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We show timing jitter spectrum measurement of free-running mode-locked lasers from 1-mHz to 40-MHz Fourier frequency. The demonstrated method can resolve different noise mechanisms that cause specific jitter characteristics from <100-ns to >1000-s time scales.
We demonstrate sub-100-attosecond-resolution time-of-flight stabilization method for optical pulse trains in atmospheric links. The rms excess fluctuation in timing for 76.2-m-long indoor free-space transfer is suppressed from >230 fs to 2.6 fs over 130-hour.
A trace gas sensor platform based on quartz-enhanced photoacoustic spectroscopy using quartz tuning forks (QTFs) with resonant frequency of 38 kHz and 40 kHz were experimentally investigated and theoretically analyzed for the first time.
In this paper we address the problem of water basins surface measurements. This problem is important in regions where coal extraction took place because of it significant impact on the landscape. We propose method based on usage of quadrotor equipped with non-metrical camera. Presented concept include discussion about quadrotor path planning, image tracing, quadrotor state estimation and altitude...
Information to be exchanged between two parties needs compression for achieving its efficient transmission. Encoded information gets distorted during its transmission over a channel due to noise. For monitoring and analysis of such noisy traffic of an adversary over communication networks, it is required to find the type of information, whether it is text or speech, then to restore it for further...
A lower extremity exoskeleton is designed and a novel control method based on RBF neural network identification is proposed to guarantee the exoskeleton identifies the pilot's motion intention independently. The propose method considers the pilot wearing assistance exoskeleton as an unknown system, and the RBF neural network is employed to identify the system's motion trajectories and the identification...
There is serious conducted electromagnetic interference (EMI) in the application of medium-power variable-frequency drive (VFD) systems. The EMI passive filters which can suppress the noise can make the VFD systems comply with the relevant electromagnetic compatibility (EMC) standards. In this paper, combined with the experiment and measuring experience in related subjects, it describes the proper...
Sound comfort becomes more and more important in residential houses. Home appliance is one of the main sources of indoor noise. Noise emission is a distinctive feature for the selection of the home appliances. Noise levels in household appliances are increasingly attracting attention from manufacturers and customers. Refrigerators as common appliances used by most families run continuously all day...
A decentralized fault diagnosis and accommodation scheme in discrete time for teams of cooperative mobile robots is presented. Each vehicle estimates, via a local observer, the overall state of the team, which is used to compute its local control input and a set of residual vectors. Each residual is sensible to a fault occurring on a single teammate, even not in direct communication, and the fault...
Finite control set predictive current control is a new solution for control of electrical drive systems. The system has a straightforward control scheme. Current errors between the reference and the predictive values are evaluated in cost function. In this paper, an extended Kalman filter is used for predictive current control to realize sensorless predictive control. The results verify that this...
Phase information recovered through interferometric techniques is mathematically wrapped in the interval (−π, π). Obtaining the original unwrapped phase is very important in numerous number of applications. This paper discusses a Fourier transform based phase unwrapping method. Kalman filter is proposed for denoising in post processing step to restore the unwrapped phase without any noise. The proposed...
Objective measures are favored and widely used by many researchers in evaluating the quality of noise-suppressed speech. A good and reliable objective measure should have property that it could evaluate speech quality in consistent and well correlated with subjective ratings. In this paper, several widely used objective measures are applied to the speech signals with the Chinese languages including...
We report on electromagnetic noise immunity design for multilayer printed circuit boards using quasi three dimensional electromagnetic simulation, and its application to products. For evaluation of the electromagnetic simulation, a prototype multilayer printed circuit board was designed and tested. The coupling of its power circuit patterns on the same layer and the coupling of ground patterns on...
In HF (3–30 MHz) communications the ambient electromagnetic background noise or ‘radio noise’ generally is the limiting factor in reception. Radio noise measurements are needed for spectrum pollution control and to provide reference levels for radio system design. This article discusses the influence of the measurement antenna on the measurement results. A novel method to compare the polarization...
Small vessels or unmanned surface vehicles only have a limited amount of space and energy available. If these vessels require an active sensing collision avoidance system it is often not possible to mount large sensor systems like X-Band radars. Thus, in this paper an energy efficient automotive radar and a laser range sensor are evaluated for tracking surrounding vessels. For these targets, those...
As is well known to all, the multi-agent systems (MASs) are not able to reach consensus with any protocol if the MASs contains system noise. The problem of consensus error calculation for MASs with both system and measurement noises is considered. The contributions of the paper are two aspects. The first one is to design a novel protocol based on the Kalman filtering and information fusion, so that...
Low noise amplifier is designed at 2.1GHz and 4.6GHz. Matching network is designed using lumped elements. Frequency transformation technique is employed to synthesis lumped element. Stabilization circuit is included for stable LNA throughout frequency range. Simulation result gives gain of 12.03dB and 10.16dB and NF of 0.5818dB and 1.2dB respectively at 2.1GHz and 4.6GHz. Input and output VSWR is...
SR-based denoising methods have shown promising performance in image denoising. However, Because of the degradation of the noisy image, conventional SR based denoising models may not be accurate enough for the reconstruction of a clean image. Therefore, to reduce the noise corruption, a novel adaptive sparse representation based SAR image despeckling algorithm is proposed in this paper, where the...
Chaotic circuits have gained increasing attention in many engineering applications. Qualitative measures such as Lyapunov Exponent (LE) are the most common methods for identifying chaotic behavior. However, the use of these measures is limited due to the short output signal length and its contamination by noise. In this paper, we propose a novel methodology for modeling and detecting chaotic vs stochastic...
Our paper addresses a question of prediction compression ratio in lossy compression of remote sensing images by coders based on discrete cosine transform (DCT) taking into account noise present in these images. Quantization step is set fixed and proportional to noise standard deviation to provide compression in optimal operation point if it exists. Simple statistics of DCT coefficients is used for...
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