Optimized designing of PID controller for variable speed wind turbine systems using PSO algorithm

The PID controller design is a very popular method for controlling industrial processes and due to its simple structure and effective operation; it is used in a wide range of industries. In this paper, a method is provided for setting up the PID controller and Particle swarm optimization (PSO) algorithm is used to design a variable speed wind turbine system. The provided method has advantages such as easy implementation, stable convergence characteristics and high performance in computing. Finally the results are displayed

Artificial olfactory system with fault-tolerant sensor array

Numerous applications of artificial olfaction resulting from research in many branches of sciences have caused considerable interest in the enhancement of these systems. In this paper, we offer an architecture which is suitable for critical applications, such as medical diagnosis, where reliability and precision are deemed important. The proposed architecture is able to tolerate failures in the sensors of the array. In this study, the discriminating ability of the proposed architecture in detecting complex odors, as well as the performance of the proposed architecture in encountering sensor failure, were investigated and compared with the generic architecture. The results demonstrated that by applying the proposed architecture in the artificial olfactory system, the performance of system in the healthy mode was identical to the classic structure. However, in the faulty situation, the proposed architecture implied high identification ability of odor samples, while the generic architecture showed very poor performance in the same situation. Based on the results, it was possible to achieve high odor identification through the developed artificial olfactory system using the proposed architecture

Experimental study on the energy absorption capability of circular corrugated tubes under lateral loading and axial loading

A new type of energy absorber called an expansion joint (i.e. a corrugated tube) is examined in this research. Several experiments are performed on three types of thin-walled specimen, namely circular tubes, preformed corrugated tubes and complete corrugated tubes, to investigate the energy absorption of steel specimens under different conditions for quasi-static lateral loading and axial loading. For this purpose, some steel specimens were compressed between two rigid platens in the axial direction, and the other specimens were laterally compressed. The preformed corrugated tubes and the complete corrugated tubes were produced by the hydroforming method. In each geometrical group of specimens, several tubes, which have different wall thicknesses, different inner diameters and different lengths and which are either empty or filled with polyurethane foam, were tested. Experiments show that, for a lateral load, the specific absorbed energies of the complete corrugated tubes are higher than those of the corresponding preformed corrugated tubes and circular tubes with the same characteristics. Tests show that, under lateral loading, a complete corrugated tube with a thicker wall and a smaller diameter is the optimum energy absorber system. Therefore, when a circular tube transforms into the corrugated tube, a better energy absorber system with a higher capability is achieved under lateral loading. Also, experiments show that, under axial loading, simple circular tubes with no forming process have higher specific absorbed energies than corrugated tubes do. Corrugated specimens have more controllable plastic deformation and a more regular deformation mode than simple tubes have. Tests under axial loading illustrate that, when the preformed corrugated tubes are filled with polyurethane foam, the specific absorbed energy increases by up to 74%. A comparison of the results on empty and filled specimens shows that, in some cases, the specific absorbed energies of corrugated tubes under lateral loading are higher than the specific absorbed energies of circular tubes under axial loading. This means that, by shaping the circular tubes into preformed corrugated tubes and complete corrugated tubes via the hydroforming process, a new thin-walled structure with a high specific absorbed energy during the lateral compression process is introduced

Implementation of adaptive fuzzy controller on the variable speed wind turbines in comparison with conventional methods

This paper introduces a linear structure of wind turbine, operator and the pitch angle controller. Then, a new method of adaptive fuzzy on the variable speed wind turbines was provided and it was compared with PID and Fuzzy Logic Controller and the simulation results were analyzed. So when the results of each simulation using PID and Fuzzy controllers and adaptive fuzzy PID controllers provided, the observed advantages and disadvantages of the rotor speed and wind turbine power can be introduced. It can be seen that in PID method the high overshoot is discussed as a disadvantage while it is overcome by using fuzzy controller and overshoot will decrease. The time of reaching to a sustained speed increases slightly and in adaptive fuzzy PID controller, the less overshoot has provided a good and effective performance for system response. The use of adaptive fuzzy PID controller causes the system does not have any steady-state error and at all moments of time, the response rate is better than PID and fuzzy controller. The importance of the amount of overshoot and rate fluctuations is that by reducing these parameters in addition to reducing the cost of preventive care, maintenance and depreciation, the fluctuations in electricity generated by induction generator also greatly reduced

Analytical and experimental studies on stress capacity with modified wood members under combined stresses

The stress capacity of joints made of modified wood members under loading can be affected by design of joints and type of adhesive. Hence, these factors were addressed in this study by assessment of stress capacity variations in corner joints under diagonal applied compressive load induced combined stresses. The joints with mitered and butted design were constructed by application of epoxy and polyvinyl acetate (PVAc) adhesives from furfurylated wood samples with two weight percentage gains (WPGs), i.e., 20% as low level and 60% as high level. Results indicated that stress capacity in both corner joints was not significantly decreased with increasing polymerization of furfuryl alcohol (FA) in wood. Despite the high compression strength in mitered joint, the induced compression stresses were low in comparison with butted joint. The stress capacity in mitered joint bonded with epoxy adhesive enhanced with increasing the level of furfurylation. This was true for shear stress parallel to grain as well. Generally, it could be concluded that mitered joint made of furfurylated members and bonded with epoxy adhesive would be stronger than other corner joints

Building-Integrated Photovoltaic/Thermal (BIPVT): LCA of a façade-integrated prototype and issues about human health, ecosystems, resources

Building-Integrated Photovoltaic/Thermal (BIPVT) technology offers multiple advantages; however, these types of installations include materials such as Photovoltaic (PV) cells and metals which considerably influence BIPVT environmental impact. Therefore, there is a need to evaluate BIPVT environmental profile, for instance by means of Life Cycle Assessment (LCA). In light of the issues mentioned above, the present article is an LCA study that assesses the environmental performance of a BIPVT prototype that has been developed and patented at the Ulster University (Belfast, UK). The investigation places emphasis on material manufacturing, based on Cumulative Energy Demand (CED), Global Warming Potential (GWP), ReCiPe, Ecological footprint and USEtox. The results show that according to all the adopted methods/environmental indicators and based on primary materials, the PV cells and the two vessels (steel) are the components with the three highest impacts. Scenarios which include recycling of steel, plastics and brass (landfill for the other materials has been assumed), based on CED, GWP 100a and ReCiPe endpoint, have been examined. It was found that steel recycling offers a considerable impact reduction, ranging from 47% to 85%. Furthermore, the impact of the proposed BIPVT module per m2 of thermal absorber has been calculated. The results, based on primary materials, show 4.92 GJprim/m2 and 0.34 t CO2.eq/m2 (GWP 100a). In addition, according to USEtox/ecotoxicity, USEtox/human toxicity-non-cancer (scenario based on primary materials), the PV cells present the highest contributions to the total impact of the module: 55% in terms of ecotoxicity and 86% concerning human toxicity/non-cancer. A comparison with literature is provided. Moreover, a separate section of the article is about factors which influence BIPVT environmental profile, discussing parameters such as the storage materials and the end-of-life management.The authors would like to thank “Ministerio de Economía y Competitividad” of Spain for the funding (grant reference ENE2016-81040-R)

Efficient Implementation of Recurrent Neural Network Accelerators

In this dissertation, we propose an accelerator for the implementation of Lthe ong Short-Term Memory layer in Recurrent Neural Networks. We analyze the effect of quantization on the accuracy of the network and we derive an architecture that improves the throughput and latency of the accelerator. The proposed technique only requires one training process, hence reducing the design time. We present the implementation results of the proposed accelerator. The performance compares favorably with other solutions presented in Literature. The goal of this thesis is to choose which circuit is better in terms of precision, area and timing. In addition, to verify that the chosen circuit works perfectly as activation functions, it is converted in Vivado HLS using C and then integrated in an LSTM Layer. A Speech recognition application has been used to test the system. The results are compared with the ones computed using the same Layer in Matlab to obtain the accuracy and to decide if the precision of the Non-Linear functions is sufficient

Investigation on the feasibility of utilization wood and OCC fiber on the surface layer of particleboard and their effects on surface hardness and roughness

The feasibility of using of wood and old corrugated container (OCC) fibers on the surface layers of particleboards was investigated. The kind of applied furnish at surface layers, the moisture and adhesive content were considered as variables and their effects on hardness and roughness of manufactured particleboards were examined. The results indicated that the application of both wood fibers and OCC on the surface layers of particleboard resulted in improving surface quality. The moisture and adhesive contents at high levels led to improved surface quality. The control samples with 10% adhesive and 14% moisture content yielded more hardness than the other. The smoothest surfaces appeared on the particleboards manufactured with wood and OCC fibers as well as 14% moisture content and 12% adhesive

An infinite family of finite ‎‎2‎‎2‎‎-groups with deficiency zero

‎‎We determine a new infinite sequence of finite $2$-groups with deficiency zero‎. ‎The groups have $2$ generators and $2$ relations‎, ‎they have coclass $3$‎ ‎and they are not metacyclic‎