We correct some unfortunate mistakes that appeared in the article D. Thaghizadeh, M. Zahraei, A. Peperko, and N. H. Aboutalebi, On the numerical ranges of matrices in max algebra, Banach J. Math. Anal., 14 (2020), 177...
We correct some unfortunate mistakes that appeared in the article D. Thaghizadeh, M. Zahraei, A. Peperko, and N. H. Aboutalebi, On the numerical ranges of matrices in max algebra, Banach J. Math. Anal., 14 (2020), 1773–1792, concerning certain notions of the numerical range in the max algebra setting. Along the way we also include a study of the characteristic max polynomial and correspondingly the max k-spectrum and the k-tropical spectrum. We also pose a related and intriguing open question.
作者:
Yu, ZhuojunThomas, Peter J.Department of Mathematics
Applied Mathematics and Statistics Case Western Reserve University ClevelandOH44106 United States Department of Mathematics
Applied Mathematics and Statistics Department of Biology Department of Electrical Control and Systems Engineering Case Western Reserve University ClevelandOH44106 United States
Although the raison d’etre of the brain is the survival of the body, there are relatively few theoretical studies of closed-loop rhythmic motor control systems. In this paper we provide a unified framework, based on ...
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Although the raison d’etre of the brain is the survival of the body, there are relatively few theoretical studies of closed-loop rhythmic motor control systems. In this paper we provide a unified framework, based on variational analysis, for investigating the dual goals of performance and robustness in powerstroke-recovery systems. To demonstrate our variational method, we augment two previously published closed-loop motor control models by equipping each model with a performance measure based on the rate of progress of the system relative to a spatially extended external substrate – such as a long strip of seaweed for a feeding task, or progress relative to the ground for a locomotor task. The sensitivity measure quantifies the ability of the system to maintain performance in response to external perturbations, such as an applied load. Motivated by a search for optimal design principles for feedback control achieving the complementary requirements of efficiency and robustness, we discuss the performance-sensitivity patterns of the systems featuring different sensory feedback architectures. In a paradigmatic half-center oscillator (HCO)-motor system, we observe that the excitation-inhibition property of feedback mechanisms determines the sensitivity pattern while the activation-inactivation property determines the performance pattern. Moreover, we show that the nonlinearity of the sigmoid activation of feedback signals allows the existence of optimal combinations of performance and sensitivity. In a detailed hindlimb locomotor system, we find that a force-dependent feedback can simultaneously optimize both performance and robustness, while length-dependent feedback variations result in significant performance-versus-sensitivity tradeoffs. Thus, this work provides an analytical framework for studying feedback control of oscillations in nonlinear dynamical systems, leading to several insights that have the potential to inform the design of control or rehabilitation sy
Counterfactual examples (CFs) are one of the most popular methods for attaching post hoc explanations to machine learning models. However, existing CF generation methods either exploit the internals of specific models...
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This note reformulates certain classical combinatorial duality theorems in the context of order lattices. For source-target networks, we generalize bottleneck path-cut and flow-cut duality results to edges with capaci...
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This study provides an initial exploration and further understanding of the factors that are parameters in evaluating the success of Enterprise Architecture (EA) implementation. An evaluation process is needed to ensu...
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A numerical model based on the computational fluid dynamics (CFD) approach was developed to investigate heat transfer from a horizontal row of circular cylinders in a tandem, side-by-side arrangement. The study involv...
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Assume F is a finite field of order pf and q is an odd prime for which pf − 1 = sqm, where m ≥ 1 and (s, q) = 1. In this article, we obtain the order of symmetric and unitary subgroup of the semisimple group algebra ...
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This study presents the generalized third-order difference operator with constant coefficients and inverse, allowing us to construct a sequence similar to the generalized k-Fibonacci sequence. We refer to this sequenc...
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Monomial polyhedra are a class of bounded singular Reinhardt domains defined as sublevel sets of holomorphic monomials. The purpose of this paper is twofold. We first establish an $$L^p$$ -norm estimate for the Bergma...
Monomial polyhedra are a class of bounded singular Reinhardt domains defined as sublevel sets of holomorphic monomials. The purpose of this paper is twofold. We first establish an $$L^p$$ -norm estimate for the Bergman projection on the monomial polyhedra $${\mathcal {U}}_{B}$$ , which can be viewed as a complement of the recent work of the $$L^p$$ regularity for the Bergman projection on monomial polyhedra by Bender et al. (Can J Math 74:732–772, 2022). Then, if $${\mathcal {U}}_{B}$$ is a monomial polyhedron associated to the matrix $$B\in {\mathbb {Z}}^{n\times n}$$ satisfying $$\det \,B=1$$ , we obtain a sharp weighted version of $$L^p$$ -norm estimate for the Bergman projection on $${\mathcal {U}}_{B}$$ .
Multi-objective learning (MOL) often arises in machine learning problems when there are multiple data modalities or tasks. One critical challenge in MOL is the potential conflict among different objectives during the ...
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Multi-objective learning (MOL) often arises in machine learning problems when there are multiple data modalities or tasks. One critical challenge in MOL is the potential conflict among different objectives during the optimization process. Recent works have developed various dynamic weighting algorithms for MOL, where the central idea is to find an update direction that avoids conflicts among objectives. Albeit its appealing intuition, empirical studies show that dynamic weighting methods may not outperform static ones. To understand this theory-practice gap, we focus on a stochastic variant of MGDA, the Multi-objective gradient with Double sampling (MoDo), and study the generalization performance and its interplay with optimization through the lens of algorithmic stability in the framework of statistical learning theory. We find that the key rationale behind MGDA--updating along conflict-avoidant direction--may hinder dynamic weighting algorithms from achieving the optimal O(1/√n) population risk, where n is the number of training samples. We further demonstrate the impact of dynamic weights on the three-way trade-off among optimization, generalization, and conflict avoidance unique in MOL. We showcase the generality of our theoretical framework by analyzing other algorithms under the framework. Experiments on various multi-task learning benchmarks are performed to demonstrate the practical applicability. Code is available at https://***/heshandevaka/Trade-Off-MOL.
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