Chaos Identification Based on Component Reordering and Visibility Graph

The identification between chaotic systems and stochastic processes is not easy since they have numerous similarities. In this study, we propose a novel approach to distinguish between chaotic systems and stochastic processes based on the component reordering procedure and the visibility graph algorithm. It is found that time series and their reordered components will show diverse characteristics in the ＇visibility domain＇. For chaotic series, there are huge differences between the degree distribution obtained from the original series and that obtained from the corresponding reordered component. For correlated stochastic series, there are only small differences between the two degree distributions. For uncorrelated stochastic series, there are slight differences between them. Based on this discovery, the well-known Kullback Leible divergence is used to quantify the difference between the two degree distributions and to distinguish between chaotic systems, correlated and uncorrelated stochastic processes. Moreover, one chaotic map, three chaotic systems and three different stochastic processes are utilized to illustrate the feasibility and effectiveness of the proposed method. Numerical results show that the proposed method is not only effective to distinguish between chaotic systems, correlated and uncorrelated stochastic processes, but also easy to operate.

Developing high-efficiency base editors by combining optimized synergistic core components with new types of nuclear localization signal peptide

The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.

Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rectangular hollow section column under tension

The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this paper.Two unknown stiffness components are considered:the TOBs connection and the enclosed RHS face.First,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated deformations.Based on the findings,the thread-shank serial-parallel stiffness model of TOB connection is proposed.For analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate analysis.According to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load conditions.Referring to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,etc.Finally,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub substructures.The proposed component stiffness equations are an effective supplement to the component-based method.

基于通信的列车自动监控系统平台设计与实现

针对基于无线通信的列车控制系统(CBTC)的需求和现状,对其原理及特点进行深入分析,特别是对移动闭塞原理的分析,并利用组件化程序设计思想与线路拓扑结构,提出并设计了一种基于CBTC的列车自动监控(ATS)系统交互式平台,并交付ATS仿真运营框架对站场运行图进行调用。

Guided Modes of Hollow Optical Fiber Based Components: Analytical Solutions

Guided modes in a hollow optical fiber are investigated using both scalar approximation and exact vectorial analysis. Effective indices of modes are seen to exhibit "nearly degenerate" groups. Besides providing an insight of modal characteristics, the analysis would prove to be useful to define design parameters for realizing components based on these fibers, and to explore new possibilities.

钛基材料中元素分析方法研究进展

综述了钛基材料中组分元素测定方法的近年研究进展情况,涉及分析方法有原子发射光谱法、原子吸收光谱法、分光光度法、滴定法、X射线荧光光谱法、质谱法、红外/热导法等(引用文献73篇)。

Fast removal of ocular artifacts from electroencephalogram signals using spatial constraint independent component analysis based recursive least squares in brain-computer interface

Ocular artifacts cause the main interfering signals within electroencephalogram （EEG） signal measurements. An adaptive filter based on reference signals from an electrooculogram （EOG） can reduce ocular interference, but collecting EOG signals during a long-term EEG recording is inconvenient and uncomfortable for the subject. To remove ocular artifacts from EEG in brain-computer interfaces （BCIs）, a method named spatial constraint independent component analysis based recursive least squares （SCICA-RLS） is proposed. The method consists of two stages. In the first stage, independent component analysis （ICA） is used to decompose multiple EEG channels into an equal number of independent components （ICs）. Ocular ICs are identified by an automatic artifact detection method based on kurtosis. Then empirical mode decomposition （EMD） is employed to remove any cerebral activity from the identified ocular ICs to obtain exact altifact ICs. In the second stage, first, SCICA applies exact artifact ICs obtained in the first stage as a constraint to extract artifact ICs from the given EEG signal. These extracted ICs are called spatial constraint ICs （SC-ICs）. Then the RLS based adaptive filter uses SC-ICs as reference signals to reduce interference, which avoids the need for parallel EOG recordings. In addition, the proposed method has the ability of fast computation as it is not necessary for SCICA to identify all ICs like ICA. Based on the EEG data recorded from seven subjects, the new approach can lead to average classification accuracies of 3.3% and 12.6% higher than those of the standard ICA and raw EEG, respectively. In addition, the proposed method has 83.5% and 83.8% reduction in time-consumption compared with the standard ICA and ICA-RLS, respectively, which demonstrates a better and faster OA reduction.

面向超级基站的PDCP层组件式设计与实现

模块化设计思想是支持超级基站协议软件多制式共平台的核心,而PDCP作为协议软件不可或缺的一层,也应当能支持多制式协议流程。现有的PDCP层实现方式,未能充分考虑超级基站协议栈多制式共平台的特点,支持协议流程切换灵活度低。针对该问题,PDCP层设计提出组件化的设计方法,定义了组件间通信方式,采用动态库的形式,通过相应功能库的添加、删除和扩展,能自组织、自生成相应的协议流程。仿真结果表明,通过读取配置文件,进行相应功能库的替换,提出的组件式设计方案能在满足功能和性能的基础上,灵活替换功能库,自生成相应协议流程,符合超级基站协议软件的特点。本研究能够为自定义网络和协议栈其余各层的实现提供参考。

Research of whispered speech vocal tract system conversion based on universal background model and effective Gaussian components

Directing to the weakness of the present fixed values mapping methods （method_F）, a vocal tract system conversion method based on the universal background model （UBM） is proposed for improving the performance of the speech conversion system from Chinese whis- pered speech to normal speech. For the numerous components of UBM, the errors produced by the acoustical probability density statistical model can＇t be ignored. Thus an effective Gaus- sian mixture components chosen method based on the posterior probability summation of the minimum spectral distortion is developed to optimizing the system performance. The proposed method （method_U） is analyzed and compared using the performance index （PI） based on Itakura-Saito spectral distortion measure. It is shown experimentally that the performance of method_U is more stability for different speakers and different phonemes than that of method_F. The average PI of method_U is better than method_F. It is shown that by selecting effective Gaussian mixture components, the PI of method_U can be further improved 5.11%. Subjective auditory tests also show that the proposed method can improve the definition and intelligibility of conversion speech.

Photonic integrated circuit components based on amorphous silicon-on-insulator technology

We present integrated-optic building blocks and functional photonic devices based on amorphous siliconon-insulator technology. Efficient deep-etched fiber-to-chip grating couplers, low-loss single-mode photonic wire waveguides, and compact power splitters are presented. Based on the sub-μm photonic wires, 2 × 2 Mach–Zehnder interferometers and add/drop microring resonators(MRRs) with low device footprints and high finesse up to 200 were realized and studied. Compact polarization rotators and splitters with ≥10 d B polarization extinction ratio were fabricated for the polarization management on-chip. The tuning and trimming capabilities of the material platform are demonstrated with efficient microheaters and a permanent device trimming method, which enabled the realization of energy-efficient photonic circuits. Wavelength multiplexers in the form of cascaded filter banks and 4 × 4 routers based on MRR switches are presented. Fabrication imperfections were analyzed and permanently corrected by an accurate laser-trimming method, thus enabling eight-channel multiplexers with record low metrics of sub-m W static power consumption and ≤1°C temperature overhead. The high quality of the functional devices, the high tuning efficiency, and the excellent trimming capabilities demonstrate the potential to realize low-cost, densely integrated, and ultralow-power 3D-stacked photonic circuits on top of CMOS microelectronics.

Software Reusability Classification and Predication Using Self-Organizing Map (SOM)

Due to rapid development in software industry, it was necessary to reduce time and efforts in the software development process. Software Reusability is an important measure that can be applied to improve software development and software quality. Reusability reduces time, effort, errors, and hence the overall cost of the development process. Reusability prediction models are established in the early stage of the system development cycle to support an early reusability assessment. In Object-Oriented systems, Reusability of software components (classes) can be obtained by investigating its metrics values. Analyzing software metric values can help to avoid developing components from scratch. In this paper, we use Chidamber and Kemerer (CK) metrics suite in order to identify the reuse level of object-oriented classes. Self-Organizing Map (SOM) was used to cluster datasets of CK metrics values that were extracted from three different java-based systems. The goal was to find the relationship between CK metrics values and the reusability level of the class. The reusability level of the class was classified into three main categorizes (High Reusable, Medium Reusable and Low Reusable). The clustering was based on metrics threshold values that were used to achieve the experiments. The proposed methodology succeeds in classifying classes to their reusability level (High Reusable, Medium Reusable and Low Reusable). The experiments show how SOM can be applied on software CK metrics with different sizes of SOM grids to provide different levels of metrics details. The results show that Depth of Inheritance Tree (DIT) and Number of Children (NOC) metrics dominated the clustering process, so these two metrics were discarded from the experiments to achieve a successful clustering. The most efficient SOM topology [2 × 2] grid size is used to predict the reusability of classes.