At present, the reconstruction error of optical fiber shape sensing is commonly represented by Euclidean distance error. However, Euclidian will be dependent on complexity, which depends length, curvature and torsion. In this paper, we establish a model distributed in frequency domain reflectometry (OFDR) based Frenet-Serret frame delivering theory, illustrates relationship between parameters such as curvature, torsion, length strain measurement We experimentally verify feasibility...

A zero drift suppression method of a distributed feedback (DFB) fiber laser hydrophone is studied. The working principle the DFB and cause, phenomenon, influence are briefly introduced. design idea implementation described in detail. differential cross-multiplication demodulation improved by adding closed-loop control to appropriate stage, problem solved without any hardware modification. Simulation analysis experiments performed verify feasibility effectiveness method. experimental results...

Due to the increasing integration of new energy sources, power system now exhibits low inertia, in which broadband oscillation problem is increasingly significant face strong coupling complex and variable systems, current lack uniform effective mathematical models analysis methods. To solve this major problem, a localization method based on combination compressed perception graph attention network (GAT) proposed. The firstly uses principle compression compress transmit time series data...

This paper analyzes the relationship between channel density and cell size of several common SiC MOSFET structures. The 750V60mΩ was fabricated based on improved hexagonal cell. Then static dynamic performance tests device were completed. Finally, specific on-resistance 2.05 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> breakdown voltage 950V are obtained.

In this paper, fiber Bragg grating (FBG) sensors for strain monitoring at cryogenic temperatures were proposed and demonstrated. The sensitivity, repeatability temperature compensation effect of FBG studied, within the range -196°C to 20°C. sensitivity was tested by quartz specimens with low thermal expansion coefficient. Experimental results show that relative change central wavelength is 0.784, which almost does not temperature. adhesive used tested. have good adaptability temperatures,...

Natural gas and biogas, as commonly used combustible gases, are widely in urban residents industrial enterprises. Gas leakage accidents occur frequently. In order to more accurately distinguish whether it is a natural leak or biogas leak, this paper proposes method for simultaneous detection of methane ethane based on TDLAS, develops set dual devices. Firstly, studied the absorption lines ethane. According lines, 1680nm DFB laser beam was scan at same time. Secondly, phase-locked amplifier...

The characteristic absorption lines of carbon monoxide gas cross with that other gases in near-infrared and midinfrared bands, the detection results are easily disturbed. Especially some environments such as coal mines petrochemicals, it is more important to avoid interference, order achieve accurate measurement monoxide. In this paper, a DFB laser beam at 2330nm was selected scanned for line Although interference components avoided, overlap methane spectra still existed. Firstly, were...

Based on the learning and integrated application of T-S modeling method Phase based Quantum Genetic Algorithm (PQGA), this article aims to provide a new effective fulfill actual demand oilfield development production. First, according forecast indicators influencing factors, establish fuzzy rule base, then prediction model, with improved quantum genetic algorithm optimize parameters through water-cut in oilfield, we prove that is effective.

The reconfigurable fault-tolerant routing algorithm in Mesh Topology Structure which belongs the field of network on chip has a feature, is that method achieves fault tolerance by using north last turning model and less-stored list. series merits: practical convenience, high fault-tolerance performance, low cost little hardware expense. Moreover, if there not any fault, XY with application certainty could ensure reliable transmission information, divides router into two parts including...

This paper presents a new self-adaptive optimization removal algorithm for evolutionary structural (ESO) method. The elements rejection based on this is determined by their own attributes (statistical distribution of element sensitivity) rather than comparing the sensitivities to manual selective parameters in traditional process. Thus, it avoids choices and adjustments series parameters, involves fewer subjective factors, makes process more adaptive. Furthermore, coefficient introduced make...

In this paper, we introduce an optimal bias voltage searching strategy and maintaining method in BOTDA system based on dual sideband modulation. The utilizes both up shifted down continuous wave light to generate Brillouin scattering light, while using the amplified pulsed boost signal by stimulated scatting effect. order obtain a clean curve along fiber under test, probe must be good noise ratio. addition, intensity of should stable as well. Therefore, propose novel control frequency shift...

the paper mainly researched on usage of particle swarm in image clustering.A fitness function is designed based principle minimum cluster distance and maximum between distance.And optimization, which combined with fuzzy clustering, used system X-ray coal purity detection developed tested.According to intensity distribution images, an area interest selected Gaussian property greatly cut down data be processed.On basis that, clustering applied, impurities are fact that always tiny...

In order to reduce the phase noise introduced by unbalanced interferometer in distributed feedback (DFB) fiber microphone modulation system, a compensation method based on stable laser source as an optical reference is proposed. The narrow linewidth incident Michelson shared microphone, so that it has same path difference. This information used offset interferometer, achieve purpose of suppression. principle composition and suppression are theoretically analyzed experimentally verified....

The impact of attitude deformation towed linear array and the fitting error point sensors on beamforming. We studied All-fiber acoustic-posture integrated based distributed feedback fiber laser (DFB-FL) hydrophone optical frequency domain reflectometry (OFDR) measurement. Analyzed principle direction finding, influence directional was analyzed. Designed an 8-element structure with a diameter 16mm, effectively combining hydrophones sensing multi-core fiber. Finally, effectiveness correction...

In order to monitor the safety of whole cable in real time and effectively, this study introduces adopts distributed optical fiber temperature sensing (DTS) technology as method monitoring. A variety statistical results are used basis for judging running state. Not only does system have no blind zone monitoring, but also provides accurate alarm information fast response, which enables managers deal with faults timely avoid heavy losses. Therefore, DTS has a high promotion value field

The demodulation parameter optimization of fiber optic acoustic sensor for broadband large signals is studied in this paper. Firstly, the performance sensors demodulating introduced. low-frequency energy result significantly increased and completely submerge effective signal. By deducing analyzing algorithm sensors, reason why it impossible to demodulate theoretically explained. An arctangent realized MATLAB. White noise with limited frequency bands are used as simulation signal sources...

Methane, as the main component of gas and natural gas, its flammable explosive characteristics to industrial production, urban safety daily life has brought great potential hazards. Accurately measuring concentration methane is significance for development environmental protection. At present, tunable semiconductor laser absorption spectroscopy (TDLAS) become one important technologies sensor measurement. However, this technology easily affected by temperature, relative error measurement...

In multispectral remote sensing image crop classification, in order to make full use of the complete spectral information image, time series data were used replace a single scene, which improved accuracy classification. Meanwhile, original U-net++ algorithm based on was utilised classify and extract crops study area, not accurate enough for with poor extraction ability maize soybean during growing period. Therefore, these problems, model is paper, incorporating dual attention mechanism...

This paper proposes an improved initialization strategy for the multi-view k-means clustering algorithm based on adaptive sparse membership and weight allocation (MVASM). The method first performs k-means++ each view to obtain labels view, then defines a cross-view consistency objective function. weights are optimized iteratively, subviews integrated according weights. is subjected clustering. similarity between calculated using labels, solved gradient descent. After iteration, center of...

By using the linearity of edge filter in a specific wavelength range twin-core long period fiber grating(LPFG), new method for measuring strain grating with high-precision and wide measurement is proposed. Namely, proceeding from demodulation principle LPFG transmission spectrum Bragg grating(FBG) reflection spectrum, we designed kind system to demodulate sensing signal, which based on light intensity, it applicable static dynamic measurement. And through theoretical calculation simulation,...