Browsing by Publisher "Institution of Engineering and Technology"
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Item Analysis of a thin, penetrable, and nonuniformly loaded cylindrical reflector illuminated by a complex line source(Institution of Engineering and Technology, 2017) Oğuzer T.; Kuyucuoglu F.; Avgin I.; Altintas A.A thin, penetrable, and cylindrical reflector is illuminated by the incident field of a complex source point. The scattered field inside the reflector is not considered and its effect is modelled through a thin layer generalised boundary condition (GBC). The authors formulate the structure as an electromagnetic boundary value problem and two resultant coupled singular integral equation system of equations are solved by using regularisation techniques. The GBC provides us to simulate the thin layer better than the resistive model which is applicable only for very thin sheets. Hence, the more reliable data can be obtained for high-contrast and low-loss dielectric material. The scattering and absorption characteristics of the front-fed and offset reflectors are obtained depending on system parameters. Also, the effects of the edge loading are examined for both E- and Hpolarisations. The convergence and the accuracy of the formulation are verified in reasonable computational running time. © The Institution of Engineering and Technology 2017.Item Area-priority-based sensor deployment optimisation with priority estimation using K-means(Institution of Engineering and Technology, 2017) Ateş E.; Kalayci T.E.; Uğur A.Deployment in wireless sensor networks (WSN) addresses maximising the coverage of sensors and reducing the total cost of deployment. The area-priority concept for WSN deployment that the authors contributed to the literature recently allows environments with regions that have different importance or priority levels. In this study, the authors propose the first priority-estimation method for area-priority-based WSN deployments. First, a satellite image of the environment that will be used in the deployment of the sensors is clustered by a K-means algorithm using the colour features of the regions. In the sensor deployment phase, this cluster information is used to determine the priorities of the sensor coverage areas on positions of the image. Sensors are initially deployed quickly using a priority queue-based technique. Then, a simulated annealing algorithm is used to maximise the total covered area priority and to minimise the gaps between the sensors. Various experiments are performed for different scenarios (land, sea, and forest) on images captured from Google Maps using different parameter values. The experiments confirm that the proposed approach performs well and outperforms the random deployment of sensors. © 2017 The Institution of Engineering and Technology.Item Energy management for on-grid and off-grid wind/PV and battery hybrid systems(Institution of Engineering and Technology, 2017) Basaran K.; Cetin N.S.; Borekci S.Renewable energy systems such as photovoltaic (PV) and wind energy systems are widely designed grid connected or autonomous. This is a problem especially in small powerful system due to the restriction on the inverter markets. Inverters which are utilised in these kinds of energy systems operate on grid or off grid. In this study, a novel power management strategy has been developed by designing a wind-PV hybrid system to operate both as an autonomous system and as a grid-connected system. The inverter used in this study has been designed to operate both on-grid and off-grid. Due to the continuous demand for energy, gel batteries are used in the hybrid system. The designed Power Management Unit performs measurement from various points in the system and in accordance with this measurement; it provides an effective energy transfer to batteries, loads and grid. The designed control unit provided the opportunity to work more efficiently up to 10% rate. © The Institution of Engineering and Technology 2016.Item Cost-effective chemical solution synthesis of bismuth telluride nanostructure for thermoelectric applications(Institution of Engineering and Technology, 2018) Mamur H.; Dilmac O.F.; Korucu H.; Bhuiyan M.R.A.In this work, the bismuth telluride (Bi2Te3) nanostructure for thermoelectric applications was successfully synthesised by a new cost-effective chemical solution process. Firstly, the metal solutions of bismuth (III) nitrate pentahydrate and tellurium dioxide were mixed together at room temperature with adjusting the hydrodynamic atmosphere and introduced the sodium hydroxide. After that, different characterisation parameters, such as X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray, and transverse electron microscopy (TEM) were obtained. Then, the average crystalline size of the Bi2Te3 nanostructure was found 23 nm. According to these obtained results, the materials consist of every specimen in nano range dimension in AFM studies. The elemental of Bi and Te were arranged with their quite stoichiometric atomic ratio observed by SEM. Ultimately, the TEM micrographs showed that the powders exhibited an aggregate phenomenon, and the primary crystalline size was about low dimension. © 2018 Institution of Engineering and Technology. All rights reserved.Item Design and fabrication of an outer rotor permanent magnet synchronous generator with fractional winding for micro-wind turbines(Institution of Engineering and Technology, 2020) Mamur H.; Şahin C.; Karaçor M.; Bhuiyan M.R.A.Permanent magnet synchronous generators (PMSGs) have been widely used in micro-wind turbines (MWTs) for direct-drive applications. The generating maximum power from the PMSGs used in the MWTs is desired. However, cogging torque (CT) and design form of the PMSGs prevent this. Therefore, various methods are applied to reduce the CT of PMSGs in the literature. Some of them are inapplicable and some are the ones that cause power loss. In this study, to overcome the expressed causes, a new design, fabrication, and application of an outer rotor PMSG with fractional winding having a slot-pole combination technique for MWTs have been suggested, designed, and implemented on an MWT. As a result of the new design combination of ±1 or ±2 between the numbers of stator slot (NS) and the number of pole-pairs (2p), the ratio of the CT value to the nominal torque value in the new prototyped outer rotor PMSG was found as 6.25%. Finally, the operating power can generate 1029 W through the prototype PMSG with fractional winding having a slot-pole combination technique integrated into the direct-drive MWT system. © The Institution of Engineering and Technology 2020Item Synthesis and characterisation of CdSe QDs by using a chemical solution route(Institution of Engineering and Technology, 2020) Akter M.; Islam Khan M.N.; Mamur H.; Amin Bhuiyan M.R.An efficient synthesis process approach based on a chemical solution route is developed for the cadmium selenide quantum dots (CdSe QDs) that utilise photonic and optoelectronic device manufacturing. The developed route consists of dissolving the cadmium chloride (CdCl2.H2O), 2-mercaptoethanol and sodium selenide anhydrous (Na2SeO3). The different characterisation parameters such as ultraviolet (UV) absorbance, x-ray diffraction (XRD), scanning electron microscopy, energy dispersive x-ray and transmission electron microscopy (TEM) were employed in order to develop the CdSe QDs. When the sample was analysed from the UV–visible studies, the bandgap was about 2.16 eV, whereas the bulk CdSe bandgap was about 1.78 eV. The developed CdSe QDs possessed a cubic crystal structure with crystalline dimensions of about 4.86 nm. Its surface morphology and structure showed the smooth appearance of the surface. The result indicated agglomerated spheres. Ultimately, according to XRD and TEM results, the crystalline dimension was determined in good agreements. © The Institution of Engineering and Technology 2020Item Use of Large Language Models for Medical Synthetic Data Generation in Mental Illness(Institution of Engineering and Technology, 2023) Aygün İ.; Kaya M.Data quantity and quality are very important for the development of medical artificial intelligence research. Nowadays, thanks to easier access to data, studies in this field produce very successful results. However, many factors such as protection of patient rights in medical data and confidentiality of personal data prevent researchers from directly accessing the data. For this reason, synthetic data creation studies are often needed both to expand the training and test sets and to create sample cases to be used in the relevant field. In this study, various synthetic patient data are created to be presented to a language model that enables the detection of psychological disorders through patient text. Synthetic data sets were produced with 200 artificial patient data created with popular LLM examples ChatGPT and Google Bard. The quality of synthetic data was measured with the help of a pre-trained BERT model using these datasets. In the experiments, it was observed that chatbots that generate instant data, such as ChatGPT and Google Bard, produced successful results at rates of 89% and 86% with the language representation model. With the experimental results, it appears that LLM studies can provide more successful results than advanced language models in various medical text production tasks. © The Institution of Engineering & Technology 2023.Item PoS-based blockchain-assisted UAV networks(Institution of Engineering and Technology, 2024) Erel-Özçevik M.[No abstract available]