- 标题
- 摘要
- 关键词
- 实验方案
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Identifying Common Errors in Distribution System Models
摘要： This paper discusses common types of errors that are frequently present in utility distribution system models and which can significantly influence distribution planning and operational assessments that rely on the model accuracy. Based on Google Earth imagery and analysis of correlation coefficients, this paper also illustrates some common error types and demonstrates methods to correct the errors. Error types include mislabeled interconnections between customers and service transformers, three-phase customers labeled as single-phase, unmarked transformers, and customers lacking coordinates. Identifying and correcting for these errors is critical for accurate distribution planning and operational assessments, such as load flow and hosting capacity analysis.
关键词： distribution system errors,error correction,distribution system models,AMI,correlation coefficients
更新于2025-09-23 15:21:01
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Persistent resonance frequency shift of MoS <sub/>2</sub> mechanical resonator by laser irradiation
摘要： Robust classification becomes challenging when each class consists of multiple subclasses. Examples include multi-font optical character recognition and automated protein function prediction. In correlation-based nearest-neighbor classification, the maximin correlation approach (MCA) provides the worst-case optimal solution by minimizing the maximum misclassification risk through an iterative procedure. Despite the optimality, the original MCA has drawbacks that have limited its wide applicability in practice. That is, the MCA tends to be sensitive to outliers, cannot effectively handle nonlinearities in datasets, and suffers from having high computational complexity. To address these limitations, we propose an improved solution, named regularized MCA (R-MCA). We first reformulate MCA as a quadratically constrained linear programming (QCLP) problem, incorporate regularization by introducing slack variables in the primal problem of the QCLP, and derive the corresponding Lagrangian dual. The dual formulation enables us to apply the kernel trick to R-MCA, so that it can better handle nonlinearities. Our experimental results demonstrate that the regularization and kernelization make the proposed R-MCA more robust and accurate for various classification tasks than the original MCA. Furthermore, when the data size or dimensionality grows, R-MCA runs substantially faster by solving either the primal or dual (whichever has a smaller variable dimension) of the QCLP. The source code of the proposed R-MCA methodology is available at http://data.snu.ac.kr/rmca.
关键词： SOCP,correlation,kernel trick,QP,maximin,QCLP,Nearest neighbor,regularization
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Robotics and Automation in Industry (ICRAI) - Rawalpindi, Pakistan (2019.10.21-2019.10.22)] 2019 International Conference on Robotics and Automation in Industry (ICRAI) - Low Cost 2D Laser Scanner Based Indoor Mapping and Classification System
摘要： Although the field of automatic speaker or speech recognition has been extensively studied over the past decades, the lack of robustness has remained a major challenge. Feature warping is a promising approach and its effectiveness significantly depends on the relative positions of each of the features in a sliding window. However, the relative positions are changed due to the non-linear effect of noise. Aiming at the problem, this paper takes the advantage of ranking feature, which is obtained directly by sorting a feature sequence in descending order, to propose a method. It first labels the central frame in a sliding window as speech or noise dominant (‘‘reliable’’ or ‘‘unreliable’’). In the unreliable case, the ranking of the central frame is estimated. Subsequently, the estimated ranking is mapped to a warped feature using a desired target distribution for recognition experiments. Through the theoretical analysis and experimental results, it is found that autocorrelation of a ranking sequence is larger than that of the corresponding feature sequence. What is more, rank correlation is not easily influenced by abnormal data or data that are highly variable. Thus, this paper deals with a ranking sequence rather than a feature sequence. The proposed feature enhancement approach is evaluated in an open-set speaker recognition system. The experimental results show that it outperforms missing data method based on linear interpolation and feature warping in terms of recognition performance in all noise conditions. Furthermore, the method proposed here is a feature-based method, which may be combined with other technologies, such as model-based, scores-based, to enhance the robustness of speaker or speech recognition system.
关键词： Robustness,ranking feature,rank correlation,open-set speaker recognition,autocorrelation,feature warping,missing data method
更新于2025-09-23 15:21:01
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Microcontact printing on metallic surfaces for optical deformation measurements
摘要： The measurement of the properties and behaviour of material is of fundamental importance in modern engineering. In recent years a breakthrough method for measuring surface deformation has been represented by digital image correlation. To determine local deformations in a material, an optical pattern is usually reproduced on the material surface. The reproduction of such patterns, especially at microscopic scale, is usually a slow and expensive procedure. A semi-automated device, able to print a suitable optical pattern on the metallic surface using micro-contact printing, was manufactured. Precision placing of the stamping head on the surface in order to avoid smearing of the pattern was reached. Specifically the stamp was placed with tolerances of some micrometres. Despite posing challenges in the handling of the ink and in the consistency of the patterns, this method proved viable for effective and fast creation of optical patterns.
关键词： microimprint,digital image correlation
更新于2025-09-23 15:21:01
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Evaluation of large plastic deformation for metals by a non-contacting technique using digital image correlation with laser speckles
摘要： The full-field deformation characterizations of a metal undergoing large plastic strains are difficult to be obtained from the conventional true stress-strain curves. In this study, we proposed using a simple non-contacting technique, digital image correlation (DIC) with laser speckles, to evaluate large plastic deformations of metals, especially for thin metal foils and for the forming at high temperatures. The feasibility and accuracy of this DIC technique were confirmed by conducting uniaxial tensile tests using different materials. As results, the measured strains indicated a good accuracy with an error range of 6% in measuring the large plastic deformation at room temperature and 10% in measuring a large strain up to 0.6 at a high temperature of 400 °C. The strain distribution measured by DIC with laser speckles and with artificial speckles showed good agreement, confirming the feasibility of this DIC technique for measuring large plastic deformations. By using this technique, the evolution of plastic zone was successfully investigated for thin metal sheets with a thickness of 0.5 mm. Furthermore, the strain fields involving localizations of 50 μm thick metal foils forming at room temperature and a large plastic deformation of metal tubes forming at 400 °C were evaluated qualitatively and quantitatively.
关键词： Large plastic deformation,Digital image correlation,Non-contacting,Laser speckle,Metal
更新于2025-09-23 15:21:01
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Camera array-based digital image correlation for high-resolution strain measurement
摘要： Digital image correlation (DIC) is a well-known technique for non-contact, non-destructive, full-field deformation measurement in experimental solid mechanics. Although DIC has been widely used in science and engineering, the resolution of strain measurement with DIC is limited by imaging resolution and is much lower than that obtained with a strain gauge. To achieve a breakthrough in strain measurement using DIC, a camera array-based DIC method is proposed herein for high-resolution strain measurement. Twenty-five industrial cameras were assembled into a plane array, with each camera capturing a part of the specimen. A novel calibration-based image stitching method is proposed and was applied to these images and their corresponding displacement fields. The strain field was then calculated based on the stitched displacement fields. The use of the camera array greatly improved the measurement spatial resolution of DIC and made high-resolution strain measurement possible. Both static error analysis and four point-bending experiments were performed to demonstrate the feasibility and effectiveness of the proposed method, and a full-field strain resolution of 10 με was achieved.
关键词： displacement field stitching,camera array,Digital image correlation,image stitching,high-resolution strain measurement
更新于2025-09-23 15:21:01
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Second-order correlations in single-particle interferometry
摘要： Interferometers with single particles are susceptible for dephasing perturbations from the environment, such as electromagnetic oscillations or mechanical vibrations. On the one hand, this limits sensitive quantum phase measurements as it reduces the interference contrast in the signal. On the other hand, it enables single-particle interferometers to be used as sensitive sensors for electromagnetic and mechanical perturbations. Recently, it was demonstrated experimentally, that a second-order correlation analysis of the spatial and temporal detection signal can decrease the electromagnetic shielding and vibrational damping requirements significantly. Thereby, the relevant matter-wave characteristics and the perturbation parameters could be extracted from the correlation analysis of a spatially ‘washed-out’ interference pattern and the original undisturbed interferogram could be reconstructed. This method can be applied to all interferometers that produce a spatial fringe pattern on a detector with high spatial and temporal single-particle resolution. In this article, we present and discuss in detail the used two-dimensional second-order correlation theory for multifrequency perturbations. The derivations of an explicit and approximate solution of the correlation function and corresponding amplitude spectra are provided. It is explained, how the numerical correlation function is extracted from the measurement data. Thereby, the influence of the temporal and spatial discretization step size on the extracted parameters, as contrast and perturbation amplitude, is analyzed. The influence of noise on the correlation function and corresponding amplitude spectrum is calculated and numerically cross-checked by a comparison of our theory with numerical single-particle simulations of a perturbed interference pattern. Thereby, an optimum spatial discretization step size is determined to achieve a maximum signal-to-noise ratio, which was used in former experiments to identify the perturbation caused by the electrical network. Our method can also be applied for the analysis of broad-band frequency noise, dephasing the interference pattern. Using Gaussian distributed noise in the simulations, we demonstrate that the relevant matter-wave parameters and the applied perturbation spectrum can be revealed by our correlation analysis.
关键词： sensor technology,dephasing,second-order correlation analysis,single-particle interferometry
更新于2025-09-23 15:21:01
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[IEEE 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - Erode (2018.2.15-2018.2.16)] 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - Identification of Duplicate Frame In CCTV DVR by Correlation Coefficient Factor
摘要： Unused frame or duplicate frame in DVR optimization reduction that capture by CCTV is a focus point of a research article. In the Current Era, all over world CCTV camera’s are widely utilized for security point of view.CCTV captures the video footage and store that footage in DVR that is called DigitalVideo Recorder its storage capacity start from 500gb to 1000 of TB depends on the specific area where this device is used, I am proposed the new frame architecture for this kind of device to reducing those footage frames that are unusable it means a frame does not record any movement during the recording. This idea is very helpful for removing unnecessary footage from the DVR those not have any kinds of movement it means that there is no further used of this unnecessary footage in DVR storage.
关键词： FPS,Correlation Coefficient,DVR,CCTV
更新于2025-09-23 15:21:01
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Saliency detection of targets in polarimetric SAR images based on globally weighted perturbation filters
摘要： In this paper, a saliency detection for Polarimetric Synthetic Aperture Radar (PolSAR) images is proposed based on weighted perturbation filters. Auxiliary data is demanded to identify polarimetric vector of targets, for a canonical perturbation filter. Only if the target signature was available and accurate, it would be satisfiable to apply the filter in practice. Besides, not every target can usually be detected by an individual filter, because of variant polarimetric characteristics of targets with respect to different aspects or shapes. To overcome these drawbacks, several perturbation filters are combined in the proposed method. By initializing with different parameters, these filters decompose PolSAR data into their index maps. Then, aiming to find out filters of interest, i.e., ones related to target pixels, we assume that targets to detect are sparse in PolSAR image. Thus, saliency weights are assigned to the filters, based on Jaccard distances of their index maps. Therein, the spatial sparseness between objects and their surrounding derives high weights for corresponding filters. And then, after globally fusion of refined filtering responses with the weights, saliency map is generated for every local pattern in PolSAR image. Finally, the target regions are extracted from this map, by thresholding and morphological operation. Experiments performed on real and simulated PolSAR data verify the performance of this method, in comparison with several common PolSAR detectors. Also, the proposed method finds out most targets in ground truth, without auxiliary polarimetric information provided.
关键词： Geometrical perturbation filter,Sparse spatial correlation,Polarimetric synthetic aperture radar,Saliency detection
更新于2025-09-23 15:21:01
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Estimation of damage thickness in fibre-reinforced composites using pulsed thermography
摘要： Non-destructive-testing (NDT), including active thermography, has become an inevitable part of composite process and product verification, post-manufacturing. However, there is no reliable NDT technique available to ensure the interlaminar bond integrity during laminates integration, bonding or repair where the presence of thin airgaps in the interface of dissimilar polymer composite materials would be detrimental to structural integrity. This paper introduces a novel approach attempting to quantify the damage thickness of composites (the thickness of air gaps inside composites) through a single-side inspection of pulsed thermography. The potential of this method is demonstrated by testing on three specimens with different types of defect, where the Pearson Correlation Coefficients of the thickness estimation for block defects and flat-bottom holes are 0.75 and 0.85, respectively. This approach will considerably enhance the degradation assessment performance of active thermography by extending damage measurement from currently two dimensions to three dimensions, and become an enabling technology on quality assurance of structural integrity.
关键词： Active thermography,system identification,bonded repair,nonlinear correlation analysis,composite damage detection
更新于2025-09-23 15:21:01