Search results for "Pose"
showing 10 items of 1189 documents
Fast nonstationary preconditioned iterative methods for ill-posed problems, with application to image deblurring
2013
We introduce a new iterative scheme for solving linear ill-posed problems, similar to nonstationary iterated Tikhonov regularization, but with an approximation of the underlying operator to be used for the Tikhonov equations. For image deblurring problems, such an approximation can be a discrete deconvolution that operates entirely in the Fourier domain. We provide a theoretical analysis of the new scheme, using regularization parameters that are chosen by a certain adaptive strategy. The numerical performance of this method turns out to be superior to state-of-the-art iterative methods, including the conjugate gradient iteration for the normal equation, with and without additional precondi…
Rotationally symmetric 1-harmonic flows from D2 TO S 2: Local well-posedness and finite time blowup
2010
The 1-harmonic flow from the disk to the sphere with constant Dirichlet boundary conditions is analyzed in the case of rotational symmetry. Sufficient conditions on the initial datum are given, such that a unique classical solution exists for short times. Also, a sharp criterion on the boundary condition is identified, such that any classical solution will blow up in finite time. Finally, nongeneric examples of finite time blowup are exhibited for any boundary condition.
On the discrete linear ill‐posed problems
1999
An inverse problem of photo‐acoustic spectroscopy of semiconductors is investigated. The main problem is formulated as the integral equation of the first kind. Two different regularization methods are applied, the algorithms for defining regularization parameters are given. Diskrečiųjų blogai sąlygotų uždavinių klausimu Santrauka Darbe nagrinejamas foto‐akustines spektroskopijos puslaidininkiuose uždavinys, kuriame i vertinami nešeju difuzijos ir rekombinacijos procesai. Reikia atstatyti šaltinio funkcija f(x), jei žinoma antrosios eiles difuzijos lygtis ir atitinkamos kraštines salygos. Naudojantis matavimu, atliktu ivairiuose dažniuose, rezultatais sprendžiamas atvirkštinis uždavinys, kel…
Optimization of conducting structures by using the homogenization method
2002
Approximation and numerical realization of a class of optimization problems with control variables represented by coefficients of linear elliptic state equations is considered. Convergence analysis of well-posed problems is performed by using one- and two-level approximation strategies. The latter is utilized in an optimization layout problem for two conductive constituents, for which the necessary steps to transfer the well-posed problem into a computational form are described and some numerical experiments are given.
Multicomponent line profile restoring by means of ill-posed inverse task solution
2017
The investigation of the criteria of usage of the Tikhonov regularization method for multicomponent overlapping line profiles restoring was done by means of model task solution. The influence of the width and kind of the instrumental function, number of the components of the profile and distance between components are discussed.
Well-posedness of a nonlinear evolution equation arising in growing cell population
2011
We prove that a nonlinear evolution equation which comes from a model of an age-structured cell population endowed with general reproduction laws is well-posed. Copyright © 2011 John Wiley & Sons, Ltd.
Dip Phenomenon in High-Curved Turbulent Flows and Application of Entropy Theory
2018
The estimation of velocity profile in turbulent open channels is a difficult task due to the significant effects of the secondary flow. The present paper investigates the mechanism of the velocity-dip phenomenon, whereby the location of the maximum velocity appears to be below the free surface. Previous studies conducted in straight channels relate the mechanism of the velocity-dip phenomenon to secondary flow induced by anisotropy of turbulence. This work focuses on high-curved channels where the secondary motion, which is also induced by the channel’s curvature, evolves along the bend. The width-to-depth ratio, B/h, is one of the most important parameters that are affecting the secondary …
Spheroids of adipose derived stem cells show their potential in differentiating towards the angiogenic lineage
2023
Introduction: Adipose derived stem cells (ASCs) are a mesenchymal stem cell population of great scientific interest due to their abundance and easiness in obtaining them from adipose tissue. Recently, several techniques for three dimensional (3D) ASCs cultivation have been developed to obtain spheroids of adipose stem cells (SASCs). It was already proved that ASCs are able to differentiate towards the endothelial lineage thus, for the first time, we investigated the ability of our 3D SASCs to differentiate endothelially and the effects of not differentiated SASC secreted factors on specific cultured cells. Materials and methods: SASCs were differentiated with a specific medium towards endot…
Exposition continue aux xéno-hormones à faibles doses chez le rat : effets multi-générationnels de mélanges sur les préférences gustatives, le compor…
2012
During the last decade, the issue of health-related endocrine disruptors (ED) has been extended to the toxicity of mixtures. The objective of this study was to define the effects of lifelong exposure to ED mixtures, at low doses defined as "non-harmful" by the authorities. In this aim, the effects of mixtures combining genistein, vinclozolin and bisphenol A, have been investigated in the rat by using an integrative and multi-generational experimental approach which takes into account maternal behavior, feeding behavior and development. Our results show that these mixtures could: a) reduce maternal behavior, b) change taste preferences (sweet, salty), c) affect the development from the in ut…
An Inter-Technology Communication Scheme for WiFi/ZigBee Coexisting Networks
2017
In this paper we show how inter-technology interference can be exploited to set-up a low-rate bi-directional communication channel between heterogeneous technologies, which coexist in ISM bands. In particular, we focus on WiFi and ZigBee networks, whose high density deployments make coexistence a critical issue. We monitor the transmission duration of the interference and, after recognizing ZigBee interference from WiFi off-the-shelf receivers, we precisely measure the channel busy intervals to map time duration to communication symbols. A similar approach is used on the ZigBee receivers for making the communication channel bidirectional. Extensive experimental results show the feasibility …