Policy recommendations for promoting touristic attractivity from local government perspective in innovative environments

The COVID-19 pandemic situation has had unprecedented negative consequences in the tourism sector, especially in the hotel industry, which has implied negative shocks directly and indirectly in city revenues, employment and economy. Recent research has indicated that technology is becoming central in finding solutions for tourism recovery through the development of newor improved ICT-enabled tourism services, which could help to achieving a higher attraction of tourists and other sources of foreign investments to cities. This paper therefore seeks to analyse the impact of blockchain technologies (BCT) on the tourism business for attracting new customers to cities with the aim at gaining insights regarding public policies to be taken by local governments for improving tourism business in their city. To achieve this aim, this paper provides an empirical research on the impact of BCT on both lowering prices and improving service quality of lodging accommodations by a sample of lodging accommodations in different Italian cities, providing insights to know if the implementation of BCT on hospitality business, can help city governments to improve smart living into the urban space, deriving some recommendations for city government to take public policies to favour the implementation of these technologies into the hospitality industry

Nesting biology of \u3ci\u3ePachymenes ghilianii\u3c/i\u3e (Spinola, 1851) (Hymenoptera: Vespidae: Eumeninae: Eumenini) in Panama

The nesting biology of the potter wasp Pachymenes ghilianii (Spinola) (Hymenoptera: Vespidae: Eumeninae) is described based on observations made in the Cerro Turega Hydric Reserve, Penonome, Panama. The collection of building material, the architecture of the nest, the process of building a cell and cell provision with geometrid larvae (Lepidoptera: Geometridae), and the emergence time of the adults are recorded. Se describe la biología de anidación de la avispa alfarera Pachymenes ghilianii (Spinola) (Hymenoptera: Vespidae: Eumeninae) en base a observaciones realizadas en la Reserva Hídrica Cerro Turega, Penonomé, Panamá. Se registran la recolección de material de construcción, la arquitectura del nido, el proceso de construcción de una celda, y aprovisionamiento de celdas con larvas geométridos (Lepidoptera: Geometridae), así como el tiempo de emergencia de los adultos

Comparing Evolutionary Algorithms and Particle Filters for Markerless Human Motion Capture

Markerless Human Motion Capture is the problem of determining the joints’ angles of a three-dimensional articulated body model that best matches current and past observations acquired by video cameras. The problem of Markerless Human Motion Capture is high-dimensional and requires the use of models with a considerable number of degrees of freedom to appropriately adapt to the human anatomy. Particle filters have become the most popular approach for Markerless Human Motion Capture, despite their difficulty to cope with high-dimensional problems. Although several solutions have been proposed to improve their performance, they still suffer from the curse of dimensionality. As a consequence, it is normally required to impose mobility limitations in the body models employed, or to exploit the hierarchical nature of the human skeleton by partitioning the problem into smaller ones. Evolutionary algorithms, though, are powerful methods for solving continuous optimization problems, specially the high-dimensional ones. Yet, few works have tackled Markerless Human Motion Capture using them. This paper evaluates the performance of three of the most competitive algorithms in continuous optimization – Covariance Matrix Adaptation Evolutionary Strategy, Differential Evolution and Particle Swarm Optimization – with two of the most relevant particle filters proposed in the literature, namely the Annealed Particle Filter and the Partitioned Sampling Annealed Particle Filter. The algorithms have been experimentally compared in the public dataset HumanEva-I by employing two body models with different complexities. Our work also analyzes the performance of the algorithms in hierarchical and holistic approaches, i.e., with and without partitioning the search space. Non-parametric tests run on the results have shown that: (i) the evolutionary algorithms employed outperform their particle filter counterparts in all the cases tested; (ii) they can deal with high-dimensional models thus leading to better accuracy; and (iii) the hierarchical strategy surpasses the holistic one

Parallelization Strategies for Markerless Human Motion Capture

Markerless Motion Capture (MMOCAP) is the problem of determining the pose of a person from images captured by one or several cameras simultaneously without using markers on the subject. Evaluation of the solutions is frequently the most time-consuming task, making most of the proposed methods inapplicable in real-time scenarios. This paper presents an efficient approach to parallelize the evaluation of the solutions in CPUs and GPUs. Our proposal is experimentally compared on six sequences of the HumanEva-I dataset using the CMAES algorithm. Multiple algorithm’s configurations were tested to analyze the best trade-off in regard to the accuracy and computing time. The proposed methods obtain speedups of 8× in multi-core CPUs, 30× in a single GPU and up to 110× using 4 GPU

Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals

A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly dispersive photonic crystals. Transmission data provide evidence for slow group velocities at the photonic band edges and for superluminal transmission at frequencies in the gap. Our experimental results are in good agreement with finite-difference-time-domain simulations.Comment: 7 pages, 11 figure

Effective gravity from a quantum gauge theory in Euclidean space-time

We consider a $SO(d)$ gauge theory in an Euclidean $d$-dimensional space-time, which is known to be renormalizable to all orders in perturbation theory for $2\le{d}\le4$. Then, with the help of a space-time representation of the gauge group, the gauge theory is mapped into a curved space-time with linear connection. Further, in that mapping the gauge field plays the role of the linear connection of the curved space-time and an effective metric tensor arises naturally from the mapping. The obtained action, being quadratic in the Riemann-Christoffel tensor, at a first sight, spoils a gravity interpretation of the model. Thus, we provide a sketch of a mechanism that breaks the $SO(d)$ color invariance and generates the Einstein-Hilbert term, as well as a cosmological constant term, allowing an interpretation of the model as a modified gravity in the Palatini formalism. In that sense, gravity can be visualized as an effective classical theory, originated from a well defined quantum gauge theory. We also show that, in the four dimensional case, two possibilities for particular solutions of the field equations are the de Sitter and Anti de Sitter space-times.Comment: 20 pages; Final version accepted for publication in Class.Quant.Gra

MATERIAL COMPUESTO ALTERNATIVO PARA SISTEMAS DE ENTIBACIÓN DE MINERÍA DE CARBÓN DE NORTE DE SANTANDER

Se desarrollaron materiales compuesto usando sistema de resinas epóxicas como matriz y desechos de polvo de cerámica como refuerzo para remplazar la madera usada comúnmente en los sistemas de entibación en las minas de carbón de Norte de Santander. La caracterización de los materiales se realizó mediante ensayos de flexión de y por un montaje a nivel laboratorio del sistema de entibación. Se estudiaron los tamaños óptimos de los capis mediante recolección de datos de campo, simulación y diseño de experimentos de las variables influyentes. Para determinación de las propiedades requeridas del sistema, se realizó ingeniería inversa usando la metodología de Ashby. Se determinó el impacto de la deforestación por el uso de la madera en el departamento de Norte de Santander

Congenital Chagas’ disease transmission in the United States: Diagnosis in adulthood

Two brothers with congenitally-acquired Chagas’ disease (CD) diagnosed during adulthood are reported. The patients were born in the USA to a mother from Bolivia who on subsequent assessment was found to be serologically positive for Trypanosoma cruzi. Serologic screening of all pregnant women who migrated from countries with endemic CD is strongly recommended