scholarly journals Phase retrieval in frame theory

2020 ◽  
Author(s):  
◽  
Dorsa Ghoreishi
Keyword(s):  
Phase Retrieval ◽  
Complete Classification ◽  
Frame Theory ◽  
Weak Phase ◽  
The Relationship

This dissertation is the study of phase retrieval in frame theory. The first part is concerned with the analysis of phase retrieval and the complete classification of norm retrieval. Norm retrieval is essential to transfer the properties of phase retrieval to the complement space. The first section includes the results regarding projections and also the characterization of phase retrieval and norm retrieval for subspaces. The second part is the study of weak phase retrieval which was motivated by the idea of reducing the number of vectors satisfying the properties close to phase retrieval. The last section provides the correlation between weak phase retrieval and phase retrieval properties along with the examples illustrating the relationship between weak phase retrieval and the related concepts.

scholarly journals Are Virtual Particles Less Real?

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 141 ◽  
Author(s):  
Gregg Jaeger
Keyword(s):  
Quantum Field ◽  
Interacting Particles ◽  
Virtual Particles ◽  
Quantum Particles ◽  
Action At A Distance ◽  
Relationship Of ◽  
The Relationship

The question of whether virtual quantum particles exist is considered here in light of previous critical analysis and under the assumption that there are particles in the world as described by quantum field theory. The relationship of the classification of particles to quantum-field-theoretic calculations and the diagrammatic aids that are often used in them is clarified. It is pointed out that the distinction between virtual particles and others and, therefore, judgments regarding their reality have been made on basis of these methods rather than on their physical characteristics. As such, it has obscured the question of their existence. It is here argued that the most influential arguments against the existence of virtual particles but not other particles fail because they either are arguments against the existence of particles in general rather than virtual particles per se, or are dependent on the imposition of classical intuitions on quantum systems, or are simply beside the point. Several reasons are then provided for considering virtual particles real, such as their descriptive, explanatory, and predictive value, and a clearer characterization of virtuality—one in terms of intermediate states—that also applies beyond perturbation theory is provided. It is also pointed out that in the role of force mediators, they serve to preclude action-at-a-distance between interacting particles. For these reasons, it is concluded that virtual particles are as real as other quantum particles.

Periods for Continuous Self-Maps of the Figure-Eight Space

2003 ◽  
Vol 13 (07) ◽  
pp. 1743-1754 ◽  
Author(s):  
Jaume Llibre ◽  
José Paraños ◽  
J. Ángel Rodríguez
Keyword(s):  
Euler Characteristic ◽  
Connected Graph ◽  
Complete Classification ◽  
Branching Points ◽  
Branching Point

Let 8 be the graph shaped like the number 8. This paper contains a characterization of all possible sets of periods for all continuous self-maps of 8 with the branching point fixed. We remark that this characterization is the first complete classification of the sets of periods for all continuous self-maps on a connected graph with negative Euler characteristic with fixed branching points.

Studies in the Epic Poem Godefroi de Bouillon

PMLA ◽  
1913 ◽  
Vol 28 (1) ◽  
pp. 56-78
Author(s):  
Hugh A. Smith
Keyword(s):  
Critical Edition ◽  
Complete Classification ◽  
Spanish Version ◽  
Epic Poem ◽  
Relationship Of ◽  
The Relationship ◽  
Exact Relationship

The only one who has attempted any very complete classification of the mss. of Godefroi de Bouillon is Pigeonneau, in his work mentioned above, Le Cycle de la Croisade, where are summed up also most of the earlier studies in this field. He has considered all the important mss. and versions that I have given above, except the Bern ms. No. 627, marked S. However, the classification of Pigeonneau is far from sufficient for our purposes. Pigeonneau's purpose was to point out the various versions contained in these mss., rather than to determine their exact relationship to each other, and the proper measure of authority due to each in a critical edition of the text or in the settlement of disputed readings. In general, then, his classification is based on the contents of the mss., the various additions and omissions of each, and not usually, it would seem, on a close line for line comparison. It is, moreover, made for the entire cycle, and the relationship of the various mss. in each of the separate branches is not always specified. This relationship may vary from branch to branch. However, the chief insufficiency, for our use, of Pigeonneau's classification, in addition to that coming necessarily from his different purpose, is his very slight treatment of the Spanish version, and the fact that he did not treat at all ms. S. Both of these are of prime importance in any exact classification of the mss.; and to determine our passages particularly, it is absolutely necessary to know their relationship to the others. Nevertheless, Pigeonneau's classification has been of use as far as it has extended. I shall, then, summarize his results, to show what had been done already, and to bring out as well what remained to be done.

On independent permutation separability criteria

2006 ◽  
Vol 6 (3) ◽  
pp. 277-288
Author(s):  
L. Clarisse ◽  
P. Wocjan
Keyword(s):  
Complete Classification ◽  
Necessary Condition ◽  
Numerical Verification ◽  
Separability Criteria

Recently, P.\ Wocjan and M.\ Horodecki [Open Syst.\ Inf.\ Dyn.\ 12, 331 (2005)] gave a characterization of combinatorially independent permutation separability criteria. Combinatorial independence is a necessary condition for permutations to yield truly independent criteria meaning that no criterion is strictly stronger that any other. In this paper we observe that some of these criteria are still dependent and analyze why these dependencies occur. To remove them we introduce an improved necessary condition and give a complete classification of the remaining permutations. We conjecture that the remaining class of criteria only contains truly independent permutation separability criteria. Our conjecture is based on the proof that for two, three and four parties all these criteria are truly independent and on numerical verification of their independence for up to 8 parties. It was commonly believed that for three parties there were 9 independent criteria, here we prove that there are exactly 6 independent criteria for three parties and 22 for four parties.

The leucine-responsive regulatory protein (lrp) gene for characterization of the relationship among Xanthomonas species

2004 ◽  
Vol 54 (2) ◽  
pp. 429-437 ◽  
Author(s):  
Jaime Cubero ◽  
James H. Graham
Keyword(s):  
Xanthomonas Campestris ◽  
Regulatory Protein ◽  
Amino Acid Level ◽  
Gene Sequences ◽  
Xanthomonas Species ◽  
Entire Sequence ◽  
The Relationship

Characterization of strains of Xanthomonas axonopodis pv. citri by using DNA fingerprints that were generated from primers for enterobacterial repetitive intergenic consensus (ERIC) elements led to the discovery of differential sequences for a leucine-responsive regulatory protein (lrp) gene in two subgroups of strains with different host ranges on Citrus spp. DNA hybridization and PCR-based assays that used different sets of primers were designed to detect the core sequence, as well as to obtain the entire sequence of the lrp gene for several Xanthomonas species and pathovars. Higher variability was observed at the nucleotide level than at the amino acid level among the different species and pathovars, revealing selection pressure on the lrp gene, which is presumably due to an essential role of the gene in bacterial metabolism. Moderate variability in the 3′ and 5′ domains was used to study relationships among different species within the genus Xanthomonas. Species of this genus that were isolated from citrus, as well as other pathovars of X. axonopodis, showed highly similar lrp gene sequences, whereas other Xanthomonas species, especially Xanthomonas campestris, had sequences that were more dissimilar to that of X. axonopodis. Thus, the lrp gene sequence is useful to distinguish X. axonopodis pv. citri groups and promising for polyphasic taxonomic analysis of the genus Xanthomonas. Data from analysis of lrp gene sequences support the current concepts for classification of xanthomonads, which are based on other approaches.

scholarly journals A influência de variáveis contextuais e situacionais na classificação de árbitros de futebol de elite

2021 ◽  
Vol 21 (1) ◽  
pp. 216-224
Author(s):  
Vitor Carvalho ◽  
Pedro Tiago Esteves ◽  
Célia Nunes ◽  
César Mendez ◽  
Bruno Travassos
Keyword(s):  
Significant Influence ◽  
Contextual Factors ◽  
Ordinal Regression ◽  
Contextual Variables ◽  
Situational Variables ◽  
Logit Function ◽  
The Relationship

Objetivo: Este estudo teve como objetivo avaliar a relação entre a classificação de árbitros de futebol de elite e variáveis contextuais e situacionais que caraterizam os jogos arbitrados no decorrer de uma época. Para tal, foi realizada uma regressão ordinal com função Link Logit entre a classificação final e variáveis contextuais e situacionais. As variáveis contextuais revelaram um efeito significativo sobre a classificação final, não se verificando efeitos significativos das variáveis situacionais, sobre a classificação dos árbitros no final da época desportiva. Na globalidade o modelo revelou-se estatisticamente significativo. A probabilidade de obtenção de melhor classificação final dos árbitros aumenta 54.2% com o aumento do número de jogos realizados na I Liga e aumenta 24.8% com aumento do número de jogos equilibrados. Diminui 61.2% com jogos realizados sem equipas Top 3. Os resultados reforçam a influência significativa que os fatores contextuais têm sobre a classificação e avaliação de um árbitro no final da época desportiva. This study aimed to evaluate the relationship between the classification of elite soccer referees in Portugal and the contextual and situational variables of the matches refereed during the 2016-2017 sports season. In order to analyze the relationship between the final classification and the level of the competition, characterization of the game, result of the game and total number of cards displayed per game, an ordinal regression with Link Logit function was used. The results revealed that the contextual variables have a significant effect on the final classification, with no significant effects of the situational variables. In general, the model statistically explains the final classification of the elite soccer referees at the end of the sports season (X2LP (5) = 40.299, p<0.001). The probability of obtaining a better final referees’ classification increases 54.2% with the increase in the number of games played in the I League (OR=1.542), and 24.8% with the increase in the number of balanced games (OR=1.248). Decreases 61.2% with the increase in the number of games without TOP 3(OR=0.388). Finally, in relation to the total number of cards displayed in a game, there were no significant effects on the ranking of referees' performance. In summary, the results reinforce the significant influence that contextual factors have on the classification and assessment of a referee at the end of the sports season. Este trabalho teve como objetivo avaliar a relação entre a classificação dos árbitros de futebol de elite em Portugal e as variáveis contextuais e situacionais dos jogos arbitrados no decorrer da época desportiva 2016-2017. No sentido de analisar qual a relação entre a classificação final e o nível da competição, caraterização do jogo, resultado do jogo e número total de cartões exibidos por jogo foi realizada uma regressão ordinal com função Link Logit. Os resultados, revelaram que as variáveis contextuais, apresentam um efeito significativo sobre a classificação final, não se verificando efeitos significativos das variáveis situacionais, sobre a classificação final dos árbitros de futebol no final da época desportiva. Na globalidade o modelo revelou-se estatisticamente significativo (X2LP (5) = 40.299, p<0.001). A probabilidade de obtenção de melhor classificação final dos árbitros aumenta 54.2% com o aumento do número de jogos realizados na I Liga (OR=1.542) e aumenta 24.8% com aumento do número de jogos equilibrados (OR=1.248). Diminui 61.2% com jogos realizados sem equipas Top 3 (OR=0.388). Por último, em relação ao número total de cartões exibidos num jogo não se verificaram efeitos significativos no ranking de desempenho dos árbitros. Em suma, os resultados reforçam a influência significativa que os fatores contextuais têm uma sobre a classificação e avaliação de um árbitro no final da época desportiva.

scholarly journals Symmetry Classification of First Integrals for Scalar Linearizable Second-Order ODEs

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
K. S. Mahomed ◽  
E. Momoniat
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Complete Classification ◽  
First Integrals ◽  
Second Order ◽  
Point Transformations ◽  
Maximal Algebra ◽  
The Relationship ◽  
Linear Odes

Symmetries of the fundamental first integrals for scalar second-order ordinary differential equations (ODEs) which are linear or linearizable by point transformations have already been obtained. Firstly we show how one can determine the relationship between the symmetries and the first integrals of linear or linearizable scalar ODEs of order two. Secondly, a complete classification of point symmetries of first integrals of such linear ODEs is studied. As a consequence, we provide a counting theorem for the point symmetries of first integrals of scalar linearizable second-order ODEs. We show that there exists the 0-, 1-, 2-, or 3-point symmetry cases. It is shown that the maximal algebra case is unique.

scholarly journals Geometric Classification of Graph C*-algebras over Finite Graphs

2018 ◽  
Vol 70 (2) ◽  
pp. 294-353 ◽  
Author(s):  
Søren Eilers ◽  
Gunnar Restorff ◽  
Efren Ruiz ◽  
Adam P.W. Sørensen
Keyword(s):  
Standard Condition ◽  
Classification Problem ◽  
Complete Classification ◽  
Type I ◽  
Simple Graphs ◽  
Finite Graphs ◽  
C Algebras ◽  
Special Case

AbstractWe address the classification problem for graph C*-algebras of finite graphs (finitely many edges and vertices), containing the class of Cuntz-Krieger algebras as a prominent special case. Contrasting earlier work, we do not assume that the graphs satisfy the standard condition (K), so that the graph C*-algebras may come with uncountably many ideals.We find that in this generality, stable isomorphism of graph C*-algebras does not coincide with the geometric notion of Cuntz move equivalence. However, adding a modest condition on the graphs, the two notions are proved to be mutually equivalent and equivalent to the C*-algebras having isomorphicK-theories. This proves in turn that under this condition, the graph C*-algebras are in fact classifiable byK-theory, providing, in particular, complete classification when the C* - algebras in question are either of real rank zero or type I/postliminal. The key ingredient in obtaining these results is a characterization of Cuntz move equivalence using the adjacency matrices of the graphs.Our results are applied to discuss the classification problem for the quantumlens spaces defined by Hong and Szymański, and to complete the classification of graph C*-algebras associated with all simple graphs with four vertices or less.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

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