Papers by Keyword: Interpolation

Abstract: The input voltage of off-grid PWM converters has a great dynamic range in amplitude and frequency. In addition, the frequent changing of these parameters also makes it hard to measure preciously via traditional ways. Details of window function are presented. A modified FFT spectrum analyzing method using interpolation is also given and checked. Finally, a feasible solution which balances both precision and real-time data processing comes up considering the speed of MCUs mainly used in industry. Simulations and experiments show that this solution settles the troubles which cant be cleared up by traditional methods.

Abstract: In this paper, we present an algorithm for reconstruction of B-spline surface such that it interpolates the four given boundary curves and the cross-boundary derivatives meanwhile approximates some given inner points. The main idea of our method is: first, we construct an initial surface which interpolates the four given boundary curves and the cross-boundary derivatives on them with minimizing the energy; then, while keeping the boundary control points of the initial surface unchanged, we reposition the inner control points of the surface such that it approximates the inner points with optimization. Examples show that our algorithm is practicable and effective.

Abstract: This paper introduces a master-slave control method of teleoperating a redundant manipulator with double handles. The master handles send motion commands in the form of increments. The mapping module transforms the commands into homogeneous matrices. And the slave manipulator links discrete motion commands in the mode of PVAT automatically, by inverse kinematics and fifth-order polynomial interpolation. Simulations and experiments are taken to prove the effectiveness of the control method in the paper.

Abstract: Overcut or speed impact exists in high-speed interpolation of consecutive tiny segments. Because the remaining distance of the current segment does not exactly equal to an interpolation cycle required distance. Taking processing accuracy as a precondition, a new inflection point processing method is proposed to solve this problem. With different solutions of different angles, this method realizes the tiny line continuous processing with high processing quality. And this method needs a small amount of calculation with strong real-time. Error analysis is done and it can meet machining accuracy requirements. Now this method has been applied to engineering practice.

Abstract: Porosity plays an important role in the characterization of transport properties. However, it is quite difficult to predict the unknown porosity values only by some sparse conditional data in the process of simulation based on current popular interpolation methods. Therefore, some interpolation or extrapolation methods are used to estimate or predict the unknown porosity for better simulated results. Any numerical modeling should incorporate all relevant information from different scale data including coarse scale support data (block data) and fine scale support data (point data) to improve interpolation accuracy. Block error simulation (BESIM) is an alternative algorithm to generate stochastic realizations conditioned to both point and block data. Under the rather severe restriction, block data are linear averages of their constituent point values. This method allows reproducing both block and point data at their locations. The experimental results demonstrate that BESIM is practical in porosity simulation.

Abstract: Energy consumption is in support of economic development, at the same time it also results in the pollution of the environment inevitably. With the increasing of contradiction of energy supply and demand, and the serious pollution of the environment, it restricts the development of economy. In order to achieve the “Twelfth Five-Year energy planning” target, we must control the energy consumption, to implement energy-saving and emission reduction measures .Based on Chinese energy consumption status, this paper focuses on the Beijing’s energy consumption, analyzes energy consumption influences factors and the relationships among them. At the same time, this paper abstracts the model of economic and environmental on the energy consumption for the complicated relationship. Also it establishes a comprehensive multidimensional Beijing city energy consumption policy simulation and control model, pro-vides energy consumption analysis and regulation of different level and the angle respectively, covers major regulation and control means in relation to the energy consumption. On the basis of analysis of influence factors, we do the mathematical simulation and prediction between them. The results show that the prediction value is very good, the error is small. Therefore, this conclusion proves that our energy consumption control of construction model is scientific.

Abstract: The local extreme is main reason to hamper the optimization process and influence the registration accuracy in medical image registration algorithm. In general, the accuracy of image registration based on mutual information is afforded by interpolation methods. In this paper, we analyze the effect of the measure and interpolation methods for medical image registration and present a medical image registration algorithm using mutual strictly concave function measure and partial volume (PV) interpolation methods. The experiment results show that for images with low local correlation the algorithm has the ability to reduce the local extreme, the registration accuracy is improved, and the algorithm expended less time than mutual information based registration method with partial volume (PV) or generalized partial volume estimation (GPVE).

Abstract: When operating a 5-axis linear cutting command G01, the controller automatically inserts point data between two NC blocks in a linear distribution fashion, and then drives the cutter along these inserted points. If a simultaneous 5-axis machining is initiated, and CL data is directly transformed one-to-one into NC data, and then cutting is performed directly without having the 5-axis controller inserting any points between NC blocks, its processing path will deviate from the original plotted path. In fact, the processing path is no longer a straight line, but a curve line. This study proposes a method to increase CL interpolation points to automatically rectify the path deviation. The extent of research of this study comprises: (1) Transforming CL data into NC data (2) Programming tool orientations (3) Obtaining all CL interpolation points and their tool orientations (4) Generating NC data.

Abstract: Before the large capacity and engineering image is analyzed carefully, which need to be effective scaled. The subsequent analysis and calculation to engineering image is subjected by image quality and scaling time. According to scaling research of large capacity engineering image, the effect for image scaling by various interpolation algorithm is individual analyzed, and more appropriate algorithm is selected. The experimental results show that the engineering image of best effect is got, when it is high-expansion scaled by double cubic interpolation, and the bilinear interpolation is more suitable for low multiple scaling image.

Abstract: Based on ElGamal system, a general authenticated encryption scheme characterized by (k, l) joint verification was put forward through integrating (t, n) threshold signature scheme and message recovery technique together. After being signed by any t ones from a company with n members, message m was transmitted to a particular verifier company with l members, and then recovered through the cooperation of any k ones from the verifier company, so as to realize a directional transmission between different companies. The security of this scheme is based on threshold scheme of Shamir and ElGamal system, and the scheme enjoys the characteristics of lower bandwidth and reduced communication cost, etc.