Inverse problems for dynamical system models of cognitive processes comprise the determination of synaptic weight matrices or kernel functions for neural networks or neural/dynamic field models, respectively. We introduce dynamic cognitive modeling as a three tier top-down approach where cognitive processes are first described as algorithms that operate on complex symbolic data structures. Second, symbolic expressions and operations are represented by states and transformations in abstract vector spaces. Third, prescribed trajectories through representation space are implemented in neurodynamical systems. We discuss the Amari equation for a neural/dynamic field theory as a special case and show that the kernel construction problem is particularly ill-posed. We suggest a Tikhonov-Hebbian learning method as regularization technique and demonstrate its validity and robustness for basic examples of cognitive computations.
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http://dx.doi.org/10.1063/1.3097067 | DOI Listing |
J Opt Soc Am A Opt Image Sci Vis
August 2024
A topology optimization method is presented and applied to a blazed diffraction grating in reflection under conical incidence. This type of grating is meant to disperse the incident light on one particular diffraction order, and this property is fundamental in spectroscopy. Conventionally, a blazed metallic grating is made of a sawtooth profile designed to work with the ±1st diffraction order in reflection.
View Article and Find Full Text PDFFront Neurol
January 2025
Biostatistics Department, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Background: Multiple sclerosis (MS) is a debilitating autoimmune disease that mostly affects women.
Objectives: In this study we evaluated the relationship of pelvic muscle strengths with urinary incontinence and quality of life in women with MS.
Materials And Methods: In this cross-sectional study 87 women with MS were recruited.
Heliyon
January 2025
Department of Mathematics, Abdul Wali Khan University Mardan, Mardan, 23200, Pakistan.
Determining coefficient estimates of inverse complex valued function is often more challenging than determining the function itself, leading to a lack of articles on inverse functions by examining sharp estimates of the third-order Hankel determinant. This article uses Carathéodory functions to estimate the initial coefficients related to problems for inverse of functions that are bounded turning and subordinated with the cosine function. It covers some inverse coefficients problems together with the second and third-order Hankel determinants.
View Article and Find Full Text PDFNihon Hoshasen Gijutsu Gakkai Zasshi
January 2025
Department of Radiology, Nara Prefecture General Medical Center.
Purpose: There are attempts to assess tumor heterogeneity by texture analysis. However, the ordered subsets-expectation maximization (OSEM) reconstruction method has problems depicting heterogeneities. The aim of this study was to identify image reconstruction parameters that improve the ability to depict internal tumor necrosis using a self-made phantom that simulates internal necrosis.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
High-Power Converter Systems (HLU), Technical University of Munich (TUM), 80333 Munich, Germany.
Gate dielectrics are essential components in nanoscale field-effect transistors (FETs), but they often face significant instabilities when exposed to harsh environments, such as radioactive conditions, leading to unreliable device performance. In this paper, we evaluate the performance of ultrascaled transition metal dichalcogenide (TMD) FETs equipped with vacuum gate dielectric (VGD) as a means to circumvent oxide-related instabilities. The nanodevice is computationally assessed using a quantum simulation approach based on the self-consistent solutions of the Poisson equation and the quantum transport equation under the ballistic transport regime.
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