Designing and Building a Wireless Network Prototype for the Management and Invoicing System of Real-Time Commands, Implemented to Smart Restaurants

This paper proposes a design and construction of a wireless network prototype for the management and invoicing system of real-time commands, which is implemented to smart bar-restaurants. It is mainly made up of three modules that are interlinked through Wi-fi wireless technology. The administration module provides all the information required for commands management and invoices to the user through the management module that uses touch-based devices, this generated information is sent directly to the preparation module. The communication of each module is performed with SQL searches on the database server developed on phpAdmin. An application was developed for each module in the Android Studio and NetBeans programming environments. The applied methodology is based on surveys that determine the prototype needs and requirements. For prototype validation, a series of tests were conducted on the integral operation and wireless communication range of the latter, establishing the maximum operating distance at 33.75 meters, so that the operation did not present malfuncions due to the Location dimensions are within range. Menu query times were verified obtaining that the system optimizes in 86.00% the time used in the traditional way. Significantly reduces command management time by 62.90%. There was no saturation in the network since the traffic generated only represented 2.76% of the router's capacity. It is recommended to hire a remote service to store the data. Keywords: wireless communication, data transmission, bandwidth, command, invoicing, wifi, system, modules. Resumen El presente artículo propone un diseño y construcción de un prototipo de red inalámbrica para la gestión y facturación de comandas en tiempo real, aplicado a la implementación de bares-restaurantes inteligentes. Está constituido por tres módulos que se comunican mediante tecnología Wi-fi. El módulo de administración proporciona la información necesaria para manejo de base de datos y facturas de usuario, el mismo que mediante el módulo de gestión utiliza dispositivos táctiles para generar pedidos, esta información es enviada directamente al módulo de preparación. La comunicación entre módulos se establece mediante consultas SQL para acceder a la base de datos creada en phpMyAdmin. Para cada módulo se desarrolló una aplicación en los entornos de programación Android Studio y NetBeans. La metodología aplicada en base a encuestas facilitó la determinación de necesidades y requerimientos del prototipo. Para la validación del sistema se realizaron pruebas sobre el funcionamiento íntegro y alcance de comunicación inalámbrica de este, estableciendo la distancia máxima de funcionamiento a los 33,75 metros, cumpliendo con las dimensiones del local en el que se implementó. Se verificaron tiempos de consulta de menú obteniendo que el sistema optimiza hasta un 86,00% los tiempos utilizados en la forma tradicional. Reduce notablemente el tiempo de toma de pedido en un 62,90%. No se presentó saturación de red ya que el tráfico generado representa el 2,76% de la capacidad del enrutador. Palabras clave: comunicación inalámbrica, transmisión de datos, ancho de banda, comanda, facturación, wifi, sistema, módulos.

Buckling Analysis of Torpedo’s Cylindrical Shell

Torpedo is a self-propelled weapon. It can be launched above or below the water surface. Torpedo’s different internal parts are housed in cylindrical, conical and spherical shell structures. Underwater applications require the minimization of the structural weight of shell structure for increased buckling strength, speed, and operating distance. To serve this purpose lightweight material such as Al-Cu alloy is preferred for the manufacturing of torpedo’s cylindrical shell. Here in the present investigation, unstiffened cylindrical shell structural member of the torpedo is considered for the evaluation of its linear buckling strength when the torpedo is subjected to hydro-static pressure under the sea water. Linear buckling analysis which is also called Eigen buckling analysis is done on unstiffened cylindrical shell geometry by using ANSYS R14.5 software. The values obtained for linear buckling strength from empirical equations mentioned in British Standards Institution, BS 5500 (now superseded by PD 5500) ‘Unfired Fusion Welded Pressure Vessels’ are validated with those results from ANSYS R14.5 and are observed to be closer to each other. The variation of the failure stress of an unstiffened cylindrical shell due to buckling for the variation of its thickness is also observed using both the empirical and simulation using ANSYS R14.5 approaches and are compared using the corresponding plots. And also, the critical buckling pressures of an unstiffened cylindrical shell with a constant thickness for the formation of different number of lobes for the simply supported boundary conditions are calculated by using empirical relations and this variation is observed using the corresponding plot. For these analyses numerical examples are considered.

The Effect of COVID-19 on the Efficiency of Intercity Bus Operation: The Case of Chungnam

This paper estimates the efficiency of operating intercity bus lines in Chungnam province over the period 2017–2020, and then empirically analyzes the determinants of the efficiency. In particular, it evaluates to what extent the efficiency in 2020 decreased due to COVID-19 and which characteristics of lines (length of a line, frequency of operation, whether a line operates via highways and includes the capital region or not) affected the efficiency during the pandemic through a tobit model. The empirical results show that the efficiency in the operation of intercity bus lines in Chungnam was higher in 2018 and 2019 compared to 2017, but dropped in 2020 by 15.8%. It appears that the efficiency is higher when a line operates more frequently and covers a longer distance, but the efficiency increases at a decreasing rate as the operating distance becomes longer. In addition, the difference in the efficiency according to operating distance due to COVID-19 seems to be statistically significant. Given that intercity bus lines are heavily dependent upon a (local) government’s financial support and the amount of this support needs to reflect the degree to which the efficiency has decreased due to COVID-19 as an external shock, it is important to precisely estimate the magnitude of the efficiency reduction from both a policy and academic standpoint.

Design and Modeling of Soft Pneumatic Helical Actuator with High Contraction Ratio

Soft contraction actuators are becoming important elements particularly for human-friendly robotic applications. However, it is challenging to achieve both a large operating distance while generating practical force. Hence, we present a new soft contraction actuator capable of realizing a high ratio contraction by pneumatic power. It can be easily fabricated using soft materials, including rubber tubes, one-way extensible cloth, and inextensible wire. Its initial shape is tubular but it can curve and coil to a helix shape owing to its different extensibilities on two sides when pressurized. A maximum contraction ratio of 78% and a 23 N contraction force can be achieved with an 11.6 mm initial outer diameter tube under 0.3 MPa. The effect of the tilt angle of a one-way extensible cloth on the helical shape is investigated, and a mathematical model illustrating the relationship between the contraction ratio and force is derived. Our experimental results suggest that this helical actuator has a much higher contraction ratio than a McKibben actuator under the same conditions. Finally, we discuss the potential application of the proposed actuator to a wearable device, i.e., for assisting the dorsiflexion of an ankle joint requiring a wide range of motion.

Performance evaluation of a multiple optical link FSO–FSO

Free-space optics (FSO) connects two distant points by a simple light beam. Currently, this technique is a complement to radio frequency systems and those based on optical fibers. However, its large-scale deployment is slowing down due to major drawbacks such as the short operating distance and its great vulnerability to atmospheric conditions. In this article, and in order to increase the connection distance of the FSO systems and maintaining an acceptable signal quality, we inserted in the transmission channel: a receiver and a transmitter that retransmit the received signal. We have chosen two weather situations. The attenuation values used are 85 dB/km and 170 dB/km. They represent two different fog densities. For an attenuation of 85 dB/km, the quality factor Q degrades and goes from the value 44.50 to 2.60 when the distance goes from 90 to 180 m. With the proposed technique, the quality factor has improved significantly since we obtained a value that is equal to 29.82 instead of 2.60 at the overall distance of 180 m. On the other hand, we increased the distance until we obtained a quality factor around 2.5. The distance obtained is equal to 360 m, which is twice the initial distance.

Acid Test of Ghana’s Educational Institutions Operating Distance Learning Programs

The outbreak of the COVID-19 pandemic is an unprecedented blow to the Ghanaian Educational System. Following the closure of all educational facilities in Ghana in March 2020, the country’s President ordered for the adoption of distance learning. This poses the question: how prepared are Ghanaian institutions to carry out distance learning using online teaching approaches? Most institutions in Ghana offering distance learning programs currently adopt the usage of the tutorial method where there is minimal or no usage of online learning technologies. This article discusses the potential usage of mobile learning by Ghanaian Educational Institutions operating distance learning programs in the wake of combating the COVID-19. It proposes a model to support the use of WhatsApp Messenger as an online tool to support distance learning programs. The proposed model is a summary comparison between a typical Learning Management System (LMS) using Jurado’s classification and the proper application of the use of WhatsApp Messenger as a mobile learning platform in a Ghanaian context.

Simulation and Ergonomic Evaluation of Welders’ Standing Posture Using Jack Software

Ergonomics research strives to make workers’ labor more efficient, safer, and more comfortable. Therefore, six digital humans and welding torch model were built and evaluated based on the Jack software in order to improve the ergonomics of welders’ standing postures. Three sets of standing welding actions were designed: walking, raising arm, and contracting arm. Through the Lower Back Analysis, Ovako Working Posture Analysis, Comfort Assessment, and Rapid Upper Limb Assessment, this paper evaluated the optimum range of the weight of the welding torch, the upper limb posture, and the neck posture of the welder. Firstly, the results show that Chinese welders should not use a welding torch with a weight of more than 6 kg when standing up. Secondly, for adult males in the 5th, 50th, 95th percentile of body size, the best operating distance is 321 mm, 371 mm, and 421 mm, respectively, and the best operating height is 1050 mm, 1100 mm, and 1150 mm, respectively; for females in the same percentiles, the optimal operating distance is 271 mm, 321 mm, and 371 mm, respectively, and the optimal operating height is 1000 mm, 1050 mm, and 1100 mm, respectively. Moreover, the horizontal and vertical rotation angle of the welder’s neck should not exceed 15° and 8.7°. The adjustment strategy not only has a positive effect on improving welders’ operational posture and preventing fatigue and injury to the welder, but it also develops research ideas for promoting safety from the perspective of ergonomics.

HYGIENIC ASSESSMENT OF THE SAFETY AND EFFICIENCY OF USING ULTRAVIOLET PLANTS OF THE CLOSED TYPE FOR DISINFECTION OF THE AIR ENVIRONMENT IN THE ROOMS OF INPATIENTS FACILITIES

Introduction. The paper presents the results of the evaluation of the safety and efficiency of using UV irradiators-recirculators of a closed type, used for disinfecting air in the premises of medical facilities. Material and methods. The studies included three types of UV irradiators-recirculators of the closed type of various brands. The safety assessment included: 1) ultraviolet radiation measurements; 2) the influence of devices on chemical pollution of indoor air; 3) the impact on the natural gas composition and microclimate; 4) measurement of ozone concentrations; 5) measurement of electromagnetic radiation; 6) measurements of sound levels. Evaluation of the effectiveness of disinfection was performed on the total microbial number; the content of mold fungi and coliphages per 1 m3 of air. Results. A safety assessment of the operation of closed-type ultraviolet irradiators-recirculators showed the devices under study, equipped with zone-free mercury lamps to be not sources of ozone and nitrogen dioxide emission into the air. However, from the bodies of two of the investigated devices, UV radiation with a wavelength of 200-280 nm was detected. It is established that UV irradiators-recirculators of the closed type can be sources of increased noise and electromagnetic radiation. The intensity of these factors inside of premises depends on the distance to the operating device. It is established the safe operating distance of such devices. It has been revealed that long-term operation of closed-type UV irradiators-recirculators can give rise elevation of the ambient air temperature and an increase in the concentration of saturated and acyclic hydrocarbons in the air. As a result of the evaluation of the disinfecting effect of the studied UV irradiators-recirculators, a different degree of effectiveness of their influence on the bacterial and fungal flora was established. Conclusion. The necessity of developing a methodological document regulating the procedure and scope of research in assessing the safety and efficiency of using UV irradiators-recirculators of a closed type for disinfecting air in medical institutions in the presence of people is substantiated.