Letteratura scientifica selezionata sul tema "Evolution semi-Groups"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Evolution semi-Groups".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Evolution semi-Groups":
1
Sauer, Niko, e Joy E. Singleton. "Evolution operators related to semi-groups of class (A)". Semigroup Forum 35, n. 1 (dicembre 1986): 317–35. http://dx.doi.org/10.1007/bf02573114.
2
Huang, Qing, e Renat Zhdanov. "Group classification of nonlinear evolution equations: Semi-simple groups of contact transformations". Communications in Nonlinear Science and Numerical Simulation 26, n. 1-3 (settembre 2015): 184–94. http://dx.doi.org/10.1016/j.cnsns.2015.01.009.
3
Zhdanov, R., e V. Lahno. "Group classification of the general second-order evolution equation: semi-simple invariance groups". Journal of Physics A: Mathematical and Theoretical 40, n. 19 (24 aprile 2007): 5083–103. http://dx.doi.org/10.1088/1751-8113/40/19/010.
4
Farhang, Amin, Habib G. Khosroshahi, Gary A. Mamon, Ali A. Dariush e Mojtaba Raouf. "Evolution of Compact and Fossil Groups of Galaxies from Semi-analytical Models of Galaxy Formation". Astrophysical Journal 840, n. 1 (4 maggio 2017): 58. http://dx.doi.org/10.3847/1538-4357/aa6b00.
5
Ilchev, Alexander, Rueben Pfukwa, Lebohang Hlalele, Marica Smit e Bert Klumperman. "Improved control through a semi-batch process in RAFT-mediated polymerization utilizing relatively poor leaving groups". Polymer Chemistry 6, n. 46 (2015): 7945–48. http://dx.doi.org/10.1039/c5py01293g.
Abstract (sommario):
The negative effect that a RAFT agent with a poor leaving group has on the evolution of molecular dispersity in a RAFT-mediated polymerization was shown to be mitigated by performing the polymerization in semi-batch mode.
6
Díaz-Giménez, E., A. Zandivarez e G. A. Mamon. "Compact groups from semi-analytical models of galaxy formation – II. Different assembly channels". Monthly Notices of the Royal Astronomical Society 503, n. 1 (24 febbraio 2021): 394–405. http://dx.doi.org/10.1093/mnras/stab535.
Abstract (sommario):
ABSTRACT We study the formation of over 6000 compact groups (CGs) of galaxies identified in mock redshift-space galaxy catalogues built from semi-analytical models of galaxy formation (SAMs) run on the Millennium Simulations. We select CGs of four members in our mock SDSS galaxy catalogues and, for each CG, we trace back in time the real-space positions of the most massive progenitors of their four galaxies. By analysing the evolution of the distance of the galaxy members to the centre of mass of the group, we identify four channels of CG formation. The classification of these assembly channels is performed with an automatic recipe inferred from a preliminary visual inspection and based on the orbit of the galaxy with the fewest number of orbits. Most CGs show late assembly, with the last galaxy arriving on its first or second passage, while only 10–20 per cent form by the gradual contraction of their orbits by dynamical friction, and only a few per cent forming early with little subsequent contraction. However, a SAM from a higher resolution simulation leads to earlier assembly. Assembly histories of CGs also depend on cosmological parameters. At similar resolution, CGs assemble later in SAMs built on parent cosmological simulations of high density parameter. Several observed properties of mock CGs correlate with their assembly history: early-assembling CGs are smaller, with shorter crossing times, and greater magnitude gaps between their brightest two members, and their brightest galaxies have smaller spatial offsets and are more passive.
7
Hubal, Halyna M. "The generalized kinetic equation for symmetric particle systems". MATHEMATICA SCANDINAVICA 110, n. 1 (1 marzo 2012): 140. http://dx.doi.org/10.7146/math.scand.a-15201.
Abstract (sommario):
The generalized kinetic equation is obtained for symmetric system of many particles interacting via a pair potential. A representation of a solution of the Cauchy problem for the BBGKY hierarchy is used in the form of an expansion over particle groups whose evolution is governed by the cumulants (semi-invariants).
8
Fukunaga, Kenji, e Makoto Kawase. "Crop Evolution of Foxtail Millet". Plants 13, n. 2 (12 gennaio 2024): 218. http://dx.doi.org/10.3390/plants13020218.
Abstract (sommario):
Studies on the domestication, genetic differentiation, and crop evolution of foxtail millet are reviewed in this paper. Several genetic studies were carried out to elucidate the genetic relationships among foxtail millet accessions originating mainly from Eurasia based on intraspecific hybrid pollen semi-sterility, isozymes, DNA markers, and single-nucleotide polymorphisms. Most studies suggest that China is the center of diversity of foxtail millet, and landraces were categorized into geographical groups. These results indicate that this millet was domesticated in China and spread over Eurasia, but independent origin in other regions cannot be ruled out. Furthermore, the evolution of genes was reviewed (i.e., the Waxy gene conferring amylose content in the endosperm, the Si7PPO gene controlling polyphenol oxidase, the HD1 and SiPRR37 genes controlling heading time, the Sh1 and SvLes1 genes involved in grain shattering, and the C gene controlling leaf sheath pigmentation), and the variation and distribution of these genes suggested complex patterns of evolution under human and/or natural selection.
9
Kuang, Yutong. "Synchronic Variation and Diachronic Evolution of Tone Patterns in Kunming Dialect". International Journal of Languages, Literature and Linguistics 8, n. 4 (dicembre 2022): 295–301. http://dx.doi.org/10.18178/ijlll.2022.8.4.365.
Abstract (sommario):
An acoustic experiment was conducted to analyze the tonal patterns of single characters in the Kunming dialect. The experimental results show that the Kunming dialect has a semi-high flat tone for the first tone, a low descending tone for the second tone, a high descending tone for the third tone, and a low tone for the fourth tone. The first and third tones are both high, while the second and fourth are both low tones, as opposed to the tonal patterns of "flat" and "low". The newer Kunming dialects show variation. The first tone starts and ends at a higher level, the third tone's bent section disappears, and the fourth tone starts and ends at a lower level, with a shorter tone duration. The variation in tone pattern starts in the middle-aged group in the old urban, and the degree of variation is female > male, old urban > old suburban, and the youth and middle-aged group > senior group, respectively. The female tone pattern has more similar vocal tone characteristics to those in the middle-aged and youth groups.
10
Prialnik, Dina. "The Cyclic Evolution of Classical Novae". International Astronomical Union Colloquium 122 (1990): 351–60. http://dx.doi.org/10.1017/s0252921100068846.
Abstract (sommario):
The cyclic evolution of classical novae (CN) cannot be observed, as in the case of recurrent or dwarf novae. The duration of a typical cycle may range from a few thousand to a few 105 years. Thus we have to rely on theoretical studies for understanding the periodic outbursts — due to thermonuclear runaways (TNR) — on the surface of accreting white dwarfs (WD). One may distinguish between two kinds of studies: a) detailed investigations of a specific aspect or a particular evolutionary phase; b) studies which emphasize the cyclic behavior of novae and their long-term evolution. The latter, which form the subject of this brief review, may be divided into four groups, each adopting a different approach to the problem:1.Steady-state (semi-analytic) solutions;2.One- (or two-) zone models;3.Quasi-static (and/or steady burning) numerical calculations;4.Full-scale hydrodynamic evolutionary computations.
Tesi sul tema "Evolution semi-Groups":
1
Zaafrani, Ibtissem. "Dynamique et stabilisation d’un plasma magnétique froid". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0312.
Abstract (sommario):
Dans cette thèse, nous considérons un modèle Euler-Maxwell linéarisé de propagation et d'absorption des ondes électromagnétiques dans un plasma magnétique. Deux types de conditions aux limites sont envisagées : conducteur parfait sur toute la frontière et Silver-Müller homogène ou non sur une partie de celle-ci. D'abord, j'établis les équations du modèle et je montre sa bonne position par la théorie des semi-groupes. Ensuite, je m'intéresse à la stabilisation du modèle. Dans un premier temps, je réalise une étude sur le comportement asymptotique en temps long de la solution. Je montre qu'elle décroît vers zéro sous certaines hypothèses physiquement raisonnables. Je conclus à sa convergence vers un état stationnaire non nul dans un espace d'énergie plus grand. Cet état stationnaire est lié aux propriétés de topologie du domaine, et s'exprime en fonction des données initiales. Dans un second temps, j'étudie la décroissance de l'énergie en utilisant la méthode du domaine fréquentiel. J'établis une décroissance polynomiale pour les deux conditions aux limites. Je démontre également un résultat conditionnel de décroissance exponentielle dans le cas Silver-Müller homogène. Dans le cas du conducteur parfait, nous montrons que le système Euler-Maxwell n'est pas exponentiellement stable. Nous concluons par un résultat de convergence vers le régime harmonique en temps en présence d'un forçage harmonique. Parmi les principales difficultés rencontrées, la résolvante de l'opérateur d'évolution est non compacte et l'absorption interne agit seulement sur les variables fluides. Aucune hypothèse d'homogénéité n'est faite, et les hypothèses topologiques et géométriques sur le domaine sont minimales. Ces résultats semblent fortement liés aux propriétés spectrales de diverses matrices décrivant l'anisotropie et d'autres propriétés du plasma. Enfin, nous donnons une extension de ces résultats à un problème d'interface vide-plasmaIn this thesis, we consider a linearized Euler-Maxwell model for the propagation and absorption of electromagnetic waves in a magnetized plasma. Two types of boundary conditions are considered: perfectly conducting on the whole boundary and Silver-Müller, homogeneous or not, on part of it. First, I establish the equations of the model and show its well-posedness by the theory of semigroups. Then, I am interested in the stabilization of the model. First, I carry out a study on the long- term asymptotic behavior of the solution. I show that it decreases towards zero under certain physically reasonable assumptions. I conclude that it converges to a non-zero stationary state in a larger energy space. This stationary state is linked to the topology properties of the domain, and is expressed as a function of the initial data. Secondly, I study the energy decay rate by using the frequency domain method. I establish a polynomial decay for both boundary conditions. I also prove a conditional exponential decay result in the homogeneous Silver-Müller case. In the perfectly conducting case, we show that the Euler-Maxwell system is not exponentially stable. We conclude by a result of convergence towards the time-harmonic regime in the presence of a harmonic forcing. Among the main difficulties encountered, the resolvent of the evolution operator is not compact and the internal absorption acts only on the fluid variables. No homogeneity assumption is made, and the topological and geometrical assumptions on the domain are minimal. These results appear strongly linked to the spectral properties of various matrices describing the anisotropy and other plasma properties. Finally, we extend those results to the case of a vacuum-plasma interface problem
Libri sul tema "Evolution semi-Groups":
1
Ladyzhenskaya, Olga. Attractors for Semi-Groups and Evolution Equations. Cambridge University Press, 2010.
2
Ladyzhenskaya, Olga. Attractors for Semi-Groups and Evolution Equations. Cambridge University Press, 2011.
3
Ladyzhenskaya, Olga. Attractors for Semi-groups and Evolution Equations (Lezioni Lincee). Cambridge University Press, 1991.
4
Ladyzhenskaya, Olga. Attractors for Semi-groups and Evolution Equations (Lezioni Lincee). Cambridge University Press, 1991.
Capitoli di libri sul tema "Evolution semi-Groups":
1
Kato, Tosio. "Semi-Groups and Temporally Inhomogenous Evolution Equations". In Equazioni differenziali astratte, 1–43. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11005-4_1.
2
Li, Shikun. "Examining Teacher Candidates' Evolution of Teaching Belief". In Handbook of Research on Diversity and Social Justice in Higher Education, 257–73. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-5268-1.ch015.
Abstract (sommario):
By using video feedback as a treatment, this quasi-experimental study is aimed to capture the dynamic evolution process of teacher candidates' belief of comprehensible input. It compares the changes in teacher candidates' belief of comprehensible input among different feedback groups. A mixed method, which contains the pre and post surveys, semi-structured interviews, and micro-teaching assignments decoding, is used to boost the internal validity of the research design. An ANCOVA analysis was conducted through controlling different co-variances. The results suggest that after the treatment there is no statistically significant difference in teacher candidates' post-treatment belief of comprehensible input. This result is aligned with the patterns that were generalized from semi-structured interviews: 1) a lack of changes in the teacher candidates' belief of comprehensible input after receiving feedback, 2) an alignment between the teacher candidates' micro-teaching performances and their belief of comprehensible input, and (3) the teacher candidates' positive perceptions of the video feedback.
3
Walsh, Allyson L., Stephen Harris e A. M. Hutson. "Abundance and habitat selection of foraging vespertilionid bats in Britain: a landscape-scale approach". In Ecology, Evolution and Behaviour of Bats, 325–44. Oxford University PressOxford, 1995. http://dx.doi.org/10.1093/oso/9780198549451.003.0021.
Abstract (sommario):
Abstract Large-scale surveys of the habitats required by foraging bats have seldom been attempted, despite a clear need for quantitative information in order to develop realistic conservation strategies. Accordingly, a standardized survey method was developed for a large-scale analysis of bat abundance and habitat selection in the whole of Britain. This was the first such survey of its kind undertaken anywhere. A random stratified sample of 1-km squares was surveyed by a network of volunteers walking fixed transects with bat detectors. They also collected information on the habitat features present in each 1-km square. Data from 910 squares were examined to test whether landscape and local habitat features influence bat activity. Significant regional differences were demonstrated between seven major land-class groups. Lowest bat activity levels occurred in upland, marginal upland and intensively farmed arable areas of the north. Habitat selection results are presented for two contrasting land-class groups. In both of these, woodland habitats and habitats associated with water were actively selected, whilst arable land, stone walls, scrub and parkland plus all grassland categories were avoided. Logistic regression models were used to identify habitats of critical importance within the two land-class groups. A variety of habitats were important in the pastural landscape but only one, semi-natural broadleaved woodland, was of critical importance in the arable landscape. The value of landscape-scale surveys for providing information on habitat use and a baseline from which to model’ the potential effects of changes in land use is discussed.
4
West-Eberhard, Mary Jane. "Material for a Synthesis". In Developmental Plasticity and Evolution. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195122343.003.0007.
Abstract (sommario):
The inconsistencies discussed in chapter 1 point toward two fundamental problems in need of solution: how to relate the environmental influence inherent in phenotype development to the genetic emphasis of evolutionary theory—Lewontin’s dilemma—and how to view the diverse phenomena of plasticity and development so as to illuminate evolutionary thinking in new ways—Wallace’s challenge. This chapter briefly describes some important, previously recognized connections among phenotypic flexibility, development, and evolution. It then defines key concepts for the chapters that follow. Important contributions toward a synthesis of development and evolution have accumulated over a period of many years. Some insights appear repeatedly in that cycle of inspiration and amnesia that characterizes important discoveries ahead of their times (for a concise review, see Hall, 1992, pp. 171-174). Some of these insights deal with the phenomenology of development and evolution—evidence that certain behavioral and developmental phenomena have influenced evolution in particular groups or in particular ways. These ideas, long familiar to evolutionary biologists, are the starting points for any attempt at a modern synthesis. Each of them will reappear again in later chapters. It does not require great sophistication in biology to realize that juveniles and adults have distinctive, divergent adaptations. Familiar extreme examples are the caterpillar and the butterfly, the tadpole and the frog. In such metamorphosing species, the juvenile has a dramatically different morphology, behavior, and ecology from that of the adult. Some hypermetamorphic insects show a striking series of differently specialized larval stages, and it is probably true of most organisms that juveniles and adults have different, evolved characteristics appropriate to their different niches, if for no other reason than the different requirements for dispersal, respiration, feeding, and defense that confront individuals of differing size (Schmidt-Nielsen, 1984; see also McKinney and McNamara, 1991). As a corrolary of this, different life stages evolve semi-independently. Thus, immature stages may evolve and diversify, undergoing their own adaptive radiations. Many authors have been impressed with the conservatism of certain aspects of early development.
Atti di convegni sul tema "Evolution semi-Groups":
1
Kirila, Kitija, e Dace Kaufmane. "ASPECTS OF INTEGRATION OF SOCIALLY EXCLUDED GROUPS IN LATVIA". In 11th SWS International Scientific Conferences on ART and HUMANITIES - ISCAH 2024. SGEM WORLD SCIENCE, 2024. http://dx.doi.org/10.35603/sws.iscah.2024/fs01.01.
Abstract (sommario):
The goal of the European Union is to reduce the risk of poverty and social exclusion. The risk of social exclusion involves various risk factors that adversely affect family life as well as everyday needs. Indirect discrimination also leads to social exclusion. In essence, social exclusion represents multidimensional marginalization that does not contribute to social integration policies aimed at creating an integrated and socially active society. French sociologist Emile Durkheim has already stressed that the inclusion and union of individuals are essential to maintaining social cohesion and preventing social exclusion. He also stressed the importance of social solidarity, which is linked to shared values, beliefs and norms in society and which can help to prevent social exclusion and promote social integration, and described the evolution of society from mechanical solidarity to organic solidarity. Social exclusion is a complex social and political problem, which is governed legally at the national and local levels, as there are socially excluded groups also in rural areas. The legislative framework was summarised using document analysis. A qualitative research approach was used to explore the manifestations of social exclusion and identify recommendations to address them. The research involved 11 semi-structured interviews with representatives of organisations working on the problems and integration of socially excluded groups. The research aims to identify the problems of and solutions to social exclusion in rural areas. The research has concluded that there are enough projects and programmes promoting wellbeing and social protection, yet the projects do not achieve the desired results in most cases. Based on the idea of social solidarity, today's society is more likely to cooperate, which indicates a more cohesive society and a willingness to seek help from responsible organisations.
2
Akbas, Sabahattin, Victor Martinez-Quiroga, Fatih Aydogan, Abderrafi M. Ougouag e Chris Allison. "Survey of Coupling Schemes in Traditional Coupled Neutronics and Thermal-Hydraulics Codes". In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52990.
Abstract (sommario):
The design and the analysis of nuclear power plants (NPPs) require computational codes to predict the behavior of the NPP nuclear components and other systems (i.e., reactor core, primary coolant system, emergency core cooling system, etc.). Coupled calculations are essential to the conduct of deterministic safety assessments. Inasmuch as the physical phenomena that govern the performance of a nuclear reactor are always present simultaneously, ideally computational modeling of a nuclear reactor should include coupled codes that represent all of the active physical phenomena. Such multi-physics codes are under development at several institutions and are expected to become operational in the future. However, in the interim, integrated codes that incorporate modeling capabilities for two to three physical phenomena will remain useful. For example, in the conduct of safety analyses, of paramount importance are codes that couple neutronics and thermal-hydraulics, especially transient codes. Other code systems of importance to safety analyses are those that couple primary system thermal-hydraulics to fission product chemistry, neutronics to fuel performance, containment behavior and structural mechanics to thermal-hydraulics, etc. This paper surveys the methods used traditionally in the coupling of neutronic and thermal-hydraulics codes. The neutron kinetics codes are used for computing the space-time evolution of the neutron flux and, hence, of the power distribution. The thermal-hydraulics codes, which compute mass, momentum and energy transfers, model the coolant flow and the temperature distribution. These codes can be used to compute the neutronic behavior and the thermal-hydraulic states separately. However, the need to account with fidelity for the dynamic feedback between the two sets of properties (via temperature and density effects on the cross section inputs into the neutronics codes) and the requirement to model realistically the transient response of nuclear power plants and to assess the associated emergency systems and procedures imply the necessity of modeling the neutronic and thermal-hydraulics simultaneously within a coupled code system. The focus of this paper is a comparison of the methods by which the coupling between neutron kinetics and thermal-hydraulics treatments has been traditionally achieved in various code systems. As discussed in the last section, the modern approaches to multi-physics code development are beyond the scope of this paper. From the field of the most commonly used coupled neutron kinetic-thermal-hydraulics codes, this study selected for comparison the coupled codes RELAP5-3D (NESTLE), TRACE/PARCS, RELAP5/PARCS, ATHLET/DYN3D, RELAP5/SCDAPSIM/MOD4.0/NESTLE. The choice was inspired by how widespread the use of the codes is, but was limited by time availability. Thus, the selection of codes is not to be construed as exhaustive, nor is there any implication of priority about the methods used by the various codes. These codes were developed by a variety of institutions (universities, research centers, and laboratories) geographically located away from each other. Each of the research group that developed these coupled code systems used its own combination of initial codes as well as different methods and assumptions in the coupling process. For instance, all these neutron kinetics codes solve the few-groups neutron diffusion equations. However, the data they use may be based on different lattice physics codes. The neutronics solvers may use different methods, ranging from point kinetics method (in some versions of RELAP5) to nodal expansion methods (NEM), to semi-analytic nodal methods, to the analytic nodal method (ANM). Similarly, the thermal-hydraulics codes use several different approaches: different number of coolant fields, homogenous equilibrium model, separate flow model, different numbers of conservation equations, etc. Therefore, not only the physical models but also the assumptions of the coupled codes and coupling techniques vary significantly. This paper compares coupled codes qualitatively and quantitatively. The results of this study are being used both to guide the selection of appropriate coupled codes and to identify further developments into coupled codes.