Conventional Pilots Research Articles

SIMULATION AND OPTIMIZATION OF A SWARM OF UNMANNED AERIAL VEHICLES

The development of unmanned aerial vehicles can be regarded as a promising direction of modern aviation. They have significantly reduced dimensional characteristics, if compared with traditional aircraft. It is also possible to form unmanned aerial vehicles, which are aimed at performing corresponding tasks. It takes less time to train a specialist to fly an unmanned aerial vehicle compared to conventional pilots. The work is related to the creation of mathematical models that allow an integral way to evaluate the effectiveness and conduct cluster structuring of a swarm of wireless aircraft. At the same time, there are opportunities to take into account the limited resources, to carry out redistribution of resources. Resources are distributed among clusters, and the principle of inverse priorities has to be applied. After that, the distribution over the drones of the network structure that has been optimized is implemented. Monitoring information is used. The main stages of solving the problem, which are based on optimization procedures, are shown.

A Low Complexity Channel Estimation and Detection for Massive MIMO Using SC-FDE

5G Communications will support millimeter waves (mm-Wave), alongside the conventional centimeter waves, which will enable much higher throughputs and facilitate the employment of hundreds or thousands of antenna elements, commonly referred to as massive Multiple Input–Multiple Output (MIMO) systems. This article proposes and studies an efficient low complexity receiver that jointly performs channel estimation based on superimposed pilots, and data detection, optimized for massive MIMO (m-MIMO). Superimposed pilots suppress the overheads associated with channel estimation based on conventional pilot symbols, which tends to be more demanding in the case of m-MIMO, leading to a reduction in spectral efficiency. On the other hand, MIMO systems tend to be associated with an increase of complexity and increase of signal processing, with an exponential increase with the number of transmit and receive antennas. A reduction of complexity is obtained with the use of the two proposed algorithms. These algorithms reduce the complexity but present the disadvantage that they generate a certain level of interference. In this article, we consider an iterative receiver that performs the channel estimation using superimposed pilots and data detection, while mitigating the interference associated with the proposed algorithms, leading to a performance very close to that obtained with conventional pilots, but without the corresponding loss in the spectral efficiency.

Analysis of Dynamic Characteristics of Pilots Under Different Intentions in Complex Flight Environment

Intention is the main embodiment of human cerebral conscious activities, which has an important influence on guiding the realization of human behaviour. It is a vital prerequisite for analysing the dynamic characteristics of pilots with different intentions. Considering the intention law of the generation, transfer and reduction, this paper analyses dynamic characteristics of pilots with different intentions, starting from the factors of effect on the intention. Taking airfield traffic pattern as an example for simulating flight experiments, the pilot’s multi-source dynamic data of human – aircraft – environment system under different intentions and their psycho-physiological-physical characteristics were recorded. Based on Matlab, one-way analysis of variance was used to extract variables with significant changes, and the variables under different intentions were compared and analysed. The results show that the conventional pilots are more conducive to control the aircraft to keep a stable flight attitude. This study is of great significance for perfecting the warning system of flight safety and improving the pilot’s micro-behaviour assessment system.

I Have a Drone: the Implications of American Drone Policy for Africa and International Humanitarian Law

Placards that bore Martin Luther King’s pictures captioned with his ‘I have a dream’ cliche juxtaposed and parodied with placards bearing Barack Hussein Obama’s pictures captioned ‘I have a drone’ welcomed the re-elected American president to Germany in June 2013. 1 This was in sharp contrast to the pop-star cult status Senator Obama the presidential candidate received during his 2008 German visit. The most prominent signature attribute of the Obama presidency in warfare is the use of drones. The Obama drone doctrine keeps American boots off the ground and unmanned drones rain death on suspected American enemies. It has also eroded the promise candidate Obamamade in 2008 to restore America’s reputation abroad. The Obama administration appropriated $5 billion on drones under the 2012 budget and America now trains lesser conventional pilots than the

Impact of UAS Pilot Communication and Execution Latencies on Air Traffic Controllers’ Acceptance of UAS Operations

Integrating Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS) requires that UAS meet or exceed the safety requirements established for conventional aircraft, and for the UAS pilots to interact with air traffic controllers (ATCos) in an acceptable manner. UAS have several characteristics that differentiate them from conventional aircraft, including the possibility of greater latencies associated with remote pilot communication and command execution. The goal of this study was to determine how adding delays to UAS pilot communications and command executions affect ATCos’ interactions with UAS and conventional aircraft. Six previously certified radar controllers and two currently certified radar controllers were recruited as participants to manage traffic in a simulated sector with conventional traffic and one UAS flying in it. The UAS pilot verbal communication and execution latencies were varied in separate scenarios to include an additional delay that was either short (1.5 s) or long (5 s), and constant or variable within each scenario.We measured both UAS and conventional pilots’ verbal communication and execution initiation latencies, and obtained ATCos’ acceptability ratings for the different delay conditions. We also examined the number of communication step-ons created by the additional communication delays implemented in the UAS control station, as well as other measures of the ATCo-pilot interactions. Although we were unable to specify a precise upper limit of acceptable latencies, we found ATCos rated UAS pilot verbal communication latencies to be acceptable when the latencies were short rather than long, and that acceptability ratings often reflect broad features of the sectors being managed. Implications of these findings for UAS integration in the NAS are discussed.

Interleaver Structures for Channel Estimation and Decoding on the Frequency Selective Fading Channel

This paper examines different designs for combined channel estimation and decoding for a point to point time varying frequency selective fading channel. The channel state information (CSI) is not known a priori at either the transmitter or the receiver. Channel estimation is performed through a combination of conventional pilots and manufactured pilots from previously decoded data. The paper examines how different interleaver structures affect the tradeoff between achievable rates, delay and complexity. When there is no delay constraint at all, the conventional pilots can be eliminated completely and a proper interleaving scheme can convert half the symbols into manufactured pilots. When there is a delay constraint, the paper explores various interleaver structures that combine the conventional pilots with the manufactured pilots in different ways to get much better achievable rates than conventional pilot-symbol aided channel estimation.

Determination of Chemical Requirements and Applicability Of Wettability Alteration Flooding

Abstract In wettability alteration flooding, a chemical agent is moved through a reservoir by the flood water to increase oil recovery by decreasing the degree of wetting of the rock by the oil. Substantial amounts of the chemical may be lost during movement through the reservoir. The extent of the loss, and therefore the economics of the process, depends in some cases on factors which are difficult to reproduce in the laboratory. Therefore, a short-duration, low-cost field test method is needed to permit evaluation of chemical requirements under actual field conditions. This paper describes a small scale test conducted at a single well for measuring chemical requirements, thereby giving a more reliable evaluation of this important factor in the applicability and economics of the process. In the test a small water slug containing the chemical agent and a nonadsorbed tracer is displaced into the reservoir by a known volume of water. The well is then placed on production. Chemical loss per barrel of pore volume contacted is calculated from the fractional recoveries of the agent tested and the nonadsorbed tracer. The method has been used to determine within the actual reservoirs the chemical requirements for both a sandstone and a dolomite reservoir. Several chemical agents are potentially available for wettability alteration flooding, although none is universally applicable. For some applications of the method, chemical costs per barrel of additional oil recovered can be substantially less than one dollar. Introduction Wettability alteration flooding provides a means of increasing oil recovery from reservoirs by decreasing the degree of wetting of the rock by the oil and increasing the displacement efficiency of the flood water. Earlier studies demonstrated a relationship between oil recovery during waterflooding and the degree of wetting of a rock surface by an oil. The application of wettability alteration flooding to the Harrisburg field of Nebraska provided a field test of this recovery process. Subsequently, additional laboratory and field tests have developed additional procedures for evaluating wettability alteration flooding, and have indicated where the process may be applicable. Applicability of this process to specific reservoirs is determined by a progression of tests to determine susceptibility of the reservoir to alteration of its wettability, to indicate the degree of recovery improvement and to estimate the amount of chemical required to process the reservoir. The economics of applying improved oil recovery processes depends not only upon the degree of improvement in oil recovery achievable by the process, but also upon the process costs and the timing of the income and the investment. Emphasis in this paper is on the expenditure aspects of the process. The work reported in this paper indicates that the chemical investments required for wettability alteration flooding are substantial. For evaluating the economics of a potential flooding application it is imperative that a sound estimate of the chemical requirements be made for the reservoir. Generally, true reservoir conditions are not adequately simulated in laboratory chemical propagation tests. Because of wide well spacings, many years might be required to obtain chemical propagation data from conventional pilots or inter-well tests. Consequently, a short-duration, low-cost method is needed to determine chemical requirements in the field. The potential applicability of wettability alteration flooding is discussed, as well as the economics of wettability alteration with respect to the inherent and imposed restrictions on the timing of income and investments.