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Abstract

In this paper a complete methodology of modeling and control of quad-rotor aircraft is exposed. In fact, a PD on-line optimized Neural Networks Approach (PD-NN) is developed and applied to control the attitude of a quad-rotor that is evolving in hostile environment with wind gust disturbances and should maintain its position despite of these troubles. Whereas PD classical controllers are dedicated for the positions, altitude and speed control. The main objective of this work is to develop a smart Self-Tuning PD controller for attitude angles control, based on neural networks capable of controlling the quad-rotor for an optimized performance thus following a desired trajectory. Many problems could arise if the quad-rotor is evolving in hostile environments presenting irregular troubles such as wind gusts modeled and applied to the overall system. The quad-rotor has to rapidly achieve tasks while guaranteeing stability and precision and must behave quickly with regards to decision making fronting turbulences. This technique offers some advantages over conventional control methods such as PD controllers. Simulation results are achieved with the use of Matlab/Simulink environment and are established on a comparative study between PD and PD-NN controllers founded on wind disturbances application. These obstacles are applied with numerous degrees of strength to test the quad-rotor comportment. Experimental results are reached with the use of the V-REP environment with which some trajectories are tracked and then applied on a BLADE Inductrix FPV+. These simulations and experimental results are acceptable and have confirmed the efficiency of the proposed PD-NN approach. In fact, this controller has fairly smaller errors than the PD controller and has an improved ability to reject troubles. Moreover, it has confirmed to be extremely vigorous and efficient fronting disturbances in the form of wind disturbances.

Open access

Abstract

The paper deals with an analysis of a drought in the small basin of the Gidra River in Slovakia due to problems with the abstraction of water from small reservoirs and ponds. A detailed hydrological assessment of the M-daily discharges for a long-term period was based on a dataset from the only gauging station on the upper part of the river. Because of the existing water structures with prescribed operations during the year, hydrometric and geodetic measurements were taken by the authors. The solution to this problem represents the conditions for the minimum required Q355 discharge in the river anytime and anywhere. This can only be solved with a master operational manual for the whole river to be able to flexibly react to the current hydrological situation.

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Abstract

In the sorting plant examined during the research, the sorting of the selectively collected mixed packaging waste is done by hand. Studies were performed on the quantitative changes of the waste stream entering and leaving the sorting plant, the composition properties according to the particle size, and lastly the number of pickings. The amount of incoming waste has increased linearly over the years. The sizes preferred by the optical separators were the guideline during the measurements. Sixty percentage of all incoming waste falls in the ideal range of 70–350 mm, 20% in the range of <70 mm and 20% in the range of >350 mm. Because there are significant differences in composition and quantities as the seasons and months alternate, these results provide important information for engineers designing a mechanized technology.

Open access

Abstract

The deteriorative processes occurring in the environment, the growth of population, the water demand of industry and agriculture, point out day after day the increasing role of water management. The economical use of drinking-water consumption as well as the cost reduction is becoming more and more important. In this research, the measure of a water supplier of Győr was examined in terms of implementing the purposes above.

Open access

Abstract

Advanced control of variable speed horizontal wind turbine was considered in the high wind speed range. The aims of control in this region are to limit and stabilize the rotor speed and electrical power to their nominal values, while reducing the fatigue loads acting on the structure. A new nonlinear technique based on combination between sliding mode control and radial basis function neural network control was investigated. The proposed hybrid controller was implemented via MATLAB on a simplified two masses numerical model of wind turbine. By applying the Lyapunov approach, this controller was shown to ensure stability. It was found also to be robust and able to reject the uncertainties associated to system nonlinearities. The obtained results were compared with those provided by an existing controller.

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Abstract

Cement replacement materials are commonly used in concrete technology. Several researchers have examined high-performance concrete after adding mineral admixtures to it, but further studies are still needed to provide the optimum dosage of these materials for instance fly ash and silica fume. This study compares three types of concrete and the mechanical properties (compressive strength, flexural strength, and splitting tensile) of these types at the age of 28 and 90 days. The test results designate that adding the mineral admixtures commonly affects the mechanical properties of all the tested types. However, silica fume is more operative than fly ash. Furthermore, adding the fly ash and silica fume in the same concrete type slightly improves the mechanical properties.

Open access

Abstract

Contact with groundwater in the disposal geological site will induce the creation of an amorphous corrosion layer on the high-level radioactive glass. This is connected to silicate saturation conditions in the surrounding medium, and it is influenced significantly by geochemical processes in the near-field minerals at that depth. The international simple glass is a six-oxide borosilicate glass that is commonly used in nuclear interest. It is a simple glass generated from its composition to be an international benchmark glass. The results of the standard materials characterization center leaching tests in double deionized water at 90 °C and an initial pH value of 6.3 showed that it reacts with Ankerite for a short period of time. The effect of Ankerite on borosilicate glass durability through magnesium-silicate precipitation has been investigated and confirmed in this study.

Open access

Abstract

Visual identification of objects is an important challenge today. Main target of frequently applied methods is to identify or classify complex objects. These methods are far less effective when objects are small and less complex, and thus less descriptor features are on hand. The main reason for this is that these features can significantly change on object occlusion or appearance of noise.

The presented solution performs identification of simple, small (size is 17 × 13 pixels) objects with elliptical shape. High pass filtered normalized cross correlation is used for region of interest detection and a simple deep neural network is used for classification of selected regions. The proposed method detected objects on a noisy image with accuracy of 96.2%.

Open access

Abstract

The displacement of a loaded pile could be vertical (axial) or horizontal (lateral); these displacements are sensitive to groundwater presence within the soil mass. This paper presents a theoretical study to investigate vertical and horizontal displacement of piles embedded in a clayey soil for different levels of groundwater under the ground surface. The study was performed using the commercial finite element package PLAXIS-3D. Three diameters of the concrete piles were considered: 0.5, 0.75 and 1 m, and were subjected to 1,000 kN axial load. The effect of 0, 5, 10, 15 and 20 m groundwater along the 20 m pile in length from the ground surface on the vertical and horizontal displacements was investigated. The results indicated that the vertical and horizontal displacements increase when the ground water level increases towards the base of pile. Also, there is a significant increase in the horizontal displacement up to 15 m of groundwater level from ground surface and decreased at levels from 15 to 20 m.

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Abstract

The reduction of energy consumption is a major issue nowadays that should be considered during the design process. High-rise buildings represent a building type with significantly high energy consumption. They serve typically as offices with fully glazed façades, generating considerable energy demand. This study aims to optimize the envelope and the shading systems of a high-rise office building (Middle Europe). For this purpose, multiple façade variants were tested by assessing the thermal and visual comfort, as well as energy demand. The IDA ICE 4.8 building energy simulation program was used for thermal and lighting modeling and to carry out building physics calculations. Results revealed the best performing, optimized façade configuration in terms of comfort and energy efficiency.

Open access