Academic literature on the topic 'Tuples of Operators'

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Journal articles on the topic "Tuples of Operators"

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Wang, Wei, Yonglu Shu, and Xingzhong Wang. "S-Mixing Tuple of Operators on Banach Spaces." Journal of Function Spaces 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/9251672.

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We consider the question: what is the appropriate formulation of Godefroy-Shapiro criterion for tuples of operators? We also introduce a new notion about tuples of operators,S-mixing, which lies between mixing and weakly mixing. We also obtain a sufficient condition to ensure a tuple of operators to beS-mixing. Moreover, we study some new properties ofS-mixing operators on several concrete Banach spaces.
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Hoffmann, Philipp H. W., and Michael Mackey. "(m, p)-isometric and (m, ∞)-isometric operator tuples on normed spaces." Asian-European Journal of Mathematics 08, no. 02 (June 2015): 1550022. http://dx.doi.org/10.1142/s1793557115500229.

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We generalize the notion of m-isometric operator tuples on Hilbert spaces in a natural way to operator tuples on normed spaces. This is done by defining a tuple analogue of (m, p)-isometric operators, so-called (m, p)-isometric operator tuples. We then extend this definition further by introducing (m, ∞)-isometric operator tuples and study properties of and relations between these objects.
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Ahmed, Ahmed. "Higher dimensional [m,C]-isometric commuting d-tuple of operators." Filomat 36, no. 12 (2022): 4173–84. http://dx.doi.org/10.2298/fil2212173a.

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In this paper we recover an [m,C]-isometric operators and (m,C)-isometric commuting tuples of operators on a Hilbert space studied respectively in [11] and [16], we introduce the class of [m,C]-isometries for tuple of commuting operators. This is a generalization of the class of [m,C]-isometric commuting operators on a Hilbert spaces. A commuting tuples of operators S = (S1,..., Sp) ? B(H)p is said to be [m,C]-isometric p-tuple of commuting operators if ?m (S,C):= ?m j=0 (?1)m?j (m j) (? |?|=j j!/?! CS?CS?)=0 for some positive integer m and some conjugation C. We consider a multi-variable generalization of these single variable [m,C]-isometric operators and explore some of their basic properties.
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Mićić, Jadranka, Zlatko Pavić, and Josip Pečarić. "Extension of Jensen's Inequality for Operators without Operator Convexity." Abstract and Applied Analysis 2011 (2011): 1–14. http://dx.doi.org/10.1155/2011/358981.

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We give an extension of Jensen's inequality for -tuples of self-adjoint operators, unital -tuples of positive linear mappings, and real-valued continuous convex functions with conditions on the operators' bounds. We also study operator quasiarithmetic means under the same conditions.
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Duggal, B. P. "Subspace gaps and Weyl's theorem for an elementary operator." International Journal of Mathematics and Mathematical Sciences 2005, no. 3 (2005): 465–74. http://dx.doi.org/10.1155/ijmms.2005.465.

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A range-kernal orthogonality property is established for the elementary operatorsℰ(X)=∑i=1nAiXBiandℰ*(X)=∑i=1nAi*XBi*, whereA=(A1,A2,…,An)andB=(B1,B2,…,Bn)aren-tuples of mutually commuting scalar operators (in the sense of Dunford) in the algebraB(H)of operators on a Hilbert spaceH. It is proved that the operatorℰsatisfies Weyl's theorem in the case in whichAandBaren-tuples of mutually commuting generalized scalar operators.
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Charlesworth, Ian, Ken Dykema, Fedor Sukochev, and Dmitriy Zanin. "Simultaneous Upper Triangular Forms for Commuting Operators in a Finite von Neumann Algebra." Canadian Journal of Mathematics 72, no. 5 (May 15, 2019): 1188–245. http://dx.doi.org/10.4153/s0008414x19000282.

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AbstractThe joint Brown measure and joint Haagerup–Schultz projections for tuples of commuting operators in a von Neumann algebra equipped with a faithful tracial state are investigated, and several natural properties are proved for these. It is shown that the support of the joint Brown measure is contained in the Taylor joint spectrum of the tuple, and also in the ostensibly smaller left Harte spectrum. A simultaneous upper triangularization result for finite commuting tuples is proved, and the joint Brown measure and joint Haagerup–Schultz projections are shown to behave well under the Arens multivariate holomorphic functional calculus of such a commuting tuple.
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Chō, Muneo. "Joint spectra of commuting normal operators on Banach spaces." Glasgow Mathematical Journal 30, no. 3 (September 1988): 339–45. http://dx.doi.org/10.1017/s0017089500007436.

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The joint spectrum for a commuting n-tuple in functional analysis has its origin in functional calculus which appeared in J. L. Taylor's epoch-making paper [19] in 1970. Since then, many papers have been published on commuting n-tuples of operators on Hilbert spaces (for example, [3], [4], [5], [8], [9], [10], [21], [22]).
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Bhatia, R., and L. Elsner. "On Joint Eigenvalues of Commuting Matrices." Canadian Mathematical Bulletin 39, no. 2 (June 1, 1996): 164–68. http://dx.doi.org/10.4153/cmb-1996-020-6.

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AbstractA spectral radius formula for commuting tuples of operators has been proved in recent years. We obtain an analog for all the joint eigenvalues of a commuting tuple of matrices. For a single matrix this reduces to an old result of Yamamoto.
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Works, Karen, and Elke A. Rundensteiner. "Preferential Resource Allocation in Stream Processing Systems." International Journal of Cooperative Information Systems 23, no. 04 (December 2014): 1450006. http://dx.doi.org/10.1142/s0218843014500063.

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Overloaded data stream management systems (DSMS) cannot process all tuples within their response time. For some DSMS it is crucial to allocate the precious resources to process the most significant tuples. Prior work has applied shedding and spilling to permanently drop or temporarily place to disk insignificant tuples. However neither approach considers that tuple significance can be multi-tiered nor that significance determination can be costly. These approaches consider all tuples not dropped to be equally significant. Unlike these prior works, we take a fresh stance by pulling the most significant tuples forward throughout the query pipeline. Proactive Promotion (PP), a new DSMS methodology for preferential CPU resource allocation, selectively pulls the most significant tuples ahead of less significant tuples. Our optimizer produces an optimal PP plan that minimizes the processing latency of tuples in the most significant tiers in this multi-tiered precedence scheme by strategically placing significance determination operators throughout the query pipeline at compile-time and by agilely activating them at run-time. Our results substantiate that PP lowers the latency and increases the throughput for significant results when compared to the state-of-the-art shedding and traditional DSMS approaches (between 2 and 18 fold for a rich diversity of datasets) with negligible overhead.
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Müller, Vladimir. "UNIVERSAL N-TUPLES OF OPERATORS." Mathematical Proceedings of the Royal Irish Academy 113A, no. 2 (2013): 143–50. http://dx.doi.org/10.1353/mpr.2013.0015.

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Dissertations / Theses on the topic "Tuples of Operators"

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Kribs, David Wallace. "Non-commuting n-tuples of operators and dilation theory." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ51206.pdf.

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Hazra, Somnath. "Homogeneous Operators." Thesis, 2017. http://etd.iisc.ernet.in/2005/3694.

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A bounded operator T on a complex separable Hilbert space is said to be homogeneous if '(T ) is unitarily equivalent to T for all ' in M•ob, where M•ob is the M•obius group. A complete description of all homogeneous weighted shifts was obtained by Bagchi and Misra. The first examples of irreducible bi-lateral homogeneous 2-shifts were given by Koranyi. We describe all irreducible homogeneous 2-shifts up to unitary equivalence completing the list of homogeneous 2-shifts of Koranyi. After completing the list of all irreducible homogeneous 2-shifts, we show that every homogeneous operator whose associated representation is a direct sum of three copies of a Complementary series representation, is reducible. Moreover, we show that such an operator is either a direct sum of three bi-lateral weighted shifts, each of which is a homogeneous operator or a direct sum of a homogeneous bi-lateral weighted shift and an irreducible bi-lateral 2-shift. It is known that the characteristic function T of a homogeneous contraction T with an associated representation is of the form T (a) = L( a) T (0) R( a); where L and R are projective representations of the M•obius group M•ob with a common multiplier. We give another proof of the \product formula". We point out that the defect operators of a homogeneous contraction in B2(D) are not always quasi-invertible (recall that an operator T is said to be quasi-invertible if T is injective and ran(T ) is dense). We prove that when the defect operators of a homogeneous contraction in B2(D) are not quasi-invertible, the projective representations L and R are unitarily equivalent to the holomorphic Discrete series representations D+ 1 and D++3, respectively. Also, we prove that, when the defect operators of a homogeneous contraction in B2(D) are quasi-invertible, the two representations L and R are unitarily equivalent to certain known pairs of representations D 1; 2 and D +1; 1 ; respectively. These are described explicitly. Let G be either (i) the direct product of n-copies of the bi-holomorphic automorphism group of the disc or (ii) the bi-holomorphic automorphism group of the polydisc Dn: A commuting tuple of bounded operators T = (T1; T2; : : : ; Tn) is said to be homogeneous with respect to G if the joint spectrum of T lies in Dn and '(T); defined using the usual functional calculus, is unitarily equivalent to T for all ' 2 G: We show that a commuting tuple T in the Cowen-Douglas class of rank 1 is homogeneous with respect to G if and only if it is unitarily equivalent to the tuple of the multiplication operators on either the reproducing kernel Hilbert space with reproducing kernel n 1 i=1 (1 ziwi) i or Q n i i n; are positive real numbers, according asQG is as in (i) or 1 ; where ; i, 1 i i=1 (1 z w ) (ii). Finally, we show that a commuting tuple (T1; T2; : : : ; Tn) in the Cowen-Douglas class of rank 2 is homogeneous with respect to M•obn if and only if it is unitarily equivalent to the tuple of the multiplication operators on the reproducing kernel Hilbert space whose reproducing kernel is a product of n 1 rank one kernels and a rank two kernel. We also show that there is no irreducible tuple of operators in B2(Dn), which is homogeneous with respect to the group Aut(Dn):
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Sarkar, Santanu. "Some Problems in Multivariable Operator Theory." Thesis, 2014. http://etd.iisc.ernet.in/handle/2005/2897.

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In this thesis we have investigated two different types of problems in multivariable operator theory. The first one deals with the defect sequence for contractive tuples and maximal con-tractive tuples. These condone deals with the wandering subspaces of the Bergman space and the Dirichlet space over the polydisc. These are described in thefollowing two sections. (I) The Defect Sequence for ContractiveTuples LetT=(T1,...,Td)bead-tuple of bounded linear operators on some Hilbert space H. We say that T is a row contraction, or, acontractive tuplei f the row operator (Pl refer the abstract pdf file)
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Kennedy, Matthew. "Free semigroup algebras and the structure of an isometric tuple." Thesis, 2011. http://hdl.handle.net/10012/6022.

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An n-tuple of operators V=(V_1,…,V_n) acting on a Hilbert space H is said to be isometric if the corresponding row operator is an isometry. A free semigroup algebra is the weakly closed algebra generated by an isometric n-tuple V. The structure of a free semigroup algebra contains a great deal of information about V. Thus it is natural to study this algebra in order to study V. A free semigroup algebra is said to be analytic if it is isomorphic to the noncommutative analytic Toeplitz algebra, which is a higher-dimensional generalization of the classical algebra of bounded analytic functions on the complex unit disk. This notion of analyticity is of central importance in the general theory of free semigroup algebras. A vector x in H is said to be wandering for an isometric n-tuple V if the set of words in the entries of V map x to an orthonormal set. As in the classical case, the analytic structure of the noncommutative analytic Toeplitz algebra is determined by the existence of wandering vectors for the generators of the algebra. In the first part of this thesis, we prove the following dichotomy: either an isometric n-tuple V has a wandering vector, or the free semigroup algebra it generates is a von Neumann algebra. This implies the existence of wandering vectors for every analytic free semigroup algebra. As a consequence, it follows that every free semigroup algebra is reflexive, in the sense that it is completely determined by its invariant subspace lattice. In the second part of this thesis we prove a decomposition for an isometric tuple of operators which generalizes the classical Lebesgue-von Neumann-Wold decomposition of an isometry into the direct sum of a unilateral shift, an absolutely continuous unitary and a singular unitary. The key result is an operator-algebraic characterization of an absolutely continuous isometric tuple in terms of analyticity. We show that, as in the classical case, this decomposition determines the weakly closed algebra and the von Neumann algebra generated by the tuple.
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Book chapters on the topic "Tuples of Operators"

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Xia, Daoxing. "Operator Identities for Subnormal Tuples of Operators." In A Panorama of Modern Operator Theory and Related Topics, 613–38. Basel: Springer Basel, 2012. http://dx.doi.org/10.1007/978-3-0348-0221-5_27.

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Dragomir, Silvestru Sever. "Inequalities for n-Tuples of Operators." In SpringerBriefs in Mathematics, 5–59. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17459-0_2.

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Colombo, Fabrizio, Irene Sabadini, and Daniele C. Struppa. "Functional calculus for n-tuples of operators." In Noncommutative Functional Calculus, 81–112. Basel: Springer Basel, 2011. http://dx.doi.org/10.1007/978-3-0348-0110-2_3.

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Voiculescu, Dan-Virgil. "Hybrid Normed Ideal Perturbations of n-Tuples of Operators II: Weak Wave Operators." In Operator Theory, Operator Algebras and Their Interactions with Geometry and Topology, 501–10. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-43380-2_24.

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Trent, Tavan T. "On the Taylor Spectrum of M-Tuples of Analytic Toeplitz Operators on the Polydisk." In Fields Institute Communications, 211–31. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1255-1_11.

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Nickel, Stefan, Claudius Steinhardt, Hans Schlenker, and Wolfgang Burkart. "Modeling with tuples." In Graduate Texts in Operations Research, 79–111. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-65481-1_6.

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Wei, Cuiping, Xijin Tang, and Xiaojie Wang. "On Prioritized 2-tuple Ordered Weighted Averaging Operators." In Active Media Technology, 513–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-35236-2_51.

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Liu, Hu-Chen, and Xiao-Yue You. "GSES Using Interval 2-Tuple Linguistic Distance Operators." In Green Supplier Evaluation and Selection: Models, Methods and Applications, 111–32. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0382-2_5.

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Labella, Álvaro, Bapi Dutta, Rosa M. Rodríguez, and Luis Martínez. "A Linguistic 2-tuple Best-Worst Method." In Lecture Notes in Operations Research, 41–51. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-89795-6_4.

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Bhunia, Pintu, Silvestru Sever Dragomir, Mohammad Sal Moslehian, and Kallol Paul. "p-Numerical Radius Inequalities of an n-Tuple of Operators." In Infosys Science Foundation Series, 85–110. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-13670-2_4.

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Conference papers on the topic "Tuples of Operators"

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PELÁEZ, J. I., J. M. DOÑA, A. M. GIL, and D. L. LA RED. "VALUATION OF COMPANIES USING 2-TUPLES AND MAJORITY OPERATORS." In Proceedings of the 4th International ISKE Conference on Intelligent Systems and Knowledge Engineering. WORLD SCIENTIFIC, 2009. http://dx.doi.org/10.1142/9789814295062_0107.

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Chen, Shyi-Ming, Li-Wei Lee, and Victor R. L. Shen. "Similarity measures between intervals of linguistic 2-tuples and the intervals of linguistic 2-tuples weighted average operator." In 2011 International Conference on Machine Learning and Cybernetics (ICMLC). IEEE, 2011. http://dx.doi.org/10.1109/icmlc.2011.6016999.

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Verhaeghe, Hélène, Christophe Lecoutre, and Pierre Schaus. "Compact-MDD: Efficiently Filtering (s)MDD Constraints with Reversible Sparse Bit-sets." In Twenty-Seventh International Joint Conference on Artificial Intelligence {IJCAI-18}. California: International Joint Conferences on Artificial Intelligence Organization, 2018. http://dx.doi.org/10.24963/ijcai.2018/192.

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Multi-Valued Decision Diagrams (MDDs) are instrumental in modeling combinatorial problems with Constraint Programming.In this paper, we propose a related data structure called sMDD (semi-MDD) where the central layer of the diagrams is non-deterministic.We show that it is easy and efficient to transform any table (set of tuples) into an sMDD.We also introduce a new filtering algorithm, called Compact-MDD, which is based on bitwise operations, and can be applied to both MDDs and sMDDs.Our experimental results show the practical interest of our approach, both in terms of compression and filtering speed.
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Wang, Yanjun, Duzheng Liu, and Lidong Wang. "Discriminative and Generalized Dependent Aggregation Operators for Hesitant 2- Tuple Linguistic Information." In 2018 14th International Conference on Natural Computation, Fuzzy Systems and Knowledge Discovery (ICNC-FSKD). IEEE, 2018. http://dx.doi.org/10.1109/fskd.2018.8687191.

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Xu, Yejun, and Ling Huang. "An Approach to Group Decision Making Problems Based on 2-Tuple Linguistic Aggregation Operators." In 2008 ISECS International Colloquium on Computing, Communication, Control, and Management. IEEE, 2008. http://dx.doi.org/10.1109/cccm.2008.40.

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Zhao, Shaowei, Junmao Li, and Dagang Li. "An efficient tuple pruning scheme for packet classification using on-chip filtering and indexing." In NOMS 2018 - 2018 IEEE/IFIP Network Operations and Management Symposium. IEEE, 2018. http://dx.doi.org/10.1109/noms.2018.8406226.

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Lei, Li, Zheng Lijuan, and Guo Ge. "A method for emergency plan evaluation under group decision makers based on 2-tuple prioritized OWA operator." In 2016 Chinese Control and Decision Conference (CCDC). IEEE, 2016. http://dx.doi.org/10.1109/ccdc.2016.7531335.

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Renu, Rahul Sharan, and Gregory Mocko. "Computationally Assisted Retrieval and Reuse of 3D Solid Models and Assembly Work Instructions." In 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/detc2021-70480.

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Abstract Many manufacturing enterprises have large collections of solid models and text-based assembly processes to support assembly operations. These data are often distributed across their extended enterprise. As these enterprises expand globally, there is often an increase in product and process variability which can often lead to challenges with training, quality control, and obstacles with change management to name a few. Thus, there is a desire to increase the consistency of assembly work instructions within and across assembly locations. The objective of this research is to retrieve existing 3d models of components and assemblies and their associated assembly work instructions. This is accomplished using 3d solid model similarity and text mining of assembly work instructions. Initially, a design study was conducted in which participants authored assembly work instructions for several different solid model assemblies. Next, a geometric similarity algorithm was used to compute similarity scores between solid models and latent semantic analysis is used to compute the similarity between text-based assembly work instructions. Finally, a correlation study between solid model-assembly instruction tuples is computed. A moderately strong positive correlation was found to exist between solid model similarity scores and their associated assembly instruction similarity scores. This indicates that designs with a similar shape have a similar assembly process and thus can serve as the basis for authoring new assembly processes. This aids in resolving differences in existing processes by linking three-dimensional solid models and their associated assembly work instructions.
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Mosobalaje, O. O., and O. D. Orodu. "Introducing Python Coding to Petroleum Engineering Undergraduates: Excerpts from a Teaching Experience." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/217148-ms.

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Abstract The post-Covid world is witnessing a rise in automation and remote work models. Oilfield operations are becoming increasingly innovation-driven with advances such as digitalization technologies, smart fields and intelligent wells. Proliferation of data is extending career frontiers in data analytics, machine learning and artificial intelligence. Human competence in computer programming is a key enabler of these trends. As a contribution to the Nigerian oil/gas human resources development, the petroleum engineering program at Covenant University recently developed and is implementing a course module on Python programing with oil/gas applications. This paper documents the philosophy, pedagogy, and prospects of this initiative and provides a guide for its implementation across the Nigerian educational space. The module opens with a seminar on the emerging oil/gas opportunities in data science – to stimulate students’ interest. Thereafter, a gentle introduction to computer programming is taught. At its core, the module teaches basics of Python programming language – input/output, objects (values, variables, keywords), conditional and repetitive structures, functions, lists, tuples and dictionaries. The module is enriched with applications in reservoir volumetrics, material balance equation, PVT properties, reservoir discretization and simulation. Hands-on experience is enhanced with class demos and take-home programming assignments featuring simple algorithms. Also, the course features a training on the use of distributed version control (GitHub) for collaboration between students and instructors. All course materials are available on an open-access GitHub repository, with hyperlinks embedded in lecture notes. Ultimately, the course assesses students’ skills with exams set in the context of quasi-real-life projects. The future prospects targeted in this initiative includes a follow-up module on petroleum data analytics and machine learning, incorporation of Python coding into other modules, and a short-course for industry professionals.
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Mennicken, M., D. Schoenweitz, M. Schnoes, and R. Schnell. "Conceptual Fan Design for Boundary Layer Ingestion." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90257.

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Abstract Aircraft concepts using boundary layer ingestion (BLI) are promising future flight systems aiming at reduced mission fuel burn. In this scenario the fan operates at inhomogeneous inflow conditions around the circumference. The accurate calculation of the resulting flow phenomena using uRANS approaches is highly time-consuming and therefore not suitable for fan design at early stages of the design process. In this paper, we introduce a throughflow based design methodology for BLI. The methodology includes the detailed design of the annulus geometry, the design of rotor and stator blades as well as the performance assessment in the BLI scenario. The throughflow approach is extended and calibrated to cover major BLI flow physics. The calibration data set consists of 12 fans with different fan pressure ratios (FPR) and meridional Mach numbers. The new design methodology is applied to design three specific fans and the effect of radial FPR is investigated. All designs are verified using 3D CFD uRANS approaches and the results indicate that either ascending or constant radial FPR should be favored. In addition an exploration study is conducted using the design methodology. This study covers 72 fan stages in the parameter space tip speed and meridional Mach number. The results suggest that there is a favorable tuple of design parameters to design a distortion tolerant fan by trading tip speed and meridional Mach number. In the end the newly gained knowledge is transferred to the DLR UHBR fan in order to improve the tolerance to BLI.
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