Possibilities And Challenges Of Radio Frequency Energy Harvesting In Dar Es Salaam, Tanzania,
2020
Department of Electronics & Telecommunications Engineering, University of Dar es Salaam
Possibilities And Challenges Of Radio Frequency Energy Harvesting In Dar Es Salaam, Tanzania, Fredrick Isingo
Tanzania Journal of Engineering and Technology (TJET)
This paper presents investigation on the possibilities and challenges of harvesting ambient Radio Frequency Energy (RFE) at Dar es Salaam region in Tanzania. The Radio Frequency (RF) signals were measured using a Rohde and Schwarz FSC 3 spectrum analyzer observing available frequencies with their respective power. Among several RF signals received, the most powerful signals observed were; 800 MHz, 950 MHz, 2100 MHz and 2400 MHz, having average signal strengths of about-30.29 dBm,-35.94 dBm,-42.90 dBm and-30.42 dBm respectively. The power possessed within these frequencies were suitable to be harvested due to their signal strengths, an overall power average of-34.89dBm was …
Direct Predictive Speed Control Of Salient Pmsm Drives In Constant Torque And Constant Power Regimes For Electric Vehicles Applications,
2020
Department of Electrical Engineering, University of Dar es Salaam, P.O. Box 35131, Dar es Salaam, Tanzania
Direct Predictive Speed Control Of Salient Pmsm Drives In Constant Torque And Constant Power Regimes For Electric Vehicles Applications, Francis Mwasilu
Tanzania Journal of Engineering and Technology (TJET)
A direct speed control of salient permanent magnet synchronous motor (PMSM) drives in constant torque and constant power regimes for electric vehicles applications is presented. The proposed speed control scheme is derived from model predictive control approach where both rotor speed and stator current are formulated in a single objective function that is periodically computed to attain the PMSM drive optimum switching states. The dynamic model of the PMSM intrinsically encompasses the unknown disturbance, which should be rejected for high-performance speed control especially in transient conditions. Consequently, the extended modified augmented state Kalman filter (ASKF) is incorporated in the proposed …
Comparative Analysis Of Multiplicative And Additive Noise Based Automated Regularizations In Non-Linear Diffusion Image Reconstruction,
2020
University of Dar es Salaam
Comparative Analysis Of Multiplicative And Additive Noise Based Automated Regularizations In Non-Linear Diffusion Image Reconstruction, Chiza Christophe
Tanzania Journal of Engineering and Technology (TJET)
Multiplicative and additive noises are often introduced in image signals during the image acquisition process and result into degradation of image features. The work done by Perona and Malik in 1990 and its modified versions revolutionized the way through which noises or speckles are removed. The Perona-Malik model requires tuning of the regularization parameter to control and prevent staircase artifacts in restored images. The current manual tuning is a challenging and time consuming practice when a long queue of images is registered for processing. Attempt to automate the regularization parameter appeared in Perona-Malik model with self-adjusting shape-defining constant. Although both …
User-Centred Scalable Big Data Visualizer For Power Consumption Data In The Electrical Secondary Distribution Network,
2020
Department of Computer Science and Engineering, University of Dar es Salaam
User-Centred Scalable Big Data Visualizer For Power Consumption Data In The Electrical Secondary Distribution Network, Ellen Kalinga
Tanzania Journal of Engineering and Technology (TJET)
Establishment of Smart Grids for electrical power has been practised worldwide for the purpose of bringing reliability, security, and efficient management of electrical power networks for enhancing quality service to the society. Apart from the potential aim, smart grid has been a challenge to developing countries, including Tanzania from cost and technology point of view. Due to the use of many smart equipment involved in smart grids like Advanced Metering Infrastructure (AMI) equipped with smart meters and sensors, handling and managing big data has been a challenge. Among the challenges is the issue of visualizing the Big Data due to …
Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks,
2020
University of Dar es salaam
Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks, Aviti Thadei Mushi
Tanzania Journal of Engineering and Technology (TJET)
Rural electrification rate (RER) in Africa is still low to date. Several countries in Sub-Saharan Africa have tried to address this problem using conventional single phase two-wire or three-phase three-wire systems, however at large costs due to the nature of dispersed rural load centres, low load demand, and low population density. Another solution of off-grid generation creates associated health problems. Therefore, this paper undertakes a review of a single wire earth return (SWER) network as a RER improvement solution. The paper undertakes intensive literature review to elucidate challenges and solutions to the implementation of SWER technology. Advantages of SWER technology …
Wind Power Integration And Its Impact On Power Quality-A Didactic Approach,
2020
University of Dar es salaam
Wind Power Integration And Its Impact On Power Quality-A Didactic Approach, Santos Kihwele Dr
Tanzania Journal of Engineering and Technology (TJET)
This paper presents a model of a wind power system integrated with realistic power system, with intention of using it in addressing power quality issues in relations to grid codes during steady-state operation transient-state operation i.e., presence of grid fault events. For that case, a didactic approach of the normal performance of power systems due to the connection of fixed-speed wind turbine with induction generators is used. A study of integrating wind farms will be presented, including the incidence of high inrush current due to switching capacitor banks, out-rush current and voltage sags due to nearby three phase faults. As …
Neural Networks On An Fpga And The Exploration Of Hardware Friendly Activation Functions,
2020
University of Nevada, Las Vegas
Neural Networks On An Fpga And The Exploration Of Hardware Friendly Activation Functions, Jiong Si, Sarah L. Harris, Evangelos Yfantis
Electrical & Computer Engineering Faculty Research
This paper describes our implementation of several neural networks built on a field programmable gate array (FPGA) and used to recognize a handwritten digit dataset—the Modified National Institute of Standards and Technology (MNIST) database. We also propose a novel hardware-friendly activation function called the dynamic Rectifid Linear Unit (ReLU)—D-ReLU function that achieves higher performance than traditional activation functions at no cost to accuracy. We built a 2-layer online training multilayer perceptron (MLP) neural network on an FPGA with varying data width. Reducing the data width from 8 to 4 bits only reduces prediction accuracy by 11%, but the FPGA area …
Mimo Antenna For Fifth Generation Mm-Wave Applications: A Bibliometric Survey,
2020
Symbiosis International University
Mimo Antenna For Fifth Generation Mm-Wave Applications: A Bibliometric Survey, Rajeshwari R. Malekar, Laxmikant K. Shevada, Hema D. Raut, Amruta S. Dixit, Sumit Kumar
Library Philosophy and Practice (e-journal)
Nowadays most discussed technology is mm-wave and 5G communication. The requirement of 5G technology is high bandwidth, high data rate, and low latency. To fulfil these requirements for the current growth in mobile communication multiple input multiple output antenna is used. This bibliometric paper throws light on the various methods used to improve mutual coupling between multiple antennas. Various mutual coupling reduction techniques that are used in MIMO antennas like Dielectric resonator antenna, Electromagnetic Bandgap Structure, Neutralization lines, Defected Ground Structures, Metamaterial, etc. are explained. Scopus database is used for this bibliometric review on mm-wave MIMO 5G technology from the …
Bibliometric Review Of Mppt Algorithms For Wind Energy Conversion Systems,
2020
Symbiosis Institute of Technology,Symbiosis International Deemed University, Pune, India
Bibliometric Review Of Mppt Algorithms For Wind Energy Conversion Systems, Jayshree Ashok Pande, Paresh Nasikkar
Library Philosophy and Practice (e-journal)
The existing conventional fuels are going up in prices and going down in availability. This has boosted the demand for renewable resources like wind energy. Wind energy being abundantly available is becoming very popular as it is a freely available pollution-free green energy. Some technical aspects like the tracking of maximum power from the wind energy conversion systems have a very high impact on the efficiency of the wind energy conversion systems. Several algorithms have been implemented for tracking the maximum power point of the wind energy conversion systems. The main objective of this paper is to study the extent …
A Bibliometric Survey On Ultra Wideband Multiple Input Multiple Output Antenna With Improved Isolation,
2020
Symbiosis International University
A Bibliometric Survey On Ultra Wideband Multiple Input Multiple Output Antenna With Improved Isolation, Laxmikant K. Shevada, Hema D. Raut, Rajeshwari R. Malekar, Amruta S. Dixit, Sumit Kumar
Library Philosophy and Practice (e-journal)
Ultra wideband (UWB) technology remains a viable choice for very high speed data communication in future applications involving large bandwidth. For boosting the data communication efficiency and to mitigate the multipath fading issue faced by UWB system with existing narrowband systems, Multiple Input Multiple Output (MIMO) antenna system is used along with UWB. Mutual coupling which must be smaller in value plays a vital role in deciding the efficiency of MIMO antenna and hence it becomes as important aspect. The mutual coupling reduction techniques of various UWB MIMO antennas are surveyed in this bibliometric paper. The bibliometric survey aims to …
Multibeam Array Antenna For Base Station In The Fifth-Generation Mobile Communication System,
2020
Universiti Malaya
Multibeam Array Antenna For Base Station In The Fifth-Generation Mobile Communication System, Intan Izafina Idrus
Student Works (2020-2029)
Research on the fifth-generation (5G) mobile communication system has been accelerated to meet the standardization of the International Telecommunications Union for higher data traffic and higher data rates. The main requirements of the 5G mobile communication systems are the utilization of millimeter waves, the deployment of small cells, and the use of multibeam array antennas for multiple-input multiple-output schemes. Multibeam array antennas play an important role in developing a new base station to enhance system capacity, improve network coverage, and reduce co-channel interference. The main objective of this thesis is to design a single-layer multibeam array antenna at 28 GHz …
Conditional Generative Adversarial Network Demosaicing Strategy For Division Of Focal Plane Polarimeters,
2020
Psoas LLC
Conditional Generative Adversarial Network Demosaicing Strategy For Division Of Focal Plane Polarimeters, Garrett Sargent, Bradley M. Ratliff, Vijayan K. Asari
Electrical and Computer Engineering Faculty Publications
Division of focal plane (DoFP), or integrated microgrid polarimeters, typically consist of a 2 × 2 mosaic of linear polarization filters overlaid upon a focal plane array sensor and obtain temporally synchronized polarized intensity measurements across a scene, similar in concept to a Bayer color filter array camera. However, the resulting estimated polarimetric images suffer a loss in resolution and can be plagued by aliasing due to the spatially-modulated microgrid measurement strategy. Demosaicing strategies have been proposed that attempt to minimize these effects, but result in some level of residual artifacts. In this work we propose a conditional generative adversarial …
Evaluation Of Mechanical Properties Of Malaysia Local Source Wood For Electric Cruiser Board Applications,
2020
Universiti Malaya
Evaluation Of Mechanical Properties Of Malaysia Local Source Wood For Electric Cruiser Board Applications, Mohamad Rosman Othaman
Student Works (2020-2029)
This research project revolves around the idea to reduce the carbon emission in mitigating the issue of climate change. An idea to introduce the electrical cruiser board by Muhammad Fiqkri Ismail from Universiti Kuala Lumpur with his idea to promote carbon less form of multimodal transportation for users in urban city of Greater Kuala Lumpur leads this research to study the elastic properties of local source woods in Malaysia that could be proposed for this application. The wood is used for the construction of the deck of cruiser board which designed three layers with the cross-ply laminate. Three types of …
Influence Of The Shaping Process On The Tensile Properties Of Steel Reinforcement Bars Carbon Steel Grades Bjtp24 And Bjts40,
2020
Department of Civil Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
Influence Of The Shaping Process On The Tensile Properties Of Steel Reinforcement Bars Carbon Steel Grades Bjtp24 And Bjts40, Nuraziz Handika, Ridha Amalia Idhar, Jessica Sjah, Essy Arijoeni, Elly Tjahjono
Makara Journal of Technology
According to the current applicable national standard in Indonesia, i.e. SNI 07 2529 1991, in addition to the limitation on the loading rate, the steel bar must be reduced, formed, or lathed, as part of the shaping process of samples. This study determined and compared the effect of the shaping process on the yield strength, ultimate strength, and percent elongation by conducting tensile tests of steel bar grade BJTS40, i.e. deformed bar type of steel, and grade BJTP24, i.e., plain bar type of steel. Three diameters of the deformed bar (BJTS40) and one diameter of the plain bar (BJTP24) were …
A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution,
2020
Nuclear Physics and Biophysics Research Group, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution, Triati Dewi Kencana Wungu, Meqorry Yusfi, Suprijadi Suprijadi
Makara Journal of Technology
In this study, density functional theory (DFT) method is used to investigate the possibility of using a smectite clay mineral called montmorillonite (MMT) in reducing heavy metals, such as Cd, through Cd adsorption. The mechanism of Cd adsorption in MMT is observed theoretically, and the tetrahedrally isomorphic substitution on the upper layer of MMT is considered to observe the role of Al and Fe in strengthening Cd adsorption. Two types of MMT are modeled in this study: Al-MMT and Fe-MMT. The Al-MMT means that Al substitutes one atom in the upper tetrahedral layer of MMT, while Fe-MMT means that Fe …
Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte,
2020
Ionic Materials Team, Faculty of Industrial Science & Technology, Universiti Malaysia, Pahang 26300, Malaysia
Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte, Nurhasniza Mamajan Khan, Noor Saadiah Mohd Ali, Ahmad Faizrin Ahmad Fuzlin, Ahmad Salihin Samsudin
Makara Journal of Technology
This study aims to produce a solid biopolymer electrolyte (SBE) by doping ammonium chloride (NH4Cl) into alginate. Solution casting was used to prepare the alginate–NH4Cl SBE system. Electrical impedance spectroscopy was performed to analyze the electrical properties of the SBE under the applied frequency range of 50 Hz–1 MHz. The incorporation of 8 wt.% NH4Cl enhances the ionic conductivity of the SBE up to 3.18 × 10-7 S/cm at ambient room temperature. Fourier transform infrared spectroscopy shows that complexation occurs between the hydroxyl (-OH), carboxylate (COO-) and ether linkage (C-O-C) functional groups due to the formation of inter- and intra-molecular …
Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading,
2020
Faculty of Civil Engineering, Babol Noshirvani University of Technology, Babol 47148-71167, Iran
Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading, Gholamreza Abdollahzadeh, Hadi Faghihmaleki, Hamed Hamidi Jamnani, Atefeh Ebrahimi Bardar
Makara Journal of Technology
In this paper, we evaluated the effect of viscoplastic dampers on the response of steel frames under blast loading. We used SAP2000 software and link elements to investigate the responses of nine-story steel frames with and without dampers. The proposed viscoplastic damper is a new type of viscous damper. The application of this damper is based on the availability of its constituent materials. The damper acts as a viscoelastic damper at low levels of vibration, but it acts as a combination of viscoelastic operator and metal-yielding device at extreme levels of vibration. With respect to the height of the structure, …
Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes,
2020
Ionic Materials Team, Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Pahang 26300, Malaysia
Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes, Ahmad Faizrin Fuzlin, Bouchta Sahraoui, Ahmad Salihin Samsudin
Makara Journal of Technology
This research presents the influence of lithium bromide (LiBr) on the electrical properties of alginate in bio-based polymer electrolytes (BBPEs) system. Bio-based alginate was prepared using the solution casting technique with various LiBr compositions. The ionic conductivity and electrical properties of the prepared BBPEs samples were studied using electrical impedance spectroscopy over a frequency range of 50 Hz–1 MHz. A maximum ionic conductivity of 7.46 × 10−5 S cm-1 was obtained for a sample containing 15 wt. % lithium bromide-doped alginate BBPEs at ambient temperature (303 K). The electrical analysis revealed that the most conductive sample based on alginate-LiBr BBPEs …
Mechanical Alloying-Assisted Coating Of Fe–Al Powders On Steel Substrate,
2020
Nano Center Indonesia, PUSPIPTEK, Banten 15314, Indonesia
Mechanical Alloying-Assisted Coating Of Fe–Al Powders On Steel Substrate, Alfian Noviyanto, Sri Harjanto, Wahyu Bambang Widayatno, Agus Sukarto Wismogroho, Muhamad Ikhlasul Amal, Nurul Taufiqu Rochman
Makara Journal of Technology
The coating layer of Fe–Al powders on the steel substrate was prepared by mechanical alloying at room temperature. Fe, Al, and the steel substrates were milled with high-energy ball milling for 32 h with a ball-to-powder ratio of 8 in an argon atmosphere to prevent oxidation during milling. Although mechanical alloying was performed for 32 h, no new phases were observed after mechanical alloying, as analyzed by X-ray diffraction. However, the crystallite size of the milled powders for 32 h decreased by factor two compared with the initial powders. Scanning electron micrographs showed that the coating layers formed >8 h …
Performance Of Free-Space Optical Communication Systems Using Optical Amplifiers Under Amplify-Forward And Amplify-Received Configurations,
2020
Informatics Engineering, Faculty of Information and Communications Technology, Universitas Nasional, Jakarta 12520, Indonesia
Performance Of Free-Space Optical Communication Systems Using Optical Amplifiers Under Amplify-Forward And Amplify-Received Configurations, Ucuk Darusalam, Arockia Bazil Raj, Fitri Yuli Zulkifli, Purnomo Sidi Priambodo, Eko Tjipto Rahardjo
Makara Journal of Technology
With the growth of digital technology in the stage of industrial revolution 4.0, the demand for broadcasting large amounts of information to last mile users has increased. Free-space optical (FSO) communication is one of the telecommunication platforms that has shown immense potential in meeting the demand for information broadcasting. In this work, the performance of FSO communication based on wavelength division multiplexing with a data rate of 80 Gbps is investigated through simulations. The configuration of optical amplifiers in the FSO system is set up on the basis of the amplify-forward and amplify-received configurations to expand the network. The investigation …
