Papers by Keyword: Noise Analysis

Abstract: The output-current of silicon microgyroscope is at the level of 10^-7A. So the requirements for circuits’ SNR are very high. This paper proposes a method to improve transimpedance amplifier interface circuit’s SNR. First of all, the operating principles of silicon microgyroscope and transimpedance amplifier interface circuit are introduced. Secondly, resistor thermal noise, amplifier’s current and voltage noise are analyzed. Then noise density in a certain frequency range is calculated based on Matlab. Besides, a method to improve SNR is proposed, namely, increasing the value of DC offset resistance. Finally, simulation based on Cadence is operated to verify the method. Simulation results fit well with the theoretical analysis. That means the method to improve the SNR is feasible.

Abstract: In this paper, noise of diamond circular saw blades has been measured, five different types of saw blades are used to measure their noise under different working condition. By analyzing of the experimental results, the effect of different factors on the saw blade noise is studied. The result shows that the increasing the speed of cutting machine or the diameter of blade, noise will become larger. The noise of saw blade with a hole or water slot would be greater than others without any hole or water slot.

Abstract: Based on the theory of multi-body system dynamics, the analytical method of finite element and boundary element, the finite element model of vehicle body, the rigid-flexible coupled model of vehicle and the acoustic boundary element model of carriage were established by applying a variety of simulation software. Road roughness was simulated and the SPL of field point in carriage under the excitation was computed at the frequency range of 20-150Hz. Considering the size and the positive /negative nature of panels acoustic contribution at SPL peak of field point, damping treatments were taken on different combinations of panels to decrease multiple field points SPL peak and the optimal treatment was finally confirmed. The results showed that noise reduction measures can generally decrease the SPL peak around the crew.

Abstract: Based on the noise analysis of the photoelectric detection circuit, error compensation aiming at photoelectric detection circuit has been performed by making use of interpolation method, look-up table method, adaptive neuro-fuzzy inference method, and surface fitting method, so as to improve the accuracy of photoelectric detection as well as reducing the system error. In the meanwhile, the error compensation effects of different methods are compared and analyzed. Finally, with the help of the MATLAB software, these effects are simulated using the measured data of photoelectric diode experimental platform as the sample data. The result of the simulation indicates that the adaptive neuro-fuzzy inference method can improve the detection accuracy better and its error compensation effect is also better than that of interpolation method, look-up table method, and surface fitting method, when they are under the same conditions.

Abstract: Most of the methods need to build a sophisticated classifier to detect the image tamper which leads the lower detection efficiency. For this problem, we propose a method based on artifacts detection techniques in the process produces of CFA, which includes one based on CFA pattern number estimation and the other noise analysis based on CFA. The techniques are based on computing a single feature and a simple threshold based on classifier, determine whether the mosaic artifacts of the CFA was changed. The experimental results show that, the proposed approach has higher performance.

Abstract: In practical applications,the solar cell is always used in the form of Solar Cell Module which consist of two or more solar cells connected in series or parallel. Therefore, the study of the Solar Cell Module reliability screening has more practical significance than the single solar cell. Based on the previous En-In Model, this paper analyzes the Solar Cell Module consists of two solar cells connected in different patternsthe series and the parallel, and obtains the corresponding noise parameters. Then, the concept of connection matrix C is put forward. In the end, this paper gives the corresponding conclusions by comparing the measurement results. The results of dual solar cells network will be the basis for future research of the Solar Cell Module reliability screening.

Abstract: The solid-state nanopore sensor offers a versatile platform for the rapid, label-free electrical detection and analysis of single molecules, especially on DNA sequencing. However, the overall signal-to-noise ratio (SNA) is a major challenge in sequencing applications. In our work, two different fluid systems made by metal and plexiglass have been designed to improve the signal to noise ratio of the solid-state nanopore sensor. From the measurements on the noise power spectra with a variety of conditions, it is found that plexiglass fluid system coupled with shielding box produces a good quality of electric signals on nanopore sensors.

Abstract: Obtaining valid data of accelerating propeller cavitation noise is benifial for finding the relationship between the ship feature and its radiated sound souce. This paper studies the criteria ruling the measurement of accelerating propeller noise signal in cavitation tunnel, and analyzes the signal model of the measured noise. Based on the signal model, the paper studies the fractional Fourier domain analysis method to extract interested cavitation noise from the measured noise.

Abstract: This paper explains about the evaluation of intake air flow, volumetric efficiency and noise of a motor-driven engine that used an adaptive valve lift and timing mechanism (AVLT) on one intake valve. This system is developed with an aim to produce a more powerful engine through variable valve timing and lift technique. The system made the valve lifts higher without increasing the valve lift duration. Therefore, a dynamic valve lift profile with respect to the engine speed can be achieved thus varies the input and output of an engine. As a result of applying the AVLT on a motor-driven engine, the engine noise, emission noise and the mass air flow entering the engine cylinder was increased. When AVLT is employed to a maximum lift, the mass air flow of default intake valve lift was improved within a range from 8% to 46.64% in 500 rpm to 2000 rpm speed range. Maximum lift produced engine noise within a range of 2.57% to 18.13% higher than the default lift throughout all speed. Also, maximum lift produced emission noise within a range of 2.47% to 19.19% higher than the default lift throughout all speed. The product of this research will be useful to optimise the height and timing of the valve lift and the AVLT mountings on the engine head during operation thus improves the engine performance, fuel economy, emission levels and reduced noise of a modified engine.

Abstract: In this paper, based on B & K pulse system, the noise test analysis had been implemented on the load test station of a company in Yinchuan. It is clear and concise that displayed noise distribution situation of the load test set by BK sound intensity probe, 3560B-type multi-analysis system and pc machine. Through the CPB analysis, it can quickly get the main segment of the noise and the real-time monitoring of the gearbox, so the quality of the product is guaranteed.