利用信号围线积分双谱分形特征实现电台识别

信号的双谱能反映信号的细微特征,可用于电台识别中,但将它直接应用于电台识别需要计算复杂的匹配模板,增加分类器的复杂度,影响识别效率。针对此问题,提出了一种将信号围线积分双谱的分形特征作为电台特征参数的识别方法。首先由信号双谱估计值求出围线积分双谱,然后利用盒维数和信息维数定量描述围线积分双谱波形的复杂度,并将这两种分形维数作为特征向量,最后利用支持向量机(SVM)实现电台分类识别。对两部实际电台所发射的2FSK信号利用所提方法进行分析,结果表明在信噪比为7 dB及以上时,电台正确识别率能达到94.29%以上,验证了所提方法的可行性。     

地质灾害造成的环境冲击探讨

时间:2008年5月12日14时28分04.0秒;纬度:31.0°N;经度:103.4°E;深度:14km;震级:里氏震级8.0级,矩震级7.9级;最大烈度:11度;震中位置:四川省汶川县映秀镇。都江堰市西21km(267°)崇州市西北48km(327°)大邑县西北48km(346°)成都西北75km(302°)汶川地震是中华人民共和国自建国以来影响最大的一次地震,震级是自2001年昆仑山大地震(8.3级)后的第二大地震,直接严重受灾地区达10万平方公里。     

基于模糊发票QR二维码的识别技术研究

主要针对谷歌二维码识别开源项目Zxing项目进行改进,提出了Improve-Zxing算法。其一,不同于Zxing项目在全图上面寻找二维码的三个定位点来做二维码的定位,利用形态学等决策对二维码进行定位;其二,不同于Zxing项目使用最大类间方差算法(OTSU)对图片全域进行二值化处理,仅对图片中二维码区域进行二值化计算。利用835张模糊发票二维码进行验证,发现改进的算法不仅能够减少二维码识别计算的时间,并且还能有效地提升模糊发票二维码图片的识别精度。     

基于信任机制的无线电环境地图重构

无线电环境地图系统中的感知节点被俘获后会受迫地向数据中心发送伪造数据，导致无线电环境地图精度降低。针对该问题，提出了基于信任机制的空间插值算法改进方案，并阐述了感知节点信任值更新策略。该方案通过改变感知节点的信任度来降低恶意节点的数据在空间插值算法中的权重，经过信任值的多次更新而最终隔离恶意节点。实验仿真中，均方根误差（RMSE）和误警区域率-正确检测区域率（FAZR-CDZR1）两种性能指标均表明所提方案能够有效遏制恶意节点的篡改数据攻击，保障了无线电环境地图的精确度。     

基于多次观测的机载天线阵列幅相误差自校正方法

针对有源幅相误差校正方法需要已知校正源位置,以及迭代自校正方法依赖初值选取等问题,提出了一种信号源位置未知条件下机载天线阵列幅相误差的自校正方法。所提方法利用机载阵列随机载平台运动过程中的多次观测数据,通过挖掘多组观测数据的特征空间结构,将外辐射源位置和阵列的幅相响应进行分步估计。所提算法在幅相响应的估计过程中,也完成了对辐射源的定位。同时,所提方法对机载平台运动轨迹、阵列具体几何形式均未做特定限制。仿真实验结果表明,当信噪比大于5 dB时,所提算法对阵列幅度误差的估计误差小于0.5 dB,对阵列相位误差的估计误差小于2°,验证了所提算法的有效性。     

四星时差定位中的卫星构型及其定位性能

针对目前多星联合定位研究中对卫星覆盖区域无法长时间高精度定位的问题，提出了一种新型的四星星座构型，并在STK软件中得到了实现。推导了在地球约束情况下基于四星时差定位的误差模型，对卫星全球飞行过程中星座构型变化时的定位性能进行了仿真。仿真结果表明，新型四星星座可以实现在卫星全球飞行过程中对覆盖区域保持高精度定位，在时差测量误差为50 ns且不考虑卫星位置误差的情况下，定位误差在±45°波束范围内优于1.5 km，对多星联合定位技术在工程设计应用上具有重要意义。     

手机

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高必需氨基酸米Y-800与11种食物氨基酸组成比较及营养评价

目的:分析比较高必需氨基酸米Y-800与11种食物的氨基酸组成,对其做出营养评价,为进一步研究开发高必需氨基酸米Y-800提供依据。方法:根据FAO/WHO的理想蛋白质条件,计算组成蛋白质的每种必需氨基酸/总氨基酸的值(E/T)和必需氨基酸/非必需氨基酸的值(E/N),对高必需氨基酸米Y-800及11种食物做出初步营养评价;蛋白质的营养评价指标包括氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)、氨基酸比值系数(RC)、氨基酸比值系数分(SRC),氨基酸呈味贡献指标选择味觉阈值比(RCT)。结果:高必需氨基酸米Y-800氨基酸种类齐全,数量丰富,E/T值为40.33%,E/N值为0.68;与所选11种食物比较AAS、CS和EAAI,高必需氨基酸米Y-800限制性氨基酸种类少,各种必需氨基酸评分较高;鲜味氨基酸为高必需氨基酸米Y-800的主要呈味氨基酸,RCT值为小麦粉高必需氨基酸米Y-800小米早籼晚籼玉米粳米。结论:高必需氨基酸米Y-800必需氨基酸含量达到了FAO/WHO提出的理想蛋白质条件且风味佳,较所选11种食物更符合人体需求,更益于人体健康。     

“361°”品牌的陕西市场推广与运营

目前,"361°"这个对于我国大多数体育爱好者都再熟悉不过的品牌已经凭借自身的市场运营和推广深入人心。良好的市场口碑和信誉度使得越来越多的人们开始关注"361°",开始喜欢"361°",而其年轻时尚的市场定位也为自己赢得了众多的客户群,尤其是学生的喜欢。本文以陕西省为调查研究区域,就"361°"品牌的市场推广与运营做出相关性阐述和分析,旨在为我国体育品牌的发展提供可行性参考依据。     

智能手机PDA

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Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.     

Challenge and Opportunity Go Hand in Hand——What Global Economic Agitation Brings to the China's Economy?

Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit.     

Sinosteel：Extraordinary Moves in Industry Chess

Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service ＆ trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,＂In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves.＂     

Walk Through Unusual Five Years—— An Exhibitor＇s Canton Fair Course

When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years＇ experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year.     

Jean-Pierre Duprieu： Willing to Be A Legate of Sino-French Business

Estaing, former French president, Valery Giscard d＇Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself＂French Confucian＂, then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually ＂Partners＂.     

China''''s Stock Market Wave

The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy.     

Trade Promotion from Neighborhood

If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning.＂ You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization （JETRO）. JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China＇s Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING.     

Auto Parts Market Potential Coming into Surface

Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship,     

Public Financial Expenditure——A Reflection of the Livelihood Improvement

In recent years.China's public finance put social construction high on the agenda and attaches more importance on livelihood insurance and improvement.The 2003-2007 public financial expenditure reflects a fact that the government isputting more emphasis on livelihood andissues concerning the people.     

Voices from the MPC and CPPCC

"Crucial for economic growth.energy utilization has its role in all economic sectors and every aspect of people's daily life.Now we are in dire need of a new profession,namely energy manager.We not only need to have passion and responsibility,but also a scientific approach to conserve energy and cut emissions.APpropriate legislation should be in place.and a special profession should be introduced to ensure the implementation of these laws and regulations."