Papers by Keyword: Filter

Abstract: Porous composites from waste glass were synthesized by simple heating process. The ability in the control of pore size was controlled by adjusting the time of melting point. In this study, the time of melting process was used a pore-forming agent in composite from waste glass. The composites from waste glass had been synthesized at 750^οC with controllable of time 1, 2, and 3 hours. The characterization was showed by BET method. The composites from waste glass have decreased value of surface area. The composites with controllable of time 1, 2, and 3 hours, each other have 0.820 m²/g, 0.734 m²/g, and 0.445 m²/g. Porous composites from waste glass could be used in various applications, such as water filter.

Abstract: An experimental study on drainage of different composite filter material in Wenzhou ultra-soft soils was carried out, to investigate the effects of anti-clogging for these composite material. A new instrument was designed to simulate draining process of the ultra-soft soils under vacuum loadings. Based on the experimental results in the form of pump quantity of water, the average settlement of the sludge, the pumping rate and the water content, a comparison was made among six composite filter material (e.g., PVA-1, PVA-2, SAP, superfine fiber, coral cashmere fiber and bamboo fiber) and a traditional non-woven fabric material. The results demonstrate that, PVA-2 composite material is the best way to keep from clogging in the ultra-soft soils. The effects of the anti-clogging is depended on the characteristics of the water absorbency and retention.

Abstract: This Paper Proposes a Scheme for Filtering of Stochastic Distributed Parameter Systems. it is Assumed that a Real-Time Environment Consists of m Groups of Sensors, each of which Provides Necessarily State Spatially Measurements from Sensing Devices. Base on Lyapunov Stability Theorem and Itô formula, a Class of Distributed Adaptive Filters with Penalty Terms Result in the State Errors Forming a Stable Evolution System and Asymptotically Converge to Stochastic Distributed Parameter Systems, and then the Preferable State Estimation is Derived. Numerical Simulation Demonstrates the Effectiveness of the Proposed Method.

Abstract: In view of the traditional measurement system is not easy to install and design shortcomings, such as volume and requires a lot of wiring, This system used STM32 microprocessor and CC2530 ZigBee wireless technology to achieve the acquisition of High-speed rotating strain, high-speed storage, wireless monitoring system. This system can be used to replace manual operation, make the test more intelligent, more convenient and more accurate. This article used the STM32F103 chips as the main control system chip, implement the collection and storage function, CC2530 ZigBee protocol implemented wireless transmission function. Acquisition module used the high-speed AD transform chip ADS1274, Four-way synchronization acquisition, which convert digital signal transmit to the main control chip, the main control chip collected data which stored in the high capacity SD card. When need data, the system get the data from the SD card by zigbee wireless transmission to the monitor software. This system used the hardware filter and software filter, join the manning window, which reduced the influence of noise and improved the system accuracy. This paper had solved the monitoring question of the high-speed acquisition structure, implemented the function which data collection, storage and remote control for the integration, according to testing, the various technical indexes reach the system requirements^[1].

Abstract: The paper analysis mean filter, median filter and morphology filter. The paper studied order morphology theory and its filter character. Based on this, the paper proposed multi-scale and multi-structure filter algorithm based on order morphology. The result of simulation shows that the algorithm can not only keep the edge and detail of medical image but also can enhance the contrast of recovery image.

Abstract: A technique for a reconditioning equalizer filter for non-constant envelope signals is described. The input to a transmitter chain is modified by a reconditioning equalizer filter, prior to being applied to the transmitter. The reconditioning equalizer filter modifies and smoothens the amplitude of the signal. The modified and smoothened signal has its peaks reduced which results in lower Crest Factor. The input to the reconditioning equalizer filter could be a baseband, intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal, it needs to be down-converted to baseband before being applied to the reconditioning equalizer filter. The reconditioning equalizer filter could be performed in a digital or analog domain.

Abstract: This paper introduces the working principle and structure of direct digital frequency synthesizer. This paper select the technology of lookup table to design DDS because it has many advantages such as less consumption hardware resources, simple structure, output only small delay and so on. As a result, signal generator can produce many waveforms with good stability and high frequency resolution. Finally, test showed that the output wave of triangular signal frequency is greater than 1MHz and the highest sine wave frequency is 30MHz, the value of peak to peak is continuously adjustable in 50mV ~ 4V range. The result of study will provide theoretical guidance for the design of DDS.

Abstract: In the digital mobile communication signal transmission system, the inter-symbol interference is one of the main factors affecting the performance. In order to make the error rate reducing to a minimum, this paper designs a new Calman digital equalization filter. It is based on Calman filter principle, and establishes the control mathematical model of observation equation and state equation, and uses MATLAB programming to realize the algorithm. In order to verify the effectiveness and reliability of this filter, this paper uses filter toolbox of MATAB to do numerical simulation on the filtering effect. Through comparing with normal digital equalization filter effect, after adding the Calman digital equalizer filter, the feedback signal is conformed to the reference signal. The duty ratio of SPWM follows the basic changing law, so as to maximize the elimination of crosstalk inter-symbol. It provides reference data for the research on mobile communication inter-symbol interference.

Abstract: This paper introduced the structure and special property with type device, analyzed how to realized programmable analogue function module with digital potentiometer. This paper gave a design example of programmable second-order active low pass filter by using digital potentiometer. The programmable filter can be application to the signal filter processing of data acquisition systems. This paper has reference value of theory and practice on the application of digital potentiometer

Abstract: In this paper we present a coaxial filter analysis software based on MATLAB. Our software can obtain scattering parameters’ curve of the filter which is composed of high-low impedance coaxial cables. In order to obtain scattering parameters’ curve, we introduce a method of making distributed parameters equivalent to lumped parameters and adopt A parameter matrix approach to get it. Our software has taken into account the influence of step capacitances. Compared with the commercial software HFSS, our software has advantages of strong pertinence, operating fast and easy to adjust. Finally, we use HFSS to validate the correctness of our software.