Is prediction possible? Chaotic behavior of Multiple Equilibria Regulation Model in cellular automata topology

In this article, we present the Multiple Equilibria Regulation (MER) Model in cellular automata topology. As argued in previous explorations of the model, for certain parameter values, the behavior of the system exhibits transient chaos (namely, the system is unpredictable but ends in a final steady state). In order to approach empirical reality, we introduce a cellular automata topology. Examining the outcome of the simulations leads us to conclude that for certain parameter values tested, the system yields chaotic behavior. Thus, cellular automata contribution has proven crucial, because the introduced topology converts the behavior of the system from transient chaos to “pure” chaos, i.e., the system is not only unpredictable on the long run but, in addition, it will never rest in a final steady state. According to these findings, authors argue the theoretical hypothesis that the urge for “prediction” in social sciences should be reconsidered in terms of “predictability horizon”. © 2004 Wiley Periodicals, Inc. Complexity 10: 23–36, 2004     

数字电视中载噪比(C/N)和调制误码率(MER)对BER的影响

为保证数字电视信号传输质量，须合理规划设计C／N和MER指标，确保BER指标符合要求。讨论数字电视系统中载噪比（C／N）和调制误码率（MER）对误码率（BER）的影响，分析QAM调制原理。     

数字电视QAM调制器的质量评测与维护

本文介绍了QAM调制器的组成、主要功能和性能指标,如何利用星座图对QAM信号质量进行分析,并讨论如何对QAM调制器进行质量评测,以及如何对其做好运行维护。     

Quest for Zeolite-like Supramolecular Assemblies: Self-Assembly of Metal–Organic Squares via Directed Hydrogen Bonding

Our conceived approach based on the directed assembly of functional metal–organic squares (MOSs), 4-membered ring (4MR) building units, permitted the construction of two novel zeolite-like supramolecular assemblies (ZSAs), namely [Co₄(ImDC)₄(En)₄]⋅9 H₂O⋅1.5 DMF ( ZSA-10 ) and [Co₄(ImDC)₄(En)₄]⋅7 H₂O ( ZSA-11 ) (H₃ImDC=4,5-imidazoledicarboxylic acid, En=ethylenediamine, DMF=N,N-dimethylformamide). The elected MOSs encompass both trans- and cis-coordinated nodes, offering complementary peripheral functional groups for their directed assembly into zeolite-like topologies via supramolecular hydrogen bonding interactions. Distinctly, ZSA-10 possesses the underling MER zeolite topology and is the only pure MER framework material (without any supporting templates) exhibiting permanent porosity up to now. ZSA-11 has the underlying ABW topology together with one type of narrow channel.     

基于零中频结构的数字电视调制系统研究

介绍了基于零中频结构的数字电视调制系统的特点、特性、硬件设计和调试方法。重点分析并仿真了零中频结构中,相位误差和幅度不平衡对射频镜像抑制和调制误差的影响,并给出了如何设计和校正零中频结构数字电视调制系统。     

调制误差比（MER）在数字电视网传输中的变化

数字电视信号在传输的过程中,调制误差比（MER）、误码率（BER）、信噪比（S/N）、电平等是体现数字电视网络质量的几个重要指标,其中调制误差率能体现数字电视信号的整体质量,它包含各种噪声、载波泄漏、IQ幅度不平衡、IQ相位误差、相位噪声等所有类型的信号损伤。通过对数字电视网络分中心机房输入输出的信号测试,比较输入输出前后信号的变化情况,并分析出其中的原因。     

数字电视中调制差错率（MER）与比特误码率（BER）的关系

随着近年来数字电视技术的不断发展,掌握和理解好数字电视传输中的主要指标十分的重要。我们只有合理地规划和调整好调制误码率(MER)等重要指标,才能更好确保比特误码率(BER)指标保持在一个良好的范围内,从而有效保证数字电视信号的优质传输。     

有线网络高端数字载波电平对MER和BER影响的测试

本试验是在有线电视高端（550MHz）以上传输数字电视情况下,讨论载波电平对MER和BER的影响,借以提高数字电视信号的传输质量.     

高速信令的最坏眼图技术研究

在对最大峰值失真法(PDA)、双边沿法(DER)及多边沿法(MER)3种主流的快速时域仿真技术进行分析的基础上,提出一种最优时域仿真法(BTDS),其通过改进获取最坏码型的方法,提高眼图精度。BTDS在眼高计算上与MER精度等价,但较MER在眼宽计算方面具有更高的精度,且克服了PDA不能计算不对称边沿的信号和DER有时推算不出最坏码型的缺陷,在高速时域仿真中具有较高的应用价值。