An Enhanced Gain of Yagi-Uda Antenna with Folded Dipole for Amateur Radio VHF Band Application

This paper presents an enhanced gain of Yagi-Uda antenna with folded dipole for amateur radio Very High Frequency (VHF) band. The analysis is performed using CST Microwave Studio Suite software. The structure of this directional antenna integrates three main parts which are directors, reflectors and feeder point of 50 Ω. The performance of the proposed antenna has a tolerable reflection coefficient below -10 dB at 144.46 MHz. A maximum gain of around 14.03 dB with a good efficiency of 75.6% is achieved. The gain of the antenna increases up to 2% when added with 7 elements of reflector than with one element of reflector and enhanced significantly by 23.6% compared to the conventional Yagi-Uda antenna

Sri Cempaka Ayu Enterprise / Ilda Izanie Ahmad... [et al.]

Sri Chempaka Ayu Enterprise is a company that offer health and beauty care to their customer. they provide traditional treatment such as ‘jamu’, traditional massage and herbs steam bath. The company is located at Alor Setar, Kedah

Performance analysis and discrimination procedure of two-group location model with some continuous and high-dimensional of binary variables

This research’s primary goal was to evaluate the performance analysis of the recently constructed smoothed location models (SLMs) for discrimination purposes by combining two kinds of multiple correspondence analysis (MCA) to handle high dimensionality problems arising from the binary variables. A previous study of SLM, together with MCA as well as principal component analysis (PCA), displayed that the misclassification rate was still very high with respect to a large number of binary variables. Thus, two new SLMs are constructed in this paper to solve this particular problem. The first model results from the combination of SLM with Burt MCA (denoted as SLM+Burt), and the second one is with the joint correspondence analysis (denoted as SLM+JCA). The findings showed that both models performed well for all sample sizes (n) and all binary variables (b) under investigation, except n=60 and b=25 for the SLM+JCA model. Overall, the SLM+JCA model yields a greater performance in contrast to the SLM+Burt model. Moreover, the concept and procedures of the discrimination for the two-group classification conducted in this paper can be extended to multi-class classification as practitioners often deal with many groups and complexities of variables

Radiation pattern reconfigurable fm antenna

In this work, a radiation pattern reconfigurable antenna design using compact printed spiral monopoles that operates at 102 MHz is reported. The proposed antenna changes its radiation behaviour that responds towards a desired direction with the use of RF switches. The antenna is printed on a 76.6mm × 50mm PCB layer providing more than 20MHz bandwidth at -10 dB threshold and is easily fabricated with low manufacturing cost. The antenna was also simulated on 500mm × 500mm ground plane that represents the roof top of a vehicl

Existing and emerging breast cancer detection technologies and its challenges: a review

Breast cancer is the most leading cancer occurring in women and is a significant factor in female mortality. Early diagnosis of breast cancer with Artificial Intelligent (AI) developments for breast cancer detection can lead to a proper treatment to affected patients as early as possible that eventually help reduce the women mortality rate. Reliability issues limit the current clinical detection techniques, such as Ultra-Sound, Mammography, and Magnetic Resonance Imaging (MRI) from screening images for precise elucidation. The capability to detect a tumor in early diagnosis, expensive, relatively long waiting time due to pandemic and painful procedure for a patient to perform. This article aims to review breast cancer screening methods and recent technological advancements systematically. In addition, this paper intends to explore the progression and challenges of AI in breast cancer detection. The next state of the art between image and signal processing will be presented, and their performance is compared. This review will facilitate the researcher to insight the view of breast cancer detection technologies advancement and its challenges

Single layer microwave absorber based on rice husk-mwcnts composites

In this paper, rice husk (RH) and multi-walled carbon nanotubes (MWCNTs) composite have been fabricated as single layer microwave absorber. The MWCNTs with various weight ratio composites with RH have been prepared. Three different weight ratio 3 wt% MWCNTs, 5 wt% MWCNTs, and 15 wt% MWCNTs of the RH-CNTs have been designed and fabricated. Moreover, the dielectric properties of different RH-CNTs specimens have been verified by using rectangular waveguide transmission line technique. Furthermore, the microwave absorption of these RH-CNTs has been analyzed using free space measurement and CST Microwave Studio (CST-MWS). The dielectric properties and microwave absorption of different RH-CNTs were investigated in 8.2-12.4 GHz (X-band). From the measurement, the dielectric properties parameter of RH-CNTs is analyzed. The dielectric constant and loss factor of the RH-CNTs composite increases with increasing of MWCNTs weight ratio. However, the magnetic properties of RH-CNTs remain constant, ur= 1-j0. The measurement and simulation result show that such RH-CNTs composites has excellent microwave absorption up to 33 dB in a certain frequency rang

Radio frequency radiation measurement for base tower station safety compliances: A case study in Pulau Pinang Malaysia

The residence of Pulau Pinang and Malaysia generally are worried with the possible health effects due to Base Tower Station (BTS) radiation. Particularly, the residents of Pulau Pinang are utilizing their mobile phones for multiple kind of tasks including communications, browsing the internet and other applications. With the recent advances in mobile communication technologies, the end user demanded a better coverage, great communication services, and faster speed for internet browsing. To fulfill the demand, service provider and communication companies are providing plenty of communication base tower leading to the beliefs of that the tower emitted radiation and cause harmful effect to human health and voiced out and complain to the municipal councils in Malaysia. In this paper, a measurement was conducted to study electromagnetic fields (EMF) radiation level in Pulau Pinang. The measurement is compared with the international standard provided by International Commission of Non-Ionizing Radiation Protection (ICNIRP). Far field measurement of different values of long term evolution (LTE) exposure was demonstrated in radiofrequency (RF) shielded environment. LTE850, LTE1800 and LTE2600 field exposure was compared in term of its\u27 electrical field and power density that adhere to the standard provided by ICNIRP

Review Article of Radio Frequency and Microwave Heating Treatment to Disinfest Kutu Beras in Malaysian Rice

This article presents the basic principle of radio frequency (RF) and microwave heating and its application in agricultural sector specifically to control rice insects for storage purpose. Experiment findings of the past few years are highlighted according to the heating mechanism which influence the response of rice and insect exposed to the microwave field

Hybridization of Strength Pareto Multiobjective Optimization with Modified Cuckoo Search Algorithm for Rectangular Array

This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space. In addition, the MCS algorithm is hybridized with the particle swarm optimization (PSO) and hill climbing (HC) stochastic techniques along with the standard strength Pareto evolutionary algorithm (SPEA) forming the MCSPSOSPEA and MCSHCSPEA, respectively. All the proposed MCS-based algorithms are examined to perform MO optimization on Zitzler-Deb-Thiele\u27s (ZDT\u27s) test functions. Pareto optimum trade-offs are done to generate a set of three non-dominated solutions, which are locations, excitation amplitudes, and excitation phases of array elements, respectively. Overall, simulations demonstrates that the proposed MCSPSOSPEA outperforms other compatible competitors, in gaining a high antenna directivity, small half-power beamwidth (HPBW), low average side lobe level (SLL) suppression, and/or significant predefined nulls mitigation, simultaneously

Hybridization of Strength Pareto Multiobjective Optimization with Modified Cuckoo Search Algorithm for Rectangular Array

This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space. In addition, the MCS algorithm is hybridized with the particle swarm optimization (PSO) and hill climbing (HC) stochastic techniques along with the standard strength Pareto evolutionary algorithm (SPEA) forming the MCSPSOSPEA and MCSHCSPEA, respectively. All the proposed MCS-based algorithms are examined to perform MO optimization on Zitzler-Deb-Thiele\u27s (ZDT\u27s) test functions. Pareto optimum trade-offs are done to generate a set of three non-dominated solutions, which are locations, excitation amplitudes, and excitation phases of array elements, respectively. Overall, simulations demonstrates that the proposed MCSPSOSPEA outperforms other compatible competitors, in gaining a high antenna directivity, small half-power beamwidth (HPBW), low average side lobe level (SLL) suppression, and/or significant predefined nulls mitigation, simultaneously