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oe1(光电查) - 科学论文

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?? 中文(中国)
  • [IEEE 2018 7th International Conference on Agro-geoinformatics (Agro-geoinformatics) - Hangzhou (2018.8.6-2018.8.9)] 2018 7th International Conference on Agro-geoinformatics (Agro-geoinformatics) - Using Stochastic Programming and Remote Sensing to Implement Ecological Restoration of Degraded Mud Flat Ecosystem

    摘要: This paper presents an interval-parameter stochastic programming (ISP) approach for supporting ecological restoration of degraded mud flat ecosystem under mud flat ecological restoration cost uncertainties. ISP is capable of performing mud flat ecological system analysis, ecological restoration cost uncertainty analysis, and solution block screening in a comprehensive and systematic way. A mud flat ecological restoration problem is used to demonstrate the applicability of the proposed ISP approach. The results indicate that solution block can be generated for the objective function and decision variables, and a variety of decision alternatives of solution block can be obtained under different cost uncertainty scenarios.

    关键词: interval-parameter stochastic programming,ecological restoration,return on investment,degraded mud flat ecosystem,sensors,satellite

    更新于2025-09-23 15:22:29

  • Feasibility of 4H-SiC p-i-n Diode for Sensitive Temperature Measurements between 20.5 K and 802 K

    摘要: For the first time, we report on the performances of 4H-SiC pin-diode temperature sensors for operating temperatures between 20.5 K and 802 K. In this huge temperature range three ranges of performance were identified with the limit temperatures at 78.2 K and 176.3 K. In each of these ranges a different dominant current transport mechanism is shown and in the manuscript a detailed analysis and discussion is reported. The sensor performances were extracted from VD-T characteristics at different fixed ID values. In particular, at ID=1 μA and in the temperature range between 78.2 K and 802 K, we found a sensor sensitivity of 2.3 mV/K up to 3.4 mV/K with a rms temperature error, eT, of less than 4.2 K and the sensor shows an excellent linearity – quantified by the coefficient of determination R2 higher than 0.9993. For even lower temperatures (below 78.2 K), low measurement currents like 10 nA are required leading to a sensitivity of 5.8 mV/K, but a lower linearity (R2=0.9095) and a rms temperature error of 9.7 K which makes the sensor only partially usable in the temperature range between 20.5 K and 78.2 K. Finally, the sensor performances are compared to other state-of-the-art solutions.

    关键词: Semiconductor device modelling,Cryogenic temperatures,Temperature sensors,4H-Silicon Carbide device,High temperatures,Semiconductor p-i-n diodes

    更新于2025-09-23 15:22:29

  • Real-time Surface Shape Sensing for Soft and Flexible Structures using Fiber Bragg Gratings

    摘要: In this paper, we present a new soft and flexible sensor which can reconstruct its surface shape in real-time. A single-core optical fiber with fiber Bragg gratings (FBGs) is capable of detecting sparse local strains at high bandwidth using wavelength-division multiplexing (WDM). The fiber was embedded into an elastomeric substrate to reconstruct its global surface morphology. Finite element analysis (FEA) was used to determine the design parameters, and also to validate the unique mapping from sparse strain measurements to the continuum shape of the sensor. To simplify the fabrication and error compensation process without precise/prior knowledge of the FBG locations in the sensor, machine learning-based modelling was applied. This enables real-time, robust and reliable shape reconstruction. It is demonstrated to outperform various applications of electronics-based sensors which require sophisticated electrode wiring and noise reduction. Experiments were performed to evaluate the sensing accuracy and repeatability.

    关键词: Soft Sensors and Actuators,Flexible Robots,Surface Shape Sensing,Fiber Bragg Gratings

    更新于2025-09-23 15:22:29

  • [IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Experimental Verification of the Optimum Diagonal Loading Level for Adaptive Matched Filtering with ?-OTDR System

    摘要: Recently, a temporal adaptive matched filtering technique has been proposed to reduce the background noise in phase-sensitive optical time domain reflectometry (φ-OTDR) systems deployed for fibre optic distributed acoustic sensing (DAS) applications. This technique utilizes noise covariance matrix inversion which is estimated from signal-free assumed training samples. The detection performance degradation due to desired signal presence in the training data and the ill-conditioning of the matrix because of the limited training data are conventionally avoided by adding some amount of white noise on the diagonal elements of the covariance matrix. In this paper, the optimum level for this diagonal loading (DL) is investigated for DAS applications and verified with real φ-OTDR data. The optimum DL level which has been analytically proven in beamforming applications is shown to be applicable in the temporal domain noise filtering for DAS applications. The experimental results validate that the optimum DL value is negative.

    关键词: diagonal loading,phase-sensitive optical time domain reflectometry (OTDR),distributed vibration sensors,optimum filtering.,Adaptive matched filter

    更新于2025-09-23 15:22:29

  • Caracterización Espectral y Detección de Flecha Seca en Palma Africana en Puntarenas, Costa Rica

    摘要: During the last decades, precision agriculture has observed significant technical progress that has permitted better management of farming, optimizing resources and applied inputs. Within the scope of geomatics, land optical sensors have allowed to expand and increase knowledge on the spectral behavior of the crops under study, providing increased benefits in the application of treatments and pest or disease prevention. The objective of this work was to characterize the African oil palm (Elaeis guineensis Jacq.), by means of field radiometry-spectrum, in healthy plants, as well as in plants affected by bud rot. The study was conducted between March and May 2016 in African oil palm farms in Parrita, Puntarenas, Costa Rica. A hyperspectral land sensor, with a 325-1075 nm wavelength range (visible and near-infrared spectrum), was used. In general, plants in healthy phytosanitary condition, which also had a treatment of “fertilization+irrigation”, presented the highest reflectivity curves: around 0.7%. The bud rot influence in the reflectance curve of the plants had, in most cases, a greater weight than the type of treatment to which they are subjected. It thus confirms the possibility of detecting the bud rot pathology through reflectance spectroscopy in conditions of field work, the main goal of this research.

    关键词: Spectroscopy,land optical sensors,reflectance,near infrared

    更新于2025-09-23 15:22:29

  • Introduction of real-time digital processing techniques for the high-sensitivity GMI sensors

    摘要: A new fully digital Giant Magneto-Impedance (GMI) sensor is presented. The design combines the off-diagonal configuration of the sensitive element with a real-time digital electronic conditioning based on a Software Defined Radio (SDR). Compared to a conventional implementation of these sensors, the proposed design exhibits key advantages. These include firstly the simplicity of obtaining a quasi-linear sensor response around the zero-field point without making use of a bias magnetic field and an offset cancelling device. Secondly, the potential of integration, the flexibility of reconfiguration as well as the low-noise and high-sensitivity are promising features of the developed concept. Noise performance of 1.8 pT/√Hz was obtained in the white noise region.

    关键词: GMI sensors,digital processing techniques,off-diagonal

    更新于2025-09-23 15:22:29

  • Electrophysiology Meets Printed Electronics: The Beginning of a Beautiful Friendship

    摘要: Electroencephalography (EEG) and surface electromyography (sEMG) are notoriously cumbersome technologies. A typical setup may involve bulky electrodes, dangling wires, and a large amplifier unit. Adapting these technologies to numerous applications has been accordingly fairly limited. Thanks to the availability of printed electronics, it is now possible to effectively simplify these techniques. Elegant electrode arrays with unprecedented performances can be readily produced, eliminating the need to handle multiple electrodes and wires. Specifically, in this Perspective paper, we focus on the advantages of electrodes printed on soft films as manifested in signal transmission at the electrode-skin interface, electrode-skin stability, and user convenience during electrode placement while achieving prolonged use. Customizing electrode array designs and implementing blind source separation methods can also improve recording resolution, reduce variability between individuals and minimize signal cross-talk between nearby electrodes. Finally, we outline several important applications in the field of neuroscience and how each can benefit from the convergence of electrophysiology and printed electronics.

    关键词: wearable sensors,EMG,printed electrodes,skin electronics,EEG

    更新于2025-09-23 15:22:29

  • Deep Belief Network for Spectral–Spatial Classification of Hyperspectral Remote Sensor Data

    摘要: With the development of high-resolution optical sensors, the classification of ground objects combined with multivariate optical sensors is a hot topic at present. Deep learning methods, such as convolutional neural networks, are applied to feature extraction and classification. In this work, a novel deep belief network (DBN) hyperspectral image classification method based on multivariate optical sensors and stacked by restricted Boltzmann machines is proposed. We introduced the DBN framework to classify spatial hyperspectral sensor data on the basis of DBN. Then, the improved method (combination of spectral and spatial information) was verified. After unsupervised pretraining and supervised fine-tuning, the DBN model could successfully learn features. Additionally, we added a logistic regression layer that could classify the hyperspectral images. Moreover, the proposed training method, which fuses spectral and spatial information, was tested over the Indian Pines and Pavia University datasets. The advantages of this method over traditional methods are as follows: (1) the network has deep structure and the ability of feature extraction is stronger than traditional classifiers; (2) experimental results indicate that our method outperforms traditional classification and other deep learning approaches.

    关键词: classification,feature extraction,multi-sensor fusion,remote sensors,deep learning,hyperspectral image

    更新于2025-09-23 15:22:29

  • The utility of an omni-directional photoelectronic sensor device to measure meso-scale variability in aeolian sediment transport activity

    摘要: Electronic sensors (i.e., acoustic, piezoelectric, and photoelectric) have been utilized extensively and effectively in recent years for measuring aeolian transport intensity. The bulk of these studies, however, position the devices in stationary, fixed orientation during field experiments. These practices work fine for shorter, micro-scale field studies; yet, during longer experiments lasting months or even years, a fixed directional orientation is unrealistic due to shifts in wind direction. This issue has ultimately limited the use of electronic sensors for meso-scale aeolian research. In light of this constraint, this paper presents a device to measure aeolian transport activity across a 360-degree azimuthal range. The Rotating Wenglor Device (RWD) was deployed on Santa Rosa Island, Florida for a three-month field study. The data reveal that the prevailing transport activity did not align with the dominant wind direction. The implications of this finding can be further elucidated when analyzing our data using the Fryberger drift potential model. Our findings indicate that the traditional Fryberger method, constructed using our wind data, produced a resultant transport drift towards the northwest; however, the RWD illustrated a resultant transport direction towards the northeast and at a rate three times slower. These finding highlights a major benefit of the RWD as it would produce a more accurate measure of meso-scale transport activity and therefore dune development than models derived strictly from meteorological station data, such as the Fryberger method. An additional advantage of the RWD is that the device operates unattended for extended periods, yet can provide high-resolution data regarding micro-scale transport dynamics.

    关键词: Sediment transport,Omni-directional,Electronic sensors,Meso-scale,Instrumentation,Wenglor

    更新于2025-09-23 15:22:29

  • Label-free nanoparticle sensors based on a triple-layer-coated microsphere structure

    摘要: We present a design for a sensitive, label-free nanoparticle sensor based on triple-layer-coated microsphere resonators. The surfaces of the microsphere structure are coated with three layers that have high, low, and high refractive indexes from inside to outside, respectively. We theoretically and numerically investigate two cladding modes, we call the inner mode and outer mode. The resonance wavelengths of the two modes are used to detect the resonance wavelength shift caused by a single-nanoparticle. Numerical calculation suggests that if we change the thickness of the middle layer, the device offers another degree of freedom to obtain higher detection sensitivity. We build a model to accurately describe a nanoparticle close to the microsphere. The method for the sensors may promote the design of biosensing applications.

    关键词: Optical materials and properties,Sensors,Simulation and modelling,Microstructure

    更新于2025-09-23 15:22:29