Technologies and techniques of location and navigation are advancing, allowing greater precision in locating people in complex and challenging conditions. These advances have attracted growing interest from the scientific community in using indoor positioning systems (IPSs) with a higher degree of precision and fast delivery time, for groups of people such as the visually impaired, to some extent improving their quality of life. Much research brings together various works that deal with the physical and logical approaches of IPSs to give the reader a more general view of the models. These surveys, however, need to be continuously revisited to update the literature on the features described. This paper presents an expansion of the range of technologies and methodologies for assisting the visually impaired in previous works, providing readers and researchers with a more recent version of what was done and the advantages and disadvantages of each approach to guide reviews and discussions about these topics. Finally, we discuss a series of considerations and future trends for the construction of indoor navigation and location systems for the visually impaired.

Industry 4.0 integrates a series of emerging technologies, such as the Internet of Things (IoT), cyber-physical systems (CPS), cloud computing, and big data, and aims to improve operational efficiency and accelerate productivity inside the industrial environment. This article provides a series of information about the required structure to adopt Industry 4.0 approaches and a brief review of related concepts to finally identify challenges and research opportunities to envision the adoption of so-called digital twins. We want to pay attention to upgrading older systems aiming to provide the well-known advantages of Industry 4.0 to such legacy systems as reducing production costs, increasing efficiency, acquiring better robustness of equipment, and reaching advanced process connectivity.

Computation and communication evolved to enable digital representations of physical systems. Decision-making support via data analysis, virtualization of machinery control, information flowing over the Internet are all trending on industrial systems. This allowed emerging one of the main concepts applied in manufacturing processes, the Digital Twins. A digital counterpart of a physical process allows management, remote control and simulations over the process in a safe environment. This work proposes guidelines to design a Digital Twin architecture using Industrial Internet of Things and the integration of current technologies, applying these aspects in an experimental application.

This paper presents an indoor navigation wearable system based on visual markers recognition and ultrasonic obstacles perception used as an audio assistance for blind people. In this prototype, visual markers identify the points of interest in the environment; additionally this location status is enriched with information obtained in real time by other sensors. A map lists these points and indicates the distance and direction between closer points, building a virtual path. The blind users wear also glasses built with sensors like RGB camera, ultrasonic, magnetometer, gyroscope, and accelerometer enhancing the amount and quality of the available information. The user navigates freely in the prepared environment identifying the location markers. Based on the origin point information or the location point information and on the gyro sensor value the path to next marker (target) is calculated. To raise the perception of the environment, avoiding possible obstacles, it is used a couple of ultrasonic sensors. The audio assistance provided to the user makes use of an audio bank, with simple known instructions to indicate precisely the desired route and obstacles. Ten blind users tested and evaluated the system. The results showed rates of about 94.92% successful recognition of the markers using only 26 frames per second and 98.33% of ultrasonic obstacles perception disposed between 0.50 meters and 4.0 meters.

The current work aims to present the evaluation of the efficiency of the accessibility features on a Virtual Reality (VR) environment. The objective was to test an open source solution named Gear VRF Accessibility, which provides a framework to be used by developers, and has the purpose of adapting Zoom, Inverted Colors, Auto-reading (Screen Reader) and Caption features in a VR environment. Interested to cover all the aspects related to the performance and satisfaction of the accessibility features hypotheses were created to be tested in a controlled environment. Regarding the fact that the solution was embedded into the Samsung Gear VR, all the participants were introduced to this device before testing the accessibility features. The performance and the level of satisfaction observed while the users executed the tasks were combined with user statements and resulted in a set of positive and negative feedbacks to improve the interaction and usage of the solution tested.