scholarly journals A New Class of Scaling Matrices for Scaled Trust Region Algorithms

2019 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Aidin Ayanzadeh ◽  
Shokoufeh Yazdanian ◽  
Ehsan Shahamatnia
Keyword(s):  
Convex Combination ◽  
Trust Region ◽  
Test Problems ◽  
Affine Scaling ◽  
New Class ◽  
Trust Region Algorithms ◽  
Essential Properties ◽  
Simple Bounds ◽  
Scaling Matrix ◽  
The Individual

A new class of affine scaling matrices for the interior point Newton-type methods is considered to solve the nonlinear systems with simple bounds. We review the essential properties of a scaling matrix and consider several well-known scaling matrices proposed in the literature. We define a new scaling matrix that is the convex combination of these matrices. The proposed scaling matrix inherits those interesting properties of the individual matrices and satisfies all the desired requirements. The numerical experiments demonstrate the superiority of the new scaling matrix in solving several important test problems.

A Regularized Affine-Scaling Trust-Region Method for Parametric Imaging of Dynamic PET Data

2021 ◽  
Vol 14 (1) ◽  
pp. 418-439
Author(s):  
S. Crisci ◽  
M. Piana ◽  
V. Ruggiero ◽  
M. Scussolini
Keyword(s):  
Trust Region Method ◽  
Trust Region ◽  
Affine Scaling ◽  
Parametric Imaging ◽  
Dynamic Pet ◽  
Region Method

Foundation for Model Integration: Semantic Backplane

2012 ◽  
Author(s):  
Gabor Simko ◽  
Tihamer Levendovszky ◽  
Sandeep Neema ◽  
Ethan Jackson ◽  
Ted Bapty ◽  
...  
Keyword(s):  
Design Flow ◽  
Model Transformations ◽  
Model Integration ◽  
Mathematical Framework ◽  
Modeling Languages ◽  
Tool Chain ◽  
Model Based ◽  
Essential Properties ◽  
The Individual ◽  
Term Algebra

One of the primary goals of the Adaptive Vehicle Make (AVM) program of DARPA is the construction of a model-based design flow and tool chain, META, that will provide significant productivity increase in the development of complex cyber-physical systems. In model-based design, modeling languages and their underlying semantics play fundamental role in achieving compositionality. A significant challenge in the META design flow is the heterogeneity of the design space. This challenge is compounded by the need for rapidly evolving the design flow and the suite of modeling languages supporting it. Heterogeneity of models and modeling languages is addressed by the development of a model integration language – CyPhy – supporting constructs needed for modeling the interactions among different modeling domains. CyPhy targets simplicity: only those abstractions are imported from the individual modeling domains to CyPhy that are required for expressing relationships across sub-domains. This “semantic interface” between CyPhy and the modeling domains is formally defined, evolved as needed and verified for essential properties (such as well-formedness and invariance). Due to the need for rapid evolvability, defining semantics for CyPhy is not a “one-shot” activity; updates, revisions and extensions are ongoing and their correctness has significant implications on the overall consistency of the META tool chain. The focus of this paper is the methods and tools used for this purpose: the META Semantic Backplane. The Semantic Backplane is based on a mathematical framework provided by term algebra and logics, incorporates a tool suite for specifying, validating and using formal structural and behavioral semantics of modeling languages, and includes a library of metamodels and specifications of model transformations.

Improved Trust Region Based MPS Method for High-Dimensional Expensive Black-Box Problems

2013 ◽  
Author(s):  
George H. Cheng ◽  
Adel Younis ◽  
Kambiz Haji Hajikolaei ◽  
G. Gary Wang
Keyword(s):  
Optimization Problems ◽  
Trust Region ◽  
Black Box ◽  
High Dimensional ◽  
Test Problems ◽  
Design Variables ◽  
Low Dimensionality ◽  
Improve Algorithm ◽  
Improved Performance ◽  
Better Than

Mode Pursuing Sampling (MPS) was developed as a global optimization algorithm for optimization problems involving expensive black box functions. MPS has been found to be effective and efficient for problems of low dimensionality, i.e., the number of design variables is less than ten. A previous conference publication integrated the concept of trust regions into the MPS framework to create a new algorithm, TRMPS, which dramatically improved performance and efficiency for high dimensional problems. However, although TRMPS performed better than MPS, it was unproven against other established algorithms such as GA. This paper introduces an improved algorithm, TRMPS2, which incorporates guided sampling and low function value criterion to further improve algorithm performance for high dimensional problems. TRMPS2 is benchmarked against MPS and GA using a suite of test problems. The results show that TRMPS2 performs better than MPS and GA on average for high dimensional, expensive, and black box (HEB) problems.

scholarly journals Nanophosphors-Based White Light Sources

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1048 ◽  
Author(s):  
Maura Cesaria ◽  
Baldassare Di Bartolo
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Volume Ratio ◽  
Light Sources ◽  
Co Doping ◽  
New Class ◽  
Luminescence Efficiency ◽  
Metal Doped ◽  
The Individual ◽  
The Impact

Miniaturization requests and progress in nanofabrication are prompting worldwide interest in nanophosphors as white-emission mercury-free lighting sources. By comparison with their bulk counterparts, nanophosphors exhibit reduced concentration quenching effects and a great potential to enhance luminescence efficiency and tunability. In this paper, the physics of the nanophoshors is overviewed with a focus on the impact of spatial confinement and surface-to-volume ratio on the luminescence issue, as well as rare earth-activated multicolor emission for white light (WL) output. In this respect, the prominently practiced strategies to achieve WL emission are single nanophosphors directly yielding WL by means of co-doping and superposition of the individual red, green, and blue emissions from different nanophosphors. Recently, a new class of efficient broadband WL emitting nanophosphors has been proposed, i.e., nominally un-doped rare earth free oxide (yttrium oxide, Y2O3) nanopowders and Cr transition metal-doped garnet nanocrystals. In regard to this unconventional WL emission, the main points are: it is strictly a nanoscale phenomenon, the presence of an emitting center may favor WL emission without being necessary for observing it, and, its inherent origin is still unknown. A comparison between such an unconventional WL emission and the existing literature is presented to point out its novelty and superior lighting performances.

scholarly journals Examination of Future Psychologists Empathy Level

2019 ◽  
Vol 39 (1) ◽  
pp. 13-17
Author(s):  
S. Dmitrieva ◽  
O. Machushnyk
Keyword(s):  
Moral Development ◽  
Interpersonal Relations ◽  
Value Orientations ◽  
Successful Implementation ◽  
Prosocial Behaviour ◽  
Essential Properties ◽  
The Individual ◽  
Further Development ◽  
Different Levels

In current conditions, the priority of young people's preparation for life and work is especially important. Consequently, the requirements for the training of a future psychologist are also changing. One of the essential properties of a psychologist, necessary for the successful implementation of their activities, is empathy. The problem of empathy is one of the most difficult psychological sciences. The implacability of this phenomenon for researchers confirms the diversity in the definitions of its essence, mechanisms, functions, the role of empathy in the personality moral development, prosocial behaviour, altruism, and others like that. The presence of the appropriate level of empathic properties of students-psychologists acts as a condition for the formation of their professional compliance. Subjective factors of empathy formation: value sphere of personality, type of interpersonal relations, level of self-centeredness, type of accentuation of character, types of attitudes to different spheres of life, level of subjective control. Therefore, in the article, empathy development is studied in students who get a psychologist's degree. It is determined that in general subjects have average empathy level. By dividing students into groups, according to their level of empathy, it has been established that different value orientations characterize boys with different levels of empathy. It is determined that the overwhelming majority of respondents have a mean self-centeredness level. It was found that the obtained data provide an opportunity for further development of empathy among students. As a result of our research, we are convinced that the objective factors for the formation of empathy are: the perception of other people, the maturity of the individual. Our research is not exhaustive; our further development will concern the deepening of the ideas about the empathy component of the personality of the future psychologist and the methods of its development.  

scholarly journals A randomized adaptive trust region line search method

2020 ◽  
Vol 10 (2) ◽  
pp. 259-263
Author(s):  
Saman Babaie-Kafaki ◽  
Saeed Rezaee
Keyword(s):  
Simulated Annealing ◽  
Numerical Experiments ◽  
Line Search ◽  
Optimization Problems ◽  
Trust Region ◽  
Search Method ◽  
Test Problems ◽  
Unconstrained Optimization Problems ◽  
Line Search Method ◽  
Region Line

Hybridizing the trust region, line search and simulated annealing methods, we develop a heuristic algorithm for solving unconstrained optimization problems. We make some numerical experiments on a set of CUTEr test problems to investigate efficiency of the suggested algorithm. The results show that the algorithm is practically promising.

Sign in / Sign up

Export Citation Format

Share Document