An Efficient Nearest Point Projection Method Based on Improved Newton Iteration

2021 ◽  
pp. 215-228
Author(s):  
Long Qi ◽  
Dongxiang Xie ◽  
Yufei Pang ◽  
Yang Liu ◽  
Jianqiang Chen ◽  
...  
2005 ◽  
Vol 2005 (19) ◽  
pp. 3103-3110
Author(s):  
Somyot Plubtieng ◽  
Rattanaporn Punpaeng

SupposeCis a nonempty closed convex subset of real Hilbert spaceH. LetT:C→Hbe a nonexpansive non-self-mapping andPis the nearest point projection ofHontoC. In this paper, we study the convergence of the sequences{xn},{yn},{zn}satisfyingxn=(1−αn)u+αnT[(1−βn)xn+βnTxn],yn=(1−αn)u+αnPT[(1−βn)yn+βnPTyn], andzn=P[(1−αn)u+αnTP[(1−βn)zn+βnTzn]], where{αn}⊆(0,1),0≤βn≤β<1andαn→1asn→∞. Our results extend and improve the recent ones announced by Xu and Yin, and many others.


2018 ◽  
Vol 10 (02) ◽  
pp. 245-261
Author(s):  
Brian H. Bowditch ◽  
Francesca Iezzi

Let [Formula: see text] be a compact surface, and [Formula: see text] be the double of a handlebody. Given a homotopy class of maps from [Formula: see text] to [Formula: see text] inducing an isomorphism of fundamental groups, we describe a canonical uniformly Lipschitz retraction of the sphere graph of [Formula: see text] to the arc graph of [Formula: see text]. We also show that this retraction is a uniformly bounded distance from the nearest point projection map.


2020 ◽  
pp. 1-32 ◽  
Author(s):  
Elizaveta Vyacheslavovna Zipunova ◽  
Evgeny Borisovich Savenkov

1999 ◽  
Vol 5 (S2) ◽  
pp. 352-353
Author(s):  
Sterling P. Newberry

Recent advances with the cone-beam approach to tomography at the Advanced Microscopy and Imaging Laboratory (AMIL) have opened the possibility of employing tomography with the Shadow Projection X-Ray Microscope routinely when the specimen properties require it. The AMIL approach has been tested on small objects, without magnification, using conventional dental x-ray sources and a modestly diverging beam angle. The shadow projection Microscope, by contrast has a tenfold greater divergence and magnifies the specimen from unity to three or more orders of magnitude in resolution beyond the previous tests. The reader is reminded of the simplicity of the xray projection method and of the clarity of its images in fig. 1 and 2. The microscope can be operated in any laboratory and readily transported to alternate locations. Now that the AMIL data base and algorithms for tomography can be handled by a Pentium II processor the data gathering and reconstructions can also be managed at any laboratory installation.


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