arXiv subjects

Antonio Perez

Publications and source records attributed to Antonio Perez.

3 recordsLinked to original sources

arXiv2026

Strategies to manage human factors in mixed reality helicopter pilot training: a systematic literature review

Introduction: Mixed reality (MR) head-mounted displays (HMDs) may offer a cost-efficient, immersive alternative to conventional flight simulation displays, but cybersickness, visual fatigue, and ergonomic strain may impair performance and training effectiveness in safety-critical aviation. Methods: We conducted a PRISMA-based systematic review of 80 sources on human factors associated with MR/virtual reality (VR) HMD use in pilot training and analogous safety-critical simulations. Drivers and mitigation strategies were organized into a dual-taxonomy, with strategies classified as hardware, software, ergonomic, physiological, or psychological. Viability was assessed against operational needs and aviation authority expectations. Results: Cybersickness, visual strain, musculoskeletal fatigue, and sensory conflict were the most consistently reported issues. Strategies that preserved simulator fidelity, including high-quality HMD selection, calibration, ergonomic setup, and structured onboarding, appeared more operationally suitable than techniques that reduced realism or visual continuity, such as field-of-view restriction. Risk-of-bias appraisal identified recurring limitations, including convenience sampling, heterogeneous designs, and limited preregistration, which reduced confidence in generalizability. Discussion: Human factors remain a major barrier to MR HMD adoption in pilot training, while operational and regulatory constraints determine which mitigations are feasible. Although the evidence is largely VR-derived, many findings may transfer to MR because both technologies share perceptual and ergonomic mechanisms. The review offers practical guidance for improving comfort and safety without compromising simulator fidelity.

cs.HC↗

arXiv2019

On the numerical index with respect to an operator

Given Banach spaces $X$ and $Y$, and a norm-one operator $G\in \mathcal{L}(X,Y)$, the numerical index with respect to $G$, $n_G(X,Y)$, is the greatest constant $k\geq 0$ such that $$\max_{|w|=1}\|G+wT\|\geq 1 + k \|T\|$$ for all $T\in \mathcal{L}(X,Y)$. We present some results on the set $\mathcal{N}(\mathcal{L}(X,Y))$ of the values of the numerical indices with respect to all norm-one operators on $\mathcal{L}(X,Y)$. We show that $\mathcal{N}(\mathcal{L}(X,Y))=\{0\}$ when $X$ or $Y$ is a real Hilbert space of dimension greater than one and also when $X$ or $Y$ is the space of bounded or compact operators on an infinite-dimensional real Hilbert space. For complex Hilbert spaces $H_1$, $H_2$ of dimension greater than one, we show that $\mathcal{N}(\mathcal{L}(H_1,H_2))\subseteq \{0,1/2\}$ and the value $1/2$ is taken if and only if $H_1$ and $H_2$ are isometrically isomorphic. Besides, $\mathcal{N}(\mathcal{L}(X,H))\subseteq [0,1/2]$ and $\mathcal{N}(\mathcal{L}(H,Y))\subseteq [0,1/2]$ when $H$ is a complex infinite-dimensional Hilbert space and $X$ and $Y$ are arbitrary complex Banach spaces. We also show that $\mathcal{N}(\mathcal{L}(L_1(μ_1),L_1(μ_2)))\subseteq \{0,1\}$ and $\mathcal{N}(\mathcal{L}(L_\infty(μ_1),L_\infty(μ_2)))\subseteq \{0,1\}$ for arbitrary $σ$-finite measures $μ_1$ and $μ_2$, in both the real and the complex cases. Also, we show that the Lipschitz numerical range of Lipschitz maps can be viewed as the numerical range of convenient bounded linear operators with respect to a bounded linear operator. Further, we provide some results which show the behaviour of the value of the numerical index when we apply some Banach space operations, as constructing diagonal operators between $c_0$-, $\ell_1$-, or $\ell_\infty$-sums of Banach spaces, composition operators on some vector-valued function spaces, and taking the adjoint to an operator.

math.FA↗

arXiv2017

Spear operators between Banach spaces

The aim of this manuscript is to study \emph{spear operators}: bounded linear operators $G$ between Banach spaces $X$ and $Y$ satisfying that for every other bounded linear operator $T:X\longrightarrow Y$ there exists a modulus-one scalar $ω$ such that $$ \|G + ω\,T\|=1+ \|T\|. $$ To this end, we introduce two related properties, one weaker called the alternative Daugavet property (if rank-one operators $T$ satisfy the requirements), and one stronger called lushness, and we develop a complete theory about the relations between these three properties. To do this, the concepts of spear vector and spear set play an important role. Further, we provide with many examples among classical spaces, being one of them the lushness of the Fourier transform on $L_1$. We also study the relation of these properties with the Radon-Nikodým property, with Asplund spaces, with the duality, and we provide some stability results. Further, we present some isometric and isomorphic consequences of these properties as, for instance, that $\ell_1$ is contained in the dual of the domain of every real operator with infinite rank and the alternative Daugavet property, and that these three concepts behave badly with smoothness and rotundity. Finally, we study Lipschitz spear operators (that is, those Lipschitz operators satisfying the Lipschitz version of the equation above) and prove that (linear) lush operators are Lipschitz spear operators.

math.FA↗