Optimal modulation formats for 2 560 km optical transmission with low power penalty

The production mechanism of non-return-to-zero (NRZ), return-to-zero (RZ) and carrier suppressed return-to-zero (CSRZ) was analyzed theoretically in this paper. We compared the transmission performance of CSRZ with RZ and NRZ formats at 10 Gb/s system by numerical simulation. And we simulated the transmission model constructed with Erbium-doped fiber amplifier (EDFA) as the solo amplifier and the chirped fiber Bragg grating (CFBG) as the solo dispersion compensator used in the system. A practical 8 × 10 Gb/s 2 560 km transmitted experiment was conducted in straight line with these different modulation formats mentioned above and the experiment results show very good agreement with the result of computer simulation. The CSRZ format is more effective than other formats in the system, and involved only 2.5 dB power penalty cost in the practical 2 560 km error-free experiment. The results also show that CSRZ will help to optimize the transmitted results and reduce the transmitted penalty further. Translated from Acta Optica Sinica, 2006, 26(3): 331–335 [译自: 光学学报]     

The face of 2010: A Delphi poll on the future of psychotherapy.

A panel of 62 psychotherapy experts using Delphi methodology predicted psychotherapy trends in the next decade. The observers forecasted changes in theoretical orientations, therapeutic interventions, psychotherapy providers, treatment formats, and future scenarios. Cognitive-behavior, culture-sensitive, cognitive, and eclectic/integrative theories were predicted to increase the most, whereas classical psychoanalysis, solution-focused theories, and transactional analysis were expected to decline. Directive, self-change, and technological interventions were judged to be in the ascendancy. Master's-level psychotherapists along with "virtual" therapy services were expected to flourish. Forecast scenarios with the highest likelihood centered on expansion of evidence-based therapy, practice guidelines, behavioral medicine, and pharmacotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ITU standardisation of very low bitrate video coding algorithms

The ITU near term standard for very low bitrate video coding, H.263 (ITU-T SG 15/1 Rapporteurs Group for Very Low Bitrate Visual Telephony, 1995), is described. Both QCIF and a sub-QCIF format (128 × 96) are mandatory picture formats for the decoder; the CIF picture format is optional. The H.263 algorithm consists of a mandatory core algorithm and four negotiable options. With H.263 a significantly better picture quality than with H.261 can be achieved, depending on the content of the video scene and the coding parameters. Also, the cost of the H.263 video codec can be kept low if only the minimum required is implemented. The negotiable options of H.263 increase the complexity of the video codec, but also significantly improve the picture quality. H.263 is part of a set of recommendations for a very low bitrate audio visual terminal that was frozen in January 1995 and is based on existing technology. A long term activity is planned by ITU for the development of a new video coding algorithm (H.263/L) with a considerable better picture quality than H.263. This standard will be developed in joint co-operation with MPEG4.     

SOS formats and meta-theory: 20 years after

In 1981 Structural Operational Semantics (SOS) was introduced as a systematic way to define operational semantics of programming languages by a set of rules of a certain shape [G.D. Plotkin, A structural approach to operational semantics, Technical Report DAIMI FN-19, Computer Science Department, Aarhus University, Aarhus, Denmark, September 1981]. Subsequently, the format of SOS rules became the object of study. Using so-called Transition System Specifications (TSS’s) several authors syntactically restricted the format of rules and showed several useful properties about the semantics induced by any TSS adhering to the format. This has resulted in a line of research proposing several syntactical rule formats and associated meta-theorems. Properties that are guaranteed by such rule formats range from well-definedness of the operational semantics and compositionality of behavioral equivalences to security-, time- and probability-related issues. In this paper, we provide an overview of SOS rule formats and meta-theorems formulated around them.     

GDI＋及多格式图像的转换

随着新一代操作系统WindowsXP的推出,传统的图形设备接口(GDI)技术被新的图形设备接口(GDI )技术取代。文中介绍了GDI 技术特点和与传统的GDI不同点。对比传统的GDI,GDI 一方面增加了新的功能,另一方面编程模式也与GDI不同了。着重介绍了GDI 在图像的格式变换方面相关知识,给出在GDI 中图像格式转换的编程方法以及实现图像格式转换的完整的示例,这些示例均已上机调试通过。这些知识对Windows下图像编程有一定的指导作用。     

浅谈数字音频文件格式及其转换应用

在广播领域使用的数字音频文件格式有多种,其中包括数字音频工作站的制作音频文件格式(S48),漫录系统音频文件格式(S48)以及Wav文件格式和MPEG-1音频压缩文件格式等等。该文针对广播电台常使用的两种音频文件格式进行介绍,并对这几种音频文件格式之间的转换方法和软件应用进行阐述。     

Is gambling involvement a confounding variable for the relationship between Internet gambling and gambling problem severity?

Internet gamblers have more problems gambling than land-based gamblers, but recent studies showed that Internet gamblers are involved in a higher number of gambling activities, which may confound the relationship between Internet gambling and gambling problems. The present study aimed to test whether the relationship between Internet gambling and gambling problems persisted when including variables related to gambling involvement as predictors, namely time spent gambling and diversity of gambling formats. Data from a large sample of French adolescents (n = 9910) were used. Associations between disordered gambling/money spent gambling with Internet gambling were performed using generalized linear models, not controlling and controlling for diversity of gambling formats and time spent gambling. The results showed that Internet gamblers had significantly more problems than land-based gamblers. The relationship decreased when diversity of gambling formats and time spent gambling were controlled separately, and became non-significant when they were both included in the model. To conclude, time spent gambling and diversity of gambling formats rather than Internet gambling should be considered a detrimental gambling behavior. They seemed to capture different aspects of gambling patterns. This study was a step forward in changing the conceptual model of problem gambling, with gambling involvement as a main variable.     

空间激光通信高速多制式光调制技术

空间激光通信调制技术以幅度调制和相位调制为主,单一通信终端只能适应特定的调制格式,灵活性较差,存在星间链路组网应用的局限性。文章基于数字处理的光调制技术,采用LiNbO₃晶体正交相位调制器,结合闭环偏压控制算法,实现了光调制格式、调制速率可变的星载光调制器,并针对空间应用对幅度调制和相位调制方式进行了优化,最大化光纤放大器效率。该技术硬件实现了625Mb/s~5Gb/s通信速率分档可调,OOK,BPSK和QPSK调制格式可变,发射EVM优于9%,实际引入灵敏度损耗小于1dB。该调制器已经完成所有空间环境试验,可广泛适用于各种体制的激光通信终端,进行星地、星间激光通信建链。同时,该调制器具备模拟调制的功能,可实现星间微波光子信号的透明转发。     

Intel的64位体系结构

Intel的64位体系结构突破了传统体系结构的局限，是真正的64位计算环境。本文对IA-64体系结构的设计原则、设计基础、指令格式、指令系统、所采用的主要技术及其它特征进行了介绍。     

配电调度应用层协议构造分析

参考了国内外电力公司自动化的情况,根据目前国内实际,尝试从数据格式、控制序列及服务原语等方面对配电系统实时数据通信应用层协议进行描述。