最新刊期
卷 ， 期 1 ， 1989
- 摘要：In this paper, the well known signal subspace projection concept proposed by Schmidt is introduced to analyse the array resolution capacity or the maximum number of signals resovable by a given uniform linear array as well as the minimum number of sensors of a uniform linear array for resolving a given group of plane waves. Special attentions are paid to determination of signal subspace in coherent signal environments. We have shown that, although the signal subspace in N （the number of sensors） dimensional vector space can not be determined in the coherent signal environment, the signal subspace in lower dimentional vector space could be constructed, and this can be carried out in three ways. Based on the above concept, the limitations on the two array resolution parameters are derived in the paper. The derivation is straight forward and intuitive. Examples are also given for illustration.2|88|2更新时间：2025-12-08
- 摘要：In this paper, the undetected error for an （n, 2, w） binary nolinear constant weight codes and the possibility of the （2w, 25, w） codes becoming optimum are analysed. Then the probability of undetected error for the （n, 28, w） codes and the condetions under which the codes become optimum are discussed. At last, some results and conjecture about the distance distribution of binary nonlinear constant weight codes are also given.2|36|10更新时间：2025-12-08
- 摘要：The decoding procedure of Reed’s algorithm for RM codes is given by using some examples in this paper. An improved algorithm is proposed to simplify the decoding procedure and decrease the decoding time.2|201|1更新时间：2025-12-08
- 摘要：In this paper, a new method for reconstruction of signal x（n） is discussed. The method is obtained under the condition of |ηn（ω）|<δ by using a series of independent random noises ηn（ω）+θ（ω） on the basis of θ（ω）. By means of such a new method an equation for estimanting errors of the recovered x（n） in comparison with their real values. The lower limit of the probability satisfying the error estimation equation is estimated. The convergence speed of such a new method is fast enough.2|65|1更新时间：2025-12-08
- 摘要：A new unsupervised segmentation algorithm is proposed in this paper. In the algorithm, the texture is first divided into overlapping windows, and texture feature is derived from each of the windows. The gray level of the pixel corresponding to each window is replaced by its feature. Then the image is projected into a feature superplane. An edge detection algorithm is applied to the feature superplane to detect where the texture feature changes rapidly. In this way, the texturel boundaries in the image are detected. The effective texture feature is crucial for the segmentation accuracy.2|80|1更新时间：2025-12-08
- 摘要：In this paper, the theoretical analysis and simulated computation of density weighted linear and planar arrays with two step amplitude quantization are presented. It is shown that when the total number of elements in the array remains constant, the peak sidel-obe level for the two step amplitude quantization array can gain 5-6 more dB reduction than that for the one step case. Finally, the generalized case for multi-step amplitude quantization is studied, and the relevant theoretical analysis and numerical results are given.2|104|3更新时间：2025-12-08
- 摘要：This paper first points out the important fact that the rectangle formulas of continuous convolution discretization, which was widely used in conventional digital deconvolution algorithms, can result in zero-time error. Then, an improved digital deconvolution equation is suggested which is equivalent to the trapezoid formulas of continuous convolution discretization and can overcome the disadvantage of conventional equation satisfactorily. Finally, a simulation in computer is given, thus confirming the theoretical result.2|72|5更新时间：2025-12-08
- 摘要：A new solution of the regressive intersection point of n-circles is developed in this paper. It is very useful for multi-port measurement technique and improves the results presented by G. F. Engen in 1980. In addition, some numerical examples are given.2|20|2更新时间：2025-12-08
- 摘要：The effects of coupling between transverse half-wave dipoles near a square conducting cylinder on the input impedance are investigated by solving the EFIE-MFIE hybrid equation by using the Moment Method. The results obtained are useful in the design of VHP TV transmitting antenna system. A procedure called the Numerical Green’s Function （NGF） is used to save the computing time.2|25|1更新时间：2025-12-08
- 摘要：In this paper, the compatibility conditions of n-ports in hybrid are presented its physical properties are interpreted andthe judge criterion is given.2|12|0更新时间：2025-12-08
- 摘要：A new method for solving the inverse black body radiation problem is presented.This method based on function transformation is of major significance with respect not only to the numerical computation but also to the uniqueness or existence of the solution.2|119|2更新时间：2025-12-08
- 摘要：The variation characteristic of received echo signals as a target acrosses obliquely a radar wave beam is described by means of a critical mathematic method. A conclusion obtained is that there is a maximum level at a point within the beam, and its place only dependes on coordinate parameters of the radar relative to the target, but not on its reflectivity. By the way, a transcendandental equation for the coordinates of the maximum point is derived for a small horn antenna and an example of application is given.2|20|0更新时间：2025-12-08
- 摘要：In order to shed more light on the nature of EL2 defect in GaAs, this paper has investigated the EPR"AsGa" spactra in detail on the basis of EPR theory and quantum chemistry. The results show that the higher-order hyperfine interactions arisen from the multi -shell As and Ga nuclei around the AsGa antisite should be taken into account.Furthermore, combined with the annealing experimens of the neutron irradiated GaAs by Goltzene et al. in 1984, the effects of a vacancy （or vacancies） around the AsGa antisite on the linewidth and the hf constant of the EPR"AsGa"spectrum are discussed. In consequence, We suggest that the EPR"AsGa"might be caused not only by the isolated AsGa but also by some of its vacancy complexes.2|43|1更新时间：2025-12-08
- 摘要：In the paper, an improved method for the simultaneous determination of GaAs FET noise figure and available power gain is given a method for the design of loss matching network and quantitative analysis of its loss is also presented. The determination of GaAs FET optimum noise parameters with different source impedances and by means of a computer-aided data processing is introduced. The practice shows that this technique is very useful in the development of low noise GaAs FET.2|32|1更新时间：2025-12-08
- 摘要：A new method for digital network logic analysis-reasoning approach is presented in this paper. In this approach the problem of logic analysis is considered as a problem of an automatic theorem proving, that is, all the knowledge of the basic logic networks, the network topology of the simulated logic and the input signal sequences are all considered as axioms, lemmas or predefined assertions, and the output signals to be found are the new assertions implied in all the premises, the process of a logic analysis is just the process to infer the new assertions （theorems） from the axioms, lemmas.The principle of the reasoning approach and the reasoning procedure for logic analysis are introduced in detail in this paper. A comparison between the new approach and the traditional logic simulation methods has also been made.2|48|1更新时间：2025-12-08
- 摘要：In compiler-based Prolog systems, programs exist in the form of object code. Unlike conventional languages, standard Prolog provides programmers with facilities for updating their programs during runtime by using built-in predicates such as assert and retract. Hence, Prolog code should be modifiable, and a powerful code manager is needed. In this paper, a scheme for managing Prolog code database in the framework of the Warren Abstract Machine （WAM） is presented. The form of the object code is first described. Then the methods for managing dynamic code and semi-static code are discussed. This scheme has been used for the implementation of a Prolog code database manager written in C on VAX-11/780.2|26|2更新时间：2025-12-08
- 摘要：In this paper, a notion is given about fast maintenance for consistency in the process of updating a database state. A practical problem that often arises is: given a database state which is known to be consisfent and a suggested modification to that state on the basis of practical requirements, will the modified state be consisfent also? We call this the maintenance problem. We propose a notion of constant time maintenance, according to which the maintenance algorithm runs in time independent of the size of the database state.2|14|1更新时间：2025-12-08
- 摘要：A review of the development and the current state of the art of free electron lasers （PEL）, including Raman FEL and Compton FEL, is presented in this paper. Some of key problems are also discussed. The trends of research and development of them are expounded.2|39|0更新时间：2025-12-08
- 摘要：An integral equation approach is presented to deal with the problems of discontinuity in rectangular waveguides. The integral equations take the modified Green Functions of the waveguide as kernel for the problems which is uniform along E-plane, and the kernel of integral equations is deduced from the Fourier Expansion of the iris surface fields for the problems which is uniform along the H-plane. A group of typical conductor obstcles in the rectangular waveguides have been treated as examples, shewing the approach presented is quite promising for engineering calculations.2|70|0更新时间：2025-12-08
- 摘要：A cw Ar+ laser was used to recrystallize a-Si film which was deposited on a metal substrate covered with insulator layer and implanted with boron ions at an energy of 60keV and a dose of 5×1015 cm-2. The piezoresistance material of high sensitivity was obtained after laser-recrystallization. Its gauge factor reached to 30, the grain size was increased to more than 10μm×40μm, the concentration profile of impurities became uniform and electrical properties of SOM were improved significantly. The devices made of this material have pressure sensitivity of 6mv/v bar .2|23|0更新时间：2025-12-08
- 摘要：Utilizing the home-made molecular beam epitaxy system （MBE）, and employing some novel techniques, GaAs/AlGaAs high electron mobility transistors have been made successfully. The trans-conductance is at the range of 80-135mS/mm. The minimum noise figure 2.49dB and the maximum power gain 10.2 dB at 4GHz are obtained.2|49|0更新时间：2025-12-08
- 摘要：A new complexity concept of sequences be introduced and some problems related are discussed.2|33|2更新时间：2025-12-08
- 摘要：The E-transform is a new series transform. It is an important tool for studying linear time-variant discrete systems. In this paper we introduce the fundamental principle of the E-tran.sform and further investigate how to use it to solve linear time-variant discrete systems.2|57|3更新时间：2025-12-08
- 摘要：Evaluating formulae of network functions and their derivatives are introduced in this paper. The algorithm of network analysis and optimization will be more efficient by using these formulae.2|23|0更新时间：2025-12-08
- 摘要：The radar MTD system implemented with general-purpose digital signal processors （DSPs） is flexible in programming, high accurate in operation, simple in structure and small in size. In this paper, the implementation of such a MTD system with DSP chips is described. Moreover, an example of single board VHP band long pulse radar MTD system implemented with DSP MB8764 is also given. The results of measurement are: the improvement factor of signal-to-noise ratio greater than 10dB and the improvement factor of signal-to-clutter ratio greater than 40dB.2|31|0更新时间：2025-12-08
- 摘要：A new fault-tolerant connecting topoiogical architecture named MSR for distributed system is given in this paper. This architecture is based on the modification of SR topology graph. So the fauh-tolerat capability is improved up to 2r-2 processor failures.2|33|1更新时间：2025-12-08
- 摘要：Starting with basic research, this paper derives a basic nonlinear equation in scalar and matrix forms, indicating a nonlinear resistance effect and dircussing the relation between R and Rum. Furthermore, the characteristic formula of nonlinear resistance and conductance in analytic form are yi-ven, and thereby the current controlled and voltage controlled polynomials ale also derived.2|76|6更新时间：2025-12-08
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0