- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Frequency Extension of Atomic Measurement of Microwave Strength Using Zeeman Effect
摘要： Measuring the field strength of an electromagnetic wave based on atomic quantum mechanics is expected to be an innovative method to realize stable and reliable measurements. However, the major issue of atomic measurements is that the measurable frequency is limited to the resonant frequency of atoms. Therefore, in this paper, we demonstrate the measurement at arbitrary frequencies using the Zeeman effect in a static magnetic field. A cesium vapor cell is placed in a static magnetic field of approximately 40 mT, which causes the resonant frequency of the cesium atom to shift from 9.2 to 8.2 GHz. In addition, the Rabi frequency due to the interaction between cesium atoms and microwaves is measured at the frequency of 8.2 GHz in this experiment.
关键词： frequency measurement,microwave measurements,metrology,microwave spectroscopy,electromagnetic measurements,Atom optics,atomic measurements,measurement standards
更新于2025-09-23 15:22:29
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A Novel Stereo Vision Measurement System Using Both Line Scan Camera and Frame Camera
摘要： In the product surface defect detection system, the detection accuracy can be greatly improved if the surface grayscale image and depth image can be adopted simultaneously. Existing 3-D cameras have the problem in precise registration of 2-D images and 3-D data, which results in inflexibility and inevitable error in practical vision tasks. Hence, we propose a novel stereo vision measurement system which is able to simultaneously acquire registered scan grayscale images and depth images without special data registration algorithm as well as the calibration method. The proposed measurement system mainly consists of a line laser system, a line scan camera, and a frame camera. The line scan camera captures clear images of objects illuminated by the line laser. In addition, the line scan camera and the frame camera form a stereo vision sensor. In this case, the line laser stripe provides location feature of the matching point for frame camera. The epipolar constraint implements the matching process between the line scan camera and the frame camera. Finally, the stereo vision measurement model is utilized to realize the 3-D coordinate reconstruction, and the z-axis coordinate is used to generate depth image. The proposed system can simultaneously obtain the image and depth information corresponding to each pixel by means of a push sweep. In the experiment, the measurement system can achieve the accuracy of 0.13 mm within a measurement range of 500 mm × 300 mm × 200 mm.
关键词： Fault diagnosis,machine vision,visual system,measurement,laser measurement applications
更新于2025-09-23 15:22:29
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Theoretical analysis of seawater depth and temperature measurement with C-type micro-structured fiber grating
摘要： A new C-type micro-structured grating structure was proposed for simultaneous measurement of depth and temperature in seawater. Because wedge-shaped defects got introduce, high birefringence was excited at fiber core of grating. Thermo sensitive materials filled in micro pores to improve the sensitivity of temperature. Then we established a mathematical model of birefringence effect in C-type structure. This work analyzed stress distribution in all directions under two disturbances. In pressure and temperature environment, reflection peaks in two-polarization states separated with a large offset. Two characteristic parameters:λB, y ? λB, x, λB, y + λB, x were proposed for corresponding measurement. Structural parameters got optimize for better performance. Calculated output signals had high sensitivity and linearity under pressure range of 0–10 MPa and temperature range of 0–40 °C. λB, y ? λB, x mainly responded to pressure, which got sensitivity ?1.709 nm/MPa. While temperature mainly influenced λB, y + λB, x and the obtained temperature sensitivity was 1.054 nm/°C. This structure would have a great potential application due to the mature demodulation technique of grating signal.
关键词： Seawater measurement,Depth measurement,Temperature sensor,C-type micro-structured grating,Optical fiber sensor
更新于2025-09-23 15:22:29
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Quantum error correction using weak measurements
摘要： The standard quantum error correction protocols use projective measurements to extract the error syndromes from the encoded states. We consider the more general scenario of weak measurements, where only partial information about the error syndrome can be extracted from the encoded state. We construct a feedback protocol that probabilistically corrects the error based on the extracted information. Using numerical simulations of one-qubit error correction codes, we show that our error correction succeeds for a range of the weak measurement strength, where (a) the error rate is below the threshold beyond which multiple errors dominate, and (b) the error rate is less than the rate at which weak measurement extracts information. We observe that error correction based on projective measurements is always superior to that based on weak measurements; so the latter is worthwhile only if the former is unavailable due to some reason, and error correction with too small a measurement strength should be avoided.
关键词： Projective measurement,Quantum error correction,Weak measurement,Quantum trajectory
更新于2025-09-23 15:22:29
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Photonic approach for microwave frequency measurement using a silicon microring resonator
摘要： We propose and experimentally demonstrate a photonic measurement approach of microwave frequency with adjustable measurement ranges and low errors based on a silicon microring resonator (MRR). The key factor is that microwave photonic filters (MPFs) with high rejection ratios could be realized by a phase modulator, an optical filter and a silicon MRR. In the experiment, by adjusting the wavelength of the laser diode, tunable MPFs with rejection ratios beyond 60 dB are realized in order to construct different amplitude comparison functions (ACFs) with high frequency resolutions (30dB/GHz). According to the mapping relationships between the microwave frequency and power ratio of the ACF, the unknown microwave frequency could be measured. The experimental results show that microwave frequency could be measured from 10 GHz to 19 GHz with a measurement resolution of 0.08 GHz. In the future, the measurement ranges and frequency resolutions could be manipulated according to practical requirements. The photonic measurement method and compact device are significant in microwave systems.
关键词： on-chip microwave system,Microwave frequency measurement,adjustable measurement range
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Information and Communication Technology Convergence (ICTC) - Jeju (2018.10.17-2018.10.19)] 2018 International Conference on Information and Communication Technology Convergence (ICTC) - High Accuracy Real Time Machine Vision for Diameter Measurement Using Simpson Algorithm
摘要： Diameter is one of the important parameters for quality measurement. Fruit classification, for example, takes diameter as one important indicator, apart from other indicators. Precision measurement has been observed and experimented for example it can be done using laser technology, however the instrument requires a lot of space, therefore mobility is almost impossible. When speed is necessity while doing measurement, a real-time measurement using camera and image processing can give a lot of contribution compared to manual measurement. This paper introduces a diameter measurement method using Simpson algorithm in real-time, using regular camera. Simpson algorithm gave high accuracy measurement with high computation speed. The design indicated good result with accuracy ranged from 93% to 99% depending on calibration.
关键词： size measurement,automatic measurement,camera vision,simpson algorithm,size classification
更新于2025-09-23 15:22:29
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[IEEE 2018 9th International Conference on Mechanical and Aerospace Engineering (ICMAE) - Budapest (2018.7.10-2018.7.13)] 2018 9th International Conference on Mechanical and Aerospace Engineering (ICMAE) - Resident Space Objects Streak Extraction and Angular Measurement Error Analysis Base on Space Image Synthesis System
摘要： To maintain awareness, space development of space-based visible system has gained much attention in recent years. Because the angular measurement accuracy of space-based sensor is very sensitive to orbit determination, it’s necessary to analyze the factors of angular measurement error, which can provide references for optimal design of space-based sensor. In this paper, a space image synthesis system is developed to provide the image source for resident space object detection and extraction. Then image extraction error and pose error of observation platform are analyzed, with which that the angle measurement error decreases as the focal length and size of pixel increase under same image extraction error can be concluded. Compared with position and velocity error of satellite, attitude angle error has greater impact on angle measurement error of RSOs. By using Otsu method and mathematical morphology method, the angle measurement error of RSOs can be controlled within 7 arcseconds.
关键词： resident space object,error analysis,angular measurement,space situational awareness,space image synthesis
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA) - Rome, Italy (2018.6.11-2018.6.13)] 2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA) - Extracting Features from Optical Coherence Tomography for Measuring Optical Nerve Thickness
摘要： Neurological pathologies, especially optical neuropathologies, can be studied by means of OCT (optical coherence tomography). Tomography generally allows to investigate inner structures of a tissue such as mass, and profiles of liquid flow. OCT is intended as an interferometry-based imaging technique that provides cross-sectional views of substrates. It allows to measure micro-scale cross-sectional imaging of biological tissue. While ultrasound uses sound waves, it acts like it but with a low coherence light. Optical nerve thickness has an impact on different neurological pathologies, and in particular as an indicator of epilepsy. We propose a dedicated technique for measuring optical nerve thickness and identifying its quality by means of processing front eye image in nanoscale. Experimental measurements have been performed, and a database of 10 teenagers has been used for that.
关键词： Micro and Nanotechnology,Optical nerve thickness measurement,Optical coherence Tomography,Neuro-disorders,Epilepsy,Atomic Force Microscopy,EEG
更新于2025-09-23 15:22:29
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Generating Underwater Images by GANs and Similarity Measurement
摘要： The complexity of the underwater environment makes it difficult to capture underwater images, therefore can not provide a large amount of training data required for image processing with deep learning. Traditional color transfer methods can only map the color distribution of source image to that of target image one by one, without considering the complexity of the underwater imaging environment, which results in the disadvantages of effectiveness and performance. In this paper, our proposed method, based on GANs(Generative Adversarial Networks), is superior in its consideration of taking underwater imaging model to train the generative network, the air images are converted into underwater images in batches, so as to achieve the purpose of data augment. Additionally, we describe several implementation details to improve the performance of GANs. Finally, we first utilize SIMILATION, SSIM(Structural Similarity Index) and MS-SSIM(Multi-Scale-Structural Similarity Index) to compute the color and structure similarity level for the purpose of evaluating the quality of generated samples. The results indicate that the proposed method performs well in data augment.
关键词： GANs,underwater imaging,similarity measurement,Data Augment
更新于2025-09-23 15:22:29
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Robust Landmark Detection and Position Measurement Based on Monocular Vision for Autonomous Aerial Refueling of UAVs
摘要： In this paper, a position measurement system, including drogue's landmark detection and position computation for autonomous aerial refueling of unmanned aerial vehicles, is proposed. A multitask parallel deep convolution neural network (MPDCNN) is designed to detect the landmarks of the drogue target. In MPDCNN, two parallel convolution networks are used, and a fusion mechanism is proposed to accomplish the effective fusion of the drogue's two salient parts' landmark detection. Considering the drogue target's geometric constraints, a position measurement method based on monocular vision is proposed. An effective fusion strategy, which fuses the measurement results of drogue's different parts, is proposed to achieve robust position measurement. The error of landmark detection with the proposed method is 3.9%, and it is obviously lower than the errors of other methods. Experimental results on the two KUKA robots platform verify the effectiveness and robustness of the proposed position measurement system for aerial refueling.
关键词： landmark detection,multitask parallel deep convolution neural network (MPDCNN),monocular vision,position measurement,Aerial refueling
更新于2025-09-23 15:22:29