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31,377 Article Results

A low cost spectroscopy with Raspberry Pi for soil macronutrient monitoring

10.12928/telkomnika.v17i4.12775
Suhaila; Universiti Teknologi Malaysia Isaak , Yusmeeraz; Universiti Teknologi Malaysia Yusof , Nor Hafizah; Universiti Tun Hussien Onn Ngajikin , Norhafizah; Universiti Teknologi Malaysia Ramli , Chuan Mu; Universiti Teknologi Malaysia Wen
Soil spectroscopy measurement is widely used to determine the macronutrients content in the soil. Spectrometer is costly equipment and commonly used to determine the transmittance, absorbance or reflectance level of various liquids and opaque solids by measuring the intensity of light as a light source passes through a sample chemical substance. This paper is reported on a low cost experimental assessment of soil macronutrient for soil spectroscopy utilizing Raspberry Pi (RPI) module in visible and near-infrared (NIR) wavelength. The sensitivity measurements are mainly due to the concentration level and the intensity of light emitting diode (LED) light source. The work is focusing on the absorbance spectroscopy particularly on linear relationship to determine the Nitrogen (N), Phosphorus (P) and Potassium (K) content level in soil using colour-developing reagent. The development of low cost and portable RPI based spectrophotometer has created new possibilities to measure the concentration level of the existed soil macronutrient within visible and infrared light wavelength of light sources. The absorbance of light was computed based on Beer-Lambert Law. The low cost RPI based spectrometer costs 80% less than the spectrometer available in the market and is capable of recording the absorbance measurements up to 5 samples. The performance of this prototype shows that it is possible to build the spectrometer using open-source software and hardware by considering the limiting factors such as light transfer to the sample, spectral filtering and the sensitivity due to the signal-to-noise ratio.
Volume: 17
Issue: 4
Page: 1867-1873
Publish at: 2019-08-01

Performance analysis for power-splitting energy harvesting based two-way full-duplex relaying network over nakagami-m fading channel

10.12928/telkomnika.v17i4.11191
Tan N.; Ton Duc Thang University Nguyen , Van-Duc; Nguyen Tat Thanh University Phan , Hoang-Nam; Ton Duc Thang University Nguyen , Minh; Ton Duc Thang University Tran , Tran Thanh; Van Hien University Trang
Energy harvesting relay network is considered as the promising solution for a wireless communication network in our time. In this research, we present and demonstrate the system performance of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading environment. Firstly, we propose the analytical expressions of the achievable throughput and outage probability of the proposed system. In the second step, the effect of various system parameters on the system performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced the analytical and the simulation results are agreed with each other.
Volume: 17
Issue: 4
Page: 1595-1603
Publish at: 2019-08-01

A weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment

10.11591/ijeecs.v15.i2.pp894-901
Terence Jerome Daim , Razak Mohd Ali Lee
Impulse Radio Ultra-Wideband (IR-UWB) radar is a type of radar functioning based on UWB transmission technology that uses an exceedingly wide bandwidth low power impulse signal to continuously transmitting and receiving the impulse signal for object detection within a range. To date, most of the proposed Ultra-Wideband (UWB) transmission technology based object positioning estimation systems for indoor environment depends on objects to be attached with an active UWB devices. In certain circumstances, it is ideal to track objects in passive manner without the requirement of any attached tracking devices or device-free object positioning estimation. IR-UWB radar has shown promising utilization in realizing device-free object positioning estimation for indoor environment.  With this motivation, in this paper a work on weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment is presented.
Volume: 15
Issue: 2
Page: 894-901
Publish at: 2019-08-01

Optimal capacitor placement in a distribution system using ETAP software

10.11591/ijeecs.v15.i2.pp650-660
M. J. Tahir , Badri. A. Bakar , M. Alam , M. S. Mazlihum
Mostly loads are inductive in nature in content of distribution side for any power system. Due to which system faces high power losses, voltage drop and reduction in system power factor. Capacitor placement is a common method to improve these factors. To maximize the reduction of inductive load impact, optimal capacitor placement (OCP) is necessary with the objective function of system cost minimization for voltage profile enhancement, power factor improvement and power losses minimization. As OCP is a non-linear problem with equality and inequality limitations, so the stated objective depends upon he placement and sizes of the capacitor banks. Electrical transient analyzer program (ETAP) software is used for the evaluation and modelling the power systems and genetic algorithm (GA) is used as an optimization technique for the minimization of the objective function. In this paper, to show the effectiveness of the technique IEEE 4bus,33bus system and NTDC 220KV real time grid system is modelled and evaluated in terms of objective minimization i-e maximum cost saving of the power system
Volume: 15
Issue: 2
Page: 650-660
Publish at: 2019-08-01

Wide to multiband elliptical monopole reconfigurable antenna for multimode systems applications

10.12928/telkomnika.v17i4.12764
I. H.; Universiti Teknologi Malaysia Idris , M. R.; Universiti Teknologi Malaysia Hamid , K.; Universiti Teknologi Malaysia Kamardin , M. K. A.; Universiti Teknologi Malaysia Rahim
Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications.
Volume: 17
Issue: 4
Page: 1663-1669
Publish at: 2019-08-01

Pre-filters in-transit malware packets detection in the network

10.12928/telkomnika.v17i4.12065
Ban Mohammed; AL-Nahrain University Khammas , Ismahani; Universiti Teknologi Malaysia Ismail , M. N.; Universiti Teknologi Malaysia Marsono
Conventional malware detection systems cannot detect most of the new malware in the network without the availability of their signatures. In order to solve this problem, this paper proposes a technique to detect both metamorphic (mutated malware) and general (non-mutated) malware in the network using a combination of known malware sub-signature and machine learning classification. This network-based malware detection is achieved through a middle path for efficient processing of non-malware packets. The proposed technique has been tested and verified using multiple data sets (metamorphic malware, non-mutated malware, and UTM real traffic), this technique can detect most of malware packets in the network-based before they reached the host better than the previous works which detect malware in host-based. Experimental results showed that the proposed technique can speed up the transmission of more than 98% normal packets without sending them to the slow path, and more than 97% of malware packets are detected and dropped in the middle path. Furthermore, more than 75% of metamorphic malware packets in the test dataset could be detected. The proposed technique is 37 times faster than existing technique.
Volume: 17
Issue: 4
Page: 1706-1714
Publish at: 2019-08-01

Velocity measurement based on inertial measuring unit

10.12928/telkomnika.v17i4.11826
Waru; Brawijaya University Djuriatno , Eka; Brawijaya University Maulana , Hasan; National Sun Yat-sen University Hasan , Effendi Dodi; Lembaga Penerbangan dan Antariksa Nasional Arisandi , Wijono; Brawijaya University Wijono
Vehicles technology have been a priority area of research over the last few decades. With the increasing the use of electronic components in the automotive industry to measure conditions around the vehicle, the focus of automotive technology development is now leading to the development of active technology. Information on the speed of conventional vehicles is generally still obtained based on the rotation of the wheel, but there are weakness in the system that is the diference between wheel and road through vehicle also changes wheel radius of the vehicle due to wind tube air preasure that can change at any time. In this research used Inertial Measuring Unit (IMU) 6 axis (accelerometer and gyroscope) which have been done filtering by using Kalman filter in order to make output sensor value more stable, results obtained at the test of 0 m/s had an RMS error of 0.8696 m/s when elevation is +450; 0.0393 m/s when elevation is 00; and 0.3030 m/s when elevation is -450. this research is expected to be an exploration for the development of a decent system that is suitable to be used as vehicle speed estimator which is as reliable as it is by using an existing speedometer on a ground vehicle generally regardless of slippage and changes in wind capacity on wheels.
Volume: 17
Issue: 4
Page: 1898-1906
Publish at: 2019-08-01

An ingenious invasive weed optimization (IWO) aided maximum power tracking for partially shaded photovoltaic array

10.11591/ijeecs.v15.i2.pp543-553
Sridhar R , Boopathi C.S , Deepanjali Das , Sakshi Agrawal , Hardik Choubisa
The inborn non-direct power voltage trademark bends concerning barometrical temperature and light makes the photovoltaic (PV) source a discontinuous one. Maximum power point (MPPT) following is a procedure through which most extreme accessible power is yielded from the PV for the given purpose of time. Prior, the customary MPPT methods, for example, perturb and observe, incremental conductance, hill climbing and so forth strategies were utilized and these methods stayed inadequate when the PV source is partially shaded (PS), since amid (PS) the power voltage (P-V) bends show different power crests. There wins each possibility that the ordinary calculations will stall out to the local maximum point and the global maximum point won't be accomplished and in this way control misfortune is brought about. The metaheuristic calculations give better arrangements however confront the downside of high weight on processor and enormous number of information prerequisites. In this way, in this paper, a novel calculation in light of invasive weed optimisation (IWO) technique is utilized to locate the Global maximum point for MPPT under in part shaded condition and it is contrasted and its nearby partner differential evolution(DE) MPPT algorithm and furthermore with the very much settled in perturb and observe (P&O) calculation. The proposed calculation is actualized in MATLAB condition and tried on a 3-board PV cluster arrangement of 150 W. The flexibility of the calculation is tried through various experiments and the outcomes demonstrate the effectiveness and exactness of the proposed calculation in finding the global maximum point.
Volume: 15
Issue: 2
Page: 543-553
Publish at: 2019-08-01

Road crack detection using adaptive multi resolution thresholding techniques

10.12928/telkomnika.v17i4.12755
Zuraini; Universiti Teknikal Malaysia Melaka Othman , Azizi; Universiti Kebangsaan Malaysia Abdullah , Fauziah; Universiti Teknikal Malaysia Melaka Kasmin , Sharifah Sakinah Syed; Universiti Teknikal Malaysia Melaka Ahmad
Machine vision is very important for ensuring the success of intelligent transportation systems, particularly in the area of road maintenance. For this reason, many studies had been focusing on automatic image-based crack detection as a replacement for manual inspection that had depended on the specialist’s knowledge and expertise. In the image processing technique, the pre-processing and edge detection stages are important for filtering out noises and in enhancing the quality of the edges in the image. Since threshold is one of the powerful methods used in the edge detection of an image, we have therefore proposed a modified Otsu-Canny Edge Detection Algorithm in the selection of the two threshold values as well as implemented a multi-resolution level fixed partitioning method in the analysis of the global and local threshold values of the image. This is then followed by a statistical measure in selecting the edge image with the best global threshold. This study had utilized the road crack image dataset that were obtained from Crackforest. The results had revealed the proposed method to not only perform better than the conventional Canny edge detection method but had also shown the maximum value derived from the local threshold of 5x5 partitioned image outperforming the other partitioned scales.
Volume: 17
Issue: 4
Page: 1874-1881
Publish at: 2019-08-01

A novel equalization scheme for the selective enhancement of optical disc and cup regions and background suppression in fundus imagery

10.12928/telkomnika.v17i4.5364
Fousia M.; MG University Shamsudeen , G.; Christ (Deemed to be University) Raju
The ratio of the diameters of Optic Cup (OC) and Optic Disc (OD), termed as ‘Cup to Disc Ratio’ (CDR), derived from the fundus imagery is a popular biomarker used for the diagnosis of glaucoma. Demarcation of OC and OD either manually or through automated image processing algorithms is error prone because of poor grey level contrast and their vague boundaries. A dedicated equalization which simultaneously compresses the dynamic range of the background and stretches the range of ODis proposed in this paper. Unlike the conventional GHE, in the proposed equalization, the original histogram is inverted and weighted nonlinearly before computing the Cumulative Probability Density (CPD). The equalization scheme is compared with Adaptive Histogram Equalization (AHE), Global Histogram Equalization (GHE) and Contrast Limited Adaptive Histogram Equalization (CLAHE) in terms of the difference between the mean grey levels of OD and the background, using a quantitative metric known as Contrast Improvement Index (CII). The CII exhibited by CLAHE, GHE and the proposed scheme are 1.1977 ± 0.0326, 1.0862 ± 0.0304 and 1.3312 ± 0.0486, respectively.The proposed method is observed to be superior to CLAHE, GHE and AHE and it can be employed in Computerized Clinical Decision Support Systems (CCDSS) to improve the accuracy of localizing the OD and the computation of CDR.
Volume: 17
Issue: 4
Page: 1715-1722
Publish at: 2019-08-01

Size miniaturization of chipless RFID tag using metamaterial structure

10.11591/ijeecs.v15.i2.pp723-732
Mohd Ezwan B. Jalil , Mohamad Kamal A. Rahim , Osman B. Ayop , Noor Asmawati Samsuri
A Chipless RFID based Modified Complementary Split Ring Resonator (MCSRR) with Different Width (DW) which is metamaterial structure is designed using PET substrate (  =3, loss tangent = 0.025 at 2 GHz) to miniaturize effective length size of conventional split ring resonator. The MCSRR structure with DW provides less size about 17% compared with the conventional MCSRR structure. The single MCSRR resonator with different width only requires a frequency range of 12 % of Complementary Split Ring Resonator (CSRR) resonator. The slotted MCSRR resonator is located underneath substrate and within substrate is connected with transmission lines. The insertion loss value of MCSRR resonator is used to encode ID information of chipless RFID with maximizing ID information using Frequency Position technique. The best swapping parameter for encoding ID number information is split gap of both ring compare with other parameter such as spacing between ring and width of ring.
Volume: 15
Issue: 2
Page: 723-732
Publish at: 2019-08-01

Automatic face and VLP’s recognition for smart parking system

10.12928/telkomnika.v17i4.11746
Reivind P.; Telkom University Persada , Suci; Telkom University Aulia , Burhanuddin; Telkom University D. , Sugondo; Telkom University H.
One of the concerning issues regarding smart city is Smart Parking. In Smart Parking, some researchers try to provide solutions and breakthroughs on several research topics among security systems, the availability of single space, an IoT framework, etc. In this study, we proposed a security system on Smart Parking based on face recognition and VLP’s (Vehicle License Plates) identification. In this research, SSIM (Structural Similarity) method as part of IQA has been applied due to its reliability and simple computation for face detection and recognition process. From the test results of 30 data, obtained the highest SSIM value 0.83 with the highest accuracy rate of 76.67%. That level of accuracy still has not reached the implementation standard of 99.9%. So that it still needs to be improved in the future studies, especially in the filtering noise section.
Volume: 17
Issue: 4
Page: 1698-1705
Publish at: 2019-08-01

Gain enhancement of dielectric resonator antenna for millimeter wave applications

10.12928/telkomnika.v17i4.12770
Irfan; Universiti Teknologi Malaysia Ali , Mohd Haizal; Universiti Teknologi Malaysia Jamaluddin , M. R.; Cranfield University Kamarudin , Abinash; Universiti Teknologi Malaysia Gaya , M. H.; Universiti Teknologi Malaysia Dahri
In this paper, dielectric resonator antenna (DRA) with enhanced gain operating on the higher order mode (𝑇𝐸𝛿15𝑥 ) is presented. The dielectric resonator antenna with dielectric constant 𝜀𝑟 of 10 and loss tangent of 0.002 is used. The DRA is fed by microstrip line through an aperture slot. The proposed antenna is designed at 26 GHz and achieved a gain of 7.9 dBi with corresponding simulated radiation efficiency of 93%. The impedance bandwidth of 1.5 GHz from 25.1 GHz to 26.6 GHz has been achieved. The reflection coefficient, antenna gain, radiation patterns, and efficiency of the antenna are studied. Simulations are performed using CST microwave studio, and their results are presented.
Volume: 17
Issue: 4
Page: 1670-1673
Publish at: 2019-08-01

A regexcriteria API to complete the power of regular expressions engine

10.11591/ijece.v9i4.pp3185-3193
Boulchahoub Hassan , Rachiq Amina , Labriji Amine , Labriji Elhoussin , Mohamed Azouazi
Regular expressions are heavily used in the field of computer programming. They are known by their strength to search or replace parts of strings according to a given structure (mails, phone, numbers, etc.). Currently  regular expressions are only used to search for some patterns or to make some substitutions in strings. However, the need may be wider than that when it comes to order the results of a regular expression or to group them according to some criteria. Developers are always called to analyze the results of a regular expression by doing some restrictions such as (equal, not equal, between) or  some projections like (maximum, average, grouping by ..) or sorts. Unfortunately, to do these treatments, the developer must implement his own algorithms which cost him a remarkable effort and a waste of time. We propose in this paper an API called RegexCriteria inspired from Hibernate Criteria to support developer while analysing the results of a regular expression.
Volume: 9
Issue: 4
Page: 3185-3193
Publish at: 2019-08-01

Design and simulate a doherty power amplifier using GaAs technology for telecommunication applications

10.11591/ijeecs.v15.i2.pp845-854
Ehsan Barmala
In this paper, a Doherty power amplifier was designed and simulated at 2.4 GHz central frequency which has high efficiency. A Doherty power amplifier is a way to increase the efficiency in the power amplifiers. OMMIC ED02AH technology and PHEMT transistors, which is made of gallium arsenide, have been used in this simulation. The Doherty power amplifier unique feature is its simple structure which is consisting of two parallel power amplifiers and transmission lines. In order to integrate the circuit, the Doherty power transmission amplifier lines were implemented using an inductor and capacitive components. Also, the Wilkinson power divider is used on the chip input. To improve the efficiency, the auxiliary amplifier dimensions is selected enlarge and the further input power is allocated it by the power divider. A parallel R-C circuit has been used at the input of transistors to improve their stability. Simulation results show that the Doherty power amplifier has 17.2 dB output power gain, 23 dBm maximum output power, and its output power P1dB =22.6dBm at compression point -1 dB, also, its maximum efficiency is 55.5%.
Volume: 15
Issue: 2
Page: 845-854
Publish at: 2019-08-01
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