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Littérature scientifique sur le sujet « Lattice naturale »

Auteur : Grafiati
Publié le 9 mars 2023
Mis à jour le 10 mars 2023

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Articles de revues sur le sujet "Lattice naturale"

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Grabowski, Adam. « Stone Lattices ». Formalized Mathematics 23, no 4 (1 décembre 2015) : 387–96. http://dx.doi.org/10.1515/forma-2015-0031.

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Summary The article continues the formalization of the lattice theory (as structures with two binary operations, not in terms of ordering relations). In the paper, the notion of a pseudocomplement in a lattice is formally introduced in Mizar, and based on this we define the notion of the skeleton and the set of dense elements in a pseudocomplemented lattice, giving the meet-decomposition of arbitrary element of a lattice as the infimum of two elements: one belonging to the skeleton, and the other which is dense. The core of the paper is of course the idea of Stone identity $$a^* \sqcup a^{**} = {\rm{T}},$$ which is fundamental for us: Stone lattices are those lattices L, which are distributive, bounded, and satisfy Stone identity for all elements a ∈ L. Stone algebras were introduced by Grätzer and Schmidt in [18]. Of course, the pseudocomplement is unique (if exists), so in a pseudcomplemented lattice we defined a * as the Mizar functor (unary operation mapping every element to its pseudocomplement). In Section 2 we prove formally a collection of ordinary properties of pseudocomplemented lattices. All Boolean lattices are Stone, and a natural example of the lattice which is Stone, but not Boolean, is the lattice of all natural divisors of p 2 for arbitrary prime number p (Section 6). At the end we formalize the notion of the Stone lattice B [2] (of pairs of elements a, b of B such that a ⩽ b) constructed as a sublattice of B 2, where B is arbitrary Boolean algebra (and we describe skeleton and the set of dense elements in such lattices). In a natural way, we deal with Cartesian product of pseudocomplemented lattices. Our formalization was inspired by [17], and is an important step in formalizing Jouni Järvinen Lattice theory for rough sets [19], so it follows rather the latter paper. We deal essentially with Section 4.3, pages 423–426. The description of handling complemented structures in Mizar [6] can be found in [12]. The current article together with [15] establishes the formal background for algebraic structures which are important for [10], [16] by means of mechanisms of merging theories as described in [11].
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Alvarado-García, Alejandro, César Cejudo-Castilla, Hugo Alberto Rincón-Mejía et Ivan Fernando Vilchis-Montalvo. « Pseudocomplements and strong pseudocomplements in lattices of module classes ». Journal of Algebra and Its Applications 17, no 01 (janvier 2018) : 1850016. http://dx.doi.org/10.1142/s0219498818500160.

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In this work, we consider the existence and construction of pseudocomplements in some lattices of module classes. The classes of modules belonging to these lattices are defined via closure under operations such as taking submodules, quotients, extensions, injective hulls, direct sums or products. We characterize the rings for which the lattices [Formula: see text]-tors (of hereditary torsion classes), [Formula: see text]-nat (the lattice of natural classes) and [Formula: see text]-conat (the lattice of conatural classes) coincide.
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Chajda, Ivan, et Helmut Länger. « Left residuated lattices induced by lattices with a unary operation ». Soft Computing 24, no 2 (1 novembre 2019) : 723–29. http://dx.doi.org/10.1007/s00500-019-04461-x.

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Abstract In a previous paper, the authors defined two binary term operations in orthomodular lattices such that an orthomodular lattice can be organized by means of them into a left residuated lattice. It is a natural question if these operations serve in this way also for more general lattices than the orthomodular ones. In our present paper, we involve two conditions formulated as simple identities in two variables under which this is really the case. Hence, we obtain a variety of lattices with a unary operation which contains exactly those lattices with a unary operation which can be converted into a left residuated lattice by use of the above mentioned operations. It turns out that every lattice in this variety is in fact a bounded one and the unary operation is a complementation. Finally, we use a similar technique by using simpler terms and identities motivated by Boolean algebras.
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BÉTERMIN, LAURENT. « ON A LATTICE GENERALISATION OF THE LOGARITHM AND A DEFORMATION OF THE DEDEKIND ETA FUNCTION ». Bulletin of the Australian Mathematical Society 102, no 1 (20 février 2020) : 118–25. http://dx.doi.org/10.1017/s000497272000012x.

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We consider a deformation $E_{L,\unicode[STIX]{x1D6EC}}^{(m)}(it)$ of the Dedekind eta function depending on two $d$-dimensional simple lattices $(L,\unicode[STIX]{x1D6EC})$ and two parameters $(m,t)\in (0,\infty )$, initially proposed by Terry Gannon. We show that the minimisers of the lattice theta function are the maximisers of $E_{L,\unicode[STIX]{x1D6EC}}^{(m)}(it)$ in the space of lattices with fixed density. The proof is based on the study of a lattice generalisation of the logarithm, called the lattice logarithm, also defined by Terry Gannon. We also prove that the natural logarithm is characterised by a variational problem over a class of one-dimensional lattice logarithms.
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Longstaff, W. E., J. B. Nation et Oreste Panaia. « Abstract reflexive sublattices and completely distributive collapsibility ». Bulletin of the Australian Mathematical Society 58, no 2 (octobre 1998) : 245–60. http://dx.doi.org/10.1017/s0004972700032226.

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There is a natural Galois connection between subspace lattices and operator algebras on a Banach space which arises from the notion of invariance. If a subspace lattice ℒ is completely distributive, then ℒ is reflexive. In this paper we study the more general situation of complete lattices for which the least complete congruence δ on ℒ such that ℒ/δ is completely distributive is well-behaved. Our results are purely lattice theoretic, but the motivation comes from operator theory.
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Restall, Greg, et Francesco Paoli. « The geometry of non-distributive logics ». Journal of Symbolic Logic 70, no 4 (décembre 2005) : 1108–26. http://dx.doi.org/10.2178/jsl/1129642117.

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AbstractIn this paper we introduce a new natural deduction system for the logic of lattices, and a number of extensions of lattice logic with different negation connectives. We provide the class of natural deduction proofs with both a standard inductive definition and a global graph-theoretical criterion for correctness, and we show how normalisation in this system corresponds to cut elimination in the sequent calculus for lattice logic. This natural deduction system is inspired both by Shoesmith and Smiley's multiple conclusion systems for classical logic and Girard's proofnets for linear logic.
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Chen, Zai Liang, Luo Hong Deng et Cong Jing. « Dynamic Performance and Structural Optimization of Large-Scale Machine Table ». Applied Mechanics and Materials 615 (août 2014) : 313–16. http://dx.doi.org/10.4028/www.scientific.net/amm.615.313.

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Designed new table for large floor boring and milling machine, used ANSYS to optimize the structure of the table as a whole. According to the contours of removable material the materials which can be removed, obtained the inner ribs layout of table and the sand holes location of rib plate. Dynamic optimization variables on basic ribs cell, studied the effect of steel lattice structure parameters influenced on the natural frequency of the lattices and the related parameter of lattices influenced on whole table, to get the ideal rib lattice structure after optimizing again. Optimized bench can reduce quality, increase rigidity and dynamic performance.
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Várilly-Alvarado, Anthony, et David Zywina. « Arithmetic E8 Lattices with Maximal Galois Action ». LMS Journal of Computation and Mathematics 12 (2009) : 144–65. http://dx.doi.org/10.1112/s1461157000001479.

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AbstractWe construct explicit examples of E8 lattices occurring in arithmetic for which the natural Galois action is equal to the full group of automorphisms of the lattice, i.e., the Weyl group of E8. In particular, we give explicit elliptic curves over Q(t) whose Mordell-Weil lattices are isomorphic to E8 and have maximal Galois action.Our main objects of study are del Pezzo surfaces of degree 1 over number fields. The geometric Picard group, considered as a lattice via the negative of the intersection pairing, contains a sublattice isomorphic to E8. We construct examples of such surfaces for which the action of Galois on the geometric Picard group is maximal.
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ADARICHEVA, KIRA, et J. B. NATION. « LATTICES OF QUASI-EQUATIONAL THEORIES AS CONGRUENCE LATTICES OF SEMILATTICES WITH OPERATORS : PART I ». International Journal of Algebra and Computation 22, no 07 (novembre 2012) : 1250065. http://dx.doi.org/10.1142/s0218196712500658.

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We show that for every quasivariety 𝒦 of structures (where both functions and relations are allowed) there is a semilattice S with operators such that the lattice of quasi-equational theories of 𝒦 (the dual of the lattice of sub-quasivarieties of 𝒦) is isomorphic to Con(S, +, 0, 𝒡. As a consequence, new restrictions on the natural quasi-interior operator on lattices of quasi-equational theories are found.
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Niederle, Josef. « Natural generalization of some lattice theory concepts to partially ordered sets ». Czechoslovak Mathematical Journal 41, no 2 (1991) : 297–99. http://dx.doi.org/10.21136/cmj.1991.102463.

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Thèses sur le sujet "Lattice naturale"

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MASCIA, CLAUDIA. « Studio di componenti del lattice di Euphorbia characias ». Doctoral thesis, Università degli Studi di Cagliari, 2015. http://hdl.handle.net/11584/266809.

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The aim of the present study was to contribute to the knowledge of the components of the latex, a milky fluid exudated from the Mediterranean shrub Euphorbia characias. The antioxidant and acetylcholinesterase inhibitory activities were explored in E. characias. The latex was extracted using several conventional methods and a new procedure involving the use of the trichloroacetic acid. The results of this research indicate that E. characias latex exhibits antioxidant activities, is rich in total polyphenolic and flavonoids content and exhibited substantial inhibition of acetylcholinesterase activity. A natural rubber was identified and characterized for the first time in the latex of E. characias. Four different methods, i.e. acetone, acetic acid, trichloroacetic acid and Triton® X-100, followed by successive treatments with cyclohexane/ethanol, were employed to extract the natural rubber. The higher yield (14%) was achieved after extraction with acetic acid. E. characias rubber showed a molecular weight of 93000 with a Mw/Mn of 2.9. 1HNMR, 13C NMR and FTIR analysis revealed the characteristic of the cis- 1,4-polyisoprene typical of natural rubber. The enzyme catalyzing the rubber molecule elongation is cisprenyltransferase called “rubber transferase”. We cloned the cDNA encoding for the E. characias rubber transferase by RT-PCR. The cDNA contains an open reading frame of 810 bp encoding a protein of 270 amino acids (GenBank JX564541). The cDNA nucleotide sequence and the deduced amino acid sequence appear to be highly homologous to the sequence of several plant cis-prenyltransferases. The results provided novel insight into latex components and will ultimately benefit the broader understanding of E. characias latex composition.
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TAGLIARO, IRENE. « NOVEL COLLOIDAL APPROACH TO PREPARE HIGHLY-LOADED SILICA-BASED ELASTOMERIC NANOCOMPOSITES ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2019. http://hdl.handle.net/10281/241175.

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L’industria degli pneumatici si prefigge di indagare possibili strategie sintetiche per ridurre l’impatto ambientale durante tutto il ciclo di vita dello pneumatico, attraverso l’uso di materiali sostenibili e lo sviluppo di tecniche innovative che riducano il consumo di energia e le emissioni di CO2. In questo contesto, questa progetto di dottorato è focalizzato sulla preparazione di nanocompositi eco-sostenibili attraverso l’uso di un approccio colloidale per aumentare la dispersione di filler idrofilici, in linea con i nuovi requisiti di sostenibilità delle politiche europee. L’approccio colloidale punta a produrre nanocompositi con filler idrofilici, la cui efficiente dispersione attraverso tecniche di miscelazione tradizionali rimane difficoltosa a causa della scarsa compatibilità con la matrice organica. Questa tecnica si focalizza sull’incremento della dispersione di filler senza alcuna modifica superficiale, con l’eliminazione delle poveri prodotte durante il mescolamento con significativi benefici per l’ambiente e i lavoratori. Due diversi approcci colloidali sono stati utilizzati: i) una tecnica di miscelazione in lattice e ii) una in situ polimerizzazione in emulsione per la produzione di nanocompositi altamente caricati contenenti filler come silice e sepiolite (Sep), questi ultimi sono considerati filler promettenti nell’ambito del rinforzo dei polimeri grazie alla loro struttura fibrosa e all’elevato rapporto di forma. La concentrazione, la carica, la forma dei nanofiller a base silicea sono stati studiati come parametri rilevanti per la stabilizzazione e destabilizzazione di lattici a base di poliisoprene naturale e sintetico. Una efficiente procedura di miscelazione in lattice è stata messa a punto per produrre compositi eco-sostenibili, chiamati masterbatches (MBs), attraverso l’incorporazione di silice o Sep nel lattice di gomma naturale (emulsione in acqua di cis-1,4-poliisoprene), attraverso la flocculazione (aggregazione risultante dalla coesione di particelle di polimero) di una miscela acquosa di nanofiller a base silicea e gomma. La tecnica di miscelazione in lattice ha dimostrato di favorire una omogenea dispersione di fibre di sepiolite idrofilica in matrice di gomma. La principali caratteristiche fisico-chimiche che controllano i processi di aggregazione in acqua come il pH, il potenziale Z, la concentrazione, assieme alle caratteristiche morfologiche del MB Sep-gomma naturale, sono state prese in considerazione allo scopo di investigare le interazioni Sep-gomma naturale. E’ stato proposto un meccanismo di flocculazione basato su attrazioni elettrostatiche e depletive, connesso all’elevato contenuto di filler (50% in peso) e alla peculiare anisotropia delle particelle di Sep. Inoltre, i MBs sono stati utilizzati per preparare compositi sostenibili attraverso la combinazione di miscelazione in lattice e mescolazione meccanica. Questo approccio combinato sfrutta la buona distribuzione del filler e previene il rilascio di polveri durante il processo. Una polimerizzazione Pickering in situ è stata considerata come alternativa per la produzione di nanocompositi eco-sostenibili. Particelle poliisoprene/filler a base silicea sono state sintetizzate sfruttando dell’effetto stabilizzante di filler inorganici che agiscono come tensioattivi riducendo la tensione superficiale e stabilizzando l’emulsione. Sulla base dei nostri risultati, viene suggerito un possibile meccanismo di polimerizzazione in emulsione stabilizzata da particelle solide. In conclusione, l’approccio colloidale, basato su miscelazione in lattice e polimerizzazione Pickering in situ, può essere considerato un metodo sostenibile, semplice ed efficace adatto per applicazioni tecnologiche altamente performanti. I risultati indicano che le strategie utilizzate sono adatte per produrre nanocompositi altamente caricati di filler a base silicea.
Sustainability has become a field of great interest in the world industry. For the scientific community the challenge lies in the identification of green synthetic approaches and new alternatives to petroleum-based materials. In the case of the tyre industry, the challenge is to identify possible design strategies and alternatives to reduce the environmental impact throughout the life cycle of tyres, by means of both the use of environmentally friendly materials and the development of innovative products, having reduced energy consumption and CO2 emissions. In this context, this PhD thesis is focused on the preparation of eco-friendly silica-based nanocomposites by using a colloidal approach to increase the dispersion of hydrophilic fillers in line with the new requirements of sustainability from the EU policies. The colloidal approach aims at compounding nanocomposites with hydrophilic fillers, whose efficient dispersion through traditional mixing still remains a challenging issue, due to their poor compatibility with the organic matrix. This technique aims at increasing the filler dispersion without any expensive surface modification, with the elimination of the volatile component released during mixing, producing significant benefits for environment and workers. Two different colloidal approaches were applied: i) latex compounding technique (LCT) and ii) in situ emulsion polymerization to prepare highly-loaded nanocomposite rubber materials containing silica-based fillers, silica and sepiolite (Sep) clay, considered a promising filler candidate for the polymer strengthening due to its fibrous structure and high particle aspect ratio (AR). The concentration, the charge and the shape of silica-based nanofillers were studied as relevant parameters on stabilization and destabilization of natural and synthetic polyisoprene latexes. An effective LCT procedure was established to produce eco-friendly composites, namely masterbaches (MBs), by incorporating silica or Sep into natural rubber latex (i.e. emulsion in water of cis-1,4-polyisoprene), through the flocculation (i.e. aggregation resulting from the bridging of polymer particles) of the silica-based nanofillers/rubber mixed aqueous system. LCT showed to favour a homogeneous dispersion of hydrophilic Sep fibers in the rubber matrix. The main physicochemical parameters which control aggregation processes in the aqueous medium, i.e. pH, -potential, concentration, as well as the morphological features of the final Sep-natural rubber MBs, were comprehensively investigated helping to figure out the Sep-NR interactions and to propose a flocculation mechanism, based on electrostatic and depletion attraction forces, remarkably connected both to the high content (50 wt.%) and to the peculiar anisotropy of Sep fibers. Furthermore, the MBs with high filler loadings were used to produce environmentally friendly composites, by combining LTC and melt mixing. This combined approach could take advantage of the good filler distribution and prevents dust from floating in the air during processing. In situ Pickering polymerization was considered as an alternative colloidal approach to produce eco-friendly nanocomposites. Polyisoprene/silica-based structured particles were synthesized on the base of the stabilizing effects of inorganic fillers which act like surfactants lowering the interfacial tension and stabilizing the emulsion. On the basis of our results, we suggested a possible mechanism for emulsion polymerizations stabilized by solid particles. In conclusion, the colloidal approach, based on both LTC and in situ Pickering emulsion polymerization, can be considered as green, simple and effective method suitable for high-performance technological applications. The outcomes indicate the suitability of the adopted strategies as a sustainable procedure for the production of high-loaded silica based-rubber nanocomposites.
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Wegener, Claudia B. « Natural dualities for varieties generated by lattice-structured algebras ». Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302397.

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Hashemi, Mohammad. « Lattice Boltzmann Simulation of Natural Convection During Dendritic Growth ». University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1459444594.

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Hardter, Eric. « Modifying the Natural State of Nucleic Acids : Three-Dimensional DNA Lattices and Extended Deoxyribonucleosides ». Thesis, Boston College, 2014. http://hdl.handle.net/2345/bc-ir:103610.

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Thesis advisor: Larry W. McLaughlin
By virtue of encoding and transferring hereditary information, nucleic acids effectively represent the blueprint for life as we know it. Given the biological relevance of this class of polymers, it comes as no surprise that scientists are constantly striving to reach a greater understanding of the innumerable genetic corridors contained within the human genome. This has led to the rational design and synthesis of numerous nucleoside analogues in an attempt to alter and subsequently control native nucleic acid structure and function. The first attempts at harnessing the latent abilities of DNA are described in Chapter 2. Multiple tetrahedral branching "hubs" were designed, synthesized and characterized, at which point single-stranded DNA could be elongated from each of the four points of origin. Ensuing hybridization studies were performed with the goal that the binding traits of these elongated tetrahedral lattices could be monitored, and that fully formed lattices could potentially function as means of drug encapsulation or molecular tethering. Chapter 3 describes direct alteration of the standard DNA backbone. Successive synthetic efforts towards creating a 6'-extended deoxyadenosine molecule are detailed, and its effects on the stability of duplexed DNA (along with sister molecules 6'-deoxythymidine and an elongated 3'-deoxythymidine) are also defined. Upon insertion into DNA, this class of extended nucleosides could ultimately lead to a new duplex structure, as well as novel binding properties
Thesis (PhD) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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Craig, Andrew Philip Knott. « Canonical extensions of bounded lattices and natural duality for default bilattices ». Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:c7137abe-b076-42ad-9691-bddfca36967e.

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This thesis presents results concerning canonical extensions of bounded lattices and natural dualities for quasivarieties of default bilattices. Part I is dedicated to canonical extensions, while Part II focuses on natural duality for default bilattices. A canonical extension of a lattice-based algebra consists of a completion of the underlying lattice and extensions of the additional operations to the completion. Canonical extensions find rich application in providing an algebraic method for obtaining relational semantics for non-classical logics. Part I gives a new construction of the canonical extension of a bounded lattice. The construction is done via successive applications of functors and thus provides an elegant exposition of the fact that the canonical extension is functorial. Many existing constructions are described via representation and duality theorems. We demonstrate precisely how our new formulation relates to existing constructions as well as proving new results about complete lattices constructed from graphs. Part I ends with an analysis of the untopologised structures used in two methods of construction of canonical extensions of bounded lattices: the untopologised graphs used in our new construction, and the so-called `intermediate structure'. We provide sufficient conditions for the intermediate structure to be a lattice and, for the case of finite lattices, identify when the dual graph is not a minimal representation of the lattice. Part II applies techniques from natural duality theory to obtain dualities for quasivarieties of bilattices used in default logic. Bilattices are doubly-ordered algebraic structures which find application in reasoning about inconsistent and incomplete information. This account is the first attempt to provide dualities or representations when there is little interaction required between the two orders. Our investigations begin by using computer programs to calculate dualities for specific examples, before using purely theoretical techniques to obtain dualities for more general cases. The results obtained are extremely revealing, demonstrating how one of the lattice orders from the original algebra is encoded in the dual structure. We conclude Part II by describing a new class of default bilattices. These provide an alternative way of interpreting contradictory information. We obtain dualities for two newly-described quasivarieties and provide insights into how these dual structures relate to previously described classes of dual structures for bilattices.
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BOCANEGRA, CIFUENTES JOHAN AUGUSTO. « Lattice Boltzmann Method : applications to thermal fluid dynamics and energy systems ». Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1060259.

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In many energy systems fluids play a fundamental role, and computational simulations are a valuable tool to study their complex dynamics. The Lattice Boltzmann Method (LBM) is a relatively new numerical method for computational fluid dynamics, but its applications can be extended to physical phenomena beyond fluid flows. This thesis presents applications of the LBM to thermal fluid dynamics and energy systems. Specific applications considered are: application to nuclear reactor engineering problems; thermal fluid dynamic behavior of a Natural Circulation Loop; nanoparticles gravitational sedimentation; acoustical problems. The main original contributions derived from this work are: first, the systematic description of the current status of LBM applications to nuclear reactors problems, including test cases and benchmark simulations; second, the development and validation of a LBM model for a single-phase natural circulation loop; third, the development and validation of a LBM model for gravitational sedimentation of nanoparticles, and fourth, the systematic description of the current status of LBM applications to acoustics, including simulations of test cases. The development of this thesis was not limited to simulations; experimental studies in parallel connected natural circulation loops of small inner diameter were conducted, showing the wide applicability of the one-dimensional theoretical models used to validate the LBM results. Additional contributions derived from this work: 1. the applicability of the method to study neutron transport and nuclear waste disposal using porous materials was shown. 2. changes in the thermophysical performance of the natural circulation loop when the loop reached a non-laminar (transition) regime were found at a Reynolds number lower than the typical range. 3. variable diffusion and sedimentation parameters were effective to model the experimental sedimentation curves. In conclusion, this work shows that the LBM is a versatile and powerful computational tool that can be used beyond the common Computational Fluid Dynamics applications.
In many energy systems fluids play a fundamental role, and computational simulations are a valuable tool to study their complex dynamics. The Lattice Boltzmann Method (LBM) is a relatively new numerical method for computational fluid dynamics, but its applications can be extended to physical phenomena beyond fluid flows. This thesis presents applications of the LBM to thermal fluid dynamics and energy systems. Specific applications considered are: application to nuclear reactor engineering problems; thermal fluid dynamic behavior of a Natural Circulation Loop; nanoparticles gravitational sedimentation; acoustical problems. The main original contributions derived from this work are: first, the systematic description of the current status of LBM applications to nuclear reactors problems, including test cases and benchmark simulations; second, the development and validation of a LBM model for a single-phase natural circulation loop; third, the development and validation of a LBM model for gravitational sedimentation of nanoparticles, and fourth, the systematic description of the current status of LBM applications to acoustics, including simulations of test cases. The development of this thesis was not limited to simulations; experimental studies in parallel connected natural circulation loops of small inner diameter were conducted, showing the wide applicability of the one-dimensional theoretical models used to validate the LBM results. Additional contributions derived from this work: 1. the applicability of the method to study neutron transport and nuclear waste disposal using porous materials was shown. 2. changes in the thermophysical performance of the natural circulation loop when the loop reached a non-laminar (transition) regime were found at a Reynolds number lower than the typical range. 3. variable diffusion and sedimentation parameters were effective to model the experimental sedimentation curves. In conclusion, this work shows that the LBM is a versatile and powerful computational tool that can be used beyond the common Computational Fluid Dynamics applications.
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Bray, Christina L., Robert G. Bryant, M. J. Cox, Gianni Ferrante, Y. Goddard, Sandip Sur et Joseph P. Hornack. « The proton Nuclear Magnetic Resonance spin-lattice relaxation rate of some hydrated synthetic and natural sands ». Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-192008.

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The proton nuclear magnetic resonance (NMR) spin-lattice relaxation rate (R1) of hydrated sands is often used to determine porosity characteristics of near-surface aquifers using magnetic resonance sounding. Large variations in R1 have been reported in laboratory measurements on hydrated sands. To understand these variations, the R1 values of several fully hydrated sands were studied as a function of grain diameter (d) and magnetic field strength (BB0). We conclude the variations are a consequence of trace paramagnetic metals in the sand grains. R1 values from magnetic resonance sounding data should not be used to predict void size in aquifers unless the exact chemical composition of the grains is known.
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Bray, Christina L., Robert G. Bryant, M. J. Cox, Gianni Ferrante, Y. Goddard, Sandip Sur et Joseph P. Hornack. « The proton Nuclear Magnetic Resonance spin-lattice relaxation rate of some hydrated synthetic and natural sands ». Diffusion fundamentals 10 (2009) 8, S. 1-3, 2009. https://ul.qucosa.de/id/qucosa%3A14098.

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The proton nuclear magnetic resonance (NMR) spin-lattice relaxation rate (R1) of hydrated sands is often used to determine porosity characteristics of near-surface aquifers using magnetic resonance sounding. Large variations in R1 have been reported in laboratory measurements on hydrated sands. To understand these variations, the R1 values of several fully hydrated sands were studied as a function of grain diameter (d) and magnetic field strength (BB0). We conclude the variations are a consequence of trace paramagnetic metals in the sand grains. R1 values from magnetic resonance sounding data should not be used to predict void size in aquifers unless the exact chemical composition of the grains is known.
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Rydén, Gabriel. « Ab initio lattice dynamics and Anharmonic effects in refractory Rock-salt structure TaN ceramic ». Thesis, Linköpings universitet, Teoretisk Fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-174208.

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Transition Metal Nitrides (TMN) are of considerable importance for the industry and have gathered a great deal of interest in the scientific community, mostly due to their unique physical and mechanical properties. To increase the understanding of what enables them to have such extraordinary properties requires the study of lattice dynamics and their phonon dispersion. In this thesis, the transition metal nitride, TaN, is studied extensively along with preliminary results for NbN. The primary tool for this investigation is simulations. Computational methods, such as ab initio Molecular Dynamics (AIMD) and the Temperature Dependent Effective Potential (TDEP) method are used to generate phonon spectra and to compute the lattice thermal conductivity. The results indicate that TaN crystal structure stabilizes dynamically at much lower temperatures than previously established with other methods. The average linear thermal expansion coefficient of TaN is a = 9.0 * 10-6 K-1, which is consistent with other TMN. The phonon-phonon lattice thermal conductivity of TaN follows a similar behaviour as for other TMN. Preliminary result for NbN suggests a behaviour at lower temperatures that are similar to that observed for TaN. However, further investigations are required to pinpoint TaN and NbN transition temperatures more exactly and include effects, such as electron-phonon scattering and isotope effects for a better estimation of the lattice thermal conductivity.
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Livres sur le sujet "Lattice naturale"

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A mathematical structure for emergent computation. Dordrecht, The Netherlands : Kluwer Academic Publishers, 1999.

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Succi, Sauro. The Lattice Boltzmann Equation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199592357.001.0001.

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Over the past near three decades, the Lattice Boltzmann method has gained a prominent role as an efficient computational method for the numerical simulation of a wide variety of complex states of flowing matter across a broad range of scales, from fully developed turbulence, to multiphase micro-flows, all the way down to nano-biofluidics and lately, even quantum-relativistic subnuclear fluids. After providing a self-contained introduction to the kinetic theory of fluids and a thorough account of its transcription to the lattice framework, this book presents a survey of the major developments which have led to the impressive growth of the Lattice Boltzmann across most walks of fluid dynamics and its interfaces with allied disciplines, such as statistical physics, material science, soft matter and biology. This includes recent developments of Lattice Boltzmann methods for non-ideal fluids, micro- and nanofluidic flows with suspended bodies of assorted nature and extensions to strong non-equilibrium flows beyond the realm of continuum fluid mechanics. In the final part, the book also presents the extension of the Lattice Boltzmann method to quantum and relativistic fluids, in an attempt to match the major surge of interest spurred by recent developments in the area of strongly interacting holographic fluids, such as quark-gluon plasmas and electron flows in graphene. It is hoped that this book may provide a source information and possibly inspiration to a broad audience of scientists dealing with the physics of classical and quantum flowing matter across many scales of motion.
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Succi, Sauro. Out of Legoland : Geoflexible Lattice Boltzmann Equations. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199592357.003.0023.

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The LBEs discussed to this point lag behind “best in class” Computational Fluid Dynamics (CFD) methods for the simulation of fluid flows in realistically complicated geometries, such as those presented by most industrial devices. This traces back to the constraint of working along the light-cones of a uniform spacetime. Various methods have been proposed to remedy this unsatisfactory state of affairs. Among others, a natural strategy is to acquire geometrical flexibility from well-established techniques which can afford it, namely Finite Volumes (FV), Finite Differences (FD) and Finite Elements (FE). Alternatively, one can stick to the cartesian geometry of standard LB, and work at progressive levels of local grid refinement. This Chapter presents the general ideas being both strategies.
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Csn, Joe Correa. 46 Ricette per Aumentare la Produzione Di Latte Materno : Con I Migliori Ingredienti Naturali per Aiutare il Corpo a Produrre Sano Latte per il Tuo Bambino. Independently Published, 2018.

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Carroll, John. Parsing. Sous la direction de Ruslan Mitkov. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780199276349.013.0012.

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This article introduces the concepts and techniques for natural language (NL) parsing, which signifies, using a grammar to assign a syntactic analysis to a string of words, a lattice of word hypotheses output by a speech recognizer or similar. The level of detail required depends on the language processing task being performed and the particular approach to the task that is being pursued. This article further describes approaches that produce ‘shallow’ analyses. It also outlines approaches to parsing that analyse the input in terms of labelled dependencies between words. Producing hierarchical phrase structure requires grammars that have at least context-free (CF) power. CF algorithms that are widely used in parsing of NL are described in this article. To support detailed semantic interpretation more powerful grammar formalisms are required, but these are usually parsed using extensions of CF parsing algorithms. Furthermore, this article describes unification-based parsing. Finally, it discusses three important issues that have to be tackled in real-world applications of parsing: evaluation of parser accuracy, parser efficiency, and measurement of grammar/parser coverage.
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Korotkikh, V., et Victor Korotkich. A Mathematical Structure for Emergent Computation (NONCONVEX OPTIMIZATION AND ITS APPLICATIONS Volume 36). Springer, 1999.

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Algebraic Statistics. American Mathematical Society, 2018.

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Chapitres de livres sur le sujet "Lattice naturale"

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Batz, Kevin, Mingshuai Chen, Benjamin Lucien Kaminski, Joost-Pieter Katoen, Christoph Matheja et Philipp Schröer. « Latticed k-Induction with an Application to Probabilistic Programs ». Dans Computer Aided Verification, 524–49. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-81688-9_25.

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AbstractWe revisit two well-established verification techniques, k-induction and bounded model checking (BMC), in the more general setting of fixed point theory over complete lattices. Our main theoretical contribution is latticed k-induction, which (i) generalizes classical k-induction for verifying transition systems, (ii) generalizes Park induction for bounding fixed points of monotonic maps on complete lattices, and (iii) extends from naturals k to transfinite ordinals $$\kappa $$ κ , thus yielding $$\kappa $$ κ -induction.The lattice-theoretic understanding of k-induction and BMC enables us to apply both techniques to the fully automatic verification of infinite-state probabilistic programs. Our prototypical implementation manages to automatically verify non-trivial specifications for probabilistic programs taken from the literature that—using existing techniques—cannot be verified without synthesizing a stronger inductive invariant first.
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Baldan, Paolo, Richard Eggert, Barbara König et Tommaso Padoan. « Fixpoint Theory – Upside Down ». Dans Lecture Notes in Computer Science, 62–81. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71995-1_4.

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AbstractKnaster-Tarski’s theorem, characterising the greatest fix- point of a monotone function over a complete lattice as the largest post-fixpoint, naturally leads to the so-called coinduction proof principle for showing that some element is below the greatest fixpoint (e.g., for providing bisimilarity witnesses). The dual principle, used for showing that an element is above the least fixpoint, is related to inductive invariants. In this paper we provide proof rules which are similar in spirit but for showing that an element is above the greatest fixpoint or, dually, below the least fixpoint. The theory is developed for non-expansive monotone functions on suitable lattices of the form $$\mathbb {M}^Y$$ M Y , where Y is a finite set and $$\mathbb {M}$$ M an MV-algebra, and it is based on the construction of (finitary) approximations of the original functions. We show that our theory applies to a wide range of examples, including termination probabilities, behavioural distances for probabilistic automata and bisimilarity. Moreover it allows us to determine original algorithms for solving simple stochastic games.
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Nagata, Hiroyasu, Kei-ichi Tainaka, Nariyuki Nakagiri et Jin Yoshimura. « Monte Carlo Simulation in Lattice Ecosystem : Top-Predator Conservation and Population Uncertainty ». Dans Natural Computing, 145–54. Tokyo : Springer Japan, 2009. http://dx.doi.org/10.1007/978-4-431-88981-6_13.

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Chopard, Bastien. « Cellular Automata and Lattice Boltzmann Modeling of Physical Systems ». Dans Handbook of Natural Computing, 287–331. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-540-92910-9_9.

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Zhang, Shilei. « Measurement of the Skyrmion Lattice Domains ». Dans Chiral and Topological Nature of Magnetic Skyrmions, 59–70. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-98252-6_3.

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Nagata, Minori, et Hiroyasu Nagata. « Top-Predator Survivor Region Is Affected by Bottom-Prey Mortality Rate on the Monte-Carlo Simulation in Lattice Model ». Dans Natural Computing, 236–43. Tokyo : Springer Japan, 2010. http://dx.doi.org/10.1007/978-4-431-53868-4_27.

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Richards, Debbie, et Kathrin Boettger. « Representing Requirements in Natural Language as Concept Lattices ». Dans Research and Development in Intelligent Systems XIX, 425–38. London : Springer London, 2003. http://dx.doi.org/10.1007/978-1-4471-0651-7_30.

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Chen, Wenjuan. « Filters and Ideals in Q-lattices ». Dans Advances in Natural Computation, Fuzzy Systems and Knowledge Discovery, 349–58. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-89698-0_37.

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Hashemi, Mohammad, Mohsen Eshraghi et Sergio Felicelli. « A Lattice Boltzmann Model for Dendritic Growth under Natural Convection ». Dans Advances in the Science and Engineering of Casting Solidification, 191–98. Hoboken, NJ, USA : John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119093367.ch23.

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Hashemi, Mohammad, Mohsen Eshraghi et Sergio Felicelli. « A Lattice Boltzmann Model for Dendritic Growth Under Natural Convection ». Dans Advances in the Science and Engineering of Casting Solidification, 191–98. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-48117-3_23.

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Actes de conférences sur le sujet "Lattice naturale"

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Kargarnovin, M. H., J. E. Jam et A. H. Hashemian. « Comparison of Natural Frequencies of Composite Cylindrical Shells : A Squared Lattice With Its Equivalent Seamless One ». Dans ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28399.

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Modern Latticed composite materials whose high specific strength and stiffness are utilized in spacecraft and rocket structures to a sufficiently high extent are now widely used in primary airframe structures. In this work a comparison between squared latticed composite cylinder shells and the equivalent hollow cylinder with same weight, outer radius, length and material is done. An analytical equation is derived for natural frequency of square latticed composite shells. The first fifth modes are taken to be compared. The analytical and FEM results are shown and compared to each other. Also, as discussed, the squared lattice cylinder shell reaches to their natural frequencies easily than the equivalent hollow cylinder shell.
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Sharpe, Conner, Carolyn Conner Seepersad, Seth Watts et Dan Tortorelli. « Design of Mechanical Metamaterials via Constrained Bayesian Optimization ». Dans ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85270.

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Advances in additive manufacturing processes have made it possible to build mechanical metamaterials with bulk properties that exceed those of naturally occurring materials. One class of these metamaterials is structural lattices that can achieve high stiffness to weight ratios. Recent work on geometric projection approaches has introduced the possibility of optimizing these architected lattice designs in a drastically reduced parameter space. The reduced number of design variables enables application of a new class of methods for exploring the design space. This work investigates the use of Bayesian optimization, a technique for global optimization of expensive non-convex objective functions through surrogate modeling. We utilize formulations for implementing probabilistic constraints in Bayesian optimization to aid convergence in this highly constrained engineering problem, and demonstrate results with a variety of stiff lightweight lattice designs.
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Leyva Gutierrez, Francisco, et Tong Wang. « Crystallography and Functionality of Natural Waxes : Insights for the Development of Tailored Lipid Materials ». Dans 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/nyok4571.

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Natural waxes are valuable industrial products consisting of complex chemical mixtures. To probe the structure−function role of select constituents, model n-alkanes, alcohols, aldehydes, and fatty acids of C18−19, C22−23, and C26−27 carbon chain lengths were synthesized and analyzed via calorimetry and X-ray powder diffraction. Pure compounds and binary mixtures crystallized into monoclinic (M), triclinic (T), and orthorhombic (O) lattices or combinations thereof. The C26 aldehyde formed an O lattice and exhibited one solid−solid phase transition similar to n-alkanes. The water vapor permeability (WVP) of model systems cast as films was determined. For pure compounds, WVP decreased in the following order: fatty acid > even n-alkane > odd n-alkane > alcohol > aldehyde. Increasing carbon chain length, which translates to increasing unit cell volume, decreased WVP. Binary mixtures generally exhibited a more complex relationship with WVP. These findings may be applicable to the agricultural postharvest, pharmaceutical, and paperboard coating industries.
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Ejiri, Shinji. « Nature of finite temperature and density phase transitions in many-flavor QCD ». Dans 31st International Symposium on Lattice Field Theory LATTICE 2013. Trieste, Italy : Sissa Medialab, 2014. http://dx.doi.org/10.22323/1.187.0146.

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Pinke, Christopher, et Owe Philipsen. « The nature of the Roberge-Weiss transition in $N_f=2$ QCD with Wilson fermions ». Dans 31st International Symposium on Lattice Field Theory LATTICE 2013. Trieste, Italy : Sissa Medialab, 2014. http://dx.doi.org/10.22323/1.187.0209.

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Arefin, Amit M. E., et Paul F. Egan. « Computational Investigation of Tissue and Blood Vessel Growth Trade-Offs in Hierarchical Lattices ». Dans ASME 2021 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/detc2021-70739.

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Abstract Computational design is growing in necessity for advancing biomedical technologies, particularly when considering complex systems with numerous trade-offs among design decisions and resulting biomechanical behavior. In tissue engineering applications, porous bone scaffold structures enabled by 3D printing can have intricate lattice structures and hierarchical features that mimic the biological hierarchy of natural bone. However, these hierarchies create challenges in predicting the tissue regeneration process and how different scales of the hierarchy drive varied biological behaviors. Smaller pores facilitate tissue growth while larger pores are necessary for blood vessel growth, however, identifying favorable trade-offs to maximize growth of both tissue and blood vessels remains a challenge, especially for complex 3D printed structures. Here, we adapt tissue and blood vessel growth models for predicting biological growth in scaffolds with varied combinations of beam diameter size, unit cell topology, and hierarchical pore size/distribution. Findings demonstrate that on a normalized scale lattices with no large voids provide greater tissue growth but less blood vessel growth in comparison to lattice layouts with large void areas. A lattice with large void channels provided the greatest blood vessel growth but poorer tissue growth, while a lattice with evenly distributed large voids provided a better compromise between the two types of growth. Overall, these findings demonstrate the merit in computational investigations for design trade-off comparisons in tissue scaffolds, and provide a foundation for future explorations of biological design decisions for regenerative medicine and 3D printed systems.
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Tantalo, Nazario. « Matching lattice QC+ED to Nature ». Dans The 39th International Symposium on Lattice Field Theory. Trieste, Italy : Sissa Medialab, 2023. http://dx.doi.org/10.22323/1.430.0249.

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Liu, Liuming, Kostas Orginos, Feng-Kun Guo, Christoph Hanhart et Ulf-G. Meissner. « Interactions of Charmed Mesons with Light Pseudoscalar Mesons from Lattice QCD and Implications on the Nature of the $D_{s0}^*(2317)$ ». Dans 31st International Symposium on Lattice Field Theory LATTICE 2013. Trieste, Italy : Sissa Medialab, 2014. http://dx.doi.org/10.22323/1.187.0239.

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Heng Zhang, Junsuo Zhao, Wenjun Zhang, Dan Li, Xi Yong, Jiayu Zhuang et Jiajia Liu. « Evolution of quantum strategies on a lattice network ». Dans The 2015 11th International Conference on Natural Computation. IEEE, 2015. http://dx.doi.org/10.1109/icnc.2015.7378021.

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Xiajiong, Shen, Wang Peipei, Wang Qian et Zhou Bo. « Association Rules Mining Based on the Discriminative Concept Lattice ». Dans 2009 Fifth International Conference on Natural Computation. IEEE, 2009. http://dx.doi.org/10.1109/icnc.2009.227.

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Rapports d'organisations sur le sujet "Lattice naturale"

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Dell, G. F., et G. Parzen. Natural Chromaticity of Lattices. Office of Scientific and Technical Information (OSTI), février 1988. http://dx.doi.org/10.2172/1119075.

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Williams, James H., Nagem Jr. et Raymond J. Computation of Natural Frequencies of Planar Lattice Structure. Fort Belvoir, VA : Defense Technical Information Center, mars 1987. http://dx.doi.org/10.21236/ada185387.

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Aursjø, Olav, Aksel Hiorth, Alexey Khrulenko et Oddbjørn Mathias Nødland. Polymer flooding : Simulation Upscaling Workflow. University of Stavanger, novembre 2021. http://dx.doi.org/10.31265/usps.203.

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There are many issues to consider when implementing polymer flooding offshore. On the practical side one must handle large volumes of polymer in a cost-efficient manner, and it is crucial that the injected polymer solutions maintain their desired rheological properties during transit from surface facilities and into the reservoir. On the other hand, to predict polymer flow in the reservoir, one must conduct simulations to find out which of the mechanisms observed at the pore and core scales are important for field behavior. This report focuses on theoretical aspects relevant for upscaling of polymer flooding. To this end, several numerical tools have been developed. In principle, the range of length scales covered by these tools is extremely wide: from the nm (10-9 m) to the mm (10-3 m) range, all the way up to the m and km range. However, practical limitations require the use of other tools as well, as described in the following paragraphs. The simulator BADChIMP is a pore-scale computational fluid dynamics (CFD) solver based on the Lattice Boltzmann method. At the pore scale, fluid flow is described by classical laws of nature. To a large extent, pore scale simulations can therefore be viewed as numerical experiments, and they have great potential to foster understanding of the detailed physics of polymer flooding. While valid across length scales, pore scale models require a high numerical resolution, and, subsequently, large computational resources. To model laboratory experiments, the NIORC has, through project 1.1.1 DOUCS, developed IORCoreSim. This simulator includes a comprehensive model for polymer rheological behavior (Lohne A. , Stavland, Åsen, Aursjø, & Hiorth, 2021). The model is valid at all continuum scales; however, the simulator implementation is not able to handle very large field cases, only smaller sector scale systems. To capture polymer behavior at the full field scale, simulators designed for that specific purpose must be used. One practical problem is therefore: How can we utilize the state-of-the-art polymer model, only found in IORCoreSim, as a tool to decrease the uncertainty in full field forecasts? To address this question, we suggest several strategies for how to combine different numerical tools. In the Methodological Approach section, we briefly discuss the more general issue of linking different scales and simulators. In the Validation section, we present two case studies demonstrating the proposed strategies and workflows.
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