谐波检测作为电能质量研究中最主要的部分,对谐波检测的评价指标就是对谐波信号的实时分析性与准确性检测.谐波检测的准确性等评价指标是避免谐波产生危害和保障用电安全的重要保障,也是谐波检测算法的最终目标和判断准确性的重要依据.针对电力系统中频率相近的谐波信号中混叠和突变等难以检测难题,本文提出了利用SVD对矩阵束算法中的Hankel矩阵进一步去噪,改进了矩阵束算法.对进一步仿真产生含有邻近谐波的稳态信号进行检测,并对含有突变谐波信号使用小波包结合SVD算法进行突变点查找.仿真信号实验验证了所提方法的准确性,证明了此方法可以对邻近谐波与突变谐波信号进行检测与定位,算法具有较强的使用性.

为了满足灭火的快捷和安全性,具有智能自动灭火功能的消防水炮成为各大商场,图书馆等公共场所的主要消防设备.由于水流在垂直方向上会受各种作用力的影响,所以水炮在定位到火源后需要在垂直上相应偏转一定的补偿角度才能成功灭火.目前的水炮大多采用较为简单的固定值补偿方法,灭火的准确度较低.本文在改进原水炮代码的基础上,根据消防水炮的射流轨迹曲线方程分析射程和水炮俯仰角的关系,设计一种求解水炮补偿角的方法.实验结果表明,使用这种方法既增强了时效性,又能保障灭火的准确性.

Short-term traffic flow prediction in intelligent transportation system can provide data support in areas such as route planning,traffic management,public safety and so on.In order to improve the prediction accuracy with missing and abnormal data,a short-term traffic flow prediction method based on the adaptive rank dynamic tensor analysis was proposed.Firstly,a four dimensional tensor consisted of week,day,time and space was constructed,which could excavate the multimodal correlation of traffic flow data.Secondly,tensor flow data with dynamic structure was formed by using sliding window model.The principal component analysis (PCA) algorithm was extended to an offline tensor analysis algorithm that could accept tensor input.Then the adaptive rank and the forgetting factor were introduced to generate an adaptive rank dynamic tensor analysis algorithm.Finally,the tensor stream data was inputted into the adaptive rank dynamic tensor analysis algorithm to realize the short-term traffic flow prediction.The experimental results show that a good prediction can be achieved even with data missing.

Objective To explore the therapeutic strategies of unruptured intracranial aneurysms (UIA) associated with intracranial and extracranial artery stenosis. Methods Clinical data of 46 UIA patients with intracranial and extracranial artery stenosis were analyzed retrospectively. The parent artery stenosis of UIA was found in 11 patients, non-parent artery stenosis in 35. In the patients with parent artery stenosis of UIA, the UIA and artery stenosis were treated by surgery in the single-stage in 5 patients, simple aneurysms in 4 and simple artery stenosis in 2. In the patients with non-parent artery stenosis of UIA, the UIA and artery stenosis were treated by surgery in the single-stage in 14 patients, simple aneurysms in 12 and simple artery stenosis in 9. Results No aneurysms rupture and cerebral ischemic syndromes secondary to intracranial hypoperfusion occurred during the operation. There was no arterial thrombosis in 30 patients during the treatment for artery stenosis. The staged therapeutics had been prepared for 1 basilar aneurysm patient with middle cerebral artery stenosis, who died of massive cerebral infarction when waiting for the second stage of treatment for middle cerebral artery stenosis. Forty-five patients were followed up for 6 to 30 months with a mean period of 18.7 months, and no relapse in aneurysms and artery stenosis. Conclusions Multiple factors of imaging, clinical and hemadynamics factors should be considered in therapeutic strategies for UIA patients with intracranial and extracranial artery stenosis in order to make the personalized treatment programs.Furthermore positive surgical strategies should be performed on UIA with high risk.

低压电力线信道上的噪声干扰且具有时变性和随机性,对于通信系统的研发影响较大.为了给电力线通信系统的研发设计提供可控制、可重复的实验环境,在对低压PLC信道噪声特性的分析、建模仿真的基础上,利用MATLAB/Simulink直接生成DSP可执行代码,设计低压电力线信道噪声发生器.利用MATLAB快速生成DSP代码的方法,实现的噪声发生器与仿真实现噪声一致,同时方法简便,大大减少DSP设计开发的工作量.

电力线通信目前用途广泛，具有广阔的市场前景。但由于存在信息安全问题以及通过复杂信道的误码问题，需通过在信源端选择加密算法来对原始信息进行加密，防止非法第三方对信息进行窃取。利用纠错编码对加密后的信息进行信道编码，提高通信过程的可靠性，提高通信质量。本文采用DES加密方式和（7，4）汉明码编码方式形成整体方案，利用CCS软件进行加解密算法以及信道编码算法的编译，并下载到DSP目标板运行，验证方案的可行性。

本文介绍了PLC多频点通信系统及开关电容滤波器的原理,给出一个利用FliterCAD滤波器设计软件设计的巴特沃斯带通滤波器的应用电路.电路通过改变开关电容滤波器的时钟频率来改变带通滤波器的中心频率,克服了在PLC信号滤波中传统的由RLC分立元件组成的带通滤波器中心频率不易调节,导致PLC在多频点通信时多个频点所需的多套匹配滤波器电路复杂、集成度低的问题.

利用MATLAB中的Simulink对OFDM系统进行建模仿真,并通过代码转换对其发送端的核心算法生成DSP代码,经编译、链接、加载后在DSP目标板运行.OFDM符号由DSP板的输出接口输出,经D/A转换及放大后送入传输信道.在示波器上观测到OFDM时域符号波形与理论波形及仿真波形三者一致,验证了通过Simlink对系统DSP代码转换生成的正确性.

针对电纸书显示屏灰度等级不足的问题,提出了利用半色调图像处理技术的改进算法实现电纸书显示优化的方法.在阐述半色调技术与电子纸特点的基础上,介绍了抖动算法和误差扩散算法,通过对这两种算法进行改进提高电纸书显示的灰度级数及视觉效果.其中重点对误差扩散算法中的阈值、滤波器及扫描方式的设定进行设计,并提出一种基于误差动态检测的新的改进算法,能有效提高图像灰度级数,改善电纸书的图像显示质量.最后在电纸书系统平台上实现仿真,通过质量评价参数客观地评测了各种算法.

低压电力线载波信道具有干扰大及时变性等特点,针对此种信道在PLC通信系统上加入组合译码HARQ算法方案.通过将HARQ过程中多次重传数据进行组合译码,获得可靠性更高的新码字,从而提高PLC系统传输的抗干扰能力.Matlab仿真和实际的测试结果表明,采用该算法的HARQ系统在改善误码率的性能方面明显优越于一般的纠错控制算法.

本文简述了数字电视前端CA系统,在此基础上比较了三层和四层的密钥授权体系,对四层固定分组和四层动态分组的授权数据结构(EMM)做了详细的介绍.在百万级用户规模下对四层固定分组选用分组大小与用户授权管理数据的相关关系进行探讨,并基于原有的四层动态分组模型提出了由三四层密钥体系相结合的改进四层动态密钥体系的分配方法,最后通过实验条件实现四层动态加密系统.

本文简述了条件接收系统及电视邮件原理，在此基础上介绍了一种电视邮件系统设计的整体思路以及后端机顶盒邮件功能的软件设计思路，并详细叙述了对机顶盒应用层软件进行二次开发的过程。通过系统设计和机顶盒的二次开发，实现了电视邮件信息的发送、接收和显示。

介绍了条件接收系统框架和基本工作原理,对无卡CA和有卡CA进行比较。在此基础上提出了一种无卡CA设计方案及其在数字电视机顶盒中的实现方法,并给出相关流程。机顶盒HI2016主芯片作为主设备,解密芯片PIC16F690作为从设备,实现接收端解密解扰功能,提供了一种DVB-C机顶盒中条件接收模块的解决方案。

PLC(Power line carrier) communication is a communication mode implemented by power line,and in recent years,gradually becomes the hot topic for home broadband research.The power line is poor in transmission environment and complex in network structure and channel feature.Based on analysis of PLC channel frequency-selective fading,this paper proposes the frequency diversity technique for improving the reliability of communication.With the application of the simulation on multiple frequencies PLC communication with Matlab programming is carried out,and the signal demodulation also conducted with frequency diversity and combining technique by demodulation module.The simulation result indicates that the frequency diversity technique is of excellent performance in resisting PLC channel frequency-selective fading.

In order to study the application of OFDM in the PLC technology, and to implement it in DSP, we build an OFDM model through MATLAB/Simulink. After validating model parameters setting correct and technical indexes achievable by simulations, the corresponding DSP codes of the model are automatically generated, compiled using CCS and loaded into the DSP development board to output the waveform of OFDM signals. Experiment results show the outputted waveform of OFDM signals is consistent with their theoretical simulation results, further show that automatic DSP code generation by transforming MATLAB models is feasible and correct, and can analyze the impact of different numbers of IFFT on the waveform of OFDM. The method will be helpful to study the performance of communication systems such as OFDM, and rapidly develop DSP applications.

A PIC16 MCU and CC2500 radio frequency(RF) chip self-selected frequency wireless data transmission system design method is presented in this paper,including system hardware circuit design and software implementation.As the system has independent frequency selection function,the frequency conflict is solved due to co-channel interference in the ISM band frequency.

本文提出了一种有效的数字电视用户管理系统(SMS)与数字电视条件接收系统(CAS)接口通信软件解决方案。该方案依托现有数字电视前端发送系统框架,详细研究了SMS与CAS之间的接口通信协议、通信方式、数据包格式以及接口功能,并给出了具体的软件流程图。该接口系统主要基于.Net平台,运用C#语言开发,通过编程实现了SMS与CA系统源授权信息的数据通信。

Objective To summarize the nursing experience in assisting the performance of emergency endovascular treatment for ruptured cerebral aneurysms.Methods In past six years at authors’ hospital,emergency endovascular treatment for ruptured cerebral aneurysms was performed in 300 patients.The perioperative and in-operation nursing care measures were retrospectively analyzed,and their effectiveness was evaluated.Results All cerebral aneurysms in 300 patients were successfully treated by emergency endovascular intervention.No nursing-related complications occurred in all patients.Conclusion Strict accomplishment of scientific and standard nursing care measures can well ensure a successful performance of emergency endovascular intervention for ruptured cerebral aneurysms and the patients can achieve an excellent recovery as well.Besides,scientific and standard nursing care can effectively prevent the occurrence of complications.

In this paper,we abstract a unified interface from the various buses according to the commonality of the character device operation interface and serial buses based on Linux.Due to the independence of the underlying specific buses,the uniform interface is convenient to upgrade and transplant the application system.The implementation of the unified interface abstracted from multi buses is elaborated and the experiment conducted on the ARM9 platform,taking I2C,1-Wire and SPI as examples,verifies the feasibility of the new method finally.

In order that users can read E-books more intuitively and comfotablely,the E-paper Book emerged for E-books' wide applications in daily life.In this paper,design of graphical user interface of E-paper Book is implemented based on Linux operating system,with Qt graphical user interface development tools.Then,text documents can be showed on the electronic paper.The program implements the creation of the main window and some dialog boxes,and the switching and the interaction between the main window and the dialog boxes.Then,text documents decoding and paging of the different encoding methods are implemented in the process of loading text documents.