107,813 research outputs found
Generalized Gap Metrics and Robust Stability of Nonlinear Systems
No full textA gap metric of Georgiou and Smith (IEEE Trans. Auto. Control, 42(9):1200--1229, 1997), which does not need causal and surjective mapping between graphs to define, is studied and generalized based on the notion of biased norm, the corresponding robust stability theorem is presented in the notion of stability with bias terms. The obtained results are then applied to studied the stability of linear system realizations, semilinear systems with bounded nonlinearities and a nonlinear system with time delay in the inputs
Complexity reduction of Nonlinear Systems
No full textA common problem in nonlinear control is the need to consider systems of high complexity. Here we consider systems, which although may be low order, have high complexity due to a complex right hand side of a differential equation (e.g. a right hand side which has many terms – such systems arise from coordinate transformations in constructive nonlinear control designs). This contribution develops a systematic method for the reduction of this complexity, complete with error bounds. In the case when the underling nonlinear system input/output operator is stable and differentiable, the operator Taylor expansion, truncated after a finite number of terms, is taken as the approximation. If the nonlinear system i/o operator is not stable, but admits a coprime factorizations, the Taylor approximation is made to both coprime factors. By bounding the gap between the polynomial system and the original nominal plant, and applying gap robust stability approaches, it is proved that local stability of approximation implies the local stability of the underlining nonlinear systems, and explicit robust stability margins and performance bounds obtained. For systems specified by a finite dimensional first order differential equation, the first order approximant is the system linearisation and the higher order approximants have greater state dimension but with polynomial right hand sides
Rhaphidophora quadrispina Liu & Bian 2021
No full textRhaphidophora quadrispina Liu & Bian, 2021 ZIJĒȃ Figs. 19–20 The complete mitogenome of Rhaphidophora quadrispina was assembled into a circular-mapping form of 15892 bp in length (GenBank accession number: OL450400), which comprised 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region (D-loop). Among these mitochondrial genes, fourteen tRNA genes and nine protein coding genes were coded with the J-strand, while other genes were encoded by the N-strand. There were 15 intergenic spacer regions and 13 overlapping regions are observed in the mitogenome ranging from 1 bp to 30 bp and 1 to 23 bp (Table 1). The overall base nucleotide composition of Rhaphidophora quadrispina mitogenome was determined to be 41.35% A, 34.18% T, 14.84% C, 9.62% G and revealed an obviously A/T (75.53%) bias (Table 2). Meanwhile, the control region had the highest A+T content (81.69%), while tRNAs were the lowest (51.34%) in the mitogenome. Except control region, AT-skew values were positive from 0.02 (PCGs-1st) to 0.48 (tRNAs) and GC-skew values were negative ranging from -0.56 (tRNAs) to -0.06 (PCGs -3rd), which indicated that the content of A and C nucleotides was more abundant than G and T. Among 13 PCGs, the longest one was ND5 gene (1735 bp), whereas the shortest was ATP8 gene (159 bp). All protein-coding genes mainly started with the standard codons ATN, except for ND5 which started with GTG. Most genes were used TAA or TAG as complete stop codons. But the termination codons of ND5 and ND4 were a single T instead of completeness. For the relative synonymous codon usage (RSCU), the first five frequently used were UUA (Leu2), AUA (Met), GUU (Val), GUA (Val) and UCA (Ser2) (Fig. 19). The lengths of tRNA genes ranging from 64 bp (trnaA and trnaH) to 72 bp (trnaV). Besides trnaS1, the other tRNA genes formed the typical cloverleaf structure (Fig. 20). The lengths of rrnL and rrnS were 1313 bp and 791 bp respectively.Published as part of Lu, Xiangyi, Liu, Jing, Huang, Xiaojuan & Bian, Xun, 2022, Contribution to the Chinese subfamily Rhaphidophorinae Walker, 1869 (Orthoptera: Rhaphidophoridae: Rhaphidophorinae) IV: Seven new species of Rhaphidophora and one new mitogenome, pp. 129-153 in Zootaxa 5087 (1) on pages 149-151, DOI: 10.11646/zootaxa.5087.1.6, http://zenodo.org/record/581987
Le sanatorium du Lang-Bian
No full textLe sanatorium du Lang-Bian. In: Annales de Géographie, t. 8, n°42, 1899. p. 476
Le sanatorium du Lang-Bian
No full textLe sanatorium du Lang-Bian. In: Annales de Géographie, t. 8, n°42, 1899. p. 476
Controllability of nonlinear systems with pre-assigned responses
No full textIn this paper, we study the approximate controllability with preassigned responses of the nonlinear delay systems x(t)=A(t)x(t)+f(t, x(t), x((t)), u(t)) and L(x(t), x(t))=A(t)x(t)+f(t, x(t), x((t)), u(t)). The controllability is not governed by an associated linear system, but by conditions on f or A involving the domain of A(t). No compactness assumptions are imposed in the main results
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
An intrinsic behavioural approach to the double time axis paradox
No full textBehavioural theory is typically developed on the double time axis. On the other hand it is known that there are intrinsic difficulties with double time axis theorems in the input output context. This paper illustrates how the behavioural approach avoids these intrinsic difficulties
Fast and Effective Techniques for T-Count Reduction via Spider Nest Identities
No full textIn fault-tolerant quantum computing systems, realising (approximately) universal quantum computation is usually described in terms of realising Clifford+T operations, which is to say a circuit of CNOT, Hadamard, and π/2-phase rotations, together with T operations (π/4-phase rotations). For many error correcting codes, fault-tolerant realisations of Clifford operations are significantly less resource-intensive than those of T gates, which motivates finding ways to realise the same transformation involving T-count (the number of T gates involved) which is as low as possible. Investigations into this problem [Matthew Amy et al., 2013; Gosset et al., 2014; Matthew Amy et al., 2014; Matthew Amy et al., 2018; Earl T. Campbell and Mark Howard, 2017; Matthew Amy and Michele Mosca, 2019] has led to observations that this problem is closely related to NP-hard tensor decomposition problems [Luke E. Heyfron and Earl T. Campbell, 2018] and is tantamount to the difficult problem of decoding exponentially long Reed-Muller codes [Matthew Amy and Michele Mosca, 2019]. This problem then presents itself as one for which must be content in practise with approximate optimisation, in which one develops an array of tactics to be deployed through some pragmatic strategy. In this vein, we describe techniques to reduce the T-count, based on the effective application of "spider nest identities": easily recognised products of parity-phase operations which are equivalent to the identity operation. We demonstrate the effectiveness of such techniques by obtaining improvements in the T-counts of a number of circuits, in run-times which are typically less than the time required to make a fresh cup of coffee
Cellular Origins and Pathogenesis of Gastrointestinal NK- and T-Cell Lymphoproliferative Disorders
No full textSIMPLE SUMMARY: Intestinal T- and NK-cell lymphoproliferative disorders are a group of rare gastrointestinal disorders that arise from immune cells in the intestinal mucosa that are also relatively unknown. Diseases such as indolent T-cell lymphoproliferative disorders of the gastrointestinal tract do not even require treatment, whereas others, such as monomorphic epitheliotropic intestinal T-cell lymphoma, will generally cause death within a year. No effective treatment is currently available, as little is known about how these tumours form or even what cells they arise from. This article summarizes the current state of knowledge about the main types of immune cells in the gastrointestinal mucosa and the processes by which they may transform into neoplasms. The clinical behaviour, pathological appearances and the molecular alterations that underlie these diseases are also discussed. ABSTRACT: The intestinal immune system, which must ensure appropriate immune responses to both pathogens and commensal microflora, comprises innate lymphoid cells and various T-cell subsets, including intra-epithelial lymphocytes (IELs). An example of innate lymphoid cells is natural killer cells, which may be classified into tissue-resident, CD56(bright) NK-cells that serve a regulatory function and more mature, circulating CD56(dim) NK-cells with effector cytolytic properties. CD56(bright) NK-cells in the gastrointestinal tract give rise to indolent NK-cell enteropathy and lymphomatoid gastropathy, as well as the aggressive extranodal NK/T cell lymphoma, the latter following activation by EBV infection and neoplastic transformation. Conventional CD4+ TCRαβ+ and CD8αβ+ TCRαβ+ T-cells are located in the lamina propria and the intraepithelial compartment of intestinal mucosa as type ‘a’ IELs. They are the putative cells of origin for CD4+ and CD8+ indolent T-cell lymphoproliferative disorders of the gastrointestinal tract and intestinal T-cell lymphoma, NOS. In addition to such conventional T-cells, there are non-conventional T-cells in the intra-epithelial compartment that express CD8αα and innate lymphoid cells that lack TCRs. The central feature of type ‘b’ IELs is the expression of CD8αα homodimers, seen in monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), which primarily arises from both CD8αα+ TCRαβ+ and CD8αα+ TCRγδ+ IELs. EATL is the other epitheliotropic T-cell lymphoma in the GI tract, a subset of which arises from the expansion and reprograming of intracytoplasmic CD3+ innate lymphoid cells, driven by IL15 and mutations of the JAK-STAT pathway
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