Contour Detection Method of 3D Fish Using a Local Kernel Regression Method

Introduction: Macroeconomic problems such as inflation and exchange rates are often highlighted as benchmarks for achieving economic progress. The stability of both must be monitored by the government in order to control the inflation rate and exchange rate. This instability is a phenomenon of fluctuation, namely the phenomenon of the rise and fall of the exchange rate of a currency based on demand and supply. Given the large impact of exchange rate fluctuations on the economy, the prediction of the wage exchange rate against the US dollar is considered necessary because it is useful to anticipate and minimize bad possibilities that arise. Method: Methods that can be used to analyze fluctuating currency exchange rate data are nonparametric regression, Nadaraya-Watson estimator, Gaussian kernel function, and Local Polynomial Regression. Results and Discussion: The results of a nonparametric regression comparison between the Nadaraya-Watson estimator, Gaussian kernel function, and local polynomial regression were obtained by MAPE of 2.508% and 0.179%, respectively. This shows that the best model uses the local polynomial regression method and predicted USD exchange rate data against IDR using the best model, namely Local polynomial Regression where the MAPE value is less than 10%, which means the prediction rate is very good. Conclusion: The nonparametric regression method of the Nadaraya-Watrson estimator, Gaussian kernel function, and local polynomial regression shows that the best model uses the local polynomial regression method.

The presence of baseline wander in ECG signal severely affects the quality of ECG signal. Baseline wander is generally eliminated at the initial stage of preprocessing of ECG signal. In this paper a method using regression estimation is applied to ECG signal to remove the baseline wander. This method uses two stage median filter and regression estimation for smoothing and correction of baseline. The cross correlation is performed between the baseline wander containing ECG signal with corrected ECG signal. Then cross-correlation coefficient is calculated. The method evolves with the lowess and loess of local regression estimation, rlowess and rloess of robust local regression estimation. We found highest coefficient of 0.9914 for the baseline wander amplitude of 0.5mV using local regression method (lowess) and lowest coefficient of 0.9688 for the amplitude of 0.8mV using robust local regression method (rlowess). Further this method is validated on MIT-BIH, Noise Stress Test Database (NSTD).

Correlations between socioeconomic factors and poverty in regression models do not reflect actual relationships, especially when data exhibit patterns of spatial heterogeneity. Spatial regression models can estimate the relationships between socioeconomic factors and poverty in defined geographical areas, explaining the imbalanced distribution of poverty, but the relationships between these factors and poverty are not always linear however, and conventional simple linear local regression models do not accurately capture these nonlinear relationships. To fill this gap, we used a local regression method, geographically weighted random forest regression (GW-RFR), that integrates a spatial weight matrix (SWM) and random forest (RF). The GW-RFR evaluates the spatial variations in the nonlinear relationships between variables. A county-level poverty data set of China was employed to estimate the performance of the GW-RFR against the random forest (RF). In this poverty application, the value of {R}^{2} was 0.128 higher than that of the RF, the NRMSE value was 1.6% lower than the RF, and the MAE value was 0.295 lower than the RF. These results showed that the relationship between poverty factors and poverty varies with space at the county level in China, and the GW-RFR was suitable for dealing with nonlinear relationships in local regression analysis.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-17513-3.

Hedger, R. D., Martin, F., Dodson, J, J., Hatin, D., Caron, F., and Whoriskey, F. G. 2008. The optimized interpolation of fish positions and speeds in an array of fixed acoustic receivers. – ICES Journal of Marine Science, 65: 1248–1259. The principal method for interpolating the positions and speeds of tagged fish within an array of fixed acoustic receivers is the weighted-mean method, which uses a box-kernel estimator, one of the simplest smoothing options available. This study aimed to determine the relative error of alternative, non-parametric regression methods for estimating these parameters. It was achieved by predicting the positions and speeds of three paths made through a dense array of fixed acoustic receivers within a coastal embayment (Gaspé Bay, Québec, Canada) by a boat with a GPS trailing an ultrasonic transmitter. Transmitter positions and speeds were estimated from the receiver data using kernel estimators, with box and normal kernels and the kernel size determined arbitrarily, and by several non-parametric methods, i.e. a kernel estimator, a smoothing spline, and local polynomial regression, with the kernel size or smoothing span determined by cross-validation. Prediction error of the kernel estimator was highly dependent upon kernel size, and a normal kernel produced less error than the box kernel. Of the methods using cross-validation, local polynomial regression produced least error, suggesting it as the optimal method for interpolation. Prediction error was also strongly dependent on array density. The local polynomial regression method was used to determine the movement patterns of a sample of tagged Atlantic salmon (Salmo salar) smolt and kelt, and American eel (Anguilla rostrata). Analysis of the estimates from local polynomial regression suggested that this was a suitable method for monitoring patterns of fish movement.

Summary We need to determine the best use of soil vis– NIR spectral libraries that are being developed at regional, national and global scales to predict soil properties from new spectral readings. To reduce the complexity of a calibration dataset derived from the C hinese vis– NIR soil spectral library ( CSSL ), we tested a local regression method that combined geographical sub‐setting with a local partial least squares regression (local‐ PLSR ) that uses a limited number of similar vis– NIR spectra ( k ‐nearest neighbours). The central idea of the local regression, and of other local statistical approaches, is to derive a local prediction model by identifying samples in the calibration dataset that are similar, in spectral variable space, to the samples used for prediction. Here, to derive our local regressions we used E uclidean distance in spectral space between the calibration dataset and prediction samples, and we also used soil geographical zoning to account for similarities in soil‐forming conditions. We tested this approach with the CSSL , which comprised 2732 soil samples collected from 20 provinces in the P eople's R epublic of C hina to predict soil organic matter ( SOM ). Results showed that the prediction accuracy of our spatially constrained local‐ PLSR method ( R 2 = 0.74, RPIQ = 2.6) was better than that from local‐ PLSR ( R 2 = 0.69, RPIQ = 2.3) and PLSR alone ( R 2 = 0.50, RPIQ = 1.5). The coupling of a local‐ PLSR regression with soil geographical zoning can improve the accuracy of local SOM predictions using large, complex soil spectral libraries. The approach might be embedded into vis– NIR sensors for laboratory analysis or field estimation.

This paper presents a vision-based object following four wheel independent steering automatic guided vehicle (4WIS-AGV) system using Kinect camera sensor. To do this task, the following steps are executed. Firstly, an image processing is done for object detection using Kinect camera sensor. A candidate colored object is detected using color-based object detection method and its position in local coordinates is obtained. NAV200 navigation sensor is used to obtain global position of the detected object and the 4WIS-AGV. Secondly, the position of the detected moving object is estimated using Kalman filter algorithm. Kalman filter is used to estimate the global position of the detected moving object. Thirdly, a backstepping controller based on Lyapunov stability is proposed to achieve object following task. Finally, the effectiveness of the proposed system is verified by using simulation and experimental results. The results show that the proposed controller makes the 4WIS-AGV follow the detected moving object well with an acceptable error.

Prediction of soil organic carbon content by diffuse reflectance spectroscopy using a local partial least square regression approach

The quality of object proposal plays an important role in boosting the performance of many computer vision tasks, such as, object detection and recognition. Due to the absence of manually annotated bounding-box in practice, the quality metric towards blind assessment of object proposal is highly desirable for singling out the optimal proposals. In this paper, we propose a blind proposal quality assessment algorithm based on the Deep Objectness Representation and Local Linear Regression (DORLLR). Inspired by the hierarchy model of the human vision system, a deep convolutional neural network is developed to extract the objectness-aware image feature. Then, the local linear regression method is utilized to map the image feature to a quality score, which tries to evaluate each individual test window based on its k-nearest-neighbors. Experimental results on a large-scale IoU labeled dataset verify that the proposed method significantly outperforms the state-of-the-art blind proposal evaluation metrics.

Event detection has an important role in detecting the switching of the state of the appliance in the residential environment. This paper proposed a robust smoothing method for cepstrum estimation using double smoothing i.e. the cepstrum smoothing and local linear regression method. The main problem is to reduce the variance of the home appliance peak signal. In the first step, the cepstrum smoothing method removed the unnecessary quefrency by applying a rectangular window to the cepstrum of the current signal. In the next step, the local regression smoothing weighted data points to be smoothed using robust least squares regression. The result of this research shows the variance of the peak signal is decreased and has a good performance with better accuracy. In noise enviromment, performance prediction quite good with values greater than 0.6 and relatively stable at values above 0.9 on SNR> 25 for single appliances. Furthermore, in multiple appliances, performance prediction quite good at SNR> 20 and begins to decrease in SNR <20 and SNR> 25.

Time-varying covariance is an important metric to measure the statistical dependence between non-stationary biological processes. Time-varying covariance is conventionally estimated from short-time data segments within a window having a certain bandwidth, but it is difficult to choose an appropriate bandwidth to estimate covariance with different degrees of non-stationarity. This paper introduces a local polynomial regression (LPR) method to estimate time-varying covariance and performs an asymptotic analysis of the LPR covariance estimator to show that both the estimation bias and variance are functions of the bandwidth and there exists an optimal bandwidth to minimize the mean square error (MSE) locally. A data-driven variable bandwidth selection method, namely the intersection of confidence intervals (ICI), is adopted in LPR for adaptively determining the local optimal bandwidth that minimizes the MSE. Experimental results on simulated signals show that the LPR-ICI method can achieve robust and reliable performance in estimating time-varying covariance with different degrees of variations and under different noise scenarios, making it a powerful tool to study the dynamic relationship between non-stationary biomedical signals. Further, we apply the LPR-ICI method to estimate time-varying covariance of functional magnetic resonance imaging (fMRI) signals in a visual task for the inference of dynamic functional brain connectivity. The results show that the LPR-ICI method can effectively capture the transient connectivity patterns from fMRI.

Retracted: Evaluation and Numerical Simulation of Music Education Informationization Based on the Local Linear Regression Method

The development of next-generation sequencing technology has provided us with great convenience in genetic association studies and many effective analysis methods were proposed continuously. However, population stratification is still a major issue in current genetic association studies. Many existing methods have been developed to remove the bias due to population stratification for common variant association studies, but such methods may be not effective for rare variant, which will lead to power reduction. Therefore, in this paper, we develop a principal component analysis strategy (called PC-LLR) based on local linear regression method to eliminate population stratification effect in both rare variant and common variant association studies. Simulation results indicate that the new PC-LLR method can eliminate population stratification effect well. It has correct type I error rates in all cases and higher powers in most cases, while most existing methods have inflated type I error rates at least in some cases. We also demonstrate that the PC-LLR is more effective to eliminate population stratification effect through applying the PC-LLR to the whole-exome sequencing data set from genetic analysis workshop 19 (GAW19).

This paper proposes a semi-functional partial linear spatial autoregressive (SAR) model, in which we allow one of the explanatory variables to be a functional variable, while the dependent variable is scalar. We aim to enable the spatial econometric models to be applied to various areas where data types can be functional data. Based on quasi-maximum likelihood estimation (QMLE) method and local linear regression method, we construct a two-stage estimator to estimate the parameters and nonparametric component. The convergence rate of the estimator of nonparametric component is given. Furthermore, Monte Carlo simulations are performed to investigate our two-stage estimator’s finite sample performance.

Conspicuous intracellular gradients manifest and/or drive intracellular polarity in pollen tubes. However, quantifying these gradients raises multiple technical challenges. Here we present a sensible computational protocol to analyze gradients in growing pollen tubes and to filter nonrepresentative time points. As an example, we use imaging data from pollen tubes expressing a genetically encoded ratiometric Ca2+ probe, Yellow CaMeleon 3.6, from which a kymograph is extracted. The tip of the pollen tube is detected with CHUKNORRIS, our previously published methodology, allowing the reconstruction of the intracellular gradient through time. Statistically confounding time points, such as growth arrest where gradients are highly oscillatory, are filtered out and a mean spatial profile is estimated with a local polynomial regression method. Finally, we estimate the gradient slope by the linear portion of the decay in mean fluorescence, offering a quantitative method to detect phenotypes of gradient steepness, location, intensity, and variability. The data manipulation protocol proposed can be achieved in a simple and efficient manner using the statistical programming language R, opening paths to perform high-throughput spatiotemporal phenotyping of intracellular gradients in apically growing cells.

Building of dams and subsequent abstraction upstream of rivers significantly affects major wetland systems. Knowledge of anthropogenic impacts of river regulation, relative to stochastic variation, is essential if managers are able to adequately manage flows to wetlands. We built annual flow and inundated area models for the Macquarie Marshes supplied by the Macquarie River, based on available annual rainfall data (1879–2006). We used LOESS, the flexible local polynomial regression method, ideal for modelling complex processes where no theoretical models exist. To compare effects of river regulation and abstraction, we developed two models, before river regulation (‘natural’ or ‘unregulated’) and after river regulation (‘regulated’). The division was when Burrendong dam, the most significant regulatory structure affecting flows, was built in 1963 and completed in 1967. After this point, water was diverted upstream, predominantly for irrigation. We developed ‘natural’ and ‘regulated’ flow models for three flow gauges Dubbo, Warren and Oxley based on annual rainfall at rainfall stations in the upper catchment and flow, and then inundated area models based on flow and local rainfall to fit annual inundated area data (1979–2006) in the Macquarie Marshes, using LOESS and leave‐one‐out samples without overfitting. We evaluated the performance of the proposed models and used these models to predict annual flows and inundated areas from 1879 to 2006. Comparison was done in terms of ‘natural’ and ‘regulated’ data using Kolmogorov–Smirnov test, identifying significant reductions in flow and wetland area. Copyright © 2009 John Wiley & Sons, Ltd.