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Digital phase shifter is widely used to achieve space scanning in phased array antenna. The quantization error will produce for discontinuous phase shifting of digital phase shifter. This paper introduces an approximate formula, derived by adding sub-array virtual elements and using the principle of pattern multiplication, about beam pointing accuracy of uniform linear array in condition of phase...
The ship anti-rolling tank test platform is a specific-designed synthesis system used to imitate the ship's movement in the sea waves. An electro-hydraulic servo system featuring high accuracy and fast response is employed. This latter has highly nonlinear phenomena such as fluid compressibility, the flow-pressure relationship and dead band due to the internal leakage and hysteresis. Usually, conventional...
Edge detection techniques in image processing and computer vision occupies a special position. How to quickly and accurately extract the image edge information of objects has been a hot research at home and abroad. This article describes several classical edge detection operator and the recent emergence of a new edge detection method, and its matlab simulation studies and a comparative analysis.
It is often very useful to know the positions of the sensor nodes in a wireless sensor network. The semidefinite programming (SDP) solution usually has a rank higher than the underlying physical space, which when projected onto the lower dimensional space generally results in high estimation error. In this paper, We describe a general subset localization based on semidefinite programming (SLSDP) approach...
With the further development of GPS and rising of new positioning system, the ground coverage rate has become a hot research object. As a mature software, STK can solve aerospace problem rapidly and accurately. The paper innovatively uses STK software to measure the coverage rate of GPS. After giving the previous result, the paper propounds a further discussion of coverage rate: the level of accuracy...
In order to get accurate measurement of static contact angle of silicone rubber, the method based on the least squares fitting is proposed to obtain static contact angle through fitting the globule edge. This method fits the globule edge by the least square method according to the rule that the globule edge is round if the globule only has little water. Then, Levenberg-Marquardt algorithm is used...
With the advent of advanced diesel after-treatment technologies, select catalyst reduction(SCR) becomes dominant technology for the new emission legislation in china. Because of sophisticated NOx sensors are becoming a critical cost challenge to OEMs, open loop SCR is mainly used at present, and which lead to be difficultly adaptive to control emission reduction and calibration workload was heavy...
To realize autonomous control of satellite, NASA uses the method of autonomous fault diagnosis. In the fault diagnosis, it is found that the fault diagnosis accuracy and the fault coverage have relation with the choice of test points. In order to solve the optimization problem of test points in the fault diagnosis of satellite aviation system, this paper presents an optimization method of test points...
Efficient feature selection is a key point in pattern classification. In this paper, we propose an improved feature selection method utilizing support vector machine approach based on recursive feature elimination (SVM-RFE) for multi-SVM classifier. This method uses class interval in SVM algorithm as the evaluation criterion, and eliminate features in a recursive way. And in this procedure, obtaining...
Yearly natural streamflow data of five hydrologic stations over the upper of Weihe basin for 1945–2000 were utilized to analyze the drought characteristics by using Run-theory and Grey system. Based on the theory of run and intercept method, the hydrologic drought duration, drought severity and the value of conditional probability were calculated to evaluate the regional hydrological drought characteristics...
It is an essential requirement to realize single-station passive location of emitter target in the modern electronic warfare and information warfare. Single-station passive location system has vast application prospect, because of its properties of flexible, convenient, high concealing, far detection range and other advantages. This paper introduces a kind of single-station passive location method...
Depth estimation is one of the key technologies of FTV system. To increase depth accuracy, a depth estimation method which can preserve temporal consistency is proposed. For current view, depth values of the previous frame and motion information between current and its previous frame are used as constraint conditions to estimate depth map of current frame, thus preserve temporal consistency of depth...
By comparing the present formal methods for drawing light intensity contour of navigation lighting, a new algorithm for fast drawing light intensity contour is proposed. This paper applies the Delaunay triangle split linear interpolation algorithm to draw the PAPI light, and uses B-spline curve for the smooth. And some source code in MATLAB language and its simulation results are also given. Compared...
Traditional optimization technologies usually try to find a global optimum, however, many optimization problems are multimodal with many global or local optima. In real world, multiple optima are usually interested in and can give people multi-choices. Crowding-based differential evolution (CRDE) algorithm is a simple but very powerful for multimodal optimization. CRDE has good explorative ability...
Aims at the nonlinearity such as friction and varieties of system parameters and unmodeled dynamics in azimuth gun control system of tank, in order to improve the low speed performance and anti-interference ability, the strategy of LADRC is proposed. Considering nonlinearity and non-model dynamics as a composite disturbance, the math model of azimuth gun control system is established firstly, then...
With the wide application of web database, Web pages are continuously deepened. In order to use Deep Web resources effectively, the Deep Web data need to be integrated on a large scale, and data sources discover is the primary work of Deep Web resources integration. The Deep Web site found efficiently is the key of the Deep Web data Integration. This paper puts forward a kind of Deep Web entry automatic...
Ancient building protection conducted in different place was an effective method for the ancient building protection. There were abundant ancient buildings in Longyou city. The ancient building structures in Longyou city were surveyed by using the traditional method. Their level control points were surveyed by using fourth-order leveling. Their distances and angles were surveyed by using ordinary...
TOPMODEL is a semi-distributed rainfall-runoff model that focuses on the spatial variations of terrain. Based on the topographical information, or soil-wetness index, TOPMODEL is generally used for simulations of hillslope water runoff. In order to facilitate the real-time flood forecasting of rainstorm areas, the grid-based distributed TOPMODEL was constructed by making significant improvements in...
The fire control system dynamic simulation test method got proposed through the way of system simulation. In this method, radiation and motion characteristics of the target were modeled by multifunctional target simulator, the 3-DOF platform was used in simulating the attitude characteristic of carrier. The composition of system, working principle and simulation results were introduced in detail in...
In order to improve the accuracy of traffic forecasts, it's important to apply the supporting vector regression in prediction of network traffic. This paper introduced key factors in supporting vector-machine regression modeling, and this model is applied to calculate the actual network traffic prediction, which compared with the BP neural network model. The results showed that supporting vector-machine...
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