Fundamental Objects Research Articles

Deriving a Control-Oriented Model for an Axisymmetric Vehicle With the Power-Law Revolution Nose

The purpose of this paper is to construct a new general vehicle model as an open fundamental material for the guidance and control research. In this study, parameterized configuration, aerodynamics calculation, control-oriented modeling, stability analysis, and nominal trajectory design are performed for the general vehicle model. First, the aerodynamic configuration is parameterized as an axisymmetric body with a power-law revolution nose. Then, an engineering method considering inviscid flow, base drag and skin friction is used for the aerodynamics calculation, and a control-oriented fitting model of longitudinal aerodynamics is established based on the analysis of the correlation between aerodynamic force and the parameters of Mach number, attack angle, elevator deflection and height. Next, the aerothermodynamic environment prediction of power-law revolution axisymmetric hypersonic vehicle (PRAHV) is discussed, and the nose heating rate formula of PRAHV is established. The stability analysis and nominal trajectory design of PRAHV is performed based on the fitting model and the heating rate formula. The stability analysis shows that both the static stability and dynamic stability of the vehicle are unstable. The nominal trajectory of unpowered longitudinal maneuvering is achieved by the hp-adaptive pseudospectral method, which demonstrated that the availability of the control-oriented model established in this paper. In conclusion, this work provides a fundamental object for further study of vehicle guidance, control, and evaluation.

TYPES OF TERRITORIAL COMMUNITIES IN WHICH A HUMAN – A MEMBER OF THE COMMUNITY FUNCTIONS

The article is devoted to the study of human participation as a member of the community in the existence and functioning of the territorial community. The article contains a description of the types of territorial communities, as well as their general features. The article defines the way a person functions as a member of the community in the territorial community. It is determined that the territorial communities of the primary level are those communities in which a person fully realizes his right to local self- government, including, first of all, the realization of their existential interests and other needs due to the implementation of human life cycle within the territorial community. , mainly in the ordinary implementation of statehood. It is noted that the activities of local councils and their executive bodies in the understanding of teleological guidelines are carried out on behalf of and in the interests of the respective territorial communities, so there is a clear methodological and procedural link that arises in the implementation of these rights and interests. This issue is quite relevant, because most local communities and their members focus and concretize their needs and interests through the formation of key issues of local importance, which is a fundamental object of the institution of local government and local government. It is determined that the possibilities of territorial communities to determine their own administrative structures are quite limited in Ukraine, they are quite exhaustively defined centrally – in the relevant Law of Ukraine "On Local Self-Government in Ukraine". In addition, the cities of Kyiv and Sevastopol have not yet established their own executive structures of local self-government, and their functions are entrusted to the relevant local state administrations. This significantly limits the implementation of the principle of organizational autonomy.

NuClick: A deep learning framework for interactive segmentation of microscopic images.

Object segmentation is an important step in the workflow of computational pathology. Deep learning based models generally require large amount of labeled data for precise and reliable prediction. However, collecting labeled data is expensive because it often requires expert knowledge, particularly in medical imaging domain where labels are the result of a time-consuming analysis made by one or more human experts. As nuclei, cells and glands are fundamental objects for downstream analysis in computational pathology/cytology, in this paper we propose NuClick, a CNN-based approach to speed up collecting annotations for these objects requiring minimum interaction from the annotator. We show that for nuclei and cells in histology and cytology images, one click inside each object is enough for NuClick to yield a precise annotation. For multicellular structures such as glands, we propose a novel approach to provide the NuClick with a squiggle as a guiding signal, enabling it to segment the glandular boundaries. These supervisory signals are fed to the network as auxiliary inputs along with RGB channels. With detailed experiments, we show that NuClick is applicable to a wide range of object scales, robust against variations in the user input, adaptable to new domains, and delivers reliable annotations. An instance segmentation model trained on masks generated by NuClick achieved the first rank in LYON19 challenge. As exemplar outputs of our framework, we are releasing two datasets: 1) a dataset of lymphocyte annotations within IHC images, and 2) a dataset of segmented WBCs in blood smear images.

Evidence-based Nomenclature and Taxonomy of Research Impact Indicators

Abstract Purpose This study aims to classify research impact indicators based on their characteristics and scope. A concept of evidence-based nomenclature of research impact (RI) indicator has been introduced for generalization and transformation of scope. Design/methodology/approch Literature was collected related to the research impact assessment. It was categorized in conceptual and applied case studies. One hundred and nineteen indicators were selected to prepare classification and nomenclature. The nomenclature was developed based on the principle—“every indicator is a contextual-function to explain the impact”. Every indicator was disintegrated into three parts, i.e. Function, Domain, and Target Areas. Findings The main functions of research impact indicators express improvement (63%), recognition (23%), and creation/development (14%). The focus of research impact indicators in literature is more towards the academic domain (59%) whereas the environment/sustainability domain is least considered (4%). As a result, research impact related to the research aspects is felt the most (29%). Other target areas include system and services, methods and procedures, networking, planning, policy development, economic aspects and commercialisation, etc. Research limitations This research applied to 119 research impact indicators. However, the inclusion of additional indicators may change the result. Practical implications The plausible effect of nomenclature is a better organization of indicators with appropriate tags of functions, domains, and target areas. This approach also provides a framework of indicator generalization and transformation. Therefore, similar indicators can be applied in other fields and target areas with modifications. Originality/value The development of nomenclature for research impact indicators is a novel approach in scientometrics. It is developed on the same line as presented in other scientific disciplines, where fundamental objects need to classify on common standards such as biology and chemistry.

Model of a solar system in the conservative geometry

Pandres has shown that an enlargement of the covariance group to the group of conservative transformations leads to a richer geometry than that of general relativity. Using orthonormal tetrads as field variables, the fundamental geometric object is the curvature vector denoted by \(C_\mu \). From an appropriate scalar Lagrangian field equations for both free-field and the field with sources have been developed. We first review models which use a free-field solution to model the Solar System and why these results are unacceptable. We also show that the standard Schwarzschild metric is also unacceptable in our theory. Finally we show that there are solutions which involve sources which agree with general relativity PPN parameters and thus approximate the Schwarzschild solution. The main difference is that the Einstein tensor is not identically zero but includes small values for the density, radial pressure and tangential pressure. Higher precision experiments should be able to determine the validity of these models. These results add further confirmation that the theory developed by Pandres is the fundamental theory of physics.

Free resolutions of function classes via order complexes

Function classes are collections of Boolean functions on a finite set, which are fundamental objects of study in theoretical computer science. We study algebraic properties of ideals associated to function classes previously defined by the third author. We consider the broad family of intersection-closed function classes, and describe cellular free resolutions of their ideals by order complexes of the associated posets. For function classes arising from matroids, polyhedral cell complexes, and more generally interval Cohen-Macaulay posets, we show that the multigraded Betti numbers are pure, and are given combinatorially by the Möbius functions. We then apply our methods to derive bounds on the VC dimension of some important families of function classes in learning theory.

Finsler geometries from topological electromagnetism

We analyse the Finsler geometries of the kinematic space of spinless and spinning electrically charged particles in an external Rañada field. We consider the most general actions that are invariant under the Lorentz, electromagnetic gauge and reparametrization transformations. The Finsler geometries form a set parametrized by the gauge fields in each case. We give a simple method to calculate the fundamental objects of the Finsler geometry of the kinematic space of a particle in a generic electromagnetic field. Then we apply this method to calculate the geodesic equations of the spinless and spinning particles. Also, we show that the electromagnetic duality in the Rañada background induces a simple dual map in the set of Finsler geometries. The duality map has a simple interpretation in terms of an electrically charged particle that interacts with the electromagnetic potential and a magnetically charged particle that interacts with the dual magnetoelectric potential. We exemplify the action of the duality map by calculating the dual geodesic equation.

Rank 4 finite-dimensional Nichols algebras of diagonal type in positive characteristic

Nichols algebras are fundamental objects in the construction of quantized enveloping algebras and in the classification of pointed Hopf algebras by lifting method of Andruskiewitsch and Schneider. Arithmetic root systems are invariants of Nichols algebras of diagonal type with a certain finiteness property. In the present paper, all rank 4 Nichols algebras of diagonal type with a finite arithmetic root system over fields of arbitrary characteristic are classified. Our proof uses the classification of the finite arithmetic root systems of rank 4.

P‐adic L‐functions on metaplectic groups

ith respect to the analytic‐algebraic dichotomy, the theory of Siegel modular forms of half‐integral weight is lopsided; the analytic theory is strong, whereas the algebraic lags behind. In this paper, we capitalise on this to establish the fundamental object needed for the analytic side of the Iwasawa main conjecture — the p ‐adic L ‐function obtained by interpolating the complex L ‐function at special values. This is achieved through the Rankin–Selberg method and the explicit Fourier expansion of non‐holomorphic Siegel Eisenstein series. The construction of the p ‐stabilisation in this setting is also of independent interest.

Prolegomena to a Semiotics of Experience. Memory, contexts and dialectic of sense

En la presente investigacion nos proponemos esbozar algunos de los temas que estimamos fundamentales en un programa para la constitucion de una Semiotica de la Experiencia. Para ello discutimos algunas propuestas de la Filosofia y la Antropologia y algunos conceptos cardinales de la Semiotica, con miras a darles una vision mas amplia, de modo que la experiencia, entendida como objeto fundamental de la investigacion semiotica, se articule a una teoria de los contextos, sin los cuales las semiosis textuales no existen o, simplemente, se ven limitadas y reducidas en su riqueza significativa.

A Formula for the Möbius Function of the Permutation Poset Based on a Topological Decomposition

The poset P of all permutations ordered by pattern containment is a fundamental object of study in the field of permutation patterns. This poset has a very rich and complex topology and an understanding of its Möbius function has proved particularly elusive, although results have been slowly emerging in the last few years. Using a variety of topological techniques we present a two term formula for the Mo ̈bius function of intervals in P. The first term in this formula is, up to sign, the number of so called normal occurrences of one permutation in another. Our definition of normal occurrences is similar to those that have appeared in several variations in the literature on the Möbius function of this and other posets, but simpler than most of them. The second term in the formula is (still) complicated, but we conjecture that it equals zero for a significant proportion of intervals. We present some cases where the second term vanishes and others where it is nonzero. Computing the Möbius function recursively from its definition has exponential complexity, whereas the computation of the first term in our formula is polynomial and the exponential part is isolated to the second term, which seems to often vanish. This is thus the first polynomial time formula for the Möbius function of what appears to be a large proportion of all intervals of P.

Protostellar disk formation by a nonrotating, nonaxisymmetric collapsing cloud: model and comparison with observations

Context. Planet-forming disks are fundamental objects that are thought to be inherited from large scale rotation through the conservation of angular momentum during the collapse of a prestellar dense core. Aims. We investigate the possibility for a protostellar disk to be formed from a motionless dense core that contains nonaxisymmetric density fluctuations. The rotation is thus generated locally by the asymmetry of the collapse. Methods. We study the evolution of the angular momentum in a nonaxisymmetric collapse of a dense core from an analytical point of view. To test the theory, we performed three-dimensional simulations of a collapsing prestellar dense core using adaptative mesh refinement. We started from a nonaxisymmetrical situation, considering a dense core with random density perturbations that follow a turbulence spectrum. We analyzed the emerging disk by comparing the angular momentum it contains with the one expected from our analytic development. We studied the velocity gradients at different scales in the simulation as is done with observations. Results. We show that the angular momentum in the frame of a stellar object, which is not located at the center of mass of the core, is not conserved due to inertial forces. Our simulations of such nonaxisymmetrical collapse quickly produce accretion disks at the small scales in the core. The analysis of the kinematics at different scales in the simulated core reveals projected velocity gradients of amplitudes similar to the ones observed in protostellar cores and for which directions vary, sometimes even reversing when small and large scales are compared. These complex kinematics patterns appear in recent observations and could be a discriminating feature with models where rotation is inherited from large scales. Our results from simulations without initial rotation are more consistent with these recent observations than when solid-body rotation is initially imprinted. Lastly, we show that the disks that formed in this scenario of nonaxisymmetrical gravitational collapse grow to reach sizes larger than those that are observed, and then fragment. We show that including a magnetic field in these simulations reduces the size of the outcoming disks and it prevents them from fragmenting, as is shown by previous studies. Conclusions. We show that in a nonaxisymmetrical collapse, the formation of a disk can be induced by small perturbations of the initial density field in the core, even in the absence of global large-scale rotation of the core. In this scenario, large disks are generic features that are natural consequences of the hydrodynamical fluid interactions and self-gravity. Since recent observations have shown that most disks are significantly smaller and have a size of a few tens of astronomical units, our study suggests that magnetic braking is the most likely explanation. The kinematics of our model are consistent with typically observed values of velocity gradients and specific angular momentum in protostellar cores. These results open a new avenue in which our understanding of the early phases of disk formation can be explored since they suggest that a fraction of the protostellar disks could be the product of nonaxisymmetrical collapse, rather than directly resulting from the conservation of preexisting large scale angular momentum in rotating cores.

Minimal and maximal lengths from position-dependent non-commutativity

Fring et al (2010 J. Phys. A: Math. Theor. 43 345401) have introduced a new set of noncommutative space-time commutation relations in two space dimensions. It had been shown that any fundamental objects introduced in this space-space noncommutativity are string-like. Taking this result into account, we generalize the seminal work of Fring et al to the case that there is also a maximal length from position-dependent noncommutativity and a minimal momentum arising from generalized versions of Heisenberg’s uncertainty relations. The existence of maximal length is related to the presence of an extra, first order term in particle’s length that provides the basic difference of our analysis with theirs. This maximal length breaks up the well known singularity problem of space time. We establish different representations of this noncommutative space and finally we study some basic and interesting quantum mechanical systems in these new variables.

On the Minimal Displacement Vector of Compositions and Convex Combinations of Nonexpansive Mappings

Monotone operators and (firmly) nonexpansive mappings are fundamental objects in modern analysis and computational optimization. It was shown in 2012 that if finitely many firmly nonexpansive mappings have or “almost have” fixed points, then the same is true for compositions and convex combinations. More recently, sharp information about the minimal displacement vector of compositions and of convex combinations of firmly nonexpansive mappings was obtained in terms of the displacement vectors of the underlying operators. Using a new proof technique based on the Brezis–Haraux theorem and reflected resolvents, we extend these results from firmly nonexpansive to general averaged nonexpansive mappings. Various examples illustrate the tightness of our results.

Smooth polyhedral surfaces

Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.

Nonmalleable Extractors and Codes, with Their Many Tampered Extensions

Randomness extractors and error correcting codes are fundamental objects in computer science. Recently, there have been several natural generalizations of these objects, in the context and study of...

Estudio Crítico sobre la Investigación Empírica de Maria Helena Wagner Rossi

Resumen: En el artículo se expone un estudio crítico sobre la investigación empírica de Maria Helena Wagner Rossi, llevada a cabo entre los años 1996-2004. Se partió de una investigación bibliográfica de carácter cualitativo, cuyo objeto de estudio fundamental lo constituyó la producción teórica de la autora sobre la naturaleza de la comprensión estético-visual de alumnos brasileños, con base en sus estudios empíricos. En el cuerpo del artículo se analizan tópicos tales como: las problemáticas concernientes a la enseñanza de las artes visuales de las que partió la autora; los objetivos y características generales de su pesquisa empírica; la manera en que fueron interpretados los datos, la epistemología involucrada y los resultados teóricos a los que arribó.

Monoidal Structures on the Categories of Quadratic Data

The notion of 2-monoidal category used here was introduced by B. Vallette in [J. Pure Appl. Algebra 208, No. 2, 699–725 (2007; Zbl 1109.18002); Trans. Am. Math. Soc. 359, No. 10, 4865–4943 (2007; Zbl 1140.18006)] for applications in the operadic context. The starting point for this article was a remark by Yu. Manin that in the category of quadratic algebras (that is,"quantum linear spaces") one can also define 2-monoidal structure(s) with rather unusual properties. Here we give a detailed exposition of these constructions, together with their generalisations to the case of quadratic operads. Their parallel exposition was motivated by the following remark. Several important operads/cooperads such as genus zero quantum cohomology operad, the operad classifying Gerstenhaber algebras, and more generally, (co)operads of homology/cohomology of some topological operads, start with collections of quadratic algebras/coalgebras rather than simply linear spaces. Suggested here enrichments of the categories to which components of these operads belong, as well of the operadic structures themselves, might lead to better understanding of these fundamental objects.

Про коронавірусну інфекцію COVID-19 в українських та європейських енциклопедіях

Today, humans have the phase of the social organization evolution, in which information, communication technologies, and knowledge are fundamental objects of production, as well as the digital environment is an important space for the development of society. There are problems of people’s digital literacy actualized by the increasing role of the existing and growing in information and knowledge in society from Internet environment. This study illustrates the issue of getting digital literacy using online encyclopedic resources on the case about informing the pandemic of coronavirus disease COVID-19 worldwide in 2019-2020. Based on analysis of the mentioned virological topic articles of the national encyclopedias of Europe (Britannica, Brockhaus, Encyclopedia of Modern Ukraine, Great Norwegian Encyclopedia, Wikipedia, etc.) the conclusion is made that encyclopedic knowledge is inert and during the pandemic, it has a low practical role for the needs of humans in the context of safe behavior and right decisions. However, Wikipedia differs from other national online encyclopedias by offering much more information including that is not commonly found in classical encyclopedias, but is useful to readers.

The Influence of EU Law on Public Administration in New Member States

The membership of Central and Eastern European countries in the European Union has influenced the development of almost all branches of law, including administrative law. The paper analyses the influence of European Union law on the fundamental object of interest of administrative law within new member states – on public administration and its laws. In this context, the influence on laws governing the organisation of public administration, laws governing the activities and tasks of public administration as well as laws governing processes in public administration will be assessed.