Depth perception is one of the important elements in virtual reality (VR). The perceived depth is influenced by the head mounted displays that inevitability decreases the virtual content's depth perception. While several questions within this area are still under research; the main objective of this study is to survey the recently conducted studies on depth perception in VR, augmented reality (AR), and mixed reality (MR). First, depth perception in the human visual system is discussed including the different visual cues involved in depth perception. Second, research performed to understand and confirm depth perception issue is examined. The contributions made to improve depth perception and specifically distance perception will be discussed with their main proposed design key, advantages, and limitations. Most of the contributions were based on using one or two depth cues to improve depth perception in VR, AR, and MR.

Virtual reality (VR) is an emerging technology with a broad range of applications in training, entertainment, and business. To maximize the potentials of virtual reality as a medium, the unwelcome feeling of cybersickness needs to be minimized. Cybersickness is a type of simulation sickness that is experienced in virtual reality. It is a significant challenge for the usability of virtual reality systems. Even with advancements in virtual reality, the usability concerns are barriers for a wide-spread acceptance. Several factors (hardware, software, human) play a part towards a pleasant virtual reality experience. In this paper, we review the potential factors which cause sickness and minimize the usability of virtual reality systems. The reviewed scientific articles are mostly part of documents indexed in digital libraries. We review the best practices from a developer’s perspective and some of the safety measures a user must follow while using the virtual reality systems from existing research. Even after following some of the guidelines and best practices virtual reality environments do not guarantee a pleasant experience for users. Limited research in virtual reality environments towards requirements specification, design, and development for maximum usability and adaptability was the main motive for this work.

This work presents the use of an ant colony optimization (ACO) based neuro-evolution algorithm to optimize the structure of a long short-term memory (LSTM) recurrent neural network (RNN) for the prediction of aircraft turbine engine vibrations. It expands upon previous work using three different LSTM architectures, with the new evolved LSTM cells showing an improvement of 1.35%, reducing prediction error from 5.51% to 4.17% when predicting excessive engine vibrations 10 seconds in the future. These results were gained using MPI on a high performance computing cluster, evolving 1000 different LSTM cell structures using 168 cores over 4 days.

The business model as known by the majority of specialists has moved from product concentration to the customer concentration. And as we all know, electronic commerce and generally the world of technology has exponentially believed that principal. In this era, many companies have begun to permeate the Electronic Customer Relationship Management (CRAG / E-CRM) more than conventional CRM to better understand their customers. As early as the first definitions of the CRM, we found among the main three axes - technology - Currently the world data is also outstanding to have a change with the advent of Big Data paradigm. There is a need to rethink and reconsider the validity of existing architectures management of electronic customer relationship. In this paper, we will see the existing architectures, and we subsequently present an architecture with features capable to respect and exploit the new data based on research works.