IA Scholar Query: Dynamic Algebras and the Nature of Induction
https://scholar.archive.org/
Internet Archive Scholar query results feedeninfo@archive.orgSat, 01 Oct 2022 00:00:00 GMTfatcat-scholarhttps://scholar.archive.org/help1440Sensored speed control of brushless DC motor based salp swarm algorithm
https://scholar.archive.org/work/6ltg5hvyzndizp75aqvjsdxxnq
<p>This article uses one of the newest and efficient meta-heuristic optimization algorithms inspired from nature called salp swarm algorithm (SSA). It imitates the exploring and foraging behavior of salps in oceans. SSA is proposed for parameters tuning of speed controller in brushless DC (BLDC) motor to achieve the best performance. The suggested work modeling and control scheme is done using MATLAB/Simulink and coding environments. In this work, a 6-step inverter is feeding a BLDC motor with a Hall sensor effect. The proposed technique is compared with other nature-inspired techniques such as cuckoo search optimizer (CSO), honey bee optimization (HBO), and flower pollination algorithm (FPA) under the same operating conditions. This comparison aims to show the superiority features of the proposed tuning technique versus other optimization strategies. The proposed tuning technique shows superior optimization features versus other bio-inspired tuning methods that are used in this work. It improves the controller performance of BLDC motor. It refining the speed response features which results in decreasing the rising time, steady-state error, peak overshoot, and settling time.</p>Wisam Najm Al-Din Abed, Omar Abbood Imran, Ali Najim Abdullahwork_6ltg5hvyzndizp75aqvjsdxxnqSat, 01 Oct 2022 00:00:00 GMTIsadore M. Singer (1924–2021) In Memoriam Part 1: Scientific Works
https://scholar.archive.org/work/aejx3oq2lvch5gdpwoqpzzlbqe
Robert Bryant, Jean-Michel Bismut, Jeff Cheeger, Phillip Griffiths, Simon Donaldson, Nigel Hitchin, H Blaine Lawson, Michail Gromov, Adam Marcus, Daniel Spielman, Nikhil Srivastava, Edward Wittenwork_aejx3oq2lvch5gdpwoqpzzlbqeSat, 01 Oct 2022 00:00:00 GMTRemembrances of Ciprian Ilie Foias
https://scholar.archive.org/work/y3ke66suwvcffakbbjadvd6avi
Robert A Becker, Hari Bercovici, Animikh Biswas, Alexey Cheskidov, Peter Constantin, Alp Eden, Art Frazho, Michael Jolly, Igor Kukavica, Carl Pearcy, Ricardo M S Rosa, Jean-Claude Saut, Allen Tannenbaum, Roger Temam, Edriss Titi, Dan Voiculescuwork_y3ke66suwvcffakbbjadvd6aviSat, 01 Oct 2022 00:00:00 GMTSession Coalgebras: A Coalgebraic View on Regular and Context-free Session Types
https://scholar.archive.org/work/7gwjvkyxsrbc5ldzvszual56sa
Compositional methods are central to the verification of software systems. For concurrent and communicating systems, compositional techniques based on behavioural type systems have received much attention. By abstracting communication protocols as types, these type systems can statically check that channels in a program interact following a certain protocol—whether messages are exchanged in the intended order. In this article, we put on our coalgebraic spectacles to investigate session types , a widely studied class of behavioural type systems. We provide a syntax-free description of session-based concurrency as states of coalgebras. As a result, we rediscover type equivalence, duality, and subtyping relations in terms of canonical coinductive presentations. In turn, this coinductive presentation enables us to derive a decidable type system with subtyping for the π-calculus, in which the states of a coalgebra will serve as channel protocols. Going full circle, we exhibit a coalgebra structure on an existing session type system, and show that the relations and type system resulting from our coalgebraic perspective coincide with existing ones. We further apply to session coalgebras the coalgebraic approach to regular languages via the so-called rational fixed point, inspired by the trinity of automata, regular languages, and regular expressions with session coalgebras, rational fixed point, and session types, respectively. We establish a suitable restriction on session coalgebras that determines a similar trinity, and reveals the mismatch between usual session types and our syntax-free coalgebraic approach. Furthermore, we extend our coalgebraic approach to account for context-free session types, by equipping session coalgebras with a stack.Alex C. Keizer, Henning Basold, Jorge A. Pérezwork_7gwjvkyxsrbc5ldzvszual56saFri, 30 Sep 2022 00:00:00 GMTComparative transcriptome analysis reveals different defence responses during the early stage of wounding stress in Chi-Nan germplasm and ordinary Aquilaria sinensis
https://scholar.archive.org/work/yfiake4bqfhphbhndzb533roxa
Agarwood is a valuable Chinese medicinal herb and spice that is produced from wounded Aquilaria spp., is widely used in Southeast Asia and is highly traded on the market. The lack of highly responsive Aquilaria lines has seriously restricted agarwood yield and the development of its industry. In this article, a comparative transcriptome analysis was carried out between ordinary A. sinensis and Chi-Nan germplasm, which is a kind of A. sinensis tree with high agarwood-producing capacity in response to wounding stress, to elucidate the molecular mechanism underlying wounding stress in different A. sinensis germplasm resources and to help identify and breed high agarwood-producing strains. A total of 2427 and 1153 differentially expressed genes (DEGs) were detected in wounded ordinary A. sinensis and Chi-Nan germplasm compared with the control groups, respectively. KEGG enrichment analysis revealed that genes participating in starch metabolism, secondary metabolism and plant hormone signal transduction might play major roles in the early regulation of wound stress. 86 DEGs related to oxygen metabolism, JA pathway and sesquiterpene biosynthesis were identified. The majority of the expression of these genes was differentially induced between two germplasm resources under wounding stress. 13 candidate genes related to defence and sesquiterpene biosynthesis were obtained by WGCNA. Furthermore, the expression pattern of genes were verified by qRT-PCR. The candidate genes expression levels were higher in Chi-Nan germplasm than that in ordinary A. sinensis during early stage of wounding stress, which may play important roles in regulating high agarwood-producing capacity in Chi-Nan germplasm. Compared with A. sinensis, Chi-Nan germplasm invoked different biological processes in response to wounding stress. The genes related to defence signals and sesquiterepene biosynthesis pathway were induced to expression differentially between two germplasm resources. A total of 13 candidate genes were identified, which may correlate with high agarwood-producting capacity in Chi-Nan germplasm during the early stage of wounding stress. These genes will contribute to the development of functional molecular markers and the rapid breeding highly of responsive Aquilaria lines.Feifei Lv, Yun Yang, Peiwen Sun, Yan Zhang, Peiwei Liu, Xiaohong Fan, Yanhong Xu, Jianhe Weiwork_yfiake4bqfhphbhndzb533roxaThu, 29 Sep 2022 00:00:00 GMTLINEAR, HIERARCHICAL THINKING AND TEXTUAL CHARACTERISTICS
https://scholar.archive.org/work/54iym2ivt5egzisuhod4odrzn4
Abstract: The article analyzes the peculiarities of linear, hierarchical thinking with clear theoretical foundations and examples. The types of thinking at different stages of human society and the factors influencing it were studied. At the same time, texts and their features, which arose on the basis of each thinking, were also introduced. On the basis of texts specific to the types of thinking, certain proposals were made.Begniyazova Qumar Allambergenovnawork_54iym2ivt5egzisuhod4odrzn4Thu, 29 Sep 2022 00:00:00 GMTBogoliubov type recursions for renormalisation in regularity structures
https://scholar.archive.org/work/zutghje3tfbjbjgtdjv5t2ikgy
Hairer's regularity structures transformed the solution theory of singular stochastic partial differential equations. The notions of positive and negative renormalisation are central and the intricate interplay between these two renormalisation procedures is captured through the combination of cointeracting bialgebras and an algebraic Birkhoff-type decomposition of bialgebra morphisms. This work revisits the latter by defining Bogoliubov-type recursions similar to Connes and Kreimer's formulation of BPHZ renormalisation. We then apply our approach to the renormalisation problem for SPDEs.Yvain Bruned, Kurusch Ebrahimi-Fardwork_zutghje3tfbjbjgtdjv5t2ikgyWed, 28 Sep 2022 00:00:00 GMTStudies of quantum chromodynamics with jets at the CMS experiment at the LHC
https://scholar.archive.org/work/tl6cqxvdijhwbnd4wxd3l6sbii
Several people played a decisive role in accomplishing this thesis and helped me in dierent aspects. In Hamburg, I would like to extend my deepest gratitude to Patrick L.S. Connor for his invaluable contribution to this work and for training me to consider scientic research as a "share, help, learn, cross-check, enjoy" cycle. Besides developing the overall analysis framework, he was always reachable for help and support, making the work with him a continuous upskilling process. I am also extremely grateful to Paolo Gunnellini for his contributions to the analysis, but mainly for his crucial guidance during my rst steps in high energy physics and his availability to help whenever I needed to. At DESY, I am deeply indebted to Hannes Jung for all his hospitality and support. Apart from that, he also gave me the opportunity to work with his wonderful team, to whom I am also grateful. In particular, many thanks toParaskevas Gianneios, University Of Ioanninawork_tl6cqxvdijhwbnd4wxd3l6sbiiWed, 28 Sep 2022 00:00:00 GMTNoise in Biomolecular Systems: Modeling, Analysis, and Control Implications
https://scholar.archive.org/work/d2oa2hquunbwjcahn3bsbabvpy
While noise is generally associated with uncertainties and often has a negative connotation in engineering, living organisms have evolved to adapt to (and even exploit) such uncertainty to ensure the survival of a species or implement certain functions that would have been difficult or even impossible otherwise. In this article, we review the role and impact of noise in systems and synthetic biology, with a particular emphasis on its role in the genetic control of biological systems, an area we refer to as Cybergenetics. The main modeling paradigm is that of stochastic reaction networks, whose applicability goes beyond biology, as these networks can represent any population dynamics system, including ecological, epidemiological, and opinion dynamics networks. We review different ways to mathematically represent these systems, and we notably argue that the concept of ergodicity presents a particularly suitable way to characterize their stability. We then discuss noise-induced properties and show that noise can be both an asset and a nuisance in this setting. Finally, we discuss recent results on (stochastic) Cybergenetics and explore their relationships to noise. Along the way, we detail the different technical and biological constraints that need to be respected when designing synthetic biological circuits. Finally, we discuss the concepts, problems, and solutions exposed in the article; raise criticisms and concerns about current ideas and approaches; suggest current (open) problems with potential solutions; and provide some ideas for future research directions.Corentin Briat, Mustafa Khammashwork_d2oa2hquunbwjcahn3bsbabvpyWed, 28 Sep 2022 00:00:00 GMTOn 𝒩=4 supersymmetry enhancements in three dimensions
https://scholar.archive.org/work/zx5j4njqcnal3pbhiquia4pjwi
We introduce a class of 3d theories consisting of strongly-coupled 𝒩=4 systems coupled to 𝒩=3 Chern-Simons gauge multiplets, which exhibit 𝒩=4 enhancements when a peculiar condition on the Chern-Simons levels is met. An example is the SU(N)^3 Chern-Simons theory coupled to the 3d T_N theory, which enhances to 𝒩=4 when 1/k_1+1/k_2+1/k_3=0. We also show that some but not all of these 𝒩=4 enhancements can be understood by considering M5-branes on a special class of Seifert manifolds. Our construction provides a large class of 𝒩=4 theories which have not been studied previously.Benjamin Assel, Yuji Tachikawa, Alessandro Tomasiellowork_zx5j4njqcnal3pbhiquia4pjwiWed, 28 Sep 2022 00:00:00 GMTHodge Operators and Exceptional Isomorphisms between Unitary Groups
https://scholar.archive.org/work/jlpanl4mwva27obtcvwk4t4m6a
We give a generalization of the Hodge operator to spaces (V,h) endowed with a hermitian or symmetric bilinear form h over arbitrary fields, including the characteristic two case. Suitable exterior powers of V become free modules over an algebra K defined using such an operator. This leads to several exceptional homomorphisms from unitary groups (with respect to h) into groups of semi-similitudes with respect to a suitable form over some subfield of K. The algebra K depends on h; it is a composition algebra unless h is symmetric and the characteristic is two.Linus Kramer, Markus J. Stroppelwork_jlpanl4mwva27obtcvwk4t4m6aWed, 28 Sep 2022 00:00:00 GMTTurbulence as Clebsch Confinement
https://scholar.archive.org/work/qrlmjshh65cfddfvw4x3lbhb44
We argue that in the strong turbulence phase, as opposed to the weak one, the Clebsch variables compactify to the sphere S_2 and are not observable as wave excitations like weak turbulence. Various topologically nontrivial configurations of this confined Clebsch field are responsible for vortex sheets. Stability equations (CVS) for closed vortex surfaces (bubbles of Clebsch field) are derived and investigated. The exact non-compact solution for the stable vortex sheet family is presented. Compact solutions are proven not to exist by De Lellis and Brué. Asymptotic conservation of anomalous dissipation on stable vortex surfaces in the turbulent limit is discovered. We derive an exact formula for this anomalous dissipation as a surface integral of the square of velocity gap times the square root of minus local normal strain. Topologically stable time-dependent solutions, which we call Kelvinons, are introduced. They have a conserved velocity circulation around static loop; this makes them responsible for asymptotic PDF tails of velocity circulation, perfectly matching numerical simulations. The loop equation for fluid dynamics is derived and studied. This equation is exactly equivalent to the Schrödinger equation in loop space, with viscosity ν playing the role of Planck's constant. Area law and the asymptotic scaling law for mean circulation at a large area are derived. The exact representation of the solution of the loop equation in terms of a singular stochastic equation for momentum loop trajectory is presented. Kelvinons are fixed points of the loop equation at turbulent limit ν→ 0. The Loop equation's linearity makes the PDF's general solution to be a superposition of Kelvinon solutions with different winding numbers.Alexander Migdalwork_qrlmjshh65cfddfvw4x3lbhb44Wed, 28 Sep 2022 00:00:00 GMTRefined probabilistic local well-posedness for a cubic Schrödinger half-wave equation
https://scholar.archive.org/work/gmxvyvkjrbgjte3erusp2j2h5q
We obtain probabilistic local well-posedness in quasilinear regimes for the Schr\"odinger half-wave equation with a cubic nonlinearity. We need to use a refined ansatz because of the lack of probabilistic smoothing in the Picard's iterations, which is due to the high-low-low frequency interactions. The proof is an adaptation of the method of Bringmann on the derivative nonlinear wave equation to Schr\"odinger-type equations. In addition, we discuss ill-posedness results for this equation.Nicolas Camps, Louise Gassot, Slim Ibrahimwork_gmxvyvkjrbgjte3erusp2j2h5qWed, 28 Sep 2022 00:00:00 GMTComputational complexity of problems for deterministic presentations of sofic shifts
https://scholar.archive.org/work/hc7nasbv6ngy5iyqhnbxgvc52q
Sofic shifts are symbolic dynamical systems defined by the set of bi-infinite sequences on an edge-labeled directed graph, called a presentation. We study the computational complexity of an array of natural decision problems about presentations of sofic shifts, such as whether a given graph presents a shift of finite type, or an irreducible shift; whether one graph presents a subshift of another; and whether a given presentation is minimal, or has a synchronizing word. Leveraging connections to automata theory, we first observe that these problems are all decidable in polynomial time when the given presentation is irreducible (strongly connected), via algorithms both known and novel to this work. For the general (reducible) case, however, we show they are all PSPACE-complete. All but one of these problems (subshift) remain polynomial-time solvable when restricting to synchronizing deterministic presentations. We also study the size of synchronizing words and synchronizing deterministic presentations.Justin Cai, Rafael Frongillowork_hc7nasbv6ngy5iyqhnbxgvc52qWed, 28 Sep 2022 00:00:00 GMTPreempting to Minimize Age of Incorrect Information under Random Delay
https://scholar.archive.org/work/crjhoo3ai5dl5kfxt7nktjro3m
We consider the problem of optimizing the decision of a preemptive transmitter to minimize the Age of Incorrect Information (AoII) when the channel has a random delay. In the system, a transmitter observes a dynamic source and makes decisions based on the system status. When the channel is busy, the transmitter can choose whether to preempt to transmit a new update. When the channel is idle, the transmitter can choose whether or not to transmit a new update. We assume that the channel has a random delay and that this delay is independent and identically distributed for any update. At the other end of the channel is a receiver that estimates the state of the dynamic source based on the updates it receives. We adopt AoII to measure the performance of the system. Therefore, this paper aims to optimize the transmitter's action in each time slot to minimize AoII. We first use the Markov decision process to formulate the optimization problem and give the corresponding value iterative algorithm to obtain the optimal policy. However, the value iteration algorithm is computationally demanding, and some approximations are made to realize the algorithm. Hence, we theoretically analyze some canonical delay distributions and obtain the corresponding optimal policies by leveraging the policy improvement theorem.Yutao Chen, Anthony Ephremideswork_crjhoo3ai5dl5kfxt7nktjro3mWed, 28 Sep 2022 00:00:00 GMTDynamical comparison and 𝒵-stability for crossed products of simple C^*-algebras
https://scholar.archive.org/work/jmfprssvxzekdkxz6nnbt2cfhq
We establish 𝒵-stability for crossed products of outer actions of amenable groups on 𝒵-stable C^*-algebras under a mild technical assumption which we call McDuff property with respect to invariant traces. We obtain such result using a weak form of dynamical comparison, which we verify in great generality. We complement our results by proving that McDuffness with respect to invariant traces is automatic in many cases of interest. This is the case, for instance, for every action of an amenable group G on a classifiable C^*-algebra A whose trace space T(A) is a Bauer simplex with finite dimensional boundary ∂_e T(A), and such that the induced action G↷∂_eT(A) is free. If G = ℤ^d and the action G↷∂_eT(A) is free and minimal, then we obtain McDuffness with respect to invariant traces, and thus 𝒵-stability of the corresponding crossed product, also in case ∂_e T(A) has infinite covering dimension.Eusebio Gardella, Shirly Geffen, Petr Naryshkin, Andrea Vaccarowork_jmfprssvxzekdkxz6nnbt2cfhqWed, 28 Sep 2022 00:00:00 GMTMathematical Components
https://scholar.archive.org/work/ahuebtxoqbcrbebz5rb2ulla4q
Mathematical Components is the name of a library of formalized mathematics for the Coq system. It covers a variety of topics, from the theory of basic data structures (e.g., numbers, lists, finite sets) to advanced results in various flavors of algebra. This library constitutes the infrastructure for the machine-checked proofs of the Four Color Theorem and of the Odd Order Theorem. The reason of existence of this book is to break down the barriers to entry. While there are several books around covering the usage of the Coq system and the theory it is based on, the Mathematical Components library is built in an unconventional way. As a consequence, this book provides a non-standard presentation of Coq, putting upfront the formalization choices and the proof style that are the pillars of the library. This books targets two classes of public. On the one hand, newcomers, even the more mathematically inclined ones, find a soft introduction to the programming language of Coq, Gallina, and the SSReflect proof language. On the other hand accustomed Coq users find a substantial account of the formalization style that made the Mathematical Components library possible.Assia Mahboubi, Enrico Tassiwork_ahuebtxoqbcrbebz5rb2ulla4qWed, 28 Sep 2022 00:00:00 GMTSimplicity of right-angled Hecke C^∗-algebras
https://scholar.archive.org/work/hctkiwwzxzhzlcsjfz2uaxwpqu
By exploiting properties of boundaries associated with Coxeter groups we obtain a complete characterization of simple right-angled multi-parameter Hecke C^∗-algebras. This extends previous results by Caspers, Larsen and the author. Based on work by Raum and Skalski, we further describe the center and the character space of right-angled Hecke C^∗-algebras.Mario Klissework_hctkiwwzxzhzlcsjfz2uaxwpquWed, 28 Sep 2022 00:00:00 GMTEfficient and Near-Optimal Online Portfolio Selection
https://scholar.archive.org/work/xucynznjczbvppsboc3eksflly
In the problem of online portfolio selection as formulated by Cover (1991), the trader repeatedly distributes her capital over d assets in each of T > 1 rounds, with the goal of maximizing the total return. Cover proposed an algorithm, termed Universal Portfolios, that performs nearly as well as the best (in hindsight) static assignment of a portfolio, with an O(dlog(T)) regret in terms of the logarithmic return. Without imposing any restrictions on the market this guarantee is known to be worst-case optimal, and no other algorithm attaining it has been discovered so far. Unfortunately, Cover's algorithm crucially relies on computing certain d-dimensional integral which must be approximated in any implementation; this results in a prohibitive Õ(d^4(T+d)^14) per-round runtime for the fastest known implementation due to Kalai and Vempala (2002). We propose an algorithm for online portfolio selection that admits essentially the same regret guarantee as Universal Portfolios – up to a constant factor and replacement of log(T) with log(T+d) – yet has a drastically reduced runtime of Õ(d^2(T+d)) per round. The selected portfolio minimizes the current logarithmic loss regularized by the log-determinant of its Hessian – equivalently, the hybrid logarithmic-volumetric barrier of the polytope specified by the asset return vectors. As such, our work reveals surprising connections of online portfolio selection with two classical topics in optimization theory: cutting-plane and interior-point algorithms.Rémi Jézéquel, Dmitrii M. Ostrovskii, Pierre Gaillardwork_xucynznjczbvppsboc3eksfllyWed, 28 Sep 2022 00:00:00 GMTMechanizing the comparison of the semantic expressiveness of recursive types
https://scholar.archive.org/work/qnwunkjrivaf7b6nqitdaipice
Recursive types extend the simply-typed lambda calculus (STLC) with the additional expressive power to enable diverging computation and to encode recursive data-types (e.g., lists). Two formulations of recursive types exist: iso-recursive and equi-recursive. The relative advantages of iso- and equi-recursion are well-studied when it comes to their impact on type-inference. However, the relative semantic expressiveness of the two formulations remains unclear so far. This paper studies the semantic expressiveness of STLC with iso- and equi-recursive types, proving that these formulations are equally expressive. In fact, we prove that they are both as expressive as STLC with only term-level recursion. We phrase these equi-expressiveness results in terms of full abstraction of three canonical compilers between these three languages (STLC with iso-, with equi-recursive types and with term-level recursion). Our choice of languages allows us to study expressiveness when interacting over both a simply-typed and a recursively-typed interface. The three proofs all rely on a typed version of a proof technique called approximate backtranslation. Together, our results show that there is no difference in semantic expressiveness between STLCs with iso- and equi-recursive types. In this paper, we focus on a simply-typed setting but we believe our results scale to more powerful type systems like System F.Dominique Devriese, Eric Mark Martin, Marco Patrignaniwork_qnwunkjrivaf7b6nqitdaipiceWed, 28 Sep 2022 00:00:00 GMT