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Convergent Data-Driven Regularizations for CT Reconstruction

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1342-1368页

作者： Samira Kabri Alexander Auras Danilo Riccio Hartmut Bauermeister Martin Benning Michael Moeller Martin burger Helmholtz imaging Deutsches Elektronen-Synchrotron DESYNotkestr.8522607 HamburgGermany institute for Vision and Graphics University of SiegenAdolf-Reichwein-Straße 2a57076 SiegenGermany School of Mathematical Sciences Queen Mary University of LondonMile End RoadLondon E14NSUK The Alan Turing institute British Library96 Euston RdLondon NW12DBUK Fachbereich Mathematik Universitat HamburgBundesstrasse 5520146 HamburgGermany

The reconstruction of images from their corresponding noisy Radon transform is a typical example of an ill-posed linear inverse problem as arising in the application of computerized tomography(CT).As the(naive)solution does not depend on the measured data continuously,regularization is needed to reestablish a continuous *** this work,we investigate simple,but yet still provably convergent approaches to learning linear regularization methods from *** specifically,we analyze two approaches:one generic linear regularization that learns how to manipulate the singular values of the linear operator in an extension of our previous work,and one tailored approach in the Fourier domain that is specific to *** prove that such approaches become convergent regularization methods as well as the fact that the reconstructions they provide are typically much smoother than the training data they were trained ***,we compare the spectral as well as the Fourier-based approaches for CT-reconstruction numerically,discuss their advantages and disadvantages and investigate the effect of discretization errors at differentresolutions.

关键词： inverse problems Regularization Computerized tomography(CT) Machine learning

importance of Stewards and Other Protection Efforts for Conservation of Red Knots (Calidris canutus rufa) and Other Shorebirds on Delaware Bay, New Jersey

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Natural Science 2024年第9期16卷 162-182页

作者： Joanna burger Amanda Dey Larry Niles Division of Life Sciences Rutgers University Piscataway NJ USA Wildlife Restoration Partnerships 109 Market Lane Greenwich NJ USA

Understanding the factors that contribute to population stability in long-distance migrant birds is increasingly important, particularly given global climate change, sea level rise, and loss or disturbance at essential habitats. While the populations of most shorebirds are declining worldwide, those that migrate through Delaware Bay, New Jersey and Delaware, are declining at the most rapid rate despite conservation efforts. in this paper, we 1) provide background information on population declines of red knots (Calidris canutus rufa) using Delaware Bay, threats to their foraging, and efforts to reduce threats, 2) summarize briefly our studies of the effects of human activities on knots and other shorebirds, 3) present data on management efforts to protect knots and other shorebirds from the activities of people, and 4) discuss the efficacy of such efforts (usually referred to as “decreasing the effect of human disturbances”). The Shorebird Project on Delaware Bay is over 25 years old and provides long-term data to help assess the status of shorebird numbers, particularly for red knot, as well as the density of horseshoe crabs (Limulus polyphemus) and their eggs. Red knots have continued to decline even more precipitously in the last few years, presenting cause for concern. Protective efforts have been successful in reducing human disruption on the N.J. Delaware Bay beaches, but the lack of uniformity in implementation across the New Jersey side, and across the whole Bay have hampered further improvements. implementation of signs, fencing, and stewards on some beaches significantly enhanced the use of these beaches by red knots, determined by examining the use of beaches pre- and post-implementation. implementation of fencing and stewards had the greatest effect. From 1986 to 2018, there was a significant shift in the percent of Delaware Bay red knots using the NJ side, where protection efforts had been implemented on many of the beaches. Merely restricting access (w

关键词： Red Knot Calidris canutus rufa Conservation Beach Monitors Human Disturbance Habitat Restoration Management Stewards Education Population Declines Coastal

多个最高摄取体素的平均SUV的变异度低于SUVmax及SUVpeak

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国际医学放射学杂志 2014年第5期 508-508页

作者： E.Laffon F.Lamare H.de Clermont i.a.burger R.Marthan 黄育斌 Service de Médecine Nucléaire H?pital du Haut-LévèqueCHU de BordeauxAvenue de Magellan33604 PessacFrance

摘要目的通过改变18F-氟脱氧葡萄糖(18F-FDG)阳性病灶平均标准摄取值(SUV)测量的最高摄取体素的数量,来评估SUV的变异度。将SUV度量值和最大SUV(SUVmax:最

关键词：体素变异度 max peak SUV 平均

术前MR成像在持续性或复发性妇科恶性肿瘤的病人盆腔廓清术前的评估作用

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国际医学放射学杂志 2013年第6期 613-613页

作者： O.F.Donati Y.Lakhman E.Sala i.a.burger H.A.Vargas D.A.Goldman 卢暄郭琪 Department of Radiology Memorial Sloan-Kettering Cancer Center 1275 York AvenueNew York NY 10065 USA

摘要目的确定评估肿瘤范围的MRi诊断性能,并评价持续性或复发性妇科癌症盆腔廓清术前行MRi检查病人的存活率与MRi特征之间的相关性。材料与方法患有持续

关键词： MRi 盆腔廓清术复发性妇科恶性肿瘤诊断准确性预测性生物标志物

基于体积的定量FDGPET/CT指标与复发性卵巢癌病人接受再次手术的最佳肿瘤细胞减灭和无进展生存期的关系

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国际医学放射学杂志 2016年第1期 90-90页

作者： H.A.Vargas i.a.burger D.A.Goldman M.Miccò R.E.Sosa W.Weber 周竹萍 Department of Radiology Memorial Sloan Kettering Cancer Center

摘要目的旨在评估接受再次手术的复发性卵巢癌病人行定量18F-脱氧葡萄糖正电子发射体层成像（FDG-PET）的摄取指标,分析最佳肿瘤细胞减灭术（OD）和无进展生存期（PFS）之间的相关性。方法 55例复发性卵巢癌在术前90 d行FDG-PET/CT检查... 详细信息

摘要目的旨在评估接受再次手术的复发性卵巢癌病人行定量18F-脱氧葡萄糖正电子发射体层成像（FDG-PET）的摄取指标,分析最佳肿瘤细胞减灭术（OD）和无进展生存期（PFS）之间的相关性。方法 55例复发性卵巢癌在术前90 d行FDG-PET/CT检查。在PET上测量标准摄取值(SUVmax)、代谢活跃的肿瘤体积（MTV）和病灶总糖酵解值（TLG）。采用精确的logistic回归分析、Kaplan-Meier曲线和log-rank检验用来评估成像指标之间、OD和PFS之间的相关性。结果

关键词：肿瘤细胞减灭无进展生存再次手术卵巢癌卵巢恶性肿瘤卵巢肿瘤复发性病人 CT

Automated synthesis of steady-state continuous processes using reinforcement learning

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Frontiers of Chemical Science and Engineering 2022年第2期16卷 288-302页

作者： Quirin Göttl Dominik GGrimm Jakob burger Technical University of Munich Campus Straubing for Biotechnology and SustainabilityLaboratory of Chemical Process Engineering94315 StraubingGermany Technical University of Munich Campus Straubing for Biotechnology and Sustainability94315 StraubingGermany Weihenstephan-Triesdorf University of Applied Sciences 94315 StraubingGermany Technical University of Munich Department of Informatics85748 GarchingGermany

Automated flowsheet synthesis is an important field in computer-aided process *** present work demonstrates how reinforcement learning can be used for automated flowsheet synthesis without any heuristics or prior knowledge of conceptual *** environment consists of a steady-state flowsheet simulator that contains all physical *** agent is trained to take discrete actions and sequentially build up flowsheets that solve a given process problem.A novel method named SynGameZero is developed to ensure good exploration schemes in the complex ***,flowsheet synthesis is modelled as a game of two competing *** agent plays this game against itself during training and consists of an artificial neural network and a tree search for forward *** method is applied successfully to a reaction-distillation process in a quaternary system.

关键词： automated process synthesis flowsheet synthesis artificial intelligence machine learning reinforcement learning

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Numerical Approximation of Oscillatory Solutions of Hyperbolic-Elliptic Systems of Conservation Laws by Multiresolution Schemes

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Advances in Applied Mathematics and Mechanics 2009年第5期1卷 581-614页

作者： Stefan Berres Raimund burger Alice Kozakevicius Departamento de Ciencias Matematicas y Fısicas Universidad Catolica de TemucoTemucoChile Ci2MA and Departamento de ingenier´ıa Matem´atica Facultad de Ciencias Fısicas y Matem´aticasUniversidad de Concepci´onCasilla 160-CConcepci´onChile Departamento de Matematica-CCNE Universidade Federal de Santa MariaAv.Roraima1000Campus Universit´arioSanta MariaRSCEP 97105-900Brazil

The generic structure of solutions of initial value problems of hyperbolic-elliptic systems,also called mixed systems,of conservation laws is not yet fully *** reason for the absence of a core well-posedness theory for these equations is the sensitivity of their solutions to the structure of a parabolic regularization when attempting to single out an admissible solution by the vanishing viscosity *** is,however,theoretical and numerical evidence for the appearance of solutions that exhibit persistent oscillations,so-called oscillatory waves,which are(in general,measure-valued)solutions that emerge from Riemann data or slightly perturbed constant data chosen from the interior of the elliptic *** capture these solutions,usually a fine computational grid is *** this work,a version of the multiresolution method applied to a WENO scheme for systems of conservation laws is proposed as a simulation tool for the efficient computation of solutions of oscillatory wave *** hyperbolic-elliptic 2×2 systems of conservation laws considered are a prototype system for three-phase flow in porous media and a system modeling the separation of a heavy-buoyant bidisperse *** the latter case,varying one scalar parameter produces elliptic regions of different shapes and numbers of points of tangency with the borders of the phase space,giving rise to different kinds of oscillation waves.

关键词： Hyperbolic-elliptic system conservation law oscillation wave numerical simulation multiresolution method sedimentation model

A Diffusively Corrected Multiclass Lighthill-Whitham-Richards Traffic Model with Anticipation Lengths and Reaction Times

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Advances in Applied Mathematics and Mechanics 2013年第5期5卷 728-758页

作者： Raimund burger Pep Mulet Luis M.Villada Ci2MA and Departamento de ingenierıa Matematica Facultad de Ciencias Fısicas y MatematicasUniversidad de ConcepcionCasilla 160-CConcepcionChile Departament de Matematica Aplicada Universitat de ValenciaAv.Dr.Moliner 50E-46100 BurjassotSpain

Multiclass Lighthill-Whitham-Richards trafficmodels[Benzoni-Gavage and Colombo,***.,14(2003),pp.587–612;Wong and Wong,***.A,36(2002),pp.827–841]give rise to first-order systems of conservation laws that are hyperbolic under usual conditions,so that their associated Cauchy problems are *** lengths and reaction times can be incorporated into these models by adding certain conservative second-order terms to these first-order conservation *** terms can be diffusive under certain circumstances,thus,in principle,ensuring the stability of the *** purpose of this paper is to analyze the stability of these diffusively correctedmodels under varying reaction times and anticipation *** is demonstrated that instabilities may develop for high reaction times and short anticipation lengths,and that these instabilities may have controlled frequencies and amplitudes due to their nonlinear nature.

关键词： Traffic flow multispecies model anticipation length reaction time diffusive correction quasilinear system of second-order PDEs stability numerical simulation

Evolution of gastroenterology training

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World Journal of Gastroenterology 2009年第15期15卷 1793-1798页

作者： Hanna Telleman Trevlyn Felicity burger Chris Jacob Johan Mulder Department of Gastroenterology and Hepatology VU Medical Center Department of Gastroenterology Witwatersrand University

There have been rapid developments in gastroenterology(GE)over the last *** until the late 1980s,GE-training was incorporated in internal Medicine *** introduction of endoscopy has necessitated the need for additional *** the world different national boards have developed their own curricula which will be discussed in this paper. Emphasis will be placed on the curriculum recently introduced in The *** internal medicine component has become a two-year requirement (Common Trunk)and the duration of training in GE has been extended to four *** of the growing complexity of GE,there are now four subspecialties:interventional Endoscopy,Neuromotility, Oncology and Hepatology that trainees can choose *** subspecialties each have predefined specific *** World Gastroenterology Organization has drawn up a standard curriculum which can be of help to the boards in different countries. The curriculum emphasizes the knowledge and skill *** curriculum also defines the training recommendations,the requirements of training facilities and competence evaluation of fellows and facilities,while less is said about research,finance and the number of gastroenterologists *** the coming decades the curriculum will need to be revised *** of the curriculum will be the next challenge for the years to come.

关键词： Career Common Trunk Curriculum Endoscopy Fellow Fellowship Gastroenterology Hepatology Program Training