Augmented complex-valued normalized subband adaptive filter: Algorithm derivation and analysis

In this paper, a novel augmented complex-valued normalized subband adaptive filter (ACNSAF) algorithm is proposed for processing the noncircular complex-valued signals. Based on the augmented statistics, the proposed algorithm is derived by computing a constraint cost function. Due to contain all second-order statistical properties, the ACNSAF algorithm can process the circular and noncircular complex-valued signals simultaneously. Moreover, the stability and mean square steady-state analysis of the proposed algorithm is derived by using the energy conservation principle. Computer simulation experiments on complex-valued system identification, prediction and noise cancelling show that the proposed algorithm achieves the improved mean square deviation and prediction gain compared to the ACNLMS algorithm. And the simulation results are consistent with the analysis results.     

A theoretical framework for defining similarity measures for boolean search request formulations, including some experimental results

Clusters of queries submitted to a given information retrieval system can be used as a basis for an effective method of clustering documents. This indirect procedure of document clustering requires the availability of a similarity measure for queries. Research carried out along these lines has resulted in the development of some methodologies for estimating such query similarities, applicable both in the case of queries characterized by sets of weighted or unweighted index terms and in the case of queries represented by Boolean combinations of index terms. This paper reports the results of further research by the author into a methodology of the latter type, i.e. a methodology for determining the similarity between queries characterized by Boolean search request formulations. The novelty of the presented approach, as compared with the methodology introduced in an earlier paper by the author, is that some relations among index terms are now taken into account. A number of similarity measures for Boolean combinations of index terms are discussed here in some detail. The rationale behind these measures is outlined, and the conditions to be met for ensuring their equivalence are identified. Moreover, the results of an experiment concerning two of the similarity measures introduced are given.     

基于LabVIEW的机械测试虚拟实验设计

针对《机械测试》课程内容抽象,实验设置所需的仪器种类多、价格昂贵等问题,利用图像化编程语言LabVIEW对信号描述和处理部分设计了不涉及硬件的模拟仿真实验,对机械量测量部分设计了依托各种传感器的综合实验系统.设计界面直观,能很大程度帮助学生理解课程内容,激发学生的创造性.     

复值型数据Improper线性回归模型的估计(英文)

复随机变量称为"improper"随机变量,若它的"伪"协方差阵不为0,否则称为"proper"随机变量.研究了误差服从独立同分布的improper复高斯分布的线性回归模型.利用极大似然方法和2阶段最小二乘方法来估计回归系数.模拟表明,这2种方法与经典复版本的最小二乘法有不同之处,并将该方法用于实际风信号数据的处理.     

Design and implementation of a rectangular frequency invariant beamformer with a full azimuth angle coverage

A novel design of the frequency invariant beamformer based on a rectangular array is proposed with two unique features: there are no taped delay-lines (TDLs) or any other temporal processing involved and the resultant beamformer has a full 360° azimuth angle coverage. This leads to a wideband beamformer with complex-valued coefficients and its implementation is not as straightforward as the traditional ones. Depending on whether the input signal is complex-valued or real-valued, special arrangements and structures are required for its effective implementation. Several design examples are provided with a satisfactory frequency invariant property. Two sets of implementation results are given based on both simulations and data collected by a planar microphone array system.     

Ordered similarity measures taking into account the rank of documents

Indices of similarity are used to quantify the difference between two sets of documents. Usually, they are based on the number of elements that they have in common. Indeed, they are calculated from the results of the intersections or unions of the compared sets. But many studies show that order of presentation of the documents is an important fact to be taken into account, particularly in the case of system's evaluation, which is not the case as far as usual measures are concerned. In this article, we propose a general method for the construction of measures of similarity taking into account the rank of presentation of the document. We will call them Ordered Similarity measures, i.e., measures of OS. Then, we present an experimentation of evaluation used to quantify the filtering impact of a system. This protocol is based on a large scale interrogation of the system and on a comparison of answer sets. We present simultaneously the results of comparisons obtained by a classical measure and by an OS measure. Finally we show how to construct OS measures derived from recall and precision.     

A collaborative filtering similarity measure based on singularities

Recommender systems play an important role in reducing the negative impact of information overload on those websites where users have the possibility of voting for their preferences on items. The most normal technique for dealing with the recommendation mechanism is to use collaborative filtering, in which it is essential to discover the most similar users to whom you desire to make recommendations. The hypothesis of this paper is that the results obtained by applying traditional similarities measures can be improved by taking contextual information, drawn from the entire body of users, and using it to calculate the singularity which exists, for each item, in the votes cast by each pair of users that you wish to compare. As such, the greater the measure of singularity result between the votes cast by two given users, the greater the impact this will have on the similarity. The results, tested on the Movielens, Netflix and FilmAffinity databases, corroborate the excellent behaviour of the singularity measure proposed.     

Robust augmented complex-valued normalized M-estimate subband adaptive filtering algorithm against colored non-circular inputs and impulsive noise

Recently, the augmented complex-valued normalized subband adaptive filtering (ACNSAF) algorithm has been proposed to process colored non-circular signals. However, its performance will deteriorate severely under impulsive noise interference. To overcome this issue, a robust augmented complex-valued normalized M-estimate subband adaptive filtering (ACNMSAF) algorithm is proposed, which is obtained by modifying the subband constraints of the ACNSAF algorithm using the complex-valued modified Huber (MH) function and is derived based on CR calculus and Lagrange multipliers. In order to improve both the convergence speed and steady-state accuracy of the fixed step size ACNMSAF algorithm, a variable step size (VSS) strategy based on the minimum mean squared deviation (MSD) criterion is devised, which allocates individual adaptive step size to each subband, fully exploiting the structural advantages of SAF and significantly improving the convergence performance of the ACNMSAF algorithm as well as its tracking capability in non-stationary environment. Then, the stability, transient and steady-state MSD performance of the ACNMSAF algorithm in the presence of colored non-circular inputs and impulsive noise are analyzed, and the stability conditions, transient and steady-state MSD formulas are also derived. Computer simulations in impulsive noise environments verify the accuracy of theoretical analysis results and the effectiveness of the proposed algorithms compared to other existing complex-valued adaptive algorithms.     

On the notions of ambiguity and information loss

One of the fundamental problems in information science is to distinguish various objects (such as books or journal articles) on the basis of associated values (such as authors and titles). Where the values fail to distinguish two distinct objects we say that the objects are ambigious under the given value assignment. To obtain a measure of ambiguity, it is only necessary to count the number of ways that the objects can be arranged for each set of ambiguous objects, multiply these counts and take logarithms. It is shown that such an approach leads to a measure in the formal sense and that the measure depends only on the definition of equality of values so that it can be simply extended to sets of values and ordered sets of values. It is also shown that it is possible to construct a function of ambiguity that one can call “information” and that the information loss that occurs when distinct values are grouped into equivalence classes (as in the use of search and sort keys) is also a measure. Finally, it is shown that ambiguity and information as here defined are directly related to Shannon's definition of “information” thus tieing this approach to that portion of information theory associated with the derivation of optimal distributions frequently used in information science models.     

团队内任务冲突与关系冲突的关系与协调

团队冲突包括任务冲突和关系冲突两种基本类型,冲突在团队互动过程中难以避免。以往文献显示,大多数情况下任务冲突总是对团队绩效有着积极的影响,而关系冲突通常对团队绩效有着消极的影响。但是任务冲突和关系冲突之间的关联性降低了团队冲突的积极效应。本文指出,通过增强团队成员之间的信任、采取适度合作的冲突处理方式、形成学习目标导向的团队等途径可以防止任务冲突转化为关系冲突,从而有助于提升团队效能。     

高精度医用透析床的称重系统的设计

本文介绍了高精度医疗透析床的称重电路设计,该系统以AT89C205单片机为核心,配合高精度A/D转换器CS5522,用来检测称重传感器的输出信号,软硬件结合实现信号智能测量、系统校准等功能。对于系统的随机误差、系统误差,使用线性拟合等算法进行误差修正和补偿,保证了系统精度。最后对该系统的性能进行了测试,结果表明:测量精度达到了设计要求.     

The contribution of information to business success: a LISREL model analysis of manufacturers in Shanghai

In an attempt to quantitatively measure the contribution of information to business development, two studies were carried out in Shanghai, China: one on small businesses and the other on medium-sized businesses. The LISREL (linear structural relations) model was applied in both studies to determine the magnitude of the contribution. Both studies showed that the use of information does contribute positively and in a statistically significant way to business success, although its contribution is not as important as some other factors such as business environment. A comparison of the LISREL models from the two studies also revealed similarities and differences in the use of information in these two businesses sectors.     

Models for spaces of duration-limited signals

This paper is a study of models of spaces of duration-limited signals considered as set functions. Models for the space of bounded signals, signals of bounded area and signals of finite energy are considered. It is shown that by using set function models and a Stieltjes integral for set functions one can derive integral representations for all bounded linear operators on each of these spaces. It is also shown that impulse functions can be treated rigorously as signals of bounded area in these models without introducing singularities, or requiring impulses to be considered as functionals on a signal space rather than as signals. Finally, analogues to differentiation and indefinite integration are introduced. The applications of these models to physical problems are illustrated by reformulating lumped parameter electrical network theory in a set function formalism, and approximate solutions to the resulting equations are shown.     

Measures of scientific growth

Numbers of publications and citation ratings have recently been used as measures of scientific growth. The present paper discusses a number of presumed weaknesses of these measures. First, a distinction is made among scientific activity, scientific productivity, and scientific progress. Then it is suggested that the above measures might depend on the particular field of science, on the speed whereby research front information becomes archival, on the phenomena of wrong papers and of ‘also ran’ papers, on the geographical differences in communication patterns, on whether we want to measure activity, productivity, or progress, and on the temporal variations in scientific communication patterns. Though some examples are given, the quantitative substantiation of the proposed effects must await further research.     

雷达信号的时——频分析和应用

针对常见的雷达脉冲信号（常规信号（NS）,线性调频信号（LFM）,双线性调频信号（DLFM）运用时频工具对调制方式的识别进行研究。运用两种时频分析方法1.短时傅里叶变换2.相位展开算法.通过这两种算法对雷达信号的调制方式进行分析,并通过仿真得到雷达信号的时--频分布以及时—频,时—相曲线,对仿真结果进行研究。通过仿真实验表明,雷达信号调制方式识别算法是可行的,有效的,而且具有良好的性能。     

A method of measuring information in language,applied to medical texts

In this study, quantitative measures of the information content of textual material have been developed based upon analysis of the linguistic structure of the sentences in the text. It has been possible to measure such properties as: (1) the amount of information contributed by a sentence to the discourse; (2) the complexity of the information within the sentence, including the overall logical structure and the contributions of local modifiers; (3) the density of information based on the ratio of the number of words in a sentence to the number of information-contributing operators.Two contrasting types of texts were used to develop the measures. The measures were then applied to contrasting sentences within one type of text. The textual material was drawn from narrative patient records and from the medical research literature. Sentences from the records were analyzed by computer and those from the literature were analyzed manually, using the same methods of analysis. The results show that quantitative measures of properties of textual information can be developed which accord with intuitively perceived differences in the informational complexity of the material.     

Effect of pulse direct current signals on electrotactic movement of nematodes Caenorhabditis elegans and Caenorhabditis briggsae

The nematodes (worms) Caenorhabditiselegans and Caenorhabditisbriggsae are well-known model organisms to study the basis of animal development and behaviour. Their sinusoidal pattern of movement is highly stereotypic and serves as a tool to monitor defects in neurons and muscles that control movement. Until recently, a simple yet robust method to initiate movement response on-demand did not exist. We have found that the electrical stimulation in a microfluidic channel, using constant DC electric field, induces movement (termed electrotaxis) that is instantaneous, precise, sensitive, and fully penetrant. We have further characterized this behaviour and, in this paper, demonstrate that electrotaxis can also be induced using a pulse DC electric signal. Worms responded to pulse DC signals with as low as 30% duty cycle by moving towards the negative electrode at the same speed as constant DC fields (average speed of C. elegans?=?296?±?43?μm/s and C. briggsae?=?356?±?20?μm/s, for both constant and pulse DC electric fields with various frequencies). C. briggsae was found to be more sensitive to electric signals compared to C. elegans. We also investigated the turning response of worms to a change in the direction of constant and pulse DC signals. The response for constant DC signal was found to be instantaneous and similar for most worms. However, in the case of pulse DC signal, alterations in duty cycle affected the turning response time as well as the number of responding worms. Our findings show that pulse DC method allows quantitative measurement of response behaviour of worms and suggest that it could be used as a tool to study the neuronal basis of such a behaviour that is not observed under constant DC conditions.     

Solutions to linear bimatrix equations with applications to pole assignment of complex-valued linear systems

We study in this paper solutions to several kinds of linear bimatrix equations arising from pole assignment and stability analysis of complex-valued linear systems, which have several potential applications in control theory, particularly, can be used to model second-order linear systems in a very dense manner. These linear bimatrix equations include generalized Sylvester bimatrix equations, Sylvester bimatrix equations, Stein bimatrix equations, and Lyapunov bimatrix equations. Complete and explicit solutions are provided in terms of the bimatrices that are coefficients of the equations/systems. The obtained solutions are then used to solve the full state feedback pole assignment problem for complex-valued linear system. For a special case of complex-valued linear systems, the so-called antilinear system, the solutions are also used to solve the so-called anti-preserving (the closed-loop system is still an antilinear system) and normalization (the closed-loop system is a normal linear system) problems. Second-order linear systems, particularly, the spacecraft rendezvous control system, are used to demonstrate the obtained theoretical results.     

Instance-prototype similarity consistency for unsupervised 2D image-based 3D model retrieval

The unsupervised 3D model retrieval is designed to joint the information of well-labeled 2D domain and unlabeled 3D domain to learn collaborative representations. Most existing methods adopted semantic alignment, but were inevitably affected by false pseudo-label. In this paper, we design a novel Instance-Prototype Similarity Consistency Network (IPSC) to guide domain alignment with similarity consistency, which can simultaneously suppress the impact of false pseudo-label information and well reduce the domain discrepancy. IPSC contains two similarity strategies, named Single instance vs Multiple prototypes and Instance-pair vs Single prototype. The first strategy utilizes a single instance as an anchor, and measures the similarities between the anchor and multiple prototypes with the same category but from different domains. The minimization between these similarities can better align the cross-domain prototypes with Kullback–Leibler (KL) divergence than traditional Euclidean similarities. The second strategy utilizes a single prototype as an anchor, and measures the similarities between this anchor and an instance-pair with the same category but from different domains. The minimization between these similarities can conduct the instance-level alignment with KL divergence, which can better suppress the negative effect of noisy pseudo-labels. We conduct various experiments on two datasets, MI3DOR-1 (21000 2D images and 7690 3D models) and MI3DOR-2 (19694 2D images and 3982 3D models), to verify the superiority of our algorithm.     

Taxonomy of e-readiness assessment measures

To benefit from the advantages of information society, on the one hand, and to be afraid of being left further behind by Global Society and the increase in the digital divide, on the other hand, stimulate countries to be part of Global Information Society. These issues have led policymakers to move towards such a society by identifying the objectives, goals and targets. Planning to achieve these objectives needs a real understanding of the current situation, which is obtained by e-readiness assessment measures. There has been a proliferation of e-readiness assessment measures in recent years that each one has a certain objective. This paper elaborates on and categorizes these measures that help scholars and policymakers to (1) select the measures that fit in with their objectives, (2) prevent the repetitive research, (3) identify the defects and flaws of previous measures and correct them in their own measures, and (4) use the experiences of previous measures to construct their own ones. Based on definitions, objectives, dimensions, methods and approaches, in this paper, the measures are categorized and finally, a measure for e-readiness assessment is presented. Since this measure is a convergence of e-readiness assessment measures, the experienced modelers have consensus on it and it is more suitable to measure e-readiness of countries. Also, it can be exploited as the basis and standard for internationally comparable information society statistics.