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Added value of merging techniques in precipitation estimates relative to gauge-interpolation algorithms of varying complexity

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JOURNAL OF HYDROLOGY 2024年 645卷

作者： Hu, Yingyi Zhang, Ling Chinese Acad Sci Northwest Inst Ecoenvironm & Resources Key Lab Cryospher Sci & Frozen Soil Engn Heihe Remote Sensing Expt Res Stn Lanzhou 730000 Peoples R China Jiangsu Ocean Univ Sch Marine Technol & Geomat Lianyungang 222005 Jiangsu Peoples R China

Data-fusion techniques leverage the strengths of multisource precipitation data and can significantly enhance the accuracy of precipitation estimates. However, the extent to which these techniques improve precipitation estimates (i.e., added value) compared to interpolation algorithms and the factors driving this improvement remain unclear. To address these gaps, this study compared the performance of two merging techniques, i.e., double machine learning (DML) and geographically weighted regression (GWR), with multiple interpolation algorithms in estimating precipitation across China. The interpolation algorithms vary in complexity and include typical methods (IDW and Kriging), semi-physical methods (GIDS, DAYMET, and MicroMet), and climatologically aided interpolation (CAI). We quantified the added value of the merging techniques over these interpolation algorithms and investigated the driving factors using a data-driven approach. Results indicate that the merging techniques outperform all the interpolation algorithms, regardless of their complexity. The merging techniques provide greater added value in gauge-scarce regions (e.g., Northeast China) than in gauge-rich regions (e.g., Northwest China). The magnitude of the added value from merging techniques is significantly influenced by the choice of interpolation algorithms due to their varying performance. Additionally, our data-driven model reveals that factors such as the amount of precipitation, number of wet days, performance of precipitation products, and gauge density are key drivers that negatively affect the added value of merging techniques. This study highlights the importance of integrating multisource data to improve precipitation estimates, especially in regions with sparse gauges, rather than relying solely on gauge-only interpolation.

关键词： Merging techniques interpolation algorithms Added value Machine learning Precipitation estimates China

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Statistical comparison of various interpolation algorithms for reconstructing regional grid ionospheric maps over China

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JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 2018年 172卷 129-137页

作者： Li, Min Yuan, Yunbin Wang, Ningbo Li, Zishen Liu, Xifeng Zhang, Xiao Inst Geodesy & Geophys State Key Lab Geodesy & Earths Dynam Wuhan Hubei Peoples R China Univ Chinese Acad Sci Beijing Peoples R China Chinese Acad Sci Acad Optoelect Beijing Peoples R China Henan Polytech Univ Jiaozuo Peoples R China

This paper presents a quantitative comparison of several widely used interpolation algorithms, i.e., Ordinary Kriging (OrK), Universal Kriging (UnK), planar fit and Inverse Distance Weighting (IDW), based on a grid-based single-shell ionosphere model over China. The experimental data were collected from the Crustal Movement Observation Network of China (CMONOC) and the International GNSS Service (IGS), covering the days of year 60-90 in 2015. The quality of these interpolation algorithms was assessed by cross-validation in terms of both the ionospheric correction performance and Single-Frequency (SF) Precise Point Positioning (PPP) accuracy on an epoch-by-epoch basis. The results indicate that the interpolation models perform better at mid-latitudes than low latitudes. For the China region, the performance of OrK and UnK is relatively better than the planar fit and IDW model for estimating ionospheric delay and positioning. In addition, the computational efficiencies of the IDW and planar fit models are better than those of OrK and UnK.

关键词： Total electron content (TEC) Regional grid ionospheric map interpolation algorithms Ionospheric

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Estimation of the Frequency Vector of a Two-Dimensional Harmonic Signal using Three-Point interpolation algorithms and Singular Value Decomposition

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OPTOELECTRONICS INSTRUMENTATION AND DATA PROCESSING 2017年第3期53卷 210-215页

作者： Gruzman, I. S. Novosibirsk State Tech Univ Pr Karla Marksa 20 Novosibirsk 630073 Russia

Computationally simple algorithms are proposed to estimate the local frequency vector of a real two-dimensional signal with slowly varying parameters in the presence of additive Gaussian noise. The rough most likely estimate of the frequency vector is refined using three-point interpolation algorithms and the singular value decomposition of a 3 x 3 matrix of discrete Fourier transform coefficients. The results of computer simulation are presented showing the efficiency of the algorithms for analyzed fragments of small size.

关键词： frequency estimation two-dimensional real signal interpolation algorithms discrete Fourier transform coefficients singular value decomposition of matrices

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Two Dimensional Autoregressive Modeling-Based interpolation algorithms for Image Super-resolution: A Comparison Study 10

Two Dimensional Autoregressive Modeling-Based Interpolation ...

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10th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI)

作者： Lu, Meiyun Huang, Liqing Xia, Youshen Fuzhou Univ Coll Math & Comp Sci Fuzhou Fujian Peoples R China

ISBN: (纸本)9781538619377

Image interpolation is a key technique of image super-resolution. Four two dimensional (2-D) autoregressive (AR) modeling-based image interpolation algorithms have been reported to have better performance in edge and texture preservation than conventional image polynomial interpolation algorithms. However, there is lack of performance comparison among them. For super-resolution reconstruction quality, this paper is going to fill up the gap by a comparison study on the four 2-D AR modeling-based interpolation methods: novel edge-directed interpolation (NEDI), soft-decision adaptive interpolation (SAI), sparse representation interpolation with nonlocal autoregressive modeling (SR-NARM), and adaptive super-pixel-guided AR modeling (ASARM). Furthermore, the four interpolation algorithms are compared in the light of peak signal to noise ratio, feature similarity index, mean squared error and structural similarity index. From comparative results we observe that ASARM method has relatively better performance than other three methods but is more time-consuming than the NEDI and SAI methods.

关键词： image super-resolution interpolation algorithms autoregressive modeling comparative analysis

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Reduction of deformations of the digital terrain model by merging interpolation algorithms

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COMPUTERS & GEOSCIENCES 2014年 64卷 61-71页

作者： Gosciewski, Dariusz Univ Warmia & Mazury Fac Geodesy & Land Management Inst Geodesy PL-10957 Olsztyn Poland

Majority of contemporary spatial information systems allow generation and visualization of the digital terrain model based on GRID type of the regular squares network. The values at nodal points for such a GRID are in most cases computed by one of the many available interpolation methods on the basis of dispersed measurement points. The commonly used solutions allow in most cases application of a selected interpolation method in a global way within the entire analyzed area, which does not secure the same accuracy of surface generated. The paper describes generation of a digital terrain model by applying a combination of interpolation methods. The criterion of method choice was dependent on the dispersion of measurement points around the GRID node. This solution allows successive complementing the resultant set of computed set with values determined with a specific error and as a result improves the accuracy of the model generated. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： GIS Digital terrain model Regular GRID structure interpolation algorithms Large observation sets

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Iterative Sine-Wave Frequency Estimation by Generalized Fourier interpolation algorithms 11

Iterative Sine-Wave Frequency Estimation by Generalized Four...

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11th International Symposium on Electronics and Telecommunications (ISETC)

作者： Belega, Daniel Petri, Dario Dallet, Dominique Politehn Univ Timisoara Dept Measurements & Opt Elect Timisoara Romania Univ Trento Dept Ind Engn Trento Italy Univ Bordeaux MATMECA IMS Lab IPB ENSEIRB Talence France

ISBN: (纸本)9781479972678

In this paper two iterative interpolation algorithms proposed in the scientific literature for estimating the frequency of complex-valued sine-waves are generalized to a generic Maximum Sidelobe Decay (MSD) window in order to achieve highly accurate estimates even when real-valued pure or harmonically distorted sine-waves are analyzed. The analytical expressions for the frequency estimations formulas are derived. Moreover the accuracy achieved when pure, noisy, and noisy and harmonically distorted sine-waves are analyzed is compared with those provided by the classical Interpolated Discrete Fourier Transform (IpDFT) and three-point IpDFT algorithms through computer simulations. The performed comparison allows us to determine in which situations the proposed algorithms can be advantageously used.

关键词： Frequency estimation interpolation algorithms sine-wave uncertainy analysis windowing

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A Comparison of interpolation algorithms for Gramophone Record Sound Reconstruction

A Comparison of Interpolation Algorithms for Gramophone Reco...

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1st International Conference on Signal Processing and Integrated Networks (SPIN)

作者： Stallmann, Christoph F. Engelbrecht, Andries P. Univ Pretoria Dept Comp Sci ZA-0002 Pretoria South Africa

ISBN: (纸本)9781479928668

Gramophone records were the main recording medium for half a century and regained widespread popularity over the past couple of years. Being an analogue storage medium, vinyl records are subject to distortions caused by scratches, dust, high temperatures and extensive playback. This paper discusses a number of well-known interpolation algorithms that can be used to reduce the noise by reconstructing the distorted gaps, which include the nearest neighbour, cosine, polynomial, spline, Hermite and Fourier interpolation. The reconstruction accuracy of these algorithms were determined by using a large dataset of songs from eight different music genres. It was found that cosine and polynomial interpolation have the best mean performance with regards to reconstruction accuracy and execution time. It was also found that certain genres can be easier reconstructed than others.

关键词： audio recording audio signal processing interpolation music polynomial approximation signal reconstruction splines (mathematics) Fourier interpolation Hermite interpolation analogue storage media cosine interpolation distorted gap reconstruction gramophone record sound reconstruction interpolation algorithms music genre nearest neighbour noise reduction polynomial interpolation recording media spline interpolation vinyl records Accuracy interpolation Mathematical model Nickel Polynomials Silicon Splines (mathematics)

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Hiding Multiple Images into a Single Image Using Up-Sampling

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IEEE TRANSACTIONS ON MULTIMEDIA 2024年 26卷 4401-4415页

作者： Ping, Ping Guo, Bobiao Bloh, Olano Teah Mao, Yingchi Xu, Feng Hohai Univ Coll Comp & Informat Nanjing 210098 Peoples R China Hohai Univ Key Lab Water Big Data Technol Minist Water Resources Nanjing 210098 Peoples R China

The goal of multiple-image hiding is to hide several secret images within another carrier image without significantly changing its appearance, and then perfectly reconstruct all of the secret images. The challenge is to ensure that the stego-image has great visual quality and can resist various steganalysis under the premise of hiding as much information as possible in one image. To address this issue, the majority of known image-hiding methods focus on hiding images using compression techniques. In this article, we present a novel multiple-image hiding method based on up-sampling and reversible color transformation. First, the interpolation algorithm up-samples the carrier image, so that the attribute of similar neighboring pixel values in the up-sampled image can significantly improve the effect of image hiding. The embedding procedure is then performed using the proposed Euclidean Distance (ED)-based block matching and reversible color transformation, which decreases the chance of local blurring in the stego-image. Experimental results show that the proposed method surpasses existing advanced methods by achieving an average of 33 dB and 28 dB of PSNR for the stego-image with a hiding capacity 2 BPP and 8 BPP, and obtaining 100% reconstructing accuracy for all secret images. It also has a high level of resistance to steganalysis and a strong robustness against various image-processing attacks.

关键词： Image reconstruction Image color analysis Compressed sensing Image coding Manganese Artificial intelligence Image quality Image hiding up-sampling interpolation algorithms euclidean distance

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Advanced CNC thread milling: a comprehensive canned cycle for efficient cutting of threads with fixed or variable pitch and radius

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2024年第5-6期133卷 2219-2233页

作者： Omirou, Sotiris Charalambides, Marios Chasos, Charalambos Frederick Univ Dept Mech Engn Nicosia Cyprus Frederick Univ Ctr Sci Dept Business Adm Nicosia Cyprus

This paper presents the design, implementation, and experimental validation of a novel canned cycle for CNC milling machines, enabling the precise and efficient cutting of threads with fixed or variable pitch and radius. Conventional canned cycles are limited to fixed pitch threads, restricting the versatility of CNC milling machines in thread machining *** development process involves integrating a sophisticated control algorithm into the CNC milling machine's software, giving the operator remarkable control over the thread cutting process. This algorithm allows the operator to choose between external or internal threads, set both initial and final radii, determine initial and final pitches, specify the number of turns, and select the left or right-hand thread type. Such flexibility enables the creation of threads with diverse geometries. Furthermore, the proposed canned cycle provides the capability to switch between roughing and finishing passes by adjusting the step motion along the prescribed helical *** tests conducted under various threading cases clearly demonstrate the efficiency of the proposed canned cycle. These results showcase its capability to address a wide range of machining scenarios, offering practical solutions applicable across a spectrum of applications.

关键词： CNC machining Canned cycles Thread cutting interpolation algorithms

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Design and implementation of an innovative canned cycle for variable pitch thread cutting on CNC milling machines

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2024年第9-10期130卷 4635-4648页

作者： Omirou, Sotiris L. Chasos, Charalambos A. Frederick Univ Dept Mech Engn Nicosia Cyprus

This paper presents the development of a new canned cycle for CNC milling machines capable of cutting threads with variable pitch, addressing a significant limitation in modern CNC systems. While existing CNC milling machines provide canned cycles for thread cutting, they lack the capability to program variable pitch, necessitating reliance on CAM systems. In response, the proposed canned cycle offers increased flexibility, quicker setup times, and reduced dependence on CAM systems. The cycle accommodates both internal and external threads, supports left-hand or right-hand threading, and incorporates a user-friendly control panel for easy programming. To validate its efficiency, the canned cycle is implemented using a G-code parametric algorithm, and a series of simulation tests are conducted. The results demonstrate the viability and advantages of the new CNC milling feature in cutting threads with variable pitch, opening up possibilities for various mechanical applications.

关键词： CNC machining Canned cycles Milling interpolation algorithms

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