基于椭圆球面波信号的多支路连续相位调制解调方法

针对现有甚低频通信模式通信速率较低、频带利用率不高的问题,探索研究一种基于椭圆球面波信号的多支路连续相位调制解调方法。具有时频域高能量聚集性的椭圆球面波信号引入连续相位调制,利用椭圆球面波信号完备正交特性,将不同阶椭圆球面波信号同时作为连续相位调制的基带调频脉冲信号,产生多支路连续相位调制信号;在信号接收端,利用传统差分相干检测对信息符号序列映射信息进行解调,通过对多个比特周期内信号求互相关值和的方法,实现椭圆球面波波形映射信息的检测与解调。仿真实验结果表明:该多支路连续相位调制解调方法与目前甚低频通信采用的最小频移键控调制模式相比,在调制信号99.9%功率带宽条件下,可有效提高频带利用率约9.43%;但在调制信号99.0%功率带宽条件下,频带利用率会降低约1.24%.

OFDM系统中的高阶调制性能比较

针对OFDM系统中的MQAM和MDAPSK两种子载波高阶调制技术,介绍了16DAPSK信号的时域和频域差分调制解调方法,比较了16DAPSK和16QAM的BER性能。仿真结果表明,在频率选择性和时间选择性衰落信道下,若信道相邻子载波和相邻OFDM符号的相关性能得到保证,采用16DAPSK调制,可以用较少的信噪比损失换取编码OFDM系统(COFDM)复杂度的大大降低。16DAPSK调制方式的这一优势同样适合更高阶的MDAPSK-COFDM系统。

光纤电流互感器光路故障自诊断告警算法

介绍了全光纤电流互感器工作原理及光路告警原理,提出并实现光纤电流互感器干涉光强调制解调算法。在调制偏置波形的基础上,引入周期性误差量δ,通过解调算法有效解调出干涉光强大小。测试表明,干涉光强的解调能够有效反映出光纤电流互感器光路衰减、偏振态劣化、突然断裂等故障,同时误差量δ的引入并不影响原来电流大小、调制器误差量ε的解调,光纤电流互感器闭环系统仍然能够在-40℃～+70℃范围内,保持GBT20840.8标准0.2级准确度。实验结果证明了所述方法的正确性。

SERIALLY CONCATENATED CONTINUOUS PHASE MODULATION WITH REDUCED ITERATIVE DEMODULATION AND DETECTION

A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection (RSSD),it has more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number,thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the perform-ance degradation is little with proper reduction scheme.

Attractor behavior in dilatonic(phantom) dark energy model with an especial potential

The dilaton in Weyl-Scale induced gravitational theory is regarded as a candidate of dark energy. When the potential of dilaton field is taken as the form Wσ ＋ σ^2e^-βσ2, that there exist attractor solutions to the canonical dilatonic dark energy model and the phontam model, and these attractors correspond to an equation of state ω = -1 and a cosmic density parameter Ωσ = 1, which are important features for a dark energy model and can fit with the current observations. We find a sufficient condition of the existence of a late time de Sitter attractor. The attractor behaviors, the evolutions of the state parameter ω and the cosmic density parameter Ω, the evolution of X （σ/σ0） and Y （σ/σ0^2） with respect to N（ln a）are shown numerically.

The Effectiveness of M-learning in the Form of Smart Phones in English Grammar Teaching

This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional paperwork practice and smart-phone-based revision methods during half semester of grammar learning. During the research, students＇ learning performances, as well as their self-report reflections, are recorded, compared, and analyzed. Statistics from the research show that students in general prefer the m-learning revision methods than the traditional paper ones. Besides, the modem methods do play an essential role in motivating students＇ learning initiatives, and thus resulting in better learning outcomes. However, on the other hand, some of the students surveyed also demonstrate their negative impression on the m-learning methods, in that they believe this modem technology can inevitably distract them from learning and there are also some technical problems to be worked out.

Urban Transformation and Nostalgia in Merdivenkoy, Istanbul

In this paper the author will try to discuss the experiences and narratives of three different categories of families living in Merdivenkoy, Fikirtepe, the oldest settlement and suburban area of the Anatolian side of Istanbul, on the backdrop of urban transformation that will change the area soon. In life story narratives, these three examples give us information about the history, economic linkage, and life styles of neighboring families. The first category basically consists of the families that live in the area for a very long time, over some decades or more. Even one of them mentioned that, their family is living there for hundreds of years. The second category, which represents the biggest group living in the area, consists of families migrated from Sivas, a central Anatolian city, in the 1950s. Third category consist of Kurds migrated from eastern Anatolian villages and cities such as Mardin. Each category has different kinds of nostalgia about the past. Interviewees from the first category talk about family narratives related to the small village Merdivenk6y, Fikirtepe and the area. Mostly, they have a story of a ＂well off＂ family, structured and detailed narratives about the family history, including relations with the Ottoman Palace such as doing some sort of production for it. They seem very sensitive about the local cultural characteristics and what＇s going on in the area; realistic about and reconciled with what will happen as a result of slum clearance. Interviewees from the second category mostly emphasize the hardship of settling in a muddy suburban area, where once ＂muddy lands＂ now turned out to become valuable urban properties on which new and modem neighborhoods, shopping malls and office buildings will be built. They are expecting to get maximum gain out of the exchange of their small property, since they are desperately in need, because of the financial crisis situation. Although their houses with small gardens near the small industrial area are small, old, and neglected for years, they expect the most. Relatively newcomers, Kurdish people in the area talk about the good old days on the one hand and the painful stories about migration and settling on the other hand. They do not think about going back to their native lands, since here it is easier for them to find jobs in the informal economy as they live very close to central parts of the city. As a part of a larger research study focused on the experience of urban transformation, we made more than 50 interviews, trying to make a general outlook of the area, working on the dynamics of change before and after the urban transformation that had been started in June 2010. By using oral history research techniques and social science methodology, we conducted in-depth interviews with the people living in the neighborhood, made observations in the neighborhood and took photographs. The author＇s work is about the reflections of nostalgia in their family histories and experiences of different categories of families living in the area referring life story narratives. As far as the author can see in each group he works on, there are different contradictions related to their position in the city and conception of the area. The urban transformation presented and is perceived as a fortune for all of them, but it will have contradictory outcomes in reality for each as indicated in other examples in the world.

Design and Management of Building＇s Resources

The developed modem control systems and buildings management resource systems would be effective if they are based on previously established optimal conditions during the building design. This is one of the key issues for a responsible architecture. The focus of this paper is on sustainable design methods and techniques for saving resources and their management throughout the building lifecycle. The main subject of the present article is the characteristics of these methods and their fundamental role in sustainable resource management during the building operation. The results which are based on conducted case studies of European and international practice in the construction of sustainable buildings are implemented here. Key features of a comprehensive approach for design and construction are outlined via comparative analysis, as well as various systems for the evaluation of sustainability for already constructed buildings. The mostly used criteria and indicators for sustainability are systematized, including those related to resource consumption. By analyzing a specific example, the role of sustainable design methods is justified as an important prerequisite for effective management of building resources in the process building maintenance. According to the conducted studies, during the longest life cycle period of a building, by implementation of control systems and resource management of building, the costs are successfully optimized. Specific directions that prove the effectiveness of such systems are systematized in the paper. Innovative approaches, complex methods and measures for design and management of buildings resources are presented as results of this study.