Conference Publications
Permanent URI for this collection
Browse
Recent Submissions
1 - 5 of 70
-
PublicationComparative study of vibration energy harvesting on home appliances using piezoelectric energy harvester(IOP Publishing, 2023)This project was developed to harvest vibration energy using a piezoelectric energy harvester. The availability of home appliance vibration energy is a promising solution to get clean energy resources to manipulate wasted energy. When the appliances’ vibration hits the piezoelectric energy harvester surface, pressure is applied to the piezoelectric transducers and converts mechanical energy into electrical energy. The piezoelectric energy harvester’s efficiency depends on the availability of the home appliances’ vibration energy; thus, using multiple piezoelectric transducers in series generates more power. The piezoelectric’ alternating current (AC) output is fed to a Cockroft-Walton voltage multiplier (CWVM) to convert into direct current (DC) and boost the output. Four piezoelectric transducers connected in series have successfully produced a voltage of up to 4.7 V. Its output voltage can be harnessed to power low-voltage electronic devices.
-
PublicationModelling and analysis of electrical performance outdoor glass insulator under various services and lightning impulse(IOP publishing, 2023)This paper is focus on modelling of glass type insulator with voltage rating of 275 kV. The glass insulators are still widely served in overhead transmission line because of its high dielectric strength capability. However, their outdoor application has resulted in the exposure to the various service conditions such as weather, pollution and lightning conditions. Further, the inclination effect of the insulator under the nominal voltage and lightning impulse is modelling through Finite Elementary Method (FEM). Then, the model of glass insulator is constructed in three different inclination angles by using the Ansys Maxwell 3D for simulation purpose. The results show the inclined insulator due to the wind load effect has the lowest breakdown voltage at most 53.33% compared with the vertical insulator. Under the outdoor environment factors such as humid, wet and contamination, the localized electric field and current density had increased significantly. Consequently, this situation may cause the power losses, localized heating effect also reduces the electrical performance of the insulators.
-
PublicationA comparative study of dual cylinders and triangle bluff bodies for piezoelectric energy harvesting(IOP Publishing, 2023)The flow patterns behind tandem bluff bodies can be used to generate electricity in piezoelectric energy harvesters. The vortices and wakes that form behind the bluff bodies create a pressure differential, which can be used to deform a piezoelectric film. In this study, we investigated the performance of dual triangle and dual cylinder bluff bodies in tandem at varying Reynolds numbers, Re, and spacing ratios, D. We compared the flow patterns behind the two types of bluff bodies. Sixteen hot wire anemometers were placed at different locations to measure the velocity developed behind the dual bluff bodies in tandem. The results showed that the velocities behind the cylinder bluff bodies were initially higher than those behind the triangle bluff bodies at lower Re. This is because the cylinder bluff bodies create a more turbulent flow, which results in higher velocities at lower Re. The best distance between the two bluff bodies was 3D and 5D, where the output velocities were maximized at more than 12ms-1. However, for dual triangle, the velocities eventually became higher than those behind the cylinder bluff bodies at higher Re and lower separation ratios (1D and 2D). 3D was the best distance for triangle to produce a higher velocity pattern, and this was best observed when Re = 10k, which is the lowest inlet velocity set. The results of the experiments are expected to show that the dual triangle bluff bodies produce higher velocities than the dual triangle bluff bodies, which will lead to a higher amount of energy being harvested. The results show that the amount of energy harvested were increase with increasing Re and decreasing D. The information enhancement can be done with turbulence analysis which could lead to the development of more efficient and versatile piezoelectric energy harvester.
-
PublicationData collection pipeline for big interior registration and modelling using 3D sensor(IOP Publishing, 2023)This paper highlights on the analysis of several data collection pipeline for big interior using Structure sensor. Data of big, large interior, collected by 3D sensors such as Structure sensor is very crucial and important as it could be used to develop 3D as-built model, where the model can be utilized for various purposes like maintenance, management as well as renovation work. However, collecting data of big interiors can be challenging as the outcome of the 3D model can be less accurate due to dimensions of the big interior which surpasses the range of the sensor. Thus, there is a need to have a proper planning when collecting 3D data representing big interior, especially rooms with clutter and occlusion due to furniture and equipment. This project concentrates on developing and testing suitable pipeline in collecting data representing big interior using Structure sensor. Three different methods were proposed, tested and analysed, where the interior is modelled using MeshLab. Results show that Method Two, which is wall by wall approach, is the most suitable among the other pipeline proposed. Thus, this method can be utilized by professionals and experts when using 3D sensors like Structure sensor in collecting big, large interior data.
-
PublicationSuperpixels-based automatic density peaks and fuzzy clustering approach in COVID-19 lung segmentation(IEEE, 2023-12)Clustering algorithms that rely on minimizing an objective function suffer from the drawback of requiring manual setting of the number of clusters. This limitation becomes particularly evident when applied to image segmentation, where the large number of pixels can lead to memory overflow issues. To overcome this challenge, a reference of Automatic Fuzzy Clustering Framework (AFCF) for image segmentation method has been used as the comparison to the Density Peaks Clustering (DPC) algorithm. AFCF used superpixel algorithm to reduce the spatial information of data during computation, DPC algorithm to generate decision graph, and prior entropy-based fuzzy clustering (PEFC) algorithm to achieve fully automatic segmentation method in determining the number of cluster and the clustering result. In this study, 50 open-source healthy, COVID-19 and pneumonia infected radiographs dataset are acquired from the Kaggle and Github. The radiographs dataset that segmented by DPC is down sampling to 100*100 pixels due to overloading computation. At the end of the image segmentation, a segmentation performance evaluation is conducted based on sensitivity, specificity, accuracy, precision, recall, F-score and time consumed. The result shows that AFCF algorithm has the better overall performance with higher accuracy of 92.48% and F-score 0.9455. Meanwhile, the most highlighted evaluation index is drop to the time consume comparison, AFCF has around 2.7 times faster processing speed compare to DPC algorithm.