Discussi on on IPTV Operations Modes

1 IPTV Values and Challenges IPTV is a promising broadband video service to which globe telecom operators are attachinggreat importance. IPTV utilizes broadband IP network and takes TV+ set- top box (or computer) asterminalto provide customers withvarious interactive multimedia servicesincluding video program,communication, and game throughflexible broadcasting modes:on- demand, living or time shifted.In China, low PC penetration rate hasbecome a bottleneck hindering thefurther developm…     

Perspective on the imaging device based on perovskite materials

Large light absorption coefficients,tunable bandgaps,high tolerance to defects,long carrier lifetimes as well as diffusion lengths render lead halide perovskite materials ideal candidates for optoelectronic devices.Except application in solar cell,photodetectors based on perovskite materials have been recognized as another game changer due to the achievements such as high responsivity of 1.9×104 A/W[1],gain factor larger than 5.0×104[1],large detectivity of 1014 J[2],high on/off ratio of 105[3],fastest response time down to 1 ns[4],large linear dynamic range exceeding 170[5]and low detachable light intensity as small as 1 pW/cm2[6],which demonstrate the potential applications of perovskite based photodetector in the areas of weak light detection.     

Research on Protecting Against SYN Flooding on a Firewall

1　IntroductionTheSYNFloodingattacksexploitTCP sthree wayhand shakemechanismanditslimitationinmaintaininghalf openconnections,andareper formedbytheattackersubmittingastreamofTCPSYN (connectionrequest)packetstothetargetsys tem ,fillingitsconnectionrequestqueue,andthusdenyinglegitimateusers accesstothetargetsys tem[1 ] .SYNFloodingdoesgreatharmtopopularwebsites,especiallytoe Businessones.Severalapproacheshavebeen proposedtocounterSYNfloodingattacks.SYNCache[2 ] andSYNCookie[3] canmiti…     

The Study of Telecommunicati on Industry Based on the Ecosystem

1IntroductionIn the long evolution, many life-forms in the naturalecosystem have formed very perfect and exact system,which has uncommon capability to adapt the change ofthe environment and can use the substance andthe ener-gy efficiently. Moreover ,the telecommunicationindus-trylooks like the natural ecosystem. Every telecommu-nication enterprise can be regarded as an ani mated life-form,competing and cooperating with others ,adjustingitself gradually to adapt the environment that changeswith…     

Study on microwave photonic filters based on lasers and dispersive fiber

A general theoretical model for microwave photonic filters based on multi-wavelength light source and dispersive media is summarized and presented, and is applied to the analysis of double-laser-based microwave photonic notch filters’ performance. The different influences of the double-sideband(DSB) modulation and the single-sideband(SSB) modulation are demon- strated and explained theoretically. Furthermore, the impact of different factors, such as frequency spacing, 3dB bandwidth and the spectrum amplitude mismatch on the performance of the microwave photonic notch filters are also studied. The numerical simulation results are in good agreement with predictions, and could be beneficial for future optimization of microwave photonic filters.     

Comments on A Signcryption

1　ＩｎｔｒｏｄｕｃｔｉｏｎＡｓｄｅｓｃｒｉｂｅｄｉｎＲｅｆ.[7],ａｓｉｇｎｃｒｙｐｔｉｏｎｓｃｈｅｍｅｉｓａｃｒｙｐｔｏｇｒａｐｈｉｃｍｅｔｈｏｄｔｈａｔｆｕｌｆｉｌｌｓｂｏｔｈｔｈｅｆｕｎｃ ｔｉｏｎｓｏｆｓｅｃｕｒｅｅｎｃｒｙｐｔｉｏｎａｎｄｄｉｇｉｔａｌｓｉｇｎａｔｕｒｅ,ｂｕｔｗｉｔｈａｃｏｓｔｓｍａｌｌｅｒｔｈａｎｔｈａｔｒｅｑｕｉｒｅｄｂｙｓｉｇｎａｔｕｒｅ ｔｈｅｎ ｅｎｃｒｙｐｔｉｏｎ .ＡｃｃｏｒｄｉｎｇｔｏＲｅｆ.[3 ],ａｄｉｇｉｔａｌｓｉｇｎａｔｕｒｅｗｉｔｈａｍｅｓｓａｇｅｒｅｃ…     

Auxiliary Fault Location on Commercial Equipment Based on Supervised Machine Learning

As the fundamental infrastructure of the Internet,the optical network carries a great amount of Internet traffic.There would be great financial losses if some faults happen.Therefore,fault location is very important for the operation and maintenance in optical networks.Due to complex relationships among each network element in topology level,each board in network element level,and each component in board level,the con-crete fault location is hard for traditional method.In recent years,machine learning,es-pecially deep learning,has been applied to many complex problems,because machine learning can find potential non-linear mapping from some inputs to the output.In this paper,we introduce supervised machine learning to propose a complete process for fault location.Firstly,we use data preprocessing,data annotation,and data augmenta-tion in order to process original collected data to build a high-quality dataset.Then,two machine learning algorithms(convolutional neural networks and deep neural networks)are applied on the dataset.The evaluation on commercial optical networks shows that this process helps improve the quality of dataset,and two algorithms perform well on fault location.     

Solaris on Intel大受欢迎

Solaris on Intel 又称 Solaris x86。这个在几个月前才投放市场的新操作系统是为了使 MS—DOS/Windows 应用程序可运行于 Solaris 环境。用户使用结果表明,Windows 应用程序在 Solaris on Intel 下运行时,其性能相当于 Sun IPC 或 IPX 工作站的性能。Solaris on Intel 的高性能和完善功能使用户大受鼓舞,但它现在还缺乏一些重要的应用软件,如 Sybase 公司的SQL Server。反过来,它又吸引许多软件公司向它移植应用软件。     

Hi-Fi on Line 12

朋友们,大家好,Hi-FiOnline又和大家见面了。今天的主角是大家都十分熟悉的美国品牌——ROTEL(路遥)。路遥是一家“老字号”的专业音响厂商,所生产的功放、CD唱机等在发烧友中均具有良好的口碑。在上一期中所介绍的980系列前后级AV功放便是其成功设计之一。今天,就让我们一起去看一看它     

喝水on the 小巴

这是我第一部纯二维手绘的动画短片,很简洁的形式,长度为一分多钟。因为技巧上有一个从生到熟的过程,所以从动笔开始经历了三个月的时间。而我之前的两个分别是泥偶动画和flash动画,而且幸运的在两次比赛中分别获得了奖项。可能是性格不够细腻吧,总对手绘动画信心不足,这次的尝     

Comment on ‘Discussion on Barkhausen and Nyquist stability criteria’

This comment is related to the recently published article entitled “On ‘Discussion on Barkhausen and Nyquist stability criteria’, Analog Integrated circuits and signal processing, Vol. 70, pp. 443–449, 2012. In this article the authors considered one of the possible four alternatives of the Wien-bridge oscillator that was previously considered in the article entitled “Discussion on Barkhausen and Nyquist stability criteria”, Analog Integrated Circuits and Signal Processing, Vol. 62, pp. 327–332, 2010, which depicts the failure of Barkhausen criterion concerning the determination of the condition of oscillation startup of sinusoidal oscillation. In the above mentioned articles the operational amplifier used is assumed ideal. In this comment it will be shown that the Wien-bridge oscillator circuit used in the above mentioned articles can behave as a sinusoidal oscillator only at relatively high frequencies when the operational amplifier can be considered non-ideal. At relatively low frequencies; when the operational amplifier can be considered ideal, the same circuit behaves as a relaxation oscillator with a square wave output rather than a sinusoidal output.     

Analysis on Design of Kohonen-network System Based on Classification of Complex Signals

The key methods of detection and classification of the electroencephalogram(EEG) used in recent years are introduced . Taking EEG for example, the design plan of Kohonen neural network system based on detection and classification of complex signals is proposed, and both the network design and signal processing are analyzed, including pre-processing of signals, extraction of signal features, classification of signal and network topology, etc.     

Research on Marketing Channel of Mobile Manufacturer Based on Analytic Hierarchy Process

Research on ＂marketing channel＂ of mobile attracts much attention in these years, but there＇re only few articles referring to how to optimize the disposition of channel resources for mobile manufacturers. Based on a typically multiplex marketing channel system of mobile manufacturer, the analytic hierarchy process （~HP） structure model is established. Through the judgment matrix, simple and total hierarchy arrangement, consistent test, this paper gets the weight of each kind of marketing channel of mobile manufacturer, it provides the practical reference value for mobile manufacturers to distribute resources of marketing channels.     

Effects of Thickness on Properties of ZnO Films Grown on Si by MOCVD

采用金属有机化学气相沉积方法,在Si(100)衬底上生长出具有高度C轴择优取向的ZnO薄膜.通过X射线衍射、原子力显微镜和室温光致发光谱研究了厚度对ZnO薄膜的结构、表面和光学性能的影响.X射线衍射图显示ZnO薄膜只有单一的(0002)峰,具有高度择优取向.AFM和PL测试表明,在取样薄膜厚度范围内,薄膜的表面质量和发光性能没有随着薄膜厚度的增加而提高.这是因为薄膜在厚度增加的生长过程中,生长模型变化且晶粒增大.     

Studies on Three-electrode Semiconductor Laserss

Using the ray trace method, three-section semiconductor lasers are studied. An analytic expression of output power for the three-section semiconductor lasers is derived for the first time. From this expression, threshold condition is also obtained.     

Research on Optical Interconnection Network

Perfectshuffle(PS)isabasicandessentialpermutationfunction.Becauseofitsregularityandsymmetry,itissuitableforimplementationbyopticalelements,therefore,itisoneofthefocusesintheresearchofopticalinterconnections.Inthispaper,severaltheoreticalproblemsandexperimentsabouttheopticalimplementationsofPSand4×4photonswitchingarestudied.Chapter1givesadetailedintroductiontotheorigination,classificationanddevelopmentofopticalinterconnections.Chapter2describestheformationofomegainterconnectionnetworksandint…     

Study on End-to-End Web Performance

1　Introduction　WithWebbeingthemainserviceinthecurrentInternet,improvingend to endwebperformancebecomesanurgentandinterestingtopicnow .Userperceivedlatencyisthemostimportantmetrictoe valuateend to endwebperformance.　Fig .1showsatypicalprocessofretrievingaWebpage (expressedasaURL) .　·AuseragentmakesDNSlookuptoresolvetheservernameintherequestedURL .　·TheuseragentestablishesaTCPconnectiontotheserver.Fig .1　ProcessofretrievingaWebpage·TheuseragentsendsarequestoftheURL (en capsula…     

Study on optical compund films

Using the compound materials and double e-gun evaporation ,the compound optical films have been successfully deposited on K9 glass substrate.The refractive index of optical compound films deposited in diffeent parameters have been measured and theoretical formula for calculation refractive index of compound films have been derived.Tt is shown that the experimental curve for the variation of re-fractive index with wavelength in 0.4-1.4цm region and the theoretical one agree very well.Using these films,the laser reflecting mirror has been successfully coat-ed.     

The Research on Mobile-agent Security

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｅｒｅｓｔｉｎｎｅｔｗｏｒｋ ｃｅｎｔｒｉｃ ｐｒｏｇｒａｍｍｉｎｇａｎｄａｐｐｌｉｃａｔｉｏｎｓｈａｓｓｕｒｇｅｄｉｎｒｅｃｅｎｔｙｅａｒｓｏｗｉｎｇｔｏｖａｒｉ ｏｕｓｆａｃｔｏｒｓ,ｓｕｃｈａｓｔｈｅｅｘｐｏｎｅｎｔｉａｌｇｒｏｗｔｈｏｆｔｈｅＩｎｔｅｒｎｅｔｕｓｅｒ ｂａｓｅ,ａｎｄｔｈｅｗｉｄｅｓｐｒｅａｄａｄｏｐｔｉｏｎｏｆｔｈｅＷｏｒｌｄｗｉｄｅＷｅｂａｓａｐｌａｔｆｏｒｍｆｏｒｉｎｆｏｒｍａｔｉｏｎｄｉｓｓｅｍｉｎａｔｉｏｎ,ｅｌｅｃｔｒｏｎｉｃｃｏｍｍ…