Fire hazard is a condition that has potentially catastrophic consequences. Artificial intelligence, through Computer Vision, in combination with UAVs has assisted dramatically to identify this risk and avoid it in a timely manner. This work is a literature review on UAVs using Computer Vision in order to detect fire. The research was conducted for the last decade in order to record the types of UAVs, the hardware and software used and the proposed datasets. The scientific research was executed through the Scopus database. The research showed that multi-copters were the most common type of vehicle and that the combination of RGB with a thermal camera was part of most applications. In addition, the trend in the use of Convolutional Neural Networks (CNNs) is increasing. In the last decade, many applications and a wide variety of hardware and methods have been implemented and studied. Many efforts have been made to effectively avoid the risk of fire. The fact that state-of-the-art methodologies continue to be researched, leads to the conclusion that the need for a more effective solution continues to arouse interest.

Robots and especially mobile robots have experienced rapid growth, making them part of everyday life. An inertial measurement unit (IMU), which is a set of sensors, plays an important role in mobile robots’ navigation. Data collected by the IMU sensors on a robot are properly converted and useful information is calculated concerning, i.e., position, orientation, and acceleration. With the advancement of technology, IMUs have been transformed from large and complex devices into small, flexible, and efficient ones. The main sensors included in an IMU are the gyroscope, the accelerometer, and the magnetometer. Additionally, there are other sensors such as a barometer, a temperature sensor, a pressure sensor, or even an attitude sensor. The components that an IMU consists of are many and the main differences concern the technology they integrate, the designer purpose, and the specifications set by the manufacturer. The purpose of this review is a comparative presentation of 42 IMU models from 7 different manufacturers over the last five years comparing main features such as structure details, connectivity, and communication protocols. Moreover, statistical results are quantitatively and qualitatively presented providing a future user the possibility to select the proper IMU.

Biometrics have been used to identify humans since the 19th century. Over time, these biometrics became 3D. The main reason for this was the growing need for more features in the images to create more reliable identification models. This work is a comprehensive review of 3D biometrics since 2011 and presents the related work, the hardware used and the datasets available. The first taxonomy of 3D biometrics is also presented. The research was conducted using the Scopus database. Three main categories of 3D biometrics were identified. These were face, hand and gait. The corresponding percentages for these categories were 74.07%, 20.37% and 5.56%, respectively. The face is further categorized into facial, ear, iris and skull, while the hand is divided into fingerprint, finger vein and palm. In each category, facial and fingerprint were predominant, and their respective percentages were 80% and 54.55%. The use of the 3D reconstruction algorithms was also determined. These were stereo vision, structure-from-silhouette (SfS), structure-from-motion (SfM), structured light, time-of-flight (ToF), photometric stereo and tomography. Stereo vision and SfS were the most commonly used algorithms with a combined percentage of 51%. The state of the art for each category and the available datasets are also presented. Finally, multimodal biometrics, generalization of 3D reconstruction algorithms and anti-spoofing metrics are the three areas that should attract scientific interest for further research. In addition, the development of devices with 2D/3D capabilities and more publicly available datasets are suggested for further research.