On completion in the category SSNσFrm

2013 ◽  
Vol 63 (2) ◽  
Author(s):  
Inderasan Naidoo
Keyword(s):  
Similar Construction ◽  
Total Boundedness ◽  
Czechoslovak Math ◽  
Samuel Compactification ◽  
Phd Thesis ◽  
Uniform Frames

AbstractWe introduce the category SSN σ Frm of super strong nearness σ-frames and show the existence of a completion for a super strong nearness σ-frame unique up to isomorphism by the similar construction presented in [WALTERS-WAYLAND, J. L.: Completeness and Nearly Fine Uniform Frames. PhD Thesis, Univ. Catholique de Louvain, 1996] and [WALTERS-WAYLAND, J. L.: A Shirota Theorem for frames, Appl. Categ. Structures 7 (1999), 271–277]. Completion is also shown to be a coreflection in SSN σ Frm. We also engage with the notion of total boundedness for nearness σ-frames and provide a characterization of the Samuel compactification of a nearness σ-frame alternative to the description in [NAIDOO, I.: Samuel compactification and uniform coreflection of nearness σ-frames, Czechoslovak Math. J. 56(131) (2006), 1229–1241].

Samuel compactification and completion of uniform frames

1990 ◽  
Vol 108 (1) ◽  
pp. 63-78 ◽  
Author(s):  
B. Banaschewski ◽  
A. Pultr
Keyword(s):  
Uniform Space ◽  
The Other ◽  
Uniform Spaces ◽  
Samuel Compactification ◽  
Uniform Frame ◽  
The One ◽  
Uniform Frames

The aim of this paper is twofold: first, to construct the compact regular coreflection of uniform frames, that is, the frame counterpart of the Samuel compactification of uniform spaces (Samuel [10]), and then to use this for a new description of the completion of a uniform frame, as an alternative to those previously given by Isbell [6] on the one hand and Kříž [8] on the other. In addition, we present a few further results, as well as new proofs of known ones, that are naturally connected with completions and arise particularly easily from our approach to them. Most prominently among these, we identify the uniform space of minimal Cauchy filters of a uniform frame as the spectrum of its completion.

scholarly journals Φωτοκαταλυτική αναγωγή του νερού με χρήση διθειολενικών συμπλόκων

2016 ◽  
Author(s):  
Ευγενία Κουτσούρη
Keyword(s):  
Hydrogen Production ◽  
Visible Region ◽  
Electron Donors ◽  
Sodium Ascorbate ◽  
Synthesis And Characterization ◽  
Chemistry Department ◽  
Thermal Conductivity Detector ◽  
Ft Ir ◽  
Phd Thesis

This work was conducted within the PhD thesis in the field of Inorganic Chemistry andInorganic Technology, at the Inorganic Laboratory of the Chemistry Department of UoA. Itcovers literature photocatalytic systems for hydrogen production with homogeneousphotocatalysis, whereas experimental deals with the synthesis and characterization of complexesthat show strong absorptions in the visible region and could act as chromophores orphotocatalysts for hydrogen production. During this thesis complexes [Cu(4,4΄-dcbpy)2]Cl,where dcbpy=2,2'-bypiridine-4,4'-dicarboxylate and [Cu(5,5΄-dcbpy)2]Cl, where dcbpy=2,2'-bypiridine-5,5'-dicarboxylate, which can be used as proton reductive catalysts, have beensynthesized. Also, rhenium complexes have been prepared following the literature procedures:[Rebpy(CO)3Br], [Rebpy(CO)3Cl], [Rebpy(CO)3(MeCN)](PF6), [Rebpy(CO)3(NCS)](PF6),which can be used as chromophores. All these complexes were characterized byphysicochemical methods, FT-IR, UV-Vis, 1H-NMR, cyclic voltammetry (CV), andspectroscopy methods, emission. During this thesis the photocatalytic systems have been testedfor hydrogen production where the complexes [Rebpy(CO)3Br], [Rebpy(CO)3Cl],[Rebpy(CO)3(MeCN)](PF6), [Rebpy(CO)3(NCS)](PF6), [Ru(bpy)3]Cl2, [Ru(dcbpy)2Cl2],[Ru(dcbpy)2qdt] were used as photosensitizers (PS), the complexes [Ni{S2C2(Ph)2}2],[Ni{S2C2(Ph)2}2](NEt4), [Ni{S2C2(Ph)(Ph-OCH3-4)}2], [Ni{S2C2(Ph)(Ph-OCH3-4)}2](NEt4),[Ni{S2C2(Ph-OCH3-4)2}2], [Ni{S2C2(Ph-OCH3-4)2}2](NEt4), [Ni{S2C2(Ph)2}2C3],[Ni{S2C2(Ph)(Ph-OCH3-4)}2C3], [Ni{S2C2(Ph-OCH3-4)2}2C3], [Ni(bdt)2](TBA), [Ni(bdt)2C3],[Ni(S4C3)Fe(CO)Cp*](BF4), [W{S2C2(C6H5)2}3], [W{S2C2(C6H5)2}3](TBA), [Cu(4,4΄-dcbpy)2]Cl, and [Cu(5,5΄-dcbpy)2]Cl as proton reductive catalysts, and the speciestriethanolamine TEOA and ascorbic acid/sodium ascorbate as sacrificial electron donors. Σhesolvents used were DMF, DMF/ H2O, CH3CN/H2O, acetone, CH2Cl2, H2O. For the detection ofH2 a gas chromatographer with a thermal conductivity detector (TCD) was used.

scholarly journals Measures of noncompactness on w-distance spaces

2021 ◽  
Vol 25 (1) ◽  
pp. 63-69
Author(s):  
Aleksandar Kostić
Keyword(s):  
Measure Of Noncompactness ◽  
Metric Spaces ◽  
Measures Of Noncompactness ◽  
Generalized Metric Spaces ◽  
Generalized Metric ◽  
Open Question ◽  
Phd Thesis ◽  
New Framework

The aim of this paper is to provide a new framework for the study of measures of noncompactness in generalized metric spaces. Firstly, we introduce the notion of w-measure of noncompactness on metric spaces with a w-distance and extend the diameter and Kuratowski functionals to this setting. At the end we give a characterization of metric completeness via our main results, providing a new answer to the open question mentioned by Arandjelović in his PhD thesis [2].

scholarly journals Sign patterns of J-orthogonal matrices

2017 ◽  
Vol 5 (1) ◽  
pp. 225-241
Author(s):  
Frank J. Hall ◽  
Zhongshan Li ◽  
Caroline T. Parnass ◽  
Miroslav Rozložník
Keyword(s):  
Orthogonal Matrix ◽  
Orthogonal Matrices ◽  
Sign Patterns ◽  
Exchange Operator ◽  
Czechoslovak Math ◽  
Siam Review ◽  
G Matrices ◽  
Block Diagonal

Abstract This paper builds upon the results in the article “G-matrices, J-orthogonal matrices, and their sign patterns", Czechoslovak Math. J. 66 (2016), 653-670, by Hall and Rozloznik. A number of further general results on the sign patterns of the J-orthogonal matrices are proved. Properties of block diagonal matrices and their sign patterns are examined. It is shown that all 4 × 4 full sign patterns allow J-orthogonality. Important tools in this analysis are Theorem 2.2 on the exchange operator and Theorem 3.2 on the characterization of J-orthogonal matrices in the paper “J-orthogonal matrices: properties and generation", SIAM Review 45 (3) (2003), 504-519, by Higham. As a result, it follows that for n ≤4 all n×n full sign patterns allow a J-orthogonal matrix as well as a G-matrix. In addition, the 3 × 3 sign patterns of the J-orthogonal matrices which have zero entries are characterized.

scholarly journals MODIFIED EXTENDER BASED FORCING

2016 ◽  
Vol 81 (4) ◽  
pp. 1432-1443
Author(s):  
DIMA SINAPOVA ◽  
SPENCER UNGER
Keyword(s):  
Extender Based Forcing ◽  
Phd Thesis ◽  
Weak Square

AbstractWe analyze the modified extender based forcing from Assaf Sharon’s PhD thesis. We show there is a bad scale in the extension and therefore weak square fails. We also present two metatheorems which give a rough characterization of when a diagonal Prikry-type forcing forces the failure of weak square.

scholarly journals Parastrophically equivalent quasigroup equations

2010 ◽  
Vol 87 (101) ◽  
pp. 39-58 ◽  
Author(s):  
Aleksandar Krapez ◽  
Dejan Zivkovic
Keyword(s):  
Functional Equations ◽  
Complete Characterization ◽  
Cubic Graphs ◽  
Quadratic Equations ◽  
Phd Thesis

Fedir M. Sokhats'kyi recently posed four problems concerning parastrophic equivalence between generalized quasigroup functional equations. Sava Krstic in his PhD thesis established a connection between generalized quadratic quasigroup functional equations and connected cubic graphs. We use this connection to solve two of Sokhats'kyi's problems, giving also complete characterization of parastrophic cancellability of quadratic equations and reducing the problem of their classification to the problem of classification of connected cubic graphs. Further, we give formulas for the number of quadratic equations with a given number of variables. Finally, we solve all equations with two variables.

scholarly journals METRIC AND TOPOLOGICAL FREEDOM FOR SEQUENTIAL OPERATOR SPACES

2017 ◽  
Vol 20 (10) ◽  
pp. 55-67
Author(s):  
N.T. Nemesh ◽  
S.M. Shteiner
Keyword(s):  
Duality Theory ◽  
Operator Space ◽  
Space Theory ◽  
Operator Spaces ◽  
Normed Spaces ◽  
Full Characterization ◽  
Definition Of ◽  
Phd Thesis ◽  
Space Homology

In 2002 Anselm Lambert in his PhD thesis [1] introduced the definition of sequential operator space and managed to establish a considerable amount of analogs of corresponding results in operator space theory. Informally speaking, the category of sequential operator spaces is situated ”between” the categories of normed and operator spaces. This article aims to describe free and cofree objects for different versions of sequential operator space homology. First of all, we will show that duality theory in above-mentioned category is in many respects analogous to that in the category of normed spaces. Then, based on those results, we will give a full characterization of both metric and topological free and cofree objects.

Resolution and Quality Issues in 3D Analysis of Inscribed Signs: An Example from Cypro-Minoan Inscriptions

2022 ◽  
Vol 15 (1) ◽  
pp. 1-12
Author(s):  
Martina Polig ◽  
Sorin Hermon ◽  
Joachim Bretschneider
Keyword(s):  
Negative Impact ◽  
3D Models ◽  
3D Analysis ◽  
Error Treatment ◽  
Digital Documentation ◽  
Documentation Systems ◽  
3D Documentation ◽  
Phd Thesis ◽  
3D Digitization

A recurrent demand in many archaeological digital documentation systems is the need for an accurate as possible registration of data. Somehow, contrary to this request, are efforts led by various computer science groups dealing with 3D documentation and focusing on developing fast and cheap solutions to record 3D models of archaeological assets. The aim of the article is to highlight the importance of aligning the 3D documentation strategy to the archaeological aims, by detailing all factors to be considered when deciding on one documentation strategy over another. The archaeological question discussed here, part of the PhD thesis of one of the co-authors (MP), relates to the Cypro-Minoan signatory and its diachronic variability. The 3D geometric characterization of signs and subsequent shape analysis is the method chosen to reach this goal. A major effort to be invested in correctly determining the shape and variability of each sign, is in assuring that the 3D captured shape is as close as possible to the archaeological reality, which is a common problem not only in palaeographical analysis but also in other fields, where features of interest are in the sub-millimetre range. The paper will illustrate how different data acquisition approaches and post-processing steps such as alignment methods and error treatment may distort the visualised result and thus have a negative impact on planned analysis. Thus, it will argue for the importance of more detailed paradata to allow an informed assessment of the reliability of 3D models and it proposes a list of values and decision-making steps that help make the 3D digitization process more robust and verifiable.

scholarly journals Equationally complete varieties of generalized groups

1975 ◽  
Vol 13 (1) ◽  
pp. 75-83 ◽  
Author(s):  
W.F. Page
Keyword(s):  
Commutative Case ◽  
Universal Algebras ◽  
Associative Operation ◽  
Infinite Sets ◽  
University Of Miami ◽  
Phd Thesis ◽  
Special Case

In previous work, Page and Butson [Algebra Universalis 3 (1973), 112–126] characterized all equationally complete classes (atoms) of m–semigroups (universal algebras with one m–ary associative operation), and hence m–groups, in the commutative case. The further characterization of the non-commutative m-group atoms was thought to hinge upon a conjecture by Page [PhD thesis, University of Miami, 1973] that a weaker form of commutativity held true. In this paper that conjecture is proved and then used to study the special case m = 4. Two additional infinite sets of atoms are thereby determined, although it is not proved that these examples exhaust the remaining atoms for m = 4.

scholarly journals Grouplike minimal sets in ACFA AND in TA

2010 ◽  
Vol 75 (4) ◽  
pp. 1462-1488
Author(s):  
Alice Medvedev
Keyword(s):  
Algebraic Geometry ◽  
Algebraic Curve ◽  
Model Companion ◽  
Full Characterization ◽  
Closed Fields ◽  
Transcendental Theory ◽  
Phd Thesis ◽  
Algebraically Closed Fields ◽  
Injective Endomorphism

AbstractThis paper began as a generalization of a part of the author's PhD thesis about ACFA and ended up with a characterization of groups definable in TA. The thesis concerns minimal formulae of the form x Є A ∧ σ(x) = f(x) for an algebraic curve A and a dominant rational function f: A → σ(A). These are shown to be uniform in the Zilber trichotomy, and the pairs (A, f) that fall into each of the three cases are characterized. These characterizations are definable in families. This paper covers approximately half of the thesis, namely those parts of it which can be made purely model-theoretic by moving from ACFA, the model companion of the class of algebraically closed fields with an endomorphism, to TA, the model companion of the class of models of an arbitrary totally-transcendental theory T with an injective endomorphism, if this model-companion exists. A TA analog of the characterization of groups definable in ACFA is obtained in the process. The full characterization of the cases of the Zilber trichotomy in the thesis is obtained from these intermediate results with heavy use of algebraic geometry.

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