Strong Properties Research Articles

Butterfly points and hyperspace selections

If f is a continuous selection for the Vietoris hyperspace ℱ(X) of the nonempty closed subsets of a space X, then the point f(X)∊ X is not as arbitrary as it might seem at first glance. In this paper, we will characterise these points by local properties at them. Briefly, we will show that p=f(X) is a strong butterfly point precisely when it has a countable clopen base in cl(U) for some open set U⊂ X\{p} with cl(U)=U ∪ {p}. Moreover, the same is valid when X is totally disconnected at p=f(X) and p is only assumed to be a butterfly point. This gives the complete affirmative solution to a question raised previously by the author. Finally, when p=f(X) lacks the above local base-like property, we will show that ℱ(X) has a continuous selection h with the stronger property that h(S)=p for every closed S⊂X with p∈S.

Generalized Jensen and Jensen–Mercer inequalities for strongly convex functions with applications

Strongly convex functions as a subclass of convex functions, still equipped with stronger properties, are employed through several generalizations and improvements of the Jensen inequality and the Jensen–Mercer inequality. This paper additionally provides applications of obtained main results in the form of new estimates for so-called strong f-divergences: the concept of the Csiszár f-divergence for strongly convex functions f, together with particular cases (Kullback–Leibler divergence, χ2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\chi ^{2}$\\end{document}-divergence, Hellinger divergence, Bhattacharya distance, Jeffreys distance, and Jensen–Shannon divergence.) Furthermore, new estimates for the Shannon entropy are obtained, and new Chebyshev-type inequalities are derived.

Microwave-assisted synthesis and 99mTc-radiolabeling of anti-inflammatory active curcumin derivatives for inflammation diagnosis and therapy

AbstractUsing a one-pot cyclo-condensation process under microwave irradiation, derivatives of curcumin have been created. Evaluation their anti-inflammatory efficacy showed that they had stronger properties than curcumin. Additionally, the most active derivative was radiolabeled with the diagnostic radioisotope technetium-99m and prepared with a high radiochemical yield (96.5 ± 0.09%) and in vitro stability of up to 6 h. The in-vivo study in inflamed mice showed that [99mTc]Tc-curcumin derivative accumulated with a high target to non-target ratio. The gathered information confirmed the efficacy of the [99mTc]Tc-curcumin derivative as a novel possible tracer for the identification and localization of inflammation.

Exponential input-to-state stability for Lur’e systems via Integral Quadratic Constraints and Zames–Falb multipliers

Abstract Absolute stability criteria that are sufficient for global exponential stability are shown, under a Lipschitz assumption, to be sufficient for the a priori stronger exponential input-to-state stability property. Important corollaries of this result are as follows: (i) absolute stability results obtained using Zames–Falb multipliers for systems containing slope-restricted nonlinearities provide exponential input-to-state-stability under a mild detectability assumption; and (ii) more generally, many absolute stability results obtained via Integral Quadratic Constraint methods provide, with the additional Lipschitz assumption, this stronger property.

Enhancing ablation resistance of CuCr contact materials through metallic element doping: First-principles calculations

In this paper, a first-principles design approach for ablation-resistant contact materials was developed. Take Cu16Cr16 for example, the melting point was used as the criterion to screen the improved doped alloys, and mechanical properties were computed to guarantee that the designed doped alloys satisfy the contacts' operational requirements. This technique revealed that Cu16Cr15W1, Cu16Cr15Os1, and Cu16Cr13Co3 have stronger properties than Cu16Cr16 in terms of melting point and resistance to deformation, which can be utilized to enhance the ablation resistance and mechanical strength of the contacts. Simultaneously, the doped alloys' brittleness guarantees the welding resistance of the contacts. As a result, strengthening contact materials can be made from these doped alloys.

Extension of monotone operators and Lipschitz maps invariant for a group of isometries

Abstract We study monotone operators in reflexive Banach spaces that are invariant with respect to a group of suitable isometric isomorphisms, and we show that they always admit a maximal extension which preserves the same invariance. A similar result applies to Lipschitz maps in Hilbert spaces, thus providing an invariant version of Kirszbraun–Valentine extension theorem. We then provide a relevant application to the case of monotone operators in $L^{p}$ -spaces of random variables which are invariant with respect to measure-preserving isomorphisms, proving that they always admit maximal dissipative extensions which are still invariant by measure-preserving isomorphisms. We also show that such operators are law invariant, a much stronger property which is also inherited by their resolvents, the Moreau–Yosida approximations, and the associated semigroup of contractions. These results combine explicit representation formulae for the maximal extension of a monotone operator based on self-dual Lagrangians and a refined study of measure-preserving maps in standard Borel spaces endowed with a nonatomic measure, with applications to the approximation of arbitrary couplings between measures by sequences of maps.

Izod impact resistance of 3D printed discontinuous fibrous composites with Bouligand structure

The Bouligand structure found in the dactyl club of mantis shrimps is known for its impact resistance. However, Bouligand-inspired reinforced composites with 3D shapes and impact resistance characteristics have not yet been demonstrated. Herein, direct ink writing was used to 3D print composites reinforced with glass microfibers assembled into Bouligand structures with controllable pitch angles. The energy absorption levels of the Bouligand composites under impact were found to surpass those of composites with unidirectional microfiber alignment. Additionally, the Bouligand composites with a pitch angle of 40° exhibited a maximum energy absorption of 2.4 kJ/m2, which was 140% higher than that of the unidirectional composites. Furthermore, the characterization of the topography of the fractured surface, supplemented with numerical simulations, revealed a combination of crack twisting and crack bridging mechanisms. Flexural tests conducted on the composites with a pitch angle of 40° revealed that these composites had the strongest properties, including a flexural strength of 36.9 MPa, a stiffness of 2.26 GPa, and energy absorption of 8 kJ/m2. These findings are promising for the microstructural design of engineered composites using direct ink writing for applications in aerospace, transportation, and defense.

PENGARUH CORE HONEYCOMB KOMPOSIT SANDWICH TERHADAP KEKUATAN COMPRESS DENGAN METODE VACUUM BAGGING

Sandwich composites are a combination of two materials with different properties, when combined to form one material that has stronger properties and resistance than its constituent materials. This structure consists of a surface layer (skin) and a core (core). This study used fiberglass woven roving skin, core polylactid acid (PLA), and put together using polyester resin. One of the new technologies used today is 3D printing, which allows the manufacture of products with three-dimensional shapes. The research aims to produce new composite products by creating vertical and horizontally oriented variations of honeycomb cores, combined with PLA cores printed using 3D printing technology. The manufacturing process uses the vacuum bagging method because the process is simpler. The test is performed by flatwise compressive method to evaluate the resistance of the specimen to a given compression load. The test results showed that of the four vertically oriented honeycomb sandwich core composite specimens, the highest maximum compressive strength value was found in vertical honeycomb 3, reaching 61,310 MPa with a maximum load of 46434 N. Meanwhile, in the four horizontally oriented honeycomb sandwich core composite specimens, the highest maximum compressive strength value was found in horizontal honeycomb 2, reaching 15,265 MPa with a maximum load of 13603 N. From the test results It was concluded that the vertically oriented honeycomb sandwich core composite has superior structural strength

Strongly mixing systems are almost strongly mixing of all orders

AbstractWe prove that any strongly mixing action of a countable abelian group on a probability space has higher-order mixing properties. This is achieved via the utilization of $\mathcal R$ -limits, a notion of convergence which is based on the classical Ramsey theorem. $\mathcal R$ -limits are intrinsically connected with a new combinatorial notion of largeness which is similar to but has stronger properties than the classical notions of uniform density one and IP $^*$ . While the main goal of this paper is to establish a universal property of strongly mixing actions of countable abelian groups, our results, when applied to ${\mathbb {Z}}$ -actions, offer a new way of dealing with strongly mixing transformations. In particular, we obtain several new characterizations of strong mixing for ${\mathbb {Z}}$ -actions, including a result which can be viewed as the analogue of the weak mixing of all orders property established by Furstenberg in the course of his proof of Szemerédi’s theorem. We also demonstrate the versatility of $\mathcal R$ -limits by obtaining new characterizations of higher-order weak and mild mixing for actions of countable abelian groups.

PENGEMBANGAN MATERIAL KOMPOSIT TAHAN PANAS DENGAN MENGGUNAKAN METODE 3D PRINTING DAN HAND LAY UP


 Sandwich composites are a combination of two materials that have different properties which are then put together to have stronger properties and resistance than their constituents, consisting of the skin and the core. In this study, ceramic fiber blanket insulation was used, leather fiber, core polylactid acid (PLA) and united using merrhyl polyester resin. This research produces a new composite product with a honeycomb core combined with a core made of PLA which is printed with 3D printing, the manufacturing process is by using a hand lay up based on its superiority which is a simpler process, making heat resistant composites by combining ceramic fiber blanket fibers insulation and merrhyl polyester resin, in the thermal conductivity test and also the impact charpy obtained the results from the impact charpy test with a honeycomb core with a ratio of 50% fiber and 50% resin to get an impact on specimen 3 of 4,848j then on impact without skin only PLA got a value of 1.5034j in the thermal conductivity test with a time of 30s to get a Q1 temperature of 1.3130C in Q2 to get a result of 3540C in this study obtained a heat-resistant composite with a mixture of ceramic fiber blankets this insulating material is suitable for the temperature conditions from the results of this test fix what the impact results and also know the ceramic fiber blanket insulation fiber which is suitable for use in composite materials that require high temperatures.

PENGARUH KONFIGURASI STRUKTUR TERHADAP KEKUATAN BENDING DARI KOMPOSIT SANDWICH 3D PRINTING

Sandwich composites are a combination of two materials that have different properties which are then put together to have stronger properties and resistance than their constituents, consisting of the skin and the core. In this study using fiberglass skin, core polylactid acid (PLA) and put together using epoxy resin. One of the new technologies today is 3D printing by working to produce three-dimensional products. In this study, it was used to produce new composite products with variations of honeycomb and rectangular cores combined with 3D printing printed PLA cores. The manufacturing process using the hand lay up method is based on its superiority that the process is simpler. Bending test with the three point bending method is carried out in order to determine the resistance of the specimen to a given bending load. The results obtained after testing where of the three honeycomb cores 1, 2 and 3 obtained the highest bending stress value in honeycomb 2 of 10.732Mpa and a maximum load of 359.573N. Then on the three rectangular cores 1.2 and 3, the highest bending stress value is obtained in rectangular 2 of 10.456Mpa and the maximum load is 252.432N. From the test results it was found that the honeycomb sandwich core composite has superior structural strength compared to the rectangular sandwich core composite.

Linear optimization over homogeneous matrix cones

A convex cone is homogeneous if its automorphism group acts transitively on the interior of the cone. Cones that are homogeneous and self-dual are called symmetric. Conic optimization problems over symmetric cones have been extensively studied, particularly in the literature on interior-point algorithms, and as the foundation of modelling tools for convex optimization. In this paper we consider the less well-studied conic optimization problems over cones that are homogeneous but not necessarily self-dual.We start with cones of positive semidefinite symmetric matrices with a given sparsity pattern. Homogeneous cones in this class are characterized by nested block-arrow sparsity patterns, a subset of the chordal sparsity patterns. Chordal sparsity guarantees that positive define matrices in the cone have zero-fill Cholesky factorizations. The stronger properties that make the cone homogeneous guarantee that the inverse Cholesky factors have the same zero-fill pattern. We describe transitive subsets of the cone automorphism groups, and important properties of the composition of log-det barriers with the automorphisms.Next, we consider extensions to linear slices of the positive semidefinite cone, and review conditions that make such cones homogeneous. An important example is the matrix norm cone, the epigraph of a quadratic-over-linear matrix function. The properties of homogeneous sparse matrix cones are shown to extend to this more general class of homogeneous matrix cones.We then give an overview of the algebraic theory of homogeneous cones due to Vinberg and Rothaus. A fundamental consequence of this theory is that every homogeneous cone admits a spectrahedral (linear matrix inequality) representation.We conclude by discussing the role of homogeneous structure in primal–dual symmetric interior-point methods, contrasting this with the well-developed algorithms for symmetric cones that exploit the strong properties of self-scaled barriers, and with symmetric primal–dual methods for general convex cones.

Reciprocal properties of random fields on undirected graphs

AbstractWe clarify and refine the definition of a reciprocal random field on an undirected graph, with the reciprocal chain as a special case, by introducing four new properties: the factorizing, global, local, and pairwise reciprocal properties, in decreasing order of strength, with respect to a set of nodes $\delta$ . They reduce to the better-known Markov properties if $\delta$ is the empty set, or, with the exception of the local property, if $\delta$ is a complete set. Conditions for each reciprocal property to imply the next stronger property are derived, and it is shown that, conditionally on the values at a set of nodes $\delta_0$ , all four properties are preserved for the subgraph induced by the remaining nodes, with respect to the node set $\delta\setminus\delta_0$ . We note that many of the above results are new even for reciprocal chains.

W-extending and pw-extending Modules

In this work, we introduce and study two concepts of modules. Thefirst one is a generalization of extending modules which is called a wextending module. And the second concept is called pw-extendingmodule which is a stronger property than w-extending. We give basicproperties, example and characterization of these concepts. Moreoverrelationship of w-extending module and pw-extending modules withother types of modules are studied.

Decompositions of Augmented Bergman Complexes

The augmented Bergman complex of a closure operator on a finite set interpolates between the order complex of proper flats and the independence complex of the operator. In 2020, Braden, Huh, Matherne, Proudfoot, and Wang showed that augmented Bergman complexes of matroids are always gallery-connected, and recently Bullock, Kelley, Reiner, Ren, Shemy, Shen, Sun, Tao, and Zhang strengthened "gallery-connected" to "shellable" by providing two classes of shelling orders: "flag-to-basis" shellings and "basis-to-flag" shellings. 
 We show that augmented Bergman complexes of matroids are vertex decomposable, a stronger property than shellable. We also prove that the augmented Bergman complex of any closure operator is shellable if and only if the order complex of its lattice of flats (that is, its non-augmented Bergman complex) is shellable. As a consequence, an augmented Bergman complex is shellable if and only if it admits a flag-to-basis shelling. Perhaps surprisingly, the same does not hold for basis-to-flag shellings: we describe a closure operator whose augmented Bergman complex is shellable, but has no shelling order with bases appearing first.

Internal indecomposability of profinite groups

It is well-known that various profinite groups appearing in anabelian geometry — e.g., the absolute Galois groups of p-adic local fields or number fields — satisfy distinctive group-theoretic properties such as slimness [i.e., the property that every open subgroup is center-free] and strong indecomposability [i.e., the property that every open subgroup has no nontrivial product decomposition]. In the present paper, we consider another group-theoretic property on profinite groups, which we shall refer to as strong internal indecomposability. This is a stronger property than both slimness and strong indecomposability. In the present paper, we examine basic properties of strong internal indecomposability and prove that the absolute Galois groups of Henselian discrete valuation fields with positive characteristic residue fields or Hilbertian fields [which may be regarded as generalizations of p-adic local fields or number fields] satisfy strong internal indecomposability.

Bitcoin as a Safe-Haven Asset and a Medium of Exchange

A monetary model is established to introduce that bitcoin does have the characteristics of a price rise when the economic situation is terrible under high risk aversion. At this time, Bitcoin has the property of a safe-haven asset, and when economic conditions are good and risk aversion is low, Bitcoin has a pro-cyclical nature. At this time, Bitcoin has a stronger property as a medium of exchange. To show the movement law of the bitcoin price, we make a logarithmic linearization of the model and simulation, and the result is consistent with the theoretical analysis. To better understand the role of bitcoin in the real economy, several standard portfolio models are used to measure the similarities and differences between gold and bitcoin in an investment portfolio. After the outbreak of COVID-19, bitcoin has shown stronger safe-haven asset properties.

소유권 보호와 정치적 예산순환

This study examines the impact of property rights institutions on the political budget cycle. A simple equilibrium model of political budget cycles suggests that property rights institutions implicitly constrain the electoral cycle by making pre-election fiscal manipulation less effective in gaining votes. Using a panel of 64 democracies over the period 1987-2016, we confirm that a political budget cycle is conditional on the strength of property rights institutions. Countries with stronger property rights institutions experience a smaller electoral cycle. Our findings imply that property rights institutions may provide a socially efficient mechanism for protecting the welfare of taxpayers.

On Finite Homogeneous Metric Spaces

This survey is devoted to recently obtained results on finite homogeneousmetric spaces. The main subject of discussion is the classification of regular and semiregular polytopes in Euclidean spacesby whether or not their vertex sets have the normal homogeneity property or the Clifford - Wolf homogeneity property.Every finite homogeneous metric subspace of an Euclidean space represents the vertex set of a compact convex polytope with the isometry group that is transitive on the set of vertices, moreover, all these vertices lie on some sphere. Consequently, the study of such subsets is closely related to the theory of convex polytopes in Euclidean spaces. The normal generalized homogeneity and the Clifford - Wolf homogeneity describe more stronger properties than the homogeneity. Therefore, it is natural to first check the presence of these properties for the vertex sets of regular and semiregular polytopes. In addition to the classification results, the paper contains a description of the main tools for the study of the relevant objects.

Covering metric spaces by few trees

A tree cover of a metric space (X,d) is a collection of trees, so that every pair x,y∈X has a low distortion path in one of the trees. If it has the stronger property that every point x∈X has a single tree with low distortion paths to all other points, we call this a Ramsey tree cover. In this paper we devise efficient algorithms to construct tree covers and Ramsey tree covers for general, planar and doubling metrics. We pay particular attention to the desirable case of distortion close to 1, and study what can be achieved when the number of trees is small. In particular, our work shows a large separation between what can be achieved by tree covers vs. Ramsey tree covers.