Indirect Image Registration with Large Diffeomorphic Deformations

The paper adapts the large deformation diffeomorphic metric mapping framework for image registration to the indirect setting where a template is registered against a target that is given through indirect noisy observations. The registration uses diffeomorphisms that transform the template through a (group) action. These diffeomorphisms are generated by solving a flow equation that is defined by a velocity field with certain regularity. The theoretical analysis includes a proof that indirect image registration has solutions (existence) that are stable and that converge as the data error tends so zero, so it becomes a well-defined regularization method. The paper concludes with examples of indirect image registration in 2D tomography with very sparse and/or highly noisy data.Comment: 43 pages, 4 figures, 1 table; revise

Solving ill-posed inverse problems using iterative deep neural networks

We propose a partially learned approach for the solution of ill posed inverse problems with not necessarily linear forward operators. The method builds on ideas from classical regularization theory and recent advances in deep learning to perform learning while making use of prior information about the inverse problem encoded in the forward operator, noise model and a regularizing functional. The method results in a gradient-like iterative scheme, where the "gradient" component is learned using a convolutional network that includes the gradients of the data discrepancy and regularizer as input in each iteration. We present results of such a partially learned gradient scheme on a non-linear tomographic inversion problem with simulated data from both the Sheep-Logan phantom as well as a head CT. The outcome is compared against FBP and TV reconstruction and the proposed method provides a 5.4 dB PSNR improvement over the TV reconstruction while being significantly faster, giving reconstructions of 512 x 512 volumes in about 0.4 seconds using a single GPU

EFFECT OF HUMIC ACID SEED TREATMENT ON YIELD AND SOME YIELD CHARACTERISTIC OF CORN PLANT (Zea mays L. indentata)

This study was aimed to determination of seed treated humic acid effects to yield and some yield characteristics of corn plant (Zea mays L. indentata) as grown second crop conditions. Study was set up according to randomized complete blocks experimental design with 3 replicates under Harran Plain conditions in 2012, Sanliurfa, Turkey. Motril hybrid corn variety was used as a plant material. Humic acid seed treatments were 0 (control), %2.5, %5, %7.5, %10, and %12 humic acid concentrations. Humic acid concentrations were applied to corn seed before sowing. Some yield and yield characteristic of corn plant such as tassel flowering duration, plant height, leaf number per plant, grain weight of ear, thousand kernel weights and grain yield were evaluated in the study. As a result of research; statistical significant differences were seen among humic acid seed treatments at tassel flowering duration and leaf number per plant (P≤0.05). Also, humic acid seed treatments were significant at grain weight of ear, thousand kernel weights and grain yield (P≤0.01). Tassel flowering duration decreased with humic acid seed treatment whereas leaf number per plant, grain weight of ear, thousand kernel weights and grain yield values increased with humic acid seed treatment. The highest values were found in % 7.5 humic acid seed treatment

Dual Metrics for a Class of Radiative Spacetimes

Second rank non-degenerate Killing tensors for some subclasses of spacetimes admitting parallel null one-planes are investigated. Lichn\'erowicz radiation conditions are imposed to provide a physical meaning to spacetimes whose metrics are described through their associated second rank Killing tensors. Conditions under which the dual spacetimes retain the same physical properties are presented.Comment: 8 pages, LaTeX, Minor revisions in the wording in Sec.5. Typo corrected in references. Journ.-ref adde

The social structure of Turkey and ombudsman

Değerli konuklar bütün gün dinledik çok şeyler öğrendik. Özellikle öğrencilerimize, pek soru sorma cesaretleri olmasa da sempozyumu sonuna kadar merakla izledikleri için teşekkür ediyorum. Hukukçu olarak amacımız Avrupa’da, dünyada neler olup bittiğini takip etmek, çağdaş çağcıl hukukçu olarak öğrencilerimizin bunlarla haşır neşir olması gerekiyor. Ben, tabi programın organizatörü olarak, bir takım işleri organize ettiğim için sürekli salonda bulunamadım, pek fazla takip olanağım olmadı

A Turkish mathematician of international repute:Cahit Arf

Taha Toros Arşivi, Dosya No: 357-Cahit ArfUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010