Siti Zuraidah Ibrahim
Thumbnail Image
Preferred name
Siti Zuraidah Ibrahim
Official Name
Siti Zuraidah, Ibrahim
Alternative Name
Ibrahim, Siti Zuraidah
Binti Ibrahim, Siti Zuraidah
Ibrahim, Siti Z.
Ibrahim, S. Z.
Main Affiliation
Scopus Author ID
35193912700
Researcher ID
DUU-6589-2022

Research Output

Filters

33
Reset filters

Settings
Now showing 1 - 10 of 33
  • Publication
    Development of the Educational Tool for Optimized Algorithm Model Using MATLAB GUI
    ( 2021-01-01)
    Aunkaew S.
    ;
    Tantiviwat S.
    ;
    Siti Zuraidah Ibrahim
    Optimization algorithms are mathematical functions that are widely used to solve objective function problems through maximization or minimization. Typically, students at the beginner level face difficulties in understanding the complex mathematical solutions used in optimization algorithms. This paper presents an educational graphical user interface (GUI) for simulation of various topology optimization algorithms that users can use to explore the behavior of local search (LS), tabu search (TS) and particle swarm optimization (PSO) algorithms. The GUI is created using the MATLAB GUIDE tool, which acts as a front-end interface that can be used for teaching as well as learning. Benchmark functions such as the De Jong first function (DF), the Griewank function (GF), the Himmelblau function (HF) and the Periodic function (PF) were used to validate the investigated optimization algorithms. The developed GUI has features where the user can enter functions, define boundary limits, specify solver parameters and select the type of output display. The results of the instance HF function shown using the GUI optimization tool are in good agreement with the benchmark function.
  • Publication
    Compact multilayer wideband symmetric five-port reflectometer
    ( 2017-04-01)
    Samir Salem Al-Bawri
    ;
    Mohd Faizal Jamlos
    ;
    Siti Zuraidah Ibrahim
    ;
    Syed Alwee Aljunid Syed Junid
    This article presents a new design of a wideband, compact, and low-cost symmetric five-port reflectometer (5PR). The proposed 5PR features a wide operational bandwidth of 3240 MHz (about 162% centered at 2 GHz). Five-symmetric branch-lines consist of SCURVE, STEE, SLIN, and Term were designed and optimized to achieve an equivalent value of 78 dB for S11, S22, S33, S44, and S55 at center frequency of 2 GHz. Such consistent value between those S-parameters proven a perfect matching impedance are successfully obtained by proposed symmetric 5PR even own a bandwidth as high as 162%. Moreover, the simulated and measured results show the proposed 5PR has realized magnitude of ≈ 0 dB (S11), 0.5 (S12, S13, S14, S15, S21, S23 … S54) as well as phase relative error of 120° which in parallel to theoretical values. With all capabilities mentioned, the proposed 5PR is a promising candidate to be installed in a microwave imaging system for biomedical applications in the future. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:802–805, 2017.
  • Publication
    Miniature microstrip bandpass filters based on quadruple-mode resonators with less via
    ( 2017-05-03)
    Sugchai Tantiviwat
    ;
    Mohammad Shahrazel Razalli
    ;
    Siti Zuraidah Ibrahim
    This article aims to design of microstrip resonators in order to reduce size of microstrip bandpass filters in wireless communication systems. Characterized by both theoritical investigation and full-wave simulation, the proposed bandpass filters are designed consist of dual-band bandpass filters and quadruple mode bandpass filters with miniaturized size. The proposed filter is found to have benefits such that the even-mode resonant frequencies can be flexibly controlled while the odd-mode resonant frequency is reserved for the fundamental frequency. Since the structure of resonators is realized using common via holes, the difficulty and complexity of the fabrication process can be shortened. In order to achieve compact size, the total number of resonators is reduced so that the implemented resonators only occupy a small area.
  • Publication
    Stochastic pricing formulation for hybrid equity warrants
    ( 2022-01-01)
    Roslan T.R.N.
    ;
    Karim S.
    ;
    Siti Zuraidah Ibrahim
    ;
    Jameel A.F.
    ;
    Yahya Z.R.
    A warrant is a financial agreement that gives the right but not the responsibility, to buy or sell a security at a specific price prior to expiration. Many researchers inadvertently utilize call option pricing models to price equity warrants, such as the Black Scholes model which had been found to hold many shortcomings. This paper investigates the pricing of equity warrants under a hybrid model of Heston stochastic volatility together with stochastic interest rates from Cox-Ingersoll-Ross model. This work contributes to exploration of the combined effects of stochastic volatility and stochastic interest rates on pricing equity warrants which fills the gap in the current literature. Analytical pricing formulas for hybrid equity warrants are firstly derived using partial differential equation approaches. Further, to implement the pricing formula to realistic contexts, a calibration procedure is performed using local optimization method to estimate all parameters involved. We then conducted an empirical application of our pricing formula, the Black Scholes model, and the Noreen Wolfson model against the real market data. The comparison between these models is presented along with the investigation of the models’ accuracy using statistical error measurements. The outcomes revealed that our proposed model gives the best performance which highlights the crucial elements of both stochastic volatility and stochastic interest rates in valuation of equity warrants. We also examine the warrants’ moneyness and found that 96.875% of the warrants are in-the-money which gives positive returns to investors. Thus, it is beneficial for warrant holders concerned in purchasing warrants to elect the best warrant with the most profitable and more benefits at a future date.
  • Publication
    Development of branchline coupler using parallel coupled transmission lines
    ( 2017-01-03)
    Rahim N.H.A.
    ;
    Rasid R.
    ;
    Siti Zuraidah Ibrahim
    ;
    Nazuhusna Khalid
    ;
    Mohammad Shahrazel Razalli
    ;
    Siang T.G.
    This paper investigates the development of branchline coupler using parallel coupled transmission lines on planar microstrip using CST Studio Suite 2010 design tool. This project operates within 4 GHz to 8 GHz frequency band. Two designs are proposed in this project which are basic branch line coupler and branch line coupler with parallel line feeding technique. The main purpose of this study is to improve bandwidth while compare the performance of both designed coupler. The designs are then investigated using CST Microwave Studio simulation tool. The designs are fabricated on microstrip printed circuit board and measured using vector network analyzer. The simulated and experimental results of both developed couplers are compared and analyzed. The overall simulated percentage bandwidth of the proposed coupler is covered from 4 to 8 GHz with percentage bandwidth of 32.32%.
  • Publication
    Tomato Diseases Classification Using Extreme Learning Machine
    ( 2023-10-06)
    Xian T.S.
    ;
    Ruzelita Ngadiran
    ;
    Iszaidy Ismail
    ;
    Amiza Amir
    ;
    Siti Zuraidah Ibrahim
    ;
    Taha T.B.
    Plant disease classification is essential to the agriculture industry. In this work, a tomato disease classification using Extreme Learning Machine (ELM) with image-based features. Extreme Learning Machine (ELM), a classification algorithm with a single layer feed-forward neural network where it can be combined with few activation functions. The image features as the input where the image is pre-processed via HSV colour space and extracted using Haralick textures, colour moments and HSV histogram. The features are then loaded in the ELM classifier to perform the ELM training and testing. The accuracy result of ELM classification is then analysed after the validation. The dataset used for disease detection is tomato plant leaves which is a subset of the Plant-Village dataset. The results produced from the ELM demonstrate an accuracy of around 84.94% which is comparable to classifiers such as the Support Vector Machine and Decision Tree.
  • Publication
    Design of 4-Channel Multiplexer Using Waveguide Cylindrical Cavity Resonator
    ( 2023-01-01)
    Siti Zuraidah Ibrahim
    ;
    Ng G.S.
    ;
    Soeung S.
    ;
    Cheab S.
    ;
    Masrakin K.
    ;
    Tantiviwat S.
    The design of a 4-channel multiplexer using a waveguide cylindrical cavity resonator of second order and fourth order is presented in this paper. The performance of the multiplexer is improved when implementing the higher order. The proposed multiplexer design is based on a manifold structure that uses a TE011 mode resonator as the filter channel element. The design procedure involves the use of FD3D and FEST 3D of CST Microwave Studio software to optimize the dimensions of the resonator and waveguide sections to achieve the desired performance parameters, such as insertion loss, return loss, and isolation. The simulated results show that the proposed multiplexer design achieves good performance by featuring the insertion loss is less than 1 dB, and the return loss is better than 10 dB over the 10 GHz band. The isolation between the channels is more than 10 dB, which is suitable for most applications. The proposed multiplexer design is simple, compact, and has good performance characteristics, making it suitable for use in various microwave applications.
  • Publication
    Target direction finding using port technique for short range radar based sensor
    ( 2017-01-03)
    Ghazali S.
    ;
    Nazuhusna Khalid
    ;
    Siti Zuraidah Ibrahim
    ;
    Tan G.
    This paper presents a target direction finding using six-port technique for short range radar based sensor. Direction finding of the target is determined by performing phase measurement of the incident wave at the receiver side. This technique is also known as Direction of Arrival (DOA) detection method. In this paper, the operation of target direction finding is performed and simulated using Keysight Advanced Design Studio (ADS) simulation tool. The six-port device is modelled in ADS using measured scattering parameters (S-parameters). To convert the received RF signal to baseband signal, RF power detector is also designed and simulated independently in ADS. The simulated results of each stage is discussed and presented in this paper.
  • Publication
    Directional and wideband antenna for ground penetrating radar (GPR) applications
    ( 2017-01-03)
    Nazuhusna Khalid
    ;
    Siti Zuraidah Ibrahim
    ;
    Mohd Nazri A. Karim
    This paper presents a directional and wideband antenna for ground penetrating radar (GPR) applications. The antenna is designed by introducing slots on bowtie patch. The design is implemented on FR4 board with dielectric constant of 4.7 and thickness of 0.8 mm. As a result of having thinner substrate, the design is compact and light weight. The bowtie antenna performance is investigated across 0.5 GHz to 3 GHz. The parametric study of the length and location of slot are also demonstrated in this paper to obtaining the best return loss across widest operational bandwidth. The both simulated and fabricated antenna bandwidth are more than 50% (fractional bandwidth). The additional reflector is included at the back of bowtie antenna in the simulation for obtaining directional radiation pattern and high gain. The comparison between simulated and measured reflection coefficient is also presented.
  • Publication
    IoT-based Door Access Using Three Security-Layers
    ( 2023-10-06)
    Aznan M.A.
    ;
    Siti Zuraidah Ibrahim
    ;
    Ku Nurul Fazira Ku Azir
    ;
    Ruzelita Ngadiran
    ;
    Mohd Noh F.H.
    This paper demonstrates an Internet-of-Things, IoT-based Door Access using three security layers, which are biometric identification, authentication, and authorized reply. The IoT-based door access is developed with Closed Circuit Television (CCTV) monitoring to control door access by authorized users using facial recognition technique and the Telegram application along with a database to record user logs. In the first security layer, the user’s face will be captured by CCTV camera and then processed to match to the registered face. In the authentication layer, the system will use Telegram Bot to send a message to the user registered Telegram Chat Identification (ID) only for entering the password. In the third security layer, if the password is valid, the system will send a signal to the hardware to unlock the door. The results showed that the developed prototype of this system successfully operated as expected.