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1778 articles for “directivity”
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Behaviour of Tri-Directional Advanced Composite Beam Using Finite Element Method
Abstract: The present work shows the modal analysis of tri-directional advanced composite beams using the finite element method. The mechanical parameters of the beam are supposed to vary in the direction of beam length (x), width (y), and thickness (h). In this work material parameters are assumed to vary according to the exponential rule of functionally graded material. To authenticate the accuracy of the present work, the result with a particular …
Published in Journal of Polymer & Composites · Vol. 13, Issue 1, 2025 · pp. 610–620 Read article
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A Review on Parasitically Coupled and a Direct Coupled Feed for a Microstrip Antenna Array
Abstract: Due to modern electronics, small size electronic systems have been increasing in integrated circuits and the physical size of systems is reduced. Hence, demand of small and low cost antennas has increased. Microstrip or patch antenna provides the lightweight, not expensive, and integration is easy. Microstrip antennas or patch antennas are one of the most attractive antennas for integrated systems and are widely used in wireless communication systems. This paper …
Published in Journal of Communication Engineering & Systems · Vol. 8, Issue 1, 2018 · pp. 15–18 Read article
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A New Effective MUSIC Algorithm for Direction of Arrival Estimation and Combining It with Beam Forming in Smart Antenna Systems
Abstract: ABSTRACT Smart antenna is now commonly used in communication systems due to its high advantages. Two important functions in smart antenna are direction of arrival estimation and beam forming. The main aim of direction of arrival estimation in smart antenna is to estimate the direction of the signal and based on this angle the beam forming will identify the exact position and phase angle of the antenna. Here we proposed …
Published in Journal of Communication Engineering & Systems · Vol. 2, Issue 2, 2012 · pp. 1–6 Read article
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Performance Optimisation of Counter-Directional Orange Peeling Machine
Abstract: The machine was designed to comprise components including frame, cutting tool/post, jaws, clamp, compression and lock, which were assembled together after fabrication. The machine is clampable on the flat surface. The machine can hold an orange centrally with the aid of two jaws located at both ends of the machine. The cutting tool has a curve like profile and helps in ensuring the cutting tool follows the orange counter-directional as …
Published in Trends in Machine design · Vol. 5, Issue 2, 2018 · pp. 63–72 Read article
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Recent developments in Nano technology applications in direct absorbing solar collectors: A Review
Abstract: Solar energy harnessing is widely promoted amongst the nations so as to encourage environment conservation. Use of solar energy is very important in the context of global warming and decrease in carbon dioxide generations. Here it becomes important for the researchers to find new methods for optimum utilization of solar energy in collectors by design modifications thereby reducing heat losses along with considering the reductions in high initial costs. Addition …
Published in Journal of Thermal Engineering and Applications · Vol. 8, Issue 2, 2021 · pp. 23–34 Read article
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Fuzzy Logic and Energy Model based Speed and Direct Torque Control of SVPWM Inverter Fed Induction Motor
Abstract: This paper presents speed and direct torque controllers based on fuzzy logic for a space-vector modulated pulse width modulated inverter fed induction motor. The direct torque control has been designed by decoupling the torque and flux based on the energy model of induction motor. The designed direct torque control system can be accomplished by using constant switching frequency with space vector modulated pulse-width modulated inverter. In order to control the …
Published in Journal of Control & Instrumentation · Vol. 5, Issue 1, 2014 · pp. 11–21 Read article
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A study to investigate the shear strength resistance of Ennore sand from conventional direct shear test.
Abstract: In this article analysis of shear strength parameters of Ennore Sand is given using the direct shear test. The shear strength parameters of cohesion and angle of shearing resistance are employed in the construction of geotechnical constructions to describe the soil's ability to sustain shear stress when subjected to a certain load. These might be measured using laboratory or field testing. When shearing a sample in a direct shear apparatus, …
Published in Journal of Geotechnical Engineering · Vol. 9, Issue 3, 2022 · pp. 19–26 Read article
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Overview of Used Lube Oil Direct Utilization to Prevent Environmental Degradation
Abstract: The direct utilization of used lube oil was investigated in this research work as a measure to reduce the environmental effects, if not properly handled. The overview of the used lube oil utilization demonstrates the significance of the various mechanisms considered in this study. The study demonstrates useful areas of application, which include asphalt production, firing cement kilns, feedstock for carbon black plant in the petrochemical industry, feedstock for fluid …
Published in Journal of Petroleum Engineering & Technology · Vol. 10, Issue 3, 2020 · pp. 32–34 Read article
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Dynamic Analysis of the Proposed Bi-directional Converter for Charging and Discharging Operation
Abstract: AbstractThis paper proposes a fifth order bi-directional converter configuration with low current ripple on either side as well as good voltage conversion range having only three switches. This converter is implemented for load power levelling between a DC grid and secondary batteries. A comparative study of proposed topology with widely used bi-directional converter configurations is made and relative merits and demerits are pointed out. With state-space and discrete-time modelling techniques, …
Published in Journal of Semiconductor Devices and Circuits · Vol. 4, Issue 2, 2017 · pp. 41–51 Read article
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Direction of Arrival Estimation in Mobile Communication Systems using MUSIC Algorithm
Abstract: AbstractAdaptive antenna arrays use multiple antenna elements to form directional patterns in order to improve the performance of wireless communication systems. The antenna arrays also have the ability to estimate the Direction-of-Arrival (DoA) of the signals received from the desired transmitters as well as the directions of interference signals. The results of DoA estimation are then used to adjust the weights of the adaptive Multi-Input Multi-Output (MIMO) antenna so that …
Published in Journal of Communication Engineering & Systems · Vol. 3, Issue 2, 2013 · pp. 20–27 Read article
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Assessment of Motorcycle Helmet Potential Across Diverse Impact Directions by Means of Simulation Approach
Abstract: To make sure motorcycle helmets are protecting riders effectively, it is essential to analyze their performance under various impact orientations and varying speeds. Analyzing materials like ABS, PVC and GFRP gives important information about how durable and impact-absorbing they are. Ansys Finite Element Analysis (FEA) functionality enables a thorough investigation of the stress distribution inside the helmet construction under various impact scenarios. The present work is to study the behavior …
Published in Journal of Polymer & Composites · Vol. 13, Issue 3, 2025 · pp. 448–460 Read article
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Investigation on Direct Torque Control of BLDC Motor Using Various Controllers
Abstract: BLDC Stands for brushless DC Motor. Direct torque control is a type of a vector control. Direct Torque control consist of two control loops one is speed control and other one is torque control. For the purpose of speed control several speed controllers are used in this work such as PI, PID Controller and Fuzzy Controller. PID Controller was used for better speed response, no steady state error but due …
Published in Journal of Instrumentation Technology & Innovations · Vol. 11, Issue 2, 2021 · pp. 19–30 Read article
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Challenges and Prospects of the Use of Horizontal Directional Drilling Techniques for Laying Oil and Gas Pipelines in Nigeria
Abstract: Nigeria pipelines, especially the petroleum and petroleum product pipelines are always vandalized by the sabotage. Huge amount of money is expended to put the damaged pipeline in good shape; and petroleum and petroleum product transfer is sometimes hampered due to leakages and damages caused by the oil thieves. Also huge money is being budgeted yearly to secure the pipelines. To combat this problem, horizontal directional drilling (HDD) is being proposed. …
Published in Journal of Petroleum Engineering & Technology · Vol. 7, Issue 2, 2017 · pp. 9–20 Read article
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Study of Direct Torque Control of Three Phase Induction Motor by Matlab
Abstract: This paper presents the proposed direct torque control using space vector control which is based on a MATLAB/Simulink technique to replace proportional integral controller to control the torque of induction motor. The status of the torque and flux linkages applied the optimal switching logic. This optimal switching logic is used for the switching of three-phase inverter. The inverter output gives the controlled voltage vector that is applied to the induction …
Published in Trends in Electrical Engineering · Vol. 8, Issue 1, 2018 · pp. 24–29 Read article
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Analytical Performance Evaluation of Coherent Detection Optical Receiver over Direct Detection in OFDM Wireless Optical Communication System under Turbulent Condition
Abstract: AbstractWireless Optical (WO) communication networks have the ability to have high-speed and robust access. WO communication network output can be greatly affected by ambient conditions. Atmospheric turbulence is among the facts about the atmosphere which can reduce the reliability underneath clear sky. Earlier, orthogonal frequency division multiplexing (OFDM) in WO is reported for the design of a high-performance communication channel for the atmospheric network. Selecting a proper detection scheme in …
Published in Trends in Opto-electro & Optical Communication · Vol. 10, Issue 1, 2020 · pp. 14–23 Read article
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Sensorless Direct Power Control of Brushless DC Motor Drive using Unknown Input Speed Observer
Abstract: This paper proposes the speed control of brushless DC (BLDC) motor via direct power control (DPC) method as a novel and effective strategy in electrical drives applications. The DPC has some advantages rather than other control methods of BLDC motor including simpler control algorithm and faster dynamic response. In proposed BLDC motor drive based on DPC strategy, space vector modulation (SVM) voltage source inverter is employed. To enhance the drive …
Published in Journal of Control & Instrumentation · Vol. 6, Issue 3, 2015 · pp. 31–41 Read article
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Direct Torque Control Based on Discrete-Time PI Controller of an SVPWM Inverter Fed Induction Motor Using Energy Model
Abstract: A direct torque control (DTC) of an induction motor (IM) with constant switching frequency has been presented in this work which is performed using space-vector modulation (SVM). The developed DTC scheme is based on the discrete-time PI controller strategy and this has been used to achieve direct control of torque of IM. To design the discrete-time PI (DTPI) controller the energy model of induction motor is simplified at the beginning …
Published in Journal of Power Electronics and Power Systems · Vol. 2, Issue 2, 2012 · pp. 45–55 Read article
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Direct Power Control of Brushless DC Motor Drive
Abstract: Recently, due to significant increase in demands of electric motors, design and manufacturing of high efficiency motors and related variable speed drives have been regarded by many suppliers. Among several kinds of motors, the brushless DC (BLDC) motor has many advantages including high torque capability. In this paper, for the first time, the possibilities of direct power control (DPC) of BLDC motors fed by a voltage source inverter have been …
Published in Journal of Power Electronics and Power Systems · Vol. 4, Issue 1, 2014 · pp. 13–24 Read article
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Direct Power Control of Induction Motor Drive
Abstract: Different variable frequency strategies have been developed for control of induction motors including V/f scalar control; field oriented control (FOC), and direct torque control (DTC). Recently, direct power control (DPC) has been developed to control dual-fed induction generators (DFIGs) and permanent magnet synchronous generators (PMSGs). In this paper, DPC is employed for speed control of induction motors fed by a voltage source inverter. DPC is basically similar to DTC method …
Published in Journal of Power Electronics and Power Systems · Vol. 4, Issue 2, 2014 · pp. 48–55 Read article
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Performance Analysis of Conventional Direct Torque Control Strategy for Wide Range Speed Control of Induction Motor Drives
Abstract: Decoupled control of induction motor drives is possible using Direct Torque Control (DTC) method which is very simple control approach paralleled to field oriented control. It is very good alternative for applications like traction or automobile where direct torque control is needed. But speed control from zero to rated or even beyond rated speed is required in such applications. Torque ripples, variable switching frequency and poor low speed performance are …
Published in Trends in Electrical Engineering · Vol. 5, Issue 3, 2015 · pp. 36–45 Read article