Multiresolution dynamic image representation with uniform andfoveal spiral scan data

This work addresses the problem of representing a dynamic image via its temporal spiral scan data. Two types of spiral scan data are considered: uniform density and foveal. Spatial sampling strategies for these two spiral scans are examined. A signal model is developed to interpret the temporal readouts of repeated spiral scans via two separate time variables, the slow time and fast time. This mathematical model is used to construct a method for forming the time progression of the target image. A method for increasing the repetition rate of the spiral data collection via utilizing both forward and backward spiral scans is presented. Results are provided.     

Facial expression recognition using frequency multiplication network with uniform rectangular features

Facial expression recognition (FER) is a popular research field in cognitive interaction systems and artificial intelligence. Many deep learning methods achieve outstanding performances at the expense of enormous computation workload. Limiting their application in small devices or offline scenarios. To cope with this drawback, this paper proposes the Frequency Multiplication Network (FMN), a deep learning method operating in the frequency domain that significantly reduces network capacity and computation workload. By taking advantage of the frequency domain conversion, this novel deep learning method utilizes multiplication layers for effective feature extraction. In conjunction with the Uniform Rectangular Features (URF), our method further improves the performance and reduces the training effort. On three publicly available datasets (CK+, Oulu, and MMI), our method achieves substantial improvements in comparison to popular approaches.     

短快拍条件下均匀矩形阵中的二维DOA估计

二维波达方向（Direction of Arrival,DOA）估计能获取比一维DOA估计更多的空间位置信息,但是二维多重信号分类(Multiple Signal Classification,MUSIC)、二维子空间旋转不变估计技术(Estimation Signal Parameter via Rotational Invariance Techniques,ESPRIT）等经典算法依赖于大量的快拍数据,当快拍数据不足时估计性能严重下降甚至失效。针对上述问题,将迭代自适应方法拓展到二维DOA估计,提出了一种适用于矩形面阵的二维DOA估计算法,首先利用加权最小二乘法估计出信号幅值,然后利用循环迭代技术对估计结果进行更新。由于每次估计结果均来自上一次迭代,而不依赖于快拍数据,因此该算法在短快拍条件下具有很高的估计精度和分辨率。仿真结果表明,在短快拍条件下,该算法具有优越的估计性能。     

Analysis of rectangular horn antennas via uniform asymptotic theory

Approximate analytic expressions for the far-field radiation pattern and modal reflection coefficient of the three-dimensional horn antenna have been developed. Based upon a multiple-image model of the two-dimensional horn-waveguide structure, this approach offers greater generality than previously proposed ray analyses with comparable complexity and accuracy. The uniform asymptotic theory (UAT), which is employed throughout, provides information when this approach is valid for a desired degree of accuracy in the solution. It is demonstrated that, in most cases, the far-field pattern of the horn is reducible to the pattern of a simple slit in an absorbing screen illuminated by an array of patterned line sources. The measured patterns of several horns are convincingly recovered by the prediction of the analytical model. The same model is used to calculate the modal reflection coefficient of the horn-waveguide structure and, again, comparison with measured results is excellent.     

Two-dimensional equirotational stack subspace fitting with anapplication to uniform rectangular arrays and ESPRIT

A two-dimensional (2-D) multiple invariance technique for computing signal subspaces for uniform rectangular arrays (URAs) of size M×N sensors is introduced. The method is based on a multiple maximum overlap configuration of the sensors in the array with m×n subarrays of (M-m+1)×(N-n+1) sensors each. We exploit the fact that the stacked subspace of the subarray sensor output signals admits a two-level equirotational stack parametrization. We introduce a TLS-type algorithm for estimating the parameters of this equirotational stack subspace model. Based on this method of equirotational stack subspace fitting, the overall array signal subspace can be estimated with a much higher accuracy than with conventional unstructured SVD and TLS techniques. Detailed experiments validate the theoretical results. We propose a variant of 2-D ESPRIT based on equirotational stack subspace fitting. This 2-D equirotational stack ESPRIT (2-D ES-ESPRIT) algorithm clearly outperforms conventional unstructured variants of 2-D ESPRIT. A detailed comparison with 2-D unitary ESPRIT is presented     

LED路灯矩形均匀照明方法综述

传统路灯照明的历史和现代路灯照明的发展,并总结了三类LED路灯实现矩形照明光斑的方法,分析了它们的照明效率,指出了LED矩形光斑路灯是未来道路照明的主要趋势。     

Computationally efficient 2-D DOA estimation for uniform rectangular arrays

A computationally efficient two-dimensional (2-D) direction-of-arrival (DOA) estimation method for uniform rectangular arrays is presented. A preprocessing transformation matrix is first introduced, which transforms both the complex-valued covariance matrix and the complex-valued search vector into real-valued ones. Then the 2-D DOA estimation problem is decoupled into two successive real-valued one-dimensional (1-D) DOA estimation problems with real-valued computations only. All these measures lead to significantly reduced computational complexity for the proposed method.     

SCATTERING ANALYSIS OF E-PLANE UNIFORM DIELECTRIC POSTS IN RECTANGULAR WAVEGUIDES

Based on the polarization current integral equation with the modified Green's Function as ker-nel, the scattering properties of the E-plane. uniform dielectric posts in rectangular waveguide arenumerically analyzed by the moment method. These posts are of arbitrary cross section and post-numberThe calculation accuracy and speed are remarkable improved by segmenting the dielectric region into manysmall rectangular oells and applying local analytic integration. The higher-order modes are considered in cal-culation, improving the computation accuracy and providing the scattering information of all modes excitedas well.     

A minimum profile uniform current density electrode

Present methods of determining the safe injected charge levels for disk-type electrodes are given in terms of an average charge density, although the charge density is higher near the periphery of the electrode. This paper describes an electrode that produces an injected charge density that is uniform over the surface of the electrode and thus permits maximum utilization of the surface. Charge density is the time integral of current density, and the alteration of the current density is obtained by adding curvature to the electrode and recessing it within a cylindrical insulating well. A novel numerical method is used to determine the recession and curvature, and this numerical method is also presented. The benefit of this technique is that it permits a reduction in the electrode size while maintaining the maximum safe injected charge level of a disk-type electrode. A minimum profile uniform current density electrode and the algorithms used in its design are presented in this paper. Finally, a flat electrode that is recessed by as little as 1/10 of its diameter is shown to have an injected current density on the electrode surface that is superior to that of a flat surface mounted electrode.     

A uniform power spectral density jamming signal

In this work a technique is described for generating a jamming signal with a continuous uniform-power-spectral density band-limited over any desired frequency band. Experimental results demonstrating the technique are presented.     

Electromagnetic field of a rectangular patch of uniform and lineardistributions of current

Closed-form expressions for a class of indefinite double integrals are presented. Using these formulas, exact analytical expressions for the magnetic vector potential and the electric and magnetic fields of a rectangular patch of uniform and linear distributions of electric current in an unbounded homogeneous medium are derived. The field expressions obtained are valid everywhere, in particular in the source region. Computed results verifying the correctness and accuracy of these expressions are presented     

Compact test generation for full scan sequential circuits usingmultiple frame vectors

A new test set compaction method that uses multiple frame vectors to test fully scanned sequential circuits is proposed. The FAN algorithm is extended to generate compact multiple frame test vectors. The proposed method generates the smallest test sets among all recognised full scan test set compaction algorithms     

旋转轴对称LED均匀照明系统设计方法

基于边缘光学理论,提出了一种应用于LED照明的光学系统设计方法,分别实现基于透镜和反射器的LED均匀照明光学系统,可在一特定距离的目标面上形成均匀圆形光斑。采用基于蒙特卡罗法的光线追迹软件对两种光学系统进行模拟仿真,结果显示,目标面上光斑的均匀度优于85%,系统效率高于90%。     

Design of thermal imprinting system with uniform residual thickness

A new thermal imprinting system for the printed circuit boards (PCBs) with both large areas and fine conducting lines was developed adopting hot airs with a high pressure. Several small nickel stamps were used to cover the large area, and the stamps were replicated from an electroforming process, in addition, a vacuum jig was utilized to avoid bubbles captured in resins or imprinted interfaces. Stefan’s equation was used to estimate residual thicknesses of the imprinted resins, and effects of imprinting conditions on the residual thickness were investigated from numerical analyses to confirm process profiles and specifications of the developed equipment. The results show that the developed imprinting system can remarkably improve the uniformity of the residual thickness after imprinting, as compared with those of the conventional press, in spite of the thickness difference between the used stamps.     

2D-DOA estimation of noncircular signals for uniform rectangular array via NC-PARAFAC method

In this paper, we propose a two-dimensional direction of arrival (2D-DOA) estimation algorithm for uniform rectangular array via noncircular-parallel factor (NC-PARAFAC) method. Compared to the conventional parallel factor (PARAFAC) algorithm, the proposed algorithm exploits the property of noncircular signals to double the array aperture. Therefore, the angle estimation performance of the proposed algorithm is better than the conventional PARAFAC method. The proposed algorithm achieves automatically paired two-dimensional angle estimates, and has better 2D-DOA estimation performance than some conventional algorithms, which include estimation of signal parameters via rotational invariance technique (ESPRIT), propagator method (PM), PARAFAC algorithm, noncircular-ESPRIT (NC-ESPRIT) and noncircular-PM (NC-PM). We also derive the Cramér–Rao bound for the 2D-DOA estimation of noncircular signals with uniform rectangular array. Simulation results verify the effectiveness and improvement of the proposed algorithm.     

统一面向产品全生命周期的知识应用体系研究

提出统一知识应用体系的概念、性质和模型,以及知识应用体系的实现与实践。建立统一知识应用体系是梳通产品研制过程各业务信息系统之间知识获取与供应渠道、知识与研制过程结合渠道的系统性工程。通过统一的企业信息系统用户验证、业务系统检索服务、研制过程描述、知识与供应、知识应用门户等方式建立统一知识应用体系。     

一类新的性能优越的伪随机序列＊

本文提出了一类新的P元(P为任意素数)的伪随机序列(称为Lz序列)的构造方法。证明了所构造的序列具有理想自相关特性;通过计算还表明该序列是平衡的非线性序列,序列的等效线性长度可以很长。     

一种具有大线性复杂度伪随机序列的构造

 本文提出了一种具有大线性复杂度、低相关性能和序列数目多的新伪随机序列构造方案.这种设计的关键之处在于利用移位序列分析法在理论上对相控序列进行改进,使用交织序列做基础序列代替原来的理想自相关序列,再利用具有理想自相关性的序列和相应的移位序列一起得到新伪随机序列.本文对其相关性能进行了分析,其最大值满足Welch界的要求;新序列的线性复杂度比现有的任意序列都要大;得到的新序列族中的序列有些是平衡的,族的数目和每一族中序列的数目都要多于现有的任意序列.     

Spectral Analysis of Auditory Evoked Potentials with Pseudorandom Noise Excitation

Pseudorandom noise (PRN) of various bandwidths was used in testing both normal and hearing impaired subjects by means of auditory-evoked potentials (AEP's). The AEP's were studied in the frequency domain via spectral analysis rather than in the time domain as is often done. Spectral analysis provides such system features as power spectral densities (PSD's) and transfer and coherence functions. The results show that these AEP's are similar to the frequency following responses obtained with pure tones. The PSD's of the evoked responses tend to correlate slightly with those of the PRN simuli, as verified by the presence of coherence between the stimulus and the response. The average coherence over the bandwidth of the stimulus decreases with increased sensory-neural hearing loss and also as the stimulus bandwidth is increased. No unique transfer functions, with respect to the subjects or the intensities of stimuli, could be obtained. However, an attempt has been made to correlate subjects' audiograms with the spectral analysis results.     

3G的安全体系结构简述

本文讨论了3G系统的安全结构,主要集中于无线链路接入部分,并对其五个功能模块 作了简要的介绍。