Articoli di riviste: "Separation estimation"

1

Pishravian, Arash, and Masoud Reza Aghabozorgi Sahaf. "Application of independent component analysis for speech–music separation using an efficient score function estimation." Journal of Electrical Engineering 63, no. 6 (2012): 380–85. http://dx.doi.org/10.2478/v10187-012-0056-0.

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In this paper speech-music separation using Blind Source Separation is discussed. The separating algorithm is based on the mutual information minimization where the natural gradient algorithm is used for minimization. In order to do that, score function estimation from observation signals (combination of speech and music) samples is needed. The accuracy and the speed of the mentioned estimation will affect on the quality of the separated signals and the processing time of the algorithm. The score function estimation in the presented algorithm is based on Gaussian mixture based kernel density estimation method. The experimental results of the presented algorithm on the speech-music separation and comparing to the separating algorithm which is based on the Minimum Mean Square Error estimator, indicate that it can cause better performance and less processing time

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Xiao, Yingchun, Yang Yang, and Feng Zhu. "A Separation Method for Electromagnetic Radiation Sources of the Same Frequency." Journal of Electromagnetic Engineering and Science 23, no. 6 (2023): 521–29. http://dx.doi.org/10.26866/jees.2023.6.r.197.

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To separate electromagnetic interference sources with an unknown source number, a new separation method is proposed, which includes five key steps: spatial spectrum estimation, source number and direction-of-arrival estimation, mixed matrix estimation, separation matrix estimation, and source signal recovery. A pseudospatial spectrum estimation network based on a convolutional neural network is proposed to estimate the number of electromagnetic radiation sources, their direction of arrival, and the mixing matrix. A new loss function is designed as an optimization criterion for estimating the separation matrix. To ensure generalization, both simulated and measured datasets are used to train the proposed network. Experimental results demonstrate that the proposed separation method outperforms existing source separation techniques in terms of correlation coefficient, root mean square error, and running time. Importantly, it exhibits strong performance in underdetermined cases, as well as in overdetermined or determined cases.

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Asadi, Haniyeh, Mohammad T. Dastorani, Roy C. Sidle, and Kaka Shahedi. "Improving Flow Discharge-Suspended Sediment Relations: Intelligent Algorithms versus Data Separation." Water 13, no. 24 (2021): 3650. http://dx.doi.org/10.3390/w13243650.

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Information on the transport of fluvial suspended sediment loads (SSL) is crucial due to its effects on water quality, pollutant transport and transformation, dam operations, and reservoir capacity. As such, adopting a reliable method to accurately estimate SSL is a key topic for watershed managers, hydrologists, river engineers, and hydraulic engineers. One of the most common methods for estimating SSL or suspended sediment concentrations (SSC) is sediment rating curve (SRC), which has several weaknesses. Here, we optimize the SRC equation using two main approaches. Firstly, three well recognized metaheuristic algorithms (genetic algorithm (GA), particle swarm optimization (PSO), and imperialist competitive algorithm (ICA)) were used together with two classical approaches (food and agriculture organization (FAO) and non-parametric smearing estimator (CF2)) to optimize the coefficients of the SRC regression model. The second approach uses separation of data based on season and flow discharge (Qw) characteristics. A support vector regression (SVR) model using only Qw as an input was employed for SSC estimation and the results were compared with the SRC and its optimized versions. Metaheuristic algorithms improved the performance of the SRC model and the PSO model outperformed the other algorithms. These results also indicate that the model performance was directly related to the temporal separation of data. Based on these findings, if data are more homogenous and related to the limited climatic conditions used in the estimation of SSC, the estimations are improved. Moreover, it was observed that optimizing SRC through metaheuristic models was much more effective than separating data in the SCR model. The results also indicated that with the same input data, SVR was superior to the SRC model and its optimized version.

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4

Todorovic-Zarkula, Slavica, Branimir Todorovic, and Miomir Stankovic. "On-line blind separation of non-stationary signals." Yugoslav Journal of Operations Research 15, no. 1 (2005): 79–95. http://dx.doi.org/10.2298/yjor0501079t.

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This paper addresses the problem of blind separation of non-stationary signals. We introduce an on-line separating algorithm for estimation of independent source signals using the assumption of non-stationary of sources. As a separating model, we apply a self-organizing neural network with lateral connections, and define a contrast function based on correlation of the network outputs. A separating algorithm for adaptation of the network weights is derived using the state-space model of the network dynamics, and the extended Kalman filter. Simulation results obtained in blind separation of artificial and real-world signals from their artificial mixtures have shown that separating algorithm based on the extended Kalman filter outperforms stochastic gradient based algorithm both in convergence speed and estimation accuracy.

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5

Yang, Xiao Yan, Xiong Zhou, and Yi Ke Tang. "A New Method for Adaptive Blind Source Separation Based on the Estimated Number of Dynamic Fault Sources." Applied Mechanics and Materials 233 (November 2012): 211–17. http://dx.doi.org/10.4028/www.scientific.net/amm.233.211.

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In fault diagnosis of large rotating machinery, the number of fault sources may be subject to dynamic changes, which often lead to the failure in accurate estimation of the number of sources and the effective isolation of the fault source. This paper introduced the expansion of the fourth-order cumulant matrices in estimating the dynamic fault source number, plus the relationship between the source signal number and the number of sensors being utilized in the selection of the blind source separation algorithm to achieve adaptive blind source separation. Experiments showed that the source number estimation algorithm could be quite effective in estimating the dynamic number of fault sources, even in the underdetermined condition. This adaptive blind source separation algorithm could then effectively achieve fault diagnosis in respect to the positive-determined, overdetermined and underdetermined blind source separation.

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Hasegawa, Yasuhisa, Mayumi Natsui, Chie Abe, Ayumi Ikeda, and Sean-Thomas B. Lundin. "Estimation of CO2 Separation Performances through CHA-Type Zeolite Membranes Using Molecular Simulation." Membranes 13, no. 1 (2023): 60. http://dx.doi.org/10.3390/membranes13010060.

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Chabazite (CHA)-type zeolite membranes are a potential material for CO2 separations because of their small pore aperture, large pore volume, and low aluminum content. In this study, the permeation and separation properties were evaluated using a molecular simulation technique with a focus on improving the CO2 separation performance. The adsorption isotherms of CO2 and CH4 on CHA-type zeolite with Si/Al = 18.2 were predicted by grand canonical Monte Carlo, and the diffusivities in zeolite micropores were simulated by molecular dynamics. The CO2 separation performance of the CHA-type zeolite membrane was estimated by a Maxwell–Stefan equation, accounting for mass transfer through the support tube. The results indicated that the permeances of CO2 and CH4 were influenced mainly by the porosity of the support, with the CO2 permeance reduced due to preferential adsorption with increasing pressure drop. In contrast, it was important for estimation of the CH4 permeance to predict the amounts of adsorbed CH4. Using molecular simulation and the Maxwell–Stefan equation is shown to be a useful technique for estimating the permeation properties of zeolite membranes, although some problems such as predicting accurate adsorption terms remain.

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7

Lui, Hoi-Shun, and Hon Tat Hui. "Direction-of-Arrival Estimation of Closely Spaced Emitters Using Compact Arrays." International Journal of Antennas and Propagation 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/104848.

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Performance evaluation of direction-of-arrival (DOA) estimation algorithms has continuously drawn significant attention in the past years. Most previous studies were conducted under the situation that antenna element separation is about half wavelength in order to avoid the appearance of grating lobes. On the other hand, recent developments in wireless communications have favoured the use of portable devices that utilize compact arrays with antenna element separations of less than half wavelength. Performance evaluation of DOA estimation algorithms employing compact arrays is an important and fundamental issue, but it has not been fully studied. In this paper, the performance of the matrix pencil method (MPM) that applies to DOA estimations is investigated through Monte Carlo simulations. The results show that closely spaced emitters can be accurately resolved using linear compact array with an array aperture as small as around half wavelength.

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8

Yokoi, Masayuki, and Takao Tashiro. "Separating Prescription From Dispensation Medicines: Economic Effect Estimation in Japan." Global Journal of Health Science 10, no. 5 (2018): 88. http://dx.doi.org/10.5539/gjhs.v10n5p88.

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This study examined the effects of the separation between dispensing and prescribing medicines by pharmacists in pharmacies and doctors in medical institutions, respectively (separation system). The methodology avails public national data. The participation of Japanese medical institutions to the separation system was optional according to the legal system. Consequently, its spreading rate for each administrative district is highly variable, allowing us to study its correlation with various medication costs and other factors, such as the generic medicine replacement ratio, proportion of elderly, and number of doctors per 100 000 individuals as independent variables. These four factors are known to be influential in medical compensation. We used regression analysis by the weighted least square method, with dependent variables being costs of daily medicines, specifically, total, internal, one-shot, external, and injection medicines; medical devices, brand-name medicines, generic medicines, and number of prescribed medicines; as well as technical fees. The analysis focused on whether the extent of the separation system reduces costs such as those for medicines, medical devices, technical fees, or number of prescribed medicines. The partial regression coefficient of the spreading rate of the separation system was found to have negative relationships with all daily costs and number of prescribed medicines, as well as the technical fee, except for external medicines, for which most of the market is represented by light analgesics (taken by patients as needed). The necessity of separating prescribing and dispensing is thus low because of the low information asymmetry between doctors and patients. The results revealed that promoting the separation system reduced medication costs, because it normalized the medication market for daily necessities by compensating information asymmetry. Furthermore, the separation system reduced excesses in prescribing medicines.

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9

Reddy, Priyanka J., Vandana Pulhani, Sanjay D. Dhole, Shailesh S. Dahiwale, Sonali P. D. Bhade, and Devendra D. Rao. "Sequential analysis of uranium and plutonium in environmental matrices by extractive liquid scintillation spectrometry." Radiochimica Acta 106, no. 10 (2018): 809–18. http://dx.doi.org/10.1515/ract-2017-2916.

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Abstract A methodology for sequential separation of uranium (U) and plutonium (Pu) followed by their estimation, using extractive liquid scintillation spectrometry was standardized for matrices like soil, fish and sediment. Various parameters for selective and efficient extraction and separation of Pu and U in the presence of interfering matrix elements with HDEHP bis(2-ethylhexy1) phosphoric acid as an extracting agent were investigated. Quenching effect of the various extracting reagents on resolution of α spectrum of analytes and reduction in these interferences is discussed in the current study. Standardized procedure gave about 91% of extraction of spiked Pu into the organic phase. Performance of the method was tested by separating and estimating U and Pu in International Atomic Agency (IAEA) certified reference materials like soil/sediment/fish.

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10

Yang, ZuYuan, BeiHai Tan, GuoXu Zhou, and JinLong Zhang. "Source number estimation and separation algorithms of underdetermined blind separation." Science in China Series F: Information Sciences 51, no. 10 (2008): 1623–32. http://dx.doi.org/10.1007/s11432-008-0138-6.

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11

Li, Chuangjian, Suping Peng, Xiaoqin Cui, Qiannan Liu, and Peng Lin. "Prestack diffraction separation by parameterizing the reflection local slope." GEOPHYSICS 87, no. 2 (2021): S35—S44. http://dx.doi.org/10.1190/geo2021-0321.1.

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Diffracted waves provide an opportunity to detect small-scale subsurface structures because they give wide illumination direction of geologic discontinuities, such as faults, pinch outs, and collapsed columns. However, separating diffracted waves is challenging because diffracted waves have greater geometric amplitude losses and are generally weaker than reflections. To retain more diffracted waves, we have developed a prestack diffraction separation method based on the local slope pattern and plane-wave destruction (PWD) method. In general, it is difficult to distinguish between hyperbolic reflections and hyperbolic diffractions using data-driven local slope estimation in the shot domain. Therefore, we transfer slope estimation in the shot domain to velocity analysis in the common-midpoint domain and ray parameter calculation in the stack domain. The connection between local slope and the normal moveout velocity and the surface-ray parameter is known, which provides a novel approach for estimating the local slope of hyperbolic reflected waves in the shot domain. The estimated slope can provide an exact slope-based operator for the PWD method, thus allowing the PWD to separate diffracted waves from reflected waves in the shot domain. Synthetic and field data tests demonstrate the feasibility and effectiveness of our prestack diffraction separation method.

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12

Toyoda, Hideki. "Separation of Modeling and Estimation Technique." Kodo Keiryogaku (The Japanese Journal of Behaviormetrics) 39, no. 2 (2012): 39–41. http://dx.doi.org/10.2333/jbhmk.39.39.

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13

Juni, M. Z., M. Singh, and L. T. Maloney. "Robust visual estimation as source separation." Journal of Vision 10, no. 14 (2010): 2. http://dx.doi.org/10.1167/10.14.2.

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14

Yahya, Iskandar, Arulampalam Kunaraj, Seri Mastura Mustaza, Steven Clowes, and S. Ravi P. Silva. "Methods for Estimating Composition of Single Walled Carbon Nanotubes Based on Electronic Type." Materials Science Forum 1055 (March 4, 2022): 77–86. http://dx.doi.org/10.4028/p-073fwj.

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— Synthesized single-walled carbon nanotubes (SWCNTs) consist of a mixture of chiralities and therefore a post-synthesis separation is essential to separate them based on electronic type i.e., metallic (m-SWCNT) or semiconducting (s-SWCNT) for device applications. A key parameter to measure the effectiveness of separation process is the enrichment composition percentage between m-SWCNT and s-SWCNT, which can be estimated via several methods based on optical characterizations. In this paper, we compare the composition percentage estimations from 3 different methods based on Raman spectroscopy and UV-Vis optical absorption spectroscopy. The estimation methods are radial breathing mode (RBM) peak analysis, optical absorption area under curve (OUA) and first derivative amplitude of the optical absorption curve (FDA). Four different SWCNT sources were used in this study, which were subjected to post-synthesis separation process via agarose gel chromatography. Raman and UV-Vis spectroscopy measurements were carried out on all samples, before and after separation. From the estimations, we observed firstly that there are some variations on the estimated enrichment compositions between different methods, although the values are comparable. Secondly, for some SWCNTs samples, only a certain estimation method showed reliable composition percentage. The results presented in this work may provide viable options for characterizations of SWCNTs as there is no direct method to quantify the absolute composition percentage of SWCNTs based on electronic type. Keywords—single-walledcarbon nanotube, separation, electronic type, optical characterization, purity percentage.

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15

HE, ZHENYA, LUXI YANG, JU LIU, ZIYI LU, CHEN HE, and YUHUI SHI. "APPROACHES FOR BLIND SEPARATION OF SOURCES BASED ON MULTIVARIATE DENSITY ESTIMATION." Journal of Circuits, Systems and Computers 09, no. 03n04 (1999): 243–53. http://dx.doi.org/10.1142/s0218126699000207.

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A class of learning algorithms is developed for the blind separation of independent source signals from their linear mixtures. The algorithms are based on the Kullback–Leibler distance. A multivariate density estimation technique is used in estimating the probability density function of independent components. Simulations using speech signals and images as sources illustrate the performances of the algorithms.

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Marengo, Edwin A., and Paul Berestesky. "Cramér-Rao Bound Study of Multiple Scattering Effects in Target Separation Estimation." International Journal of Antennas and Propagation 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/572923.

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The information about the distance of separation between two-point targets that is contained in scattering data is explored in the context of the scalar Helmholtz operator via the Fisher information and associated Cramér-Rao bound (CRB) relevant to unbiased target separation estimation. The CRB results are obtained for the exact multiple scattering model and, for reference, also for the single scattering or Born approximation model applicable to weak scatterers. The effects of the sensing configuration and the scattering parameters in target separation estimation are analyzed. Conditions under which the targets' separation cannot be estimated are discussed for both models. Conditions for multiple scattering to be useful or detrimental to target separation estimation are discussed and illustrated.

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Hu, Dong, Yuping Huang, Qiang Zhang, Lijian Yao, Zidong Yang, and Tong Sun. "Numerical Simulation on Spatial-Frequency Domain Imaging for Estimating Optical Absorption and Scattering Properties of Two-Layered Horticultural Products." Applied Sciences 11, no. 2 (2021): 617. http://dx.doi.org/10.3390/app11020617.

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Spatial-frequency domain imaging (SFDI) is a wide-field, noncontact, and label-free imaging modality that is currently being explored as a new means for estimating optical absorption and scattering properties of two-layered turbid materials. The accuracy of SFDI for optical property estimation, however, depends on light transfer model and inverse algorithm. This study was therefore aimed at providing theoretical analyses of the diffusion model and inverse algorithm through numerical simulation, so as to evaluate the potential for estimating optical absorption and reduced scattering coefficients of two-layered horticultural products. The effect of varying optical properties on reflectance prediction was first simulated, which indicated that there is good separation in diffuse reflectance over a large range of spatial frequencies for different reduced scattering values in the top layer, whereas there is less separation in diffuse reflectance for different values of absorption in the top layer, and even less separation for optical properties in the bottom layer. To implement the nonlinear least-square method for extracting the optical properties of two-layered samples from Monte Carlo-generated reflectance, five curve fitting strategies with different constrained parameters were conducted and compared. The results confirmed that estimation accuracy improved as fewer variables were to be estimated each time. A stepwise method was thus suggested for estimating optical properties of two-layered samples. Four factors influencing optical property estimation of the top layer, which is the basis for accurately implementing the stepwise method, were investigated by generating absolute error contour maps. Finally, the relationship between light penetration depth and spatial frequency was studied. The results showed that penetration depth decreased with the increased spatial frequency and also optical properties, suggesting that appropriate selection of spatial frequencies for a stepwise method to estimate optical properties from two-layered samples provides potential for estimation accuracy improvement. This work lays a foundation for improving optical property estimation of two-layered horticultural products using SFDI.

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Hu, Dong, Yuping Huang, Qiang Zhang, Lijian Yao, Zidong Yang, and Tong Sun. "Numerical Simulation on Spatial-Frequency Domain Imaging for Estimating Optical Absorption and Scattering Properties of Two-Layered Horticultural Products." Applied Sciences 11, no. 2 (2021): 617. http://dx.doi.org/10.3390/app11020617.

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Spatial-frequency domain imaging (SFDI) is a wide-field, noncontact, and label-free imaging modality that is currently being explored as a new means for estimating optical absorption and scattering properties of two-layered turbid materials. The accuracy of SFDI for optical property estimation, however, depends on light transfer model and inverse algorithm. This study was therefore aimed at providing theoretical analyses of the diffusion model and inverse algorithm through numerical simulation, so as to evaluate the potential for estimating optical absorption and reduced scattering coefficients of two-layered horticultural products. The effect of varying optical properties on reflectance prediction was first simulated, which indicated that there is good separation in diffuse reflectance over a large range of spatial frequencies for different reduced scattering values in the top layer, whereas there is less separation in diffuse reflectance for different values of absorption in the top layer, and even less separation for optical properties in the bottom layer. To implement the nonlinear least-square method for extracting the optical properties of two-layered samples from Monte Carlo-generated reflectance, five curve fitting strategies with different constrained parameters were conducted and compared. The results confirmed that estimation accuracy improved as fewer variables were to be estimated each time. A stepwise method was thus suggested for estimating optical properties of two-layered samples. Four factors influencing optical property estimation of the top layer, which is the basis for accurately implementing the stepwise method, were investigated by generating absolute error contour maps. Finally, the relationship between light penetration depth and spatial frequency was studied. The results showed that penetration depth decreased with the increased spatial frequency and also optical properties, suggesting that appropriate selection of spatial frequencies for a stepwise method to estimate optical properties from two-layered samples provides potential for estimation accuracy improvement. This work lays a foundation for improving optical property estimation of two-layered horticultural products using SFDI.

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Kumar, R. Suresh, and P. Manimegalai. "Detection and Separation of Eeg Artifacts Using Wavelet Transform." International Journal of Informatics and Communication Technology (IJ-ICT) 7, no. 3 (2018): 149. http://dx.doi.org/10.11591/ijict.v7i3.pp149-156.

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Bio-medical signal processing is one of the most important techniques of multichannel sensor network and it has a substantial concentration in medical application. However, the real-time and recorded signals in multisensory instruments contains different and huge amount of noise, and great work has been completed in developing most favorable structures for estimating the signal source from the noisy signal in multichannel observations. Methods have been developed to obtain the optimal linear estimation of the output signal through the Wide-Sense-Stationary (WSS) process with the help of time-invariant filters. In this process, the input signal and the noise signal are assumed to achieve the linear output signal. During the process, the non-stationary signals arise in the bio-medical signal processing in addition to it there is no effective structure to deal with them. Wavelets transform has been proved to be the efficient tool for handling the non-stationary signals, but wavelet provide any possible way to approach multichannel signal processing. Based on the basic structure of linear estimation of non-stationary multichannel data and statistical models of spatial signal coherence acquire through the wavelet transform in multichannel estimation. The above methods can be used for Electroencephalography (EEG) signal denoising through the original signal and then implement the noise reduction technique to evaluate their performance such as SNR, MSE and computation time.

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Muramatsu, Hisayoshi. "Separation and estimation of periodic/aperiodic state." Automatica 140 (June 2022): 110263. http://dx.doi.org/10.1016/j.automatica.2022.110263.

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21

Langkam, Sabita, and Alok Kanti Deb. "Dual estimation approach to blind source separation." IET Signal Processing 11, no. 5 (2017): 527–36. http://dx.doi.org/10.1049/iet-spr.2016.0357.

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Polzehl, Jörg, and Vladimir Spokoiny. "Propagation-Separation Approach for Local Likelihood Estimation." Probability Theory and Related Fields 135, no. 3 (2005): 335–62. http://dx.doi.org/10.1007/s00440-005-0464-1.

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23

Hassan, Norsalina, and Dzati Athiar Ramli. "Sparse Component Analysis (SCA) Based on Adaptive Time—Frequency Thresholding for Underdetermined Blind Source Separation (UBSS)." Sensors 23, no. 4 (2023): 2060. http://dx.doi.org/10.3390/s23042060.

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Blind source separation (BSS) recovers source signals from observations without knowing the mixing process or source signals. Underdetermined blind source separation (UBSS) occurs when there are fewer mixes than source signals. Sparse component analysis (SCA) is a general UBSS solution that benefits from sparse source signals which consists of (1) mixing matrix estimation and (2) source recovery estimation. The first stage of SCA is crucial, as it will have an impact on the recovery of the source. Single-source points (SSPs) were detected and clustered during the process of mixing matrix estimation. Adaptive time–frequency thresholding (ATFT) was introduced to increase the accuracy of the mixing matrix estimations. ATFT only used significant TF coefficients to detect the SSPs. After identifying the SSPs, hierarchical clustering approximates the mixing matrix. The second stage of SCA estimated the source recovery using least squares methods. The mixing matrix and source recovery estimations were evaluated using the error rate and mean squared error (MSE) metrics. The experimental results on four bioacoustics signals using ATFT demonstrated that the proposed technique outperformed the baseline method, Zhen’s method, and three state-of-the-art methods over a wide range of signal-to-noise ratio (SNR) ranges while consuming less time.

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Inoue, S., K. Wada, A. Nukui, et al. "Estimation of phase separation rates of PbO–B2O3 melts." Journal of Materials Research 10, no. 6 (1995): 1561–64. http://dx.doi.org/10.1557/jmr.1995.1561.

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The rate of liquid-liquid phase separation was experimentally studied in the PbO-B2O3 system. The in situ measurements were made by observing the melts with a videocamera continuously as the melts were cooled down from homogenization temperatures at a rate of 2.5 °C/min. The time interval between the beginning and the completion of the darkening of the visual field was determined as a measure of the separation rate. The phase-separation rate was estimated to be at least 900 times larger than that of the metastable phase separation below the liquidus.

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Bukkapatnam, Satish T. S., Soundar R. T. Kumara, and Akhlesh Lakhtakia. "Fractal Estimation of Flank Wear in Turning." Journal of Dynamic Systems, Measurement, and Control 122, no. 1 (1999): 89–94. http://dx.doi.org/10.1115/1.482446.

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A novel fractal estimation methodology, that uses—for the first time in metal cutting literature—fractal properties of machining dynamics for online estimation of cutting tool flank wear, is presented. The fractal dimensions of the attractor of machining dynamics are extracted from a collection of sensor signals using a suite of signal processing methods comprising wavelet representation and signal separation, and are related to the instantaneous flank wear using a recurrent neural network. The performance of the resulting estimator, evaluated using actual experimental data, establishes our methodology to be viable for online flank wear estimation. This methodology is adequately generic for sensor-based prediction of gradual damage in mechanical systems, specifically manufacturing processes. [S0022-0434(00)02401-1]

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Shang, Yanjie, Yakai Feng, Lipin Ren, et al. "Pupal Age Estimation of Sarcophaga peregrina (Diptera: Sarcophagidae) at Different Constant Temperatures Utilizing ATR-FTIR Spectroscopy and Cuticular Hydrocarbons." Insects 14, no. 2 (2023): 143. http://dx.doi.org/10.3390/insects14020143.

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Sarcophaga peregrina (Robineau-Desvoidy, 1830) (Diptera: Sarcophagidae) is a forensically important flesh fly that has potential value in estimating the PMImin. The precise pupal age estimation has great implications for PMImin estimation. During larval development, the age determination is straightforward by the morphological changes and variation of length and weight, however, the pupal age estimation is more difficult due to anatomical and morphological changes not being visible. Thus, it is necessary to find new techniques and methods that can be implemented by standard experiments for accurate pupal age estimation. In this study, we first investigated the potential of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and cuticular hydrocarbons (CHCs) for the age estimations of S. peregrina pupae at different constant temperatures (20 °C, 25 °C, and 30 °C). The orthogonal projections latent structure discrimination analysis (OPLS-DA) classification model was used to distinguish the pupae samples of different developmental ages. Then, a multivariate statistical regression model, partial least squares (PLS), was established with the spectroscopic and hydrocarbon data for pupal age estimations. We identified 37 CHCs with a carbon chain length between 11 and 35 in the pupae of S. peregrina. The results of the OPLS-DA model show a significant separation between different developmental ages of pupae (R2X > 0.928, R2Y > 0.899, Q2 > 0.863). The PLS model had a satisfactory prediction with a good fit between the actual and predicted ages of the pupae (R2 > 0.927, RMSECV < 1.268). The results demonstrate that the variation tendencies of spectroscopy and hydrocarbons were time-dependent, and ATR-FTIR and CHCs may be optimal for the age estimations of pupae of forensically important flies with implications for PMImin estimation in forensic practice.

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Zhu, Zhanyu, Xingjie Chen, and Zhaomin Lv. "Underdetermined Blind Source Separation Method Based on a Two-Stage Single-Source Point Screening." Electronics 12, no. 10 (2023): 2185. http://dx.doi.org/10.3390/electronics12102185.

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Underdetermined blind source separation is a signal processing technique that is more suitable for practical applications and aims to separate the source signals from the mixed signals. The mixing matrix estimation is a major step in the underdetermined blind source separation. Since the current methods for estimating the mixing matrix have the disadvantages of insufficient accuracy or weak noise immunity, a two-stage single-source point screening that combines the cosine angle algorithm and the L1-norm optimization algorithm is proposed. During the first stage, the first-stage single-source points are extracted from the original mixed signals using the cosine angle algorithm. During the second stage, based on the L1-norm optimization algorithm, the reference single-source points are extracted from the original mixed signals. The reference single-source points are then clustered to obtain the clustering center, which is defined as the reference center. In combination with the reference center, the deviation and interference points in the first-stage single-source points are eliminated by the cosine distance. The remaining signal points are considered as the second-stage single-source points, which are clustered to obtain the mixing matrix estimation. Experiments on simulated and speech signals show that the proposed method can obtain more accurate and robust mixing matrix estimation, leading to better separation of the source signals.

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Hrytsaka, O. M. "Theoretical researches of threshing and separation processes of bread mass by the threshing-separating device." Mehanization and electrification of agricultural, no. 12 (2020): 60–66. http://dx.doi.org/10.37204/0131-2189-2020-12-7.

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Annotation Purpose. Theoretical researches of increase of efficiency of working processes of threshing, separation of grain mass by combine harvesters by improvement and use of a multi-drum design of the threshing-separating device with rational design and technological parameters of work capable to provide necessary agrotechnical requirements. Methods. In theoretical researches the analysis of interaction of the threshing-separating device with grain mass with use of mathematical modeling of processes of threshing of grain, separation of a rough heap and their estimation is carried out. Results. The mathematical model of the mobile multi-drum thresher modernized as a result of change of settings that allowed to increase efficiency of its work is considered; the dependences of quality on the design parameters of the threshing-separating device during the implementation of technological processes of grain harvesting due to the reduction of the total level of injuries and grain losses are obtained. Conclusions. A mathematical model of improvement of the threshing process, separation of grain mass in the threshing gap of the threshing-separating device was developed, which allowed to obtain the dependences of the influence of structural and technological parameters on the level of threshing and separation. It is established that a significant reserve for improving the process of threshing, separation of grain mass is changes in the settings of threshing drums. Keywords: combine harvester, mathematical model, threshing-separating device, theoretical research, grain harvesting, threshing process.

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29

Rasheed, Ashraf Saad, and Ali Saad Ali. "A Study of Retention Behavior and Method Development of Salbutamol Sulfate in Hydrophilic Interaction Chromatography." International Journal of Drug Delivery Technology 10, no. 03 (2020): 344–48. http://dx.doi.org/10.25258/ijddt.10.3.6.

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For chromatographical separation and estimation of salbutamol sulfate, zwitterionic stationary phases with large capacity were obtained by zwitter-molecules attached to a polystyrene-divinylbenzene (PS/DVB) particle. Salbutamol sulfate retention activity was studied with eluent at various pH mobile phase, mobile phase concentrations, and acetonitrile (ACN) percentage. The methods of separation are based on separating the salbutamol sulfate into hydrophobic and cations interactions. Linearity of 0.01 to 0.9 μg.mL-1 for two columns was developed with direct calibration curves, %RSD percent (0.48 ± 0.12 and 0.49 ± 0.22), LoD (0.058 and 0.04 μg.mL-1), and LoQ (0.203 and 0.14 μg.mL-1) were created, respectively.

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30

Eriksen, H. K., C. Dickinson, C. R. Lawrence, et al. "Cosmic Microwave Background Component Separation by Parameter Estimation." Astrophysical Journal 641, no. 2 (2006): 665–82. http://dx.doi.org/10.1086/500499.

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31

Yu, Runyi, Erhan A. Ince, and Aykut Hocanin. "Subspace Alignment and Separation for Multiple Frequency Estimation." IEEE Signal Processing Letters 22, no. 1 (2015): 16–20. http://dx.doi.org/10.1109/lsp.2014.2346252.

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32

Donno, D., A. Nehorai, and U. Spagnolini. "Seismic Velocity and Polarization Estimation for Wavefield Separation." IEEE Transactions on Signal Processing 56, no. 10 (2008): 4794–809. http://dx.doi.org/10.1109/tsp.2008.927459.

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33

Jia, Peng, Hong-Yuan Zhang, and Xi-Zhi Shi. "Blind Source Separation Based on Nonparametric Density Estimation." Circuits, Systems, and Signal Processing 22, no. 1 (2003): 57–67. http://dx.doi.org/10.1007/s00034-004-7013-5.

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34

Ince, Erhan A., Runyi Yu, and Aykut Hocanin. "Entropy-based subspace separation for multiple frequency estimation." Digital Signal Processing 23, no. 1 (2013): 30–37. http://dx.doi.org/10.1016/j.dsp.2012.09.014.

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35

Cho, Yong G., and Musa R. Kamal. "Estimation of stress for separation of two platelets." Polymer Engineering and Science 44, no. 6 (2004): 1187–95. http://dx.doi.org/10.1002/pen.20112.

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36

Xianci, Xiao. "Single channel signal component separation using Bayesian estimation." Journal of Systems Engineering and Electronics 18, no. 1 (2007): 33–39. http://dx.doi.org/10.1016/s1004-4132(07)60046-2.

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37

Ding, Y. P., and Y. L. She. "DOA Estimation of Radar Array Signals Based on Blind Source Separation." Journal of Physics: Conference Series 2383, no. 1 (2022): 012074. http://dx.doi.org/10.1088/1742-6596/2383/1/012074.

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Target orientation estimation is the premise to achieve target positioning and tracking. The classical DOA estimation algorithm needs to know the array structure and other informations. When those information cannot be obtained accurately, the performance of the algorithm will be degraded or even invalid. In this paper, a DOA estimation method for array signals based on blind source separation is proposed. The received mixed signals are separated by blind source separation, and the array steering matrix is estimated. Then the signal receiving channel is dimensionally reduced and transformed, and the covariance matrix is reconstructed. Finally use the MUSIC algorithm to achieve DOA estimation. Through simulation experiments, the results show that the method can realize DOA estimation under the condition of unknown array steering matrix, and it is robust.

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38

Nizhnyk, Vadym, Yurii Feshchuk, and Volodymyr Borovykov. "Methodology of Estimation of Fire Separation Distances between Construction Facilities by Calculation." Materials Science Forum 1006 (August 2020): 93–100. http://dx.doi.org/10.4028/www.scientific.net/msf.1006.93.

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Based on analysis of appropriate literary sources we established that estimation of fire separation distances was based of two criteria: heat flux and temperature. We proposed to use “ignition temperature of materials” as principal criterion when determining fire separation distances between adjacent construction facilities. Based on the results derived while performing complete factorial we created mathematical model to describe trend of changing fire separation distances depending on caloric power of fire load (Q), openings factor of the external enclosing structures (k) and duration of irradiation (t); moreover, its adequacy was confirmed. Based on linear regression equations we substantiated calculation and tabular method for the determination of fire separation distances for a facility being irradiated which contains combustible or otherwise non-combustible façade and a facility where liquid oil products turn. We developed and proposed general methodology for estimation of fire separation distances between construction facilities by calculation.

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39

Nesterenko, Olexandr, Serhii Leshchenko, Olexiy Vasylkovskyi, and Dmytro Petrenko. "Estimation of Uniformity of Distribution and Clogging of Grain at its Multilevel Introduction into the Pneumo-separating Channel." National Interagency Scientific and Technical Collection of Works. Design, Production and Exploitation of Agricultural Machines, no. 51 (2021): 111–16. http://dx.doi.org/10.32515/2414-3820.2021.51.111-116.

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The uniformity of grain distribution in a pneumatic separation channel is an important factor and it significantly affects the quality of grain cleaning. Indeed, with uneven feeding, impurities entering the pneumatic separating channel, to a large extent, are located in the middle or lower layers of grain flow, which impairs the possibility of their release into the settling chamber. Feeders are used to create a more uniform distribution of grain in the operating area of the pneumatic separating channel. They provide conditions under which grain material is fed into the air stream by a thin layer of directed jet. This feeding can significantly improve the interaction of the components of the input grain material with air, increasing the likelihood of their release, as well as minimize the contact of particles of the grain mixture, which significantly increases the efficiency of air flow. Based on the review and analysis of feeder designs, we have proposed a feeder for multi-level grain introduction. The use of such a feeder can significantly improve the quality of pneumo-separation, but there is a possibility of light impurities in the upper grain layers, which can affect the completeness of the separation of the purified grain. Experimental studies were conducted to determine the effect of multilevel introduction on the content of light impurities in the purified grain along the height of the pneumatic separation channel, as well as to analyze the distribution of grain mixture in the operating separation area. As a result of the conducted research it is determined that the number of involved levels of introduction of the feeding device influences the degree of clogging of the cleared grain, thus, uniformity of distribution of grain improves at increase in quantity of levels. In particular, when using up to 4 levels of the feeder under load qbi = 350 kg/dm•h at each level, the amount of light impurities entering the purified grain is not more than 3% of their total weight in the source material.

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40

Huang, Rong Yau, Li Hsu Yeh, Hao Hsien Chen, et al. "Estimation of Construction Waste Generation and Management in Taiwan." Advanced Materials Research 243-249 (May 2011): 6292–95. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.6292.

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This study examines construction waste generation and management in Taiwan. We verify the factors probable affecting the output of construction wastes by using data for the output of declared construction wastes produced from demolition projects in Taiwan in the last year, expert interviews, and research achievements in the past, and find “ on-site separation” is the factor with effects on the output of construction wastes via cross-correlation by algorithms such as K-Means and Decision Tree C5.0. It can be seen that the output (0.092(t/M3) with on-site separation or 0.329(t/M3) without on-site separation is highly correlated with the composition ratio of construction wastes and referred to as a valid conclusion.

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41

Boccignone, Giuseppe, Alessandro D’Amelio, Omar Ghezzi, Giuliano Grossi, and Raffaella Lanzarotti. "An Evaluation of Non-Contact Photoplethysmography-Based Methods for Remote Respiratory Rate Estimation." Sensors 23, no. 7 (2023): 3387. http://dx.doi.org/10.3390/s23073387.

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The respiration rate (RR) is one of the physiological signals deserving monitoring for assessing human health and emotional states. However, traditional devices, such as the respiration belt to be worn around the chest, are not always a feasible solution (e.g., telemedicine, device discomfort). Recently, novel approaches have been proposed aiming at estimating RR in a less invasive yet reliable way, requiring the acquisition and processing of contact or remote Photoplethysmography (contact reference and remote-PPG, respectively). The aim of this paper is to address the lack of systematic evaluation of proposed methods on publicly available datasets, which currently impedes a fair comparison among them. In particular, we evaluate two prominent families of PPG processing methods estimating Respiratory Induced Variations (RIVs): the first encompasses methods based on the direct extraction of morphological features concerning the RR; and the second group includes methods modeling respiratory artifacts adopting, in the most promising cases, single-channel blind source separation. Extensive experiments have been carried out on the public BP4D+ dataset, showing that the morphological estimation of RIVs is more reliable than those produced by a single-channel blind source separation method (both in contact and remote testing phases), as well as in comparison with a representative state-of-the-art Deep Learning-based approach for remote respiratory information estimation.

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42

Sharma, Gaurav. "Per-separation clustered-dot color halftone watermarks: separation estimation based on spatial frequency content." Journal of Electronic Imaging 19, no. 4 (2010): 043007. http://dx.doi.org/10.1117/1.3497615.

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43

Wang, Chunrong, Erdong Xia, Kun-Chieh Wang, and Jing Zhao. "A mixed-copula-based integral method for reliability analysis of a novel multi-functional rescue end-effector." Advances in Mechanical Engineering 15, no. 1 (2023): 168781322211474. http://dx.doi.org/10.1177/16878132221147463.

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To improve the performance of a conventional rescue equipment, we designed a novel multi-functional rescue end-effector comprising a separation mechanism and a grasping mechanism. The failure causes of the separation mechanism are analyzed, and three main failure modes are determined. Meanwhile, their performance functions are established as well. To solve the complex correlations among multiple failure modes, a novel mixed copula function that can capture the upper and lower tail dependencies simultaneously is proposed, which comprises the Gumbel copula and the Clayton copula. Further, a novel procedure that adopts the non-parametric kernel density estimation (NKDE) technique to estimate the probability density function (PDF) and the cumulative distribution function (CDF) for each performance function of the separation mechanism is proposed. The parameters of the mixed copula function are estimated using the method of maximum likelihood estimation. Subsequently, to further study the separation mechanism’s reliability during working, a time-variant parameter estimation method is introduced to build the time-variant mixed copula function. Finally, both the reliability and time-variant reliability of the separation mechanism are analyzed via the proposed integral methods. Comparisons with other analysis schemes show that the proposed integral method is not only effective but also efficient in analyzing the reliability of our target mechanism.

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44

Chen, Yong Qiang, and Jun Liu. "Mixing Matrix Estimation in Blind Source Separation Based on Generalized Gaussian Mixture Modal." Advanced Engineering Forum 4 (June 2012): 217–21. http://dx.doi.org/10.4028/www.scientific.net/aef.4.217.

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The accurate estimation of mixing matrix is critical for blind separation, for solving the problems of traditional methods such as bad robustness and low accuracy, a method based on statistical modal is proposed. The generalized Gaussian mixture modal is used to fit the distribution of single-source-points, a new objective function for clustering is obtained from the view of maximum likelihood estimation. Constrained particle swarm optimization is used to optimize the objective function, by which the mixing matrix is estimated. This method is applicable to determined and underdetermined blind source separation. The simulation shows that the proposed method has higher estimation accuracy and is more robust than traditional methods.

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45

Clares-Crespo, César, Roberto Gil-Pita, Manuel Rosa-Zurera, Joaquín García-Gómez, and Inma Mohíno-Herranz. "Mixture Models Applied to the Estimation of Mixing Parameters in Multi-Channel Blind Source Separation Algorithms." International Journal of Signal Processing Systems 7, no. 3 (2019): 85–91. http://dx.doi.org/10.18178/ijsps.7.3.85-91.

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46

Min Kong, Min Kong, Jiangnan Xiao Jiangnan Xiao, Ze Dong Ze Dong, Liuqingqing Yang Liuqingqing Yang, Lin Chen Lin Chen, and Jianjun Yu Jianjun Yu. "Enhanced fourth-power algorithm for phase estimation with frequency separation in direct-detection optical OFDM systems." Chinese Optics Letters 11, no. 6 (2013): 060602–60607. http://dx.doi.org/10.3788/col201311.060602.

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47

Parmentier, B., J. Dooge, and M. Bruen. "Root selection methods in flood analysis." Hydrology and Earth System Sciences 7, no. 2 (2003): 151–61. http://dx.doi.org/10.5194/hess-7-151-2003.

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Abstract. In the 1970s, de Laine developed a root-matching procedure for estimating unit hydrograph ordinates from estimates of the fast component of the total runoff from multiple storms. Later, Turner produced a root selection method which required only data from one storm event and was based on recognising a pattern typical of unit hydrograph roots. Both methods required direct runoff data, i.e. prior separation of the slow response. This paper introduces a further refinement, called root separation, which allows the estimation of both the unit hydrograph ordinates and the effective precipitation from the full discharge hydrograph. It is based on recognising and separating the quicker component of the response from the much slower components due to interflow and/or baseflow. The method analyses the z-transform roots of carefully selected segments of the full hydrograph. The root patterns of these separate segments tend to be dominated by either the fast response or the slow response. This paper shows how their respective time-scales can be distinguished with an accuracy sufficient for practical purposes. As an illustration, theoretical equations are derived for a conceptual rainfall-runoff system with the input split between fast and slow reservoirs in parallel. These are solved analytically to identify the reservoir constants and the input splitting parameter. The proposed method, called "root separation", avoids the subjective selection of rainfall roots in the Turner method as well as the subjective matching of roots in the original de Laine method. Keywords: unit hydrograph,identification methods, z-transform, polynomial roots, root separation, fast andslow response, Nash cascade

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48

Compaleo, Jacob, and Inder J. Gupta. "Application of Sparse Representation to Bartlett Spectra for Improved Direction of Arrival Estimation." Sensors 21, no. 1 (2020): 77. http://dx.doi.org/10.3390/s21010077.

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A new technique for high-resolution direction of arrival estimation is presented. The method utilizes the traditional Bartlett spectra and sparse representation to locate emitters in single and multiple emitter scenarios. A method for selecting the sparse representation regularization parameter is also presented. Using Monte Carlo simulations, we show that the proposed approach achieves accurate direction of arrival (DOA) estimations that are unbiased and a variance that approaches the Cramer–Rao lower bound. We show that our method outperforms the popular MUSIC algorithm, and is slightly better than the sparse representation based L1-SVD algorithm when angular separation between emitters is small, signal SNR is low, and a small number of snapshots are used in DOA estimation.

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Sukovata, Lidia. "A Comparison of Three Approaches for Larval Instar Separation in Insects—A Case Study of Dendrolimus pini." Insects 10, no. 11 (2019): 384. http://dx.doi.org/10.3390/insects10110384.

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The number of larval instars is important from both theoretical and practical perspectives. Three previous studies based on head capsule widths (HCWs) have suggested that Dendrolimus pini larvae pass through seven instars, but the estimated HCW means differed greatly. Various methods are available for determining the number of instars; however, these methods have not been compared on the same dataset. Therefore, the main goal of this study was to compare three approaches for instar separation in D. pini larvae: visual approach followed by non-linear least squares (NLLS) estimation, kernel density estimation (KDE) followed by NLLS, and model-based clustering. Two criteria were used to assess whether the resulting instar separations adhered to Brooks-Dyar’s rule: Crosby’s growth rule and a coefficient of determination indicating the goodness of fit of a straight line to the ln-transformed mean HCW of the respective instars. Our results showing that D. pini larvae pass through eight instars differed greatly from reports in the literature. The best results were obtained by KDE followed by NLLS. For proper instar separation, both criteria of Brooks-Dyar’s rule must be met.

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50

Zhang, Xuedong, Qi He, and Zaixiao Gong. "A mode separation method based on sparse Bayesian learning for explosive sources in a shallow water waveguide." Journal of the Acoustical Society of America 155, no. 3_Supplement (2024): A46. http://dx.doi.org/10.1121/10.0026749.

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This paper presents a mode separation method based on sparse Bayesian learning (SBL) for explosive sources in a shallow water waveguide. In previous work [Niu et al., JASA, 2021, 4366], the SBL dictionary was constructed by assuming a large number of horizontal wavenumbers and utilized an approximate mode-frequency dispersion relation for low frequencies. Then, modes were separated in the frequency domain by estimating the coefficients of the dictionary atoms. However, challenges inherent to explosive sources, such as bandwidth expansion and the bubble-pulse effect, result in a mismatch in the dictionary matrix built using the approximate mode-frequency dispersion relation for low frequencies, leading to unsuccessful mode separation. To address these issues, this paper builds the SBL dictionary matrix by utilizing the acoustic model (e.g., Kraken) to derive horizontal wavenumbers under various environmental hypotheses and combines it with the secondary bubble-pulse model. By estimating the coefficients of the dictionary atoms, both environmental parameter estimation and mode separation can be achieved simultaneously. Simulation and experimental data results demonstrate the validation of the proposed method.

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