Agriculture represents the main source of food in the world, but it also represents challenges such as population growth, urbanization and aging, global economic growth, investment, trade, and food prices and competition for natural resources. The development of technology can help us cope with these challenges. The internet of things (IoT) technology represents the future of computing and communications. These can be useful to improve traditional agriculture methods around the world. By implementing these modern technologies is possible to reduce costs and maintenance and, to increase the performance of our agriculture processes and goods. Particularly, one of this relatively new technology is the LoRa communication protocol that uses long wavelengths for the communication link to obtain long ranges. This is extremely useful in agriculture where the communicating areas are extensive crop fields and greenhouses. This paper proposes and presents the development of a mobile LoRaWANgateway device that can be applied to increase greenhouses' productivity and accuracy. The presented development includes the use of a Heltec's Mini LoRa Gateway controlled by a Raspberry Pi 3 B+. It is powered by an external Li-On battery and uses a defined number of LoRa nodes with sensors. Sensors will measure humidity and temperature and send the data, which are gathered by the mobile LoRaWAN gateway. These data are processed using third-party free online services. This document illustrates and explains the development and application of data collectors for agriculture and their advantages.

Real-time haptic interactions occur under two exploration modes: active and passive. In this paper, we present a series of experiments that evaluate the main perceptual characteristics of both exploration modes. In particular, we focus on haptic shape recognition as it represents a fundamental task in many applications using haptic environments. The results of four experiments conducted with a group of 10 voluntary subjects show that the differences in motor activity between active and passive haptics ease the perception of surfaces for the first case and the perception of pathways for the latter. In addition, the guidance nature of passive haptics makes the pathway direction easy to recognize. This work shows that this last observation could find application in more challenging tasks such as navigation in space.

This paper presents an analysis to determine the effect of the stress enhancement factor due to the presence of protrusions in the semiconductor shields of HVDC cables. The theoretical analysis of the electric field containing protrusions is based on a harmonic solution for the electric field for spherical and spheroidal protrusions. HVDC analysis takes into account the additional space charge accumulation due to the presence of protrusions.