Random Noise Research Papers - Academia.edu (original) (raw)
7 Followers
Recent papers in Random Noise
This paper investigates the estimation behavior of six increasingly complex 15N models, for estimating flux rates between phytoplankton and dissolved N pools in aquatic ecosystems. The development of these models over the last 40 years... more
This paper investigates the estimation behavior of six increasingly complex 15N models, for estimating flux rates between phytoplankton and dissolved N pools in aquatic ecosystems. The development of these models over the last 40 years reflects increasing realism in the pools and fluxes that constitute the N cycle. The purpose of this paper is to assess how the model results are influenced by the underlying assumptions. For example, with respect to uptake of 15N by phytoplankton, is anything gained by assuming that regenerated N become isotopically enriched after the introduction of the 15N label, or is it just as accurate to assume that no source other than the initial 15N label contributes to the enrichment signal in phytoplankton? To conduct an objective assessment of the models, we compared them to (1) a set of reference values generated numerically by a process oriented model, and (2) real experimental data. The results show that for a number of 15N models, properties such as a...
Constructing an estimator for functional estimation is one of the problems in statistical inference. In this paper, the problem of constructing an estimator for a studentized sum is considered in the nonparametric set-up. In this set-up,... more
Constructing an estimator for functional estimation is one of the problems in statistical inference. In this paper, the problem of constructing an estimator for a studentized sum is considered in the nonparametric set-up. In this set-up, data are used to infer to an unknown quantity while making as few assumptions as possible. This non-smooth functional lack some degree of properties traditionally relied upon in estimation. Smooth functionals converge at the rate of n 1 2 while non-smooth functionals converge at the rate slower than n 1 2 . This highlights the reason why standard techniques fail to give sharp results. A clear and accurate approximation is obtained by using an approximation that admits cumulant generating function; saddle point approximation. An optimal estimator is obtained using the MiniMax criterion where the lower and upper bounds are constructed. While working in the context of MiniMax estimation, the lower bounds are most important. The MiniMax lower bound is o...
Chebyshev-tau pseudospectral methods have been widely used for decades in the linear and nonlinear simulations of neutral fluid dynamics. In this work, we apply these techniques to different reduced models of fluid like plasma equations... more
Chebyshev-tau pseudospectral methods have been widely used for decades in the linear and nonlinear simulations of neutral fluid dynamics. In this work, we apply these techniques to different reduced models of fluid like plasma equations that describe various instabilities commonly present in many plasma confinement configurations, ranging from laboratory to space plasmas. Nonlinear high-resolution simulations are performed for a plasma slab, periodic in one direction and satisfying Dirichlet boundary conditions in the other. As opposed to Fourier-Fourier methods, usually applied to homogeneous problems, the Chebyshev-Fourier method allows for the study of equilibrium states that are inhomogeneous along one direction and have Dirichlet, Neumann or Robin boundary conditions. Adaptive fifth/sixth order RK time integration scheme is used to advance the initial condition. Simulations show the formation of long-lived coherent structures from different equilibrium states with a random nois...
Summary Linear Feedback Shift Registers (LFSRs) are commonly used in applications where pseudorandom bit streams are required. LFSRs are the functional building blocks of circuits like the pseudo-random noise (PN) code generator (XAPP211)... more
Summary Linear Feedback Shift Registers (LFSRs) are commonly used in applications where pseudorandom bit streams are required. LFSRs are the functional building blocks of circuits like the pseudo-random noise (PN) code generator (XAPP211) and Gold code ...
At the current stage of technology, depth maps acquired using cameras based on a time-of-flight principle have much lower spatial resolution compared to images that are captured by conventional color cameras. The main idea of our work is... more
At the current stage of technology, depth maps acquired using cameras based on a time-of-flight principle have much lower spatial resolution compared to images that are captured by conventional color cameras. The main idea of our work is to use high resolution color images to improve the spatial resolution and image quality of the depth maps.
The results of the analysis of the achievable disturbance attenuation to get an Angstrom motion control resolution and macroscopic travel in a precision magnetically-suspended motion control system are presented in this paper. Noise... more
The results of the analysis of the achievable disturbance attenuation to get an Angstrom motion control resolution and macroscopic travel in a precision magnetically-suspended motion control system are presented in this paper. Noise sources in the transducers, electronics, and mechanical vibrations are used to develop the control design.
Through Ginzburg-Landau and Navier-Stokes equations, we study turbulence phenomena for viscous incompresible and compressible fluids by a second order phase transition. For this model, the velocity is defined by the sum of classical and... more
Through Ginzburg-Landau and Navier-Stokes equations, we study turbulence phenomena for viscous incompresible and compressible fluids by a second order phase transition. For this model, the velocity is defined by the sum of classical and whirling components. Moreover, the laminar-turbulent transition is controlled by rotational effects of the fluid. Hence, the thermodynamic compatibility of the differential system is proved. This model can explain the turbulence by instability effects motivated by a double well potential of the Ginzburg-Landau equation. The same model is used to understand the origins of tornadoe and the birth of the vortices resulting from the fall of water in a vertical tube. Finally, we demonstrate how the weak Coriolis force is able to change the direction of rotation of the vortices by modifying the minima of the phase field potential.
One of the main factors that affects the performance of MLP neural networks trained using the backpropagation algorithm in mineral-potential mapping isthe paucity of deposit relative to barren training patterns. To overcome this problem,... more
One of the main factors that affects the performance of MLP neural networks trained using the backpropagation algorithm in mineral-potential mapping isthe paucity of deposit relative to barren training patterns. To overcome this problem, random noise is added to the original training patterns in order to create additional synthetic deposit training data. Experiments on the effect of the number of
Time-dependent amplitude and phase information of stacked seismic data are processed independently using complex trace analysis in order to facilitate interpretation by improving resolution and decreasing random noise. We represent... more
Time-dependent amplitude and phase information of stacked seismic data are processed independently using complex trace analysis in order to facilitate interpretation by improving resolution and decreasing random noise. We represent seismic traces using their envelopes and instantaneous phases obtained by the Hilbert transform. The proposed method reduces the amplitudes of the low-frequency components of the envelope, while preserving the phase information. Several tests are performed in order to investigate the behavior of the present method for resolution improvement and noise suppression. Applications on both 1D and 2D synthetic data show that the method is capable of reducing the amplitudes and temporal widths of the side lobes of the input wavelets, and hence, the spectral bandwidth of the input seismic data is enhanced, resulting in an improvement in the signal-to-noise ratio. The bright-spot anomalies observed on the stacked sections become clearer because the output seismic t...
There has been a long debate about the effect of written corrective feedback (WCF) on improving L2 learners’ linguistic accuracy in writing. Some scholars question the effectiveness of WCF on improving EFL/ESL learners’ linguistic... more
There has been a long debate about the effect of written corrective feedback (WCF) on improving L2 learners’ linguistic accuracy in writing. Some scholars question the effectiveness of WCF on improving EFL/ESL learners’ linguistic accuracy. However, other researchers argue for the value WCF to the improvement of L2 learners’ writing performance. The current paper conducts an experiment aiming to investigate whether or what type of WCF has any short- and long-terms effects on improving learners’ linguistic accuracy in writing. The study includes 105 third-year-undergraduate EFL students from the English Department in Iraqi Kurdistan Region’s two public universities. The subjects were divided into two main groups: treatment and control. The former was assigned as no corrective feedback group that was merely provided with comments on writing content, and the latter was subdivided into two experimental groups that received either indirect or direct WCF. Data was collected from learner’s...
ABSTRACTRecent improvements in the local wavenumber approach have made it possible to estimate both the depth and model type of buried bodies from magnetic data. However, these improvements require calculation of third‐order derivatives... more
ABSTRACTRecent improvements in the local wavenumber approach have made it possible to estimate both the depth and model type of buried bodies from magnetic data. However, these improvements require calculation of third‐order derivatives of the magnetic field, which greatly enhances noise. As a result, the improvements are restricted to data of high quality. We present an alternative method to estimate both the depth and model type using the first‐order local wavenumber approach without the need for third‐order derivatives of the field. Our method is based on normalization of the first‐order local wavenumber anomalies and provides a generalized equation to estimate the depth of some 2D magnetic sources regardless of the source structure. Information about the nature of the sources is obtained after the source location has been estimated. The method was tested using synthetic magnetic anomaly data with random noise and using three field examples.
Abstract. Switches are everyday objects that interface humans to many func-tionalities and influence our perception of the machinery that they are attached to. This study is aimed at a better understanding of the perceptual attributes of... more
Abstract. Switches are everyday objects that interface humans to many func-tionalities and influence our perception of the machinery that they are attached to. This study is aimed at a better understanding of the perceptual attributes of switches. Specifically, the perceptual thresholds for dynamic ...