引的框架识别算法。通过改进的脉冲重复间隔(Pulse Repetition Interval,PRI)变换法对信号进行周期估计,实现同向交错信号分离的目的。通过仿真对比,该框架识别算法对动态偏移的脉冲信号有很好的识别效果,能在更低信噪比条件下识别正确率达到90%。此外,改进的PRI变换法对抖动范围10%的周期信号,估计误差不超过2%。  相似文献   

8.
提出了一种基于CDMA/TDMA混合多址的GSM与CDMA扩容方法。在发送端,通过扩频码对GSM信号进行直接序列扩频,使其多址方式由TDMA变换为CDMA/TDMA,然后与CDMA信号在空间同频传输,这样就可以解决两个系统在Um接口的兼容问题;在接收端,使用相同的扩频码对CDMA/TDMA信号进行解扩,使其多址方式由CDMA/TDMA还原为TDMA,由此可以将GSM与CDMA两种信号进行分离。文章提出了用互补码集作为多址接入码,并给出了一个时隙内GSM用户被扩频调制的具体过程。理论分析和仿真结果表明,该方法可使系统总容量扩大2倍。  相似文献   

9.
针对基于核函数的非线性盲源分离算法性能对核函数及其参数选择依赖性强这一问题 ,提出采用批处理方法代替聚类和核主成分分析方法来构造低维近似子空间的正交基,以 改进基于核函数的非线性盲源分离算法对核函数及其参数变化的稳健性,并对这种改进的非 线性盲源分离算法进行了完整的分析。通过仿真实验,对分离信号与源信号求相似度,可以 看到提出的基于批处理的非线性盲源分离算法能够取得更稳健、准确的分离效果。  相似文献   

10.
李彬 《电子商务》2013,(11):57-58
针对Web挖掘中的用户相似性问题,本文提出了一种基于相对曼哈顿距离的用户聚类算法。首先根据Web服务器日志数据信息,建立URL和用户关联矩阵,元素值分别为用户的访问次数及访问时间,并以此构建平均时间矩阵。在此基础上利用相对曼哈顿距离给出客户之间的距离,确定阈值后进行聚类。最后定义了类关联度,对聚类结果进行了确认和筛选,算例表明该算法具有良好的可操作性和准确性。  相似文献   

11.
Holding 88 percent of train media resources across China, based on "Time Cube", on the 2008 Intermedia Recommendation and Introduction Meeting on December 19, 2007, HTC announced its high-profile strategy of tour marketing and tapping the immeasurable potentials on the train. Meanwhile, HTC officially launched its brand new product Olympic Train on the meeting, providing a fabulous platform for all the brands that are prepared to do a smart marketing on the occasion of 2008 Olympic Games.  相似文献   

12.
In the end of 2007, Air China Limited (hereinafter "Air China") and Shanghai Airlines, formally joined Star Alliance at a ceremony held in the new Terminal Three at Beijing Capital International Airport. With the addition of the two Chinese airlines, Star Alliance now has 19 member carriers operating 17,000 daily flights to 897 destinations in 160 countries.  相似文献   

13.
Under the guidance of the theme slogan of the 29th Olympic Games - One World One Dream, with dream, love and dedication as its theme, the 2008 Music Grand Ceremony & 1000 People Charity Concert on 100 days cotmtdown to Paralympic Gamesis officiaily launched on December 22, 2007. The 2008 Music Grand Ceremony is sponsored by China Disabled Persons' Federation, and co-hosted by National Paralympic Committee of China,  相似文献   

14.
MUYANG GROUP     
With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research & development,project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.  相似文献   

15.
Aseries of events that occurred in October 2007, are rewriting the history of China's energy industry: November 3 an Energy Law Committee asked the public for suggestions on improvements; forty top experts came together to form the National Energy Expert Advisory Committee on November 6; and the National Oil Reserve Center (NORC)became the nerve centre of oil reserves on November 18. Yet, behind the progress of these recent activities remains the fact that international oil prices still hover around a very high price of US$ 90/barrel, and China's oil imports are close to accounting for half of its total oil reserves.  相似文献   

16.
2007 China Harbor Ten People elected the entrepreneurs who contributed a lot to port economy and enterprises this year trough their talent management.These ten people embody their social responsibility,professional skills,creative ability,and charming personality.Bearing full confidence in China's port economy,the port entrepreneurs are brave enough to explore a brand new area,so as to promote harbor economic development. At the very beginning of 2008,China Shipping Website,Dalian Maritime University,and China Port and Shipping In- stitute jointly select the 2007 China Harbor Ten People,demonstrate port entrepreneurs' stunning minds,disclose their secrets to success,and providing abundant experiences to others in harbor development.The top ten people are various excellence during the ups and downs harbor development.  相似文献   

17.
Since the normalization of the diplomatic ties between China and ) Japan, the bilateral economic relations have deepened continually. According to the statistic of Japan, China passed U.S. to become Japan's top trade partner as well as is the second largest export market for Japan and is the largest import resource for Japan. Japan companies such as Mitsui, Sumitomo, Sony and Panasonic, have set the subsidiaries in China and explored their scales. This year 2008 marks the 30th anniversary of the signing of the ChinaJapan Treaty of Peace and Friendship.  相似文献   

18.
China's textile and apparel industry suffered an unprecedented cold market for exports in the first quarter this year,the result of a few factors including: the appreciating RMB, decreasing export rebate rate,expanding influence of the U.S. subprime crisis, increasing costs of production and rising labor cost.  相似文献   

19.
The May 12 earthquake in Sichuan caught Chinese people by surprise and took the nation's heart. While mourning the dead and searching for the missing, many services must be provided for the survivors in the wake of the earthquake. Available post-quake financial services have become an important part of the reconstruction effort in the disasterstricken areas of Sichuan province.  相似文献   

20.
Aristotle saw ethics as a habit that is modeled and developed though practice. Shelly's Victor Frankenstein, though well intentioned in his goals, failed to model ethical behavior for his creation, abandoning it to its own recourse. Today we live in an era of unfettered mergers and acquisitions where once separate and independent media increasingly are concentrated under the control and leadership of the fictitious but legal personhood of a few conglomerated corporations. This paper will explore the impact of mega-media mergers on ethical modeling in journalism. It will diagram the behavioral context underlying the development of ethical habits, discuss leadership theory as it applies to management, and address the question of whether the creation of mega-media conglomerates will result in responsible corporate citizens or monsters who turn on their creators.  相似文献   

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