Functioning Fuzzy Logic in Optimizing the Solar Systems Work

Fuzzy logic has been used in many fields, either to control a specific movement, improve the productivity of a machine, or monitor the work of an electrical or mechanical system or the like. In this chapter, we will discuss what are the basic factors that must be taken to use the fuzzy logic in the aforementioned matters in general, and then focus on its employment in the field of renewable energy. Three main axes for renewable energy are solar panels, a wind turbine and finally, solar collectors. The key to working and the basis of the static system is the mechanism for selecting the inputs that directly affect the output in addition to the methods and activation functions of the fuzzy logic.

Study of biodegradation of Poly(butylene adipate co-terephthalate) (PBAT) by maritime microorganisms from the Atlhantic Coast of Recife-PE (Brazil)

Biodegradable polymers undergo a degradation process resulting from the action of microorganisms such as bacteria, fungi and algae. Poly(butylene adipate co-terephthalate) (PBAT) is considered a biodegradable synthetic polymer, even if its degradation has been confirmed under industrial composting conditions, the investigation of its degradation in the marine environment is still limited. Therefore, this work aims to study the biodegradation in the marine environment, of the biodegradable polymer (PBAT), and for that, it was submerged in a static system, using seawater from the coastal region of Pernambuco/Brazil as a fluid. The samples were studied by chemical, thermal and microbiological analyses, after 7, 14, 30, 90, 120 and 180 days of immersion. Microbiological analyzes indicated that aerobic heterotrophic bacteria (AHB), anaerobic heterotrophic bacteria (AnHB) and iron precipitating bacteria (IPB) were quantified in the system at all times at high concentrations, with the exception of Sulfate reducing bacteria (SRB), fungi and Pseudomonas that showed lower concentrations compared to other bacterial groups. Biodegradation was observed by the percentage of mass loss of approximately 2.25%. In the DSC, the expansion of melting peaks after exposure to the marine environment was noted, while the TGA did not show changes in the curve trends. The FTIR showed that no new band appeared, nor displacement, since the vibrations of the covalent bonds of the groups are present regardless of the biodegradation. Indicating that no significant microbiological degradation of PBAT was observed.

A 4 mm-Long Implant Rehabilitation in the Posterior Maxilla with Dynamic Navigation Technology: A Case Report after a Three-Years Post-loading Follow-Up

The use of short (<8 mm long) and ultra-short (<6 mm long) implants allows the prosthetic rehabilitation of the posterior ridges of the jaws avoiding reconstructive procedures. Nevertheless, this approach requires vast experience to ensure the primary stability of the fixture in a correct position. Computer-aided implantology (CAI) achieves better results than the free-hand one in terms of placement accuracy, reducing the surgical risks and the operative timings. Dynamic navigation (DN) allows the surgeon to track the position and movements of the drill in real-time on the CT imaging data set. It is more versatile than the computed static system, enabling the operator to change the guidance coordinates according to the intra-operative feedbacks. A mono-edentulous upper right first molar site was rehabilitated with a four mm-long implant to avoid reconstructive techniques, drastically rejected by the patients. The case was managed within a DN protocol considering the minimal available bone and the prosthetic demands. The phases of this procedure were strictly documented up to a 3-year follow-up. No intra-operative problems occurred, and adequate primary stability of the implant was obtained. The prosthetic loading was carried out within only six weeks without any complications. No variation of the baseline clinical scenario as evidenced clinically and radiographically at the end of follow-up. No similar cases are reported in the literature.

Output Voltage and Resistance Assessment of Load-Independent-Voltage-Output Frequency Operating Inductive Wireless Power Transfer Link Utilizing Input DC-Side Measurements Only

The paper puts forward a method for predicting output voltage and resistance of a series-series (SS) compensated inductive wireless power transfer (IWPT) link operating at load-independent-voltage-output (LIVO) frequency. The link is a part of the static system (reported by the authors in earlier works), wirelessly delivering power into an enclosed compartment without any secondary-to-primary feedback. The proposed algorithm employs input DC-side quantities (which are slow-varying and nearly noise-free, thus measured utilizing low-cost, low-bandwidth sensors) only to monitor output DC-side quantities, required for protection and/or control. It is shown that high estimation accuracy is retained as long as system parameter values are known and the phasor-domain equivalent circuit is valid (i.e., upon continuous-conduction mode (CCM) of the diode rectifier, where the proposed methodology utilizes the recently revealed modified diode rectifier equivalent model for enhanced accuracy). Under light loading (i.e., in discontinuous conduction mode (DCM)), a nonlinear correction is combined with the proposed technique to retain accuracy. The proposed methodology is well-verified by application to a 400 V to 400 V, 1 kW static IWPT link by simulations and experiments.

Theoretical foundations and limits of word embeddings: what types of meaning can they capture?

Measuring meaning is a central problem in cultural sociology and word embeddings may offer powerful new tools to do so. But like any tool, they build on and exert theoretical assumptions. In this paper I theorize the ways in which word embeddings model three core premises of a structural linguistic theory of meaning: that meaning is relational, coherent, and may be analyzed as a static system. In certain ways, word embedding methods are vulnerable to the same, enduring critiques of these premises. In other ways, they offer novel solutions to these critiques. More broadly, formalizing the study of meaning with word embeddings offers theoretical opportunities to clarify core concepts and debates in cultural sociology, such as the coherence of meaning. Just as network analysis specified the once vague notion of social relations (Borgatti et al. 2009), formalizing meaning with embedding methods can push us to specify and reimagine meaning itself.

Aircraft air data system fault detection and reconstruction scheme design

Purpose The purpose of this study is to detect and reconstruct a fault in pitot probe and static ports, which are components of the air data system in commercial aircrafts, without false alarm and no need for pitot-static measurements. In this way, flight crew will be prevented from flying according to incorrect data and aircraft accidents that may occur will be prevented. Design/methodology/approach Real flight data collected from a local airline was used to design the relevant system. Correlation analysis was performed to select the data related to the airspeed and altitude. Fault detection and reconstruction were carried out by using adaptive neural fuzzy inference system and artificial neural networks, which are machine learning methods. MATLAB software was used for all the calculations. Findings No false alarm was detected when the fault test following the fault modeling was carried out at 0–2 s range by filtering the residual signal. When the fault was detected, fault reconstruction process was initiated so that system output could be achieved according to estimated sensor data. Practical implications The presented alternative analytical redundant airspeed and altitude calculation scheme could be used when the pitot-static system contains any fault condition. Originality/value Instead of using the methods based on hardware redundancy, the authors designed a new system within the scope of this study. Fault situations that may occur in pitot probes and static ports are modeled and different fault scenarios that can be encountered in all flight phases have been examined.

Designing of control and expulsion equipment for the pitot-static system of passenger airplanes

The article discusses the issue of automating the serial process of bleeding and control of the pitot- static system of passenger airplanes. A functional diagram and basic design of some parts of the combined equipment are proposed. This equipment makes it possible to alternate the above-mentioned operations with great effectiveness. At the system control stage, the pressure or vacuum in it is created by a pressure-vacuum pneumatic unit. This pneumatic unit consists of a compressor and a set of electromagnetic valves that allow the compressor to be connected to the pumping or scavenging line. The value of the generated pressure is regulated by the flow rate in the pressure/scavenging channel and in the venting channel. Simulation of changes in ambient temperature is achieved due to blowing heated or cooled air over the temperature sensors of the aircraft. Pressure or vacuum in the controlled system is created in turn, in each of its lines. At the expulsion stage, a compressed-nitrogen cylinder acts as the pressure source. The pressurized gas passes through the pitot and is released into the atmosphere, cleaning out the contaminations. No manual operations are required for installing and removing connection hoses after connecting the proposed combined equipment to the pitot-static system. Remote-controlled electromagnetic valves connect the channels of the controlled system to the pressure-vacuum pneumatic unit and the source of compressed nitrogen. This reduces the duration of successive operations for the systems maintenance.

ASTATIC IDENTIFIER IN THE CONTROL SYSTEM OF THE GYROTHEODOLITE’S SENSITIVE ELEMENT

The basic features of working conditions of means of ground orientation are considered. It is shown that in the presence of external vibration the appearance of additional measurement error is possible. The main characteristics of external vibration are given. A new feedback controller structure has been proposed, which includes an astatic state identifier. The mathematical model of the device in the form of space of states taking into account external vibration is considered. It is proposed to control the position of the sensitive element by the method of modal control by an incomplete state vector. It is assumed that the measured parameter for identifying the state vector is the angle of deviation of the sensitive element of the gyrotheodolite in azimuth. The analysis of observability at the set structure of matrices of a condition and measurements is carried out. To reduce the estimation error that occurs due to the presence of uncontrolled vibration, the state identifier uses both proportional and integrated feedback channels. The coefficients of an observer with an astatic component in the equation of state are determined under the assumption that the evaluation process should be aperiodic. Simulation of the work of the astatic identifier on the basis of the developed software model is carried out. The coefficients of the software model are selected on the basis of constructive solutions used at the present stage of development of systems for determining azimuthal directions based on gyrotheodolites. The coefficients of the observer for the given parameters of the device are calculated. The simulation results showed that the application of the proposed method can significantly reduce the impact of the constant component of external vibration. The error of estimating the angular coordinates and velocities used in the control system of the position of the sensing element, the astatic status identifier goes to zero, while the static system has a constant component of the error. In further research it is planned to build a generalized system, which includes control of the motion of the sensing element both in the azimuth and in the non-gyrostabilized plane.

Positioning control of square arrangements of solar panels by solar tracing using fuzzy logic

In this project a fuzzy control system is developed to follow the sun with its respective dynamics. The positioning of the panel must take into account changes in the weather, the disturbances that may occur, the area in which the tracker is located and so on. To do this, the maximum capture point positioning control system is studied using fuzzy logic. Prior to design and implementation, corresponding design criteria were established in instrumentation, mechanical structure, control, communication, and processing for prototype development. By means of the above, the photovoltaic array positioning system is designed, to then carry out the efficient implementation thanks to the calculations and adjustments made. After having the physical structure, we start to develop the positioning control of quadruple arrangements of solar panels with two degrees of freedom per maximum point of capture of solar radiation using fuzzy control, taking into account that the radiation sensors give a reference point. for the setpoint in the control loop and after this, control signals are sent to the selected actuators. Finally, the control system is validated for the positioning of the tracker with the fuzzy control loop implemented; In addition, the system is compared with the strategy implemented before a static system in order to analyze its efficiency. In order for the solar tracking system to show greater efficiency compared to the static system, radiation sensors are implemented that compensate for the influence of climatic disturbances that any solar panel tends to suffer.