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29,758 Article Results

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

Solving one-dimensional unconstrained global optimization problem using parameter free filled function method

10.12928/telkomnika.v17i4.10885
Ismail Bin; Laboratory of Statistical Computational and Operation Research, Institute of Mathematical Research, UPM Mohd , Yosza; Univerisiti Teknikal Malaysia Melaka (UTeM) Dasril , Ridwan; Institut Teknologi Telkom Purwokerto Pandiya , Herlina; Universitas Padjadjaran Napitupulu
It is generally known that almost all filled function methods for one-dimensional unconstrained global optimization problems have computational weaknesses. This paper introduces a relatively new parameter free filled function, which creates a non-ascending bridge from any local isolated minimizer to other first local isolated minimizer with lower or equal function value. The algorithm’s unprecedented function can be used to determine all extreme and inflection points between the two considered consecutive local isolated minimizers. The proposed method never fails to carry out its job. The results of the several testing examples have shown the capability and efficiency of this algorithm while at the same time, proving that the computational weaknesses of the filled function methods can be overcomed.
Volume: 17
Issue: 4
Page: 2125-2138
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

Dominated destinations of tourist inside Iraq using personal information and frequency of travel

10.12928/telkomnika.v17i4.11956
Rula; Institute of informatics for Postgraduate studies Amjed , Muayad Sadik; University of Technology Croock
Tourism today is one of the most important economic and social sectors in the world, which plays a prominent role in the development of countries. This importance has grown as an industry through the social media networks.In this paper, a proposed method has been introduced distinguish the main factors that impact the Frequency of Travel (FoT) among Iraq local tourists. Application (API) graphics and scrapy are utilized to collect information from TripAdvisor social network in a period of (2015-2018). The collected information are reprocessed and coded for the specified nominal data using tied rank. It is important to note that the adopted technique does not lose any data about the attribute and brings different properties beforehand obscure. Data mining ordinal logistic regression is used to extract user's behavior upon local tourism in Iraq. The expected outcome of this work is to discover out the effect of personal information and the type of places on the selection of the local touristic places in Iraq. The collected information was exploited to know the preferred local touristic trends, because there are no statistics on the number of domestic tourists in Iraq. The proposed model was used for analyzing personal information and types of preferred tourism places as a factors affecting frequency of travel in Iraq. The obtained results show the prediction of preferred touristic places by tourists in Iraq.
Volume: 17
Issue: 4
Page: 1723-1730
Publish at: 2019-08-01

An energy efficient void avoidance opportunistic routing protocol for underwater sensor

10.12928/telkomnika.v17i4.12779
Azlina; Universiti Teknologi Malaysia Kamaruddin , Md Asri; Universiti Teknologi Malaysia Ngadi , Hafizah; Universiti Teknologi Malaysia Harun
Underwater sensor network is an emerging technology due to its numerous applications in aqueous environments. However, limitations of these networks include limited bandwidth, high propagation delays and power constraints. Hence, new routing protocols must be designed specifically for USN. Opportunistic routing offers a promising method to overcome these limitations. The proposed protocol is a novel energy-efficient void avoidance opportunistic routing algorithm. The protocol deals with the issue of void holes during transmission while reducing energy consumption and keeping the packet delivery ratio at a satisfactory level. To evaluate the performance, two common metrics have been used for routing protocols in USNs; energy consumption and packet delivery ratio. Simulations were carried out in ns2 with Aqua-Sim. The performance of the proposed routing protocol is compared to VAPR. The performance evaluation of EEVA-OR indicate its benefit as compared to VAPR in terms of void detection, energy consumption and packet delivery ratio.
Volume: 17
Issue: 4
Page: 1948-1956
Publish at: 2019-08-01

Analyzing the deformation of copper conductor from a fire impact

10.12928/telkomnika.v17i4.10116
Didik; Pakuan University Notosudjono , Tatang Kukuh; ISTN Jakarta Wibawa , Bagus Dwi; Brawijaya University Ramadhon
Fire is an oxidation reaction of the three elements (fuel, oxygen, heat) that can result in loss of property, injury, even death. Electricity potential that may results on fire is the short circuit current that occurs on the equipments and electrical installation cables. The remaining wires at the first fire location are subject to fire damage and can cause electrical short circuit. The purpose of this study is to analyze the short-circuit electrical deformation of copper cable using SEM EDS and MICRO XRF instrument. Based on the study result, there is a dominant change of oxygen elements in single cable and fiber sample causing fire that is 35,96% and 21,24%, those values are higher than Oxygen on a burned short circuited cable that is 19,54% and 12,1%. The microstructure of the cable that causes fire looks like irregular clumps whereas the burned cable looks like a clump of clumps.
Volume: 17
Issue: 4
Page: 2008-2016
Publish at: 2019-08-01

Novel design of triple-bands EBG

10.12928/telkomnika.v17i4.12616
M. K.; Universiti Teknikal Malaysia Melaka (UTeM) Abdulhameed , M. S. Mohamad; Universiti Teknikal Malaysia Melaka (UTeM) Isa , Z.; Universiti Teknikal Malaysia Melaka (UTeM) Zakaria , I. M.; Universiti Teknikal Malaysia Melaka (UTeM) Ibrahim , Mowafak K.; University of Kerbala Mohsen , Ahmed M.; Universiti Teknikal Malaysia Melaka (UTeM) Dinar , Mothana L.; Universiti Teknikal Malaysia Melaka (UTeM) Attiah
This paper presents a novel design for a triple band electromagnetic band gap (EBG) structures that provides three band gaps, with operating frequency of below 10 GHz, while the ordinary mushroom like EBG structure gives only one band gap. Complexity reduction (reduce the number of unit cells and Vias) was achieved by replacing each four cells of the Mushroom like EBG by the one of double slotted type EBG (DSTEBG) or triple side slotted EBG (TSSEBG). The Mushroom like EBG was further modified by increasing its size and inserting the slots to gain more capacitance and inductance which resulted into triple band stop.The new designs wer compared with bandwidths expressed by other EBGs and -20 dB cut-off frequencies. The size of EBG element and the gap between EBG elements, and slot width were investigated to analyse their effect on the transmission response. The structures were designed from 2.54 mm Rogers RT/Duroid 6010 substrate with relative permittivity of 10.2 and loss tangent of 0.0023. Among the investigated EBGs, the single band mushroom like EBG and the triple band of the TSSEBG demonstrated better bandwidth and lower resonance frequency performance, whereas the DSTEBG showed larger bandwidth for the first and third band. The proposed EBGs could be useful in the antenna design and other microwave circuits.
Volume: 17
Issue: 4
Page: 1683-1691
Publish at: 2019-08-01

Portable health monitoring kit using photolethysmogram signal

10.11591/ijeecs.v15.i2.pp638-649
N. F. A. Jamal , K. A. Sidek
This study investigates the feasibility of photoplethysmogram (PPG) signals in monitoring health condition and designing a portable health monitoring kit which is suitable for home use. The aim of this study is to ease people in monitoring their health continuously without the need to go to the hospital which can save a lot of time. The focus of this study is to find heart rate and blood pressure recording. The type of PPG sensor used in this project is a non-invasive PPG which measures the blood volume changes in any part of the body. A total of 16 subjects consisting of male and female with age range of 20 to 60 years old were involved in this research. The heart rate and blood pressure for each subject were acquired and analyzed. Based on the result, it shows that higher heart rate reading is associated with female and younger age groups. Meanwhile, for blood pressure value, male subjects tend to have higher blood pressure as compared to female subjects. However, there is no specific pattern for blood pressure in terms of the age group. In the case of HRV analysis based on Kubios software, the SDNN value is higher for male and older age subjects. Meanwhile, the RMSSD value is lower for male and older age subjects. Therefore, PPG signal has the capability to monitor the health status of an individual, which acts as an alternative biological signal for the existing health monitoring systems.
Volume: 15
Issue: 2
Page: 638-649
Publish at: 2019-08-01

Real interpolation method for transfer function approximation of distributed parameter system

10.12928/telkomnika.v17i4.11088
Phu Tran; Industrial University of Ho Chi Minh City Tin , Minh; Ton Duc Thang University Tran , Le Anh; Ton Duc Thang University Vu , Nguyen Quang; Ton Duc Thang University Dung , Tran Thanh; Van Hien University Trang
Distributed parameter system (DPS) presents one of the most complex systems in the control theory. The transfer function of a DPS possibly contents: rational, nonlinear and irrational components. This thing leads that studies of the transfer function of a DPS are difficult in the time domain and frequency domain. In this paper, a systematic approach is proposed for linearizing DPS. This approach is based on the real interpolation method (RIM) to approximate the transfer function of DPS by rational-order transfer function. The results of the numerical examples show that the method is simple, computationally efficient, and flexible.
Volume: 17
Issue: 4
Page: 1941-1947
Publish at: 2019-08-01

Dual element MIMO planar inverted-F antenna for 5G millimeter wave application

10.12928/telkomnika.v17i4.12762
H. M. R.; Universiti Kuala Lumpur British Malaysian Institute Nurul , Z.; Universiti Kuala Lumpur British Malaysian Institute Mansor , M. K. A.; Universiti Teknologi Malaysia Rahim
This work presents a 28 GHz Dual Element Multiple Input Multiple Output (MIMO) Planar Inverted-F Antenna for millimeter wave 5G mobile terminal. The antenna design employs PIFA design concept as it is a common antenna type use for mobile phone as it provides wide bandwidth and good performance. The antenna design begins with a characterization of the single element PIFA design and then extended to Dual Element MIMO PIFA design. The single element PIFA design is enhanced to MIMO design by extending the ground plane and locate the second PIFA at the other end. Isolation between the antenna elements of the MIMO PIFA is analyzed by varying the gap distance between the antenna elements. The result for Envelope Correlation Coefficient, Diversity Gain and Multiplexing Efficiency is also presented. The simulation computed using Computer Simulation Technology (CST) Microwave Studio software.
Volume: 17
Issue: 4
Page: 1648-1655
Publish at: 2019-08-01

Certificateless and provably-secure digital signature scheme based on elliptic curve

10.11591/ijece.v9i4.pp3228-3231
Dhanashree Toradmalle , Jayabhaskar Muthukuru , B Sathyanarayana
With the internet today available at the user’s beck, and call data or Information Security plays a vital role. Confidentiality, Integrity, Availability, and Non-repudiation are the pillars of security on which every application on the web is based on. With these basic requirements the users also need the security in low resource constrained environments making it more challenging for the security experts to design secured cryptographic algorithms. Digital Signatures play a pivotal role in Authentication. They help in verifying the integrity of the data being exchanged. Elliptical curves are the strongest contenders in Digital Signatures, and much research is being done to enhance the method in many ways. The paper briefs a secured and improved ECDSA Elliptical Curve Digital Signature Algorithm which is an improved and secured version of the Digital Signature Algorithm.
Volume: 9
Issue: 4
Page: 3228-3231
Publish at: 2019-08-01

Parallel Operation of Current-Source Inverter for Low-Voltage High-Current Grid-Connected Photovoltaic System

10.11591/ijece.v9i4.pp2220-2229
Suroso Suroso , Daru Tri Nugroho , Amran Amran , Toshihiko Noguchi
Solar energy is very potential to be developed in a tropical country such as in Indonesia. This energy source is eco-friendly because it can eliminate air pollution such as caused by conventional fossil fuels. This research article presents analysis results of a novel grid-connected photovoltaic system using low-voltage high-current system. The electrical energy produced by the photovoltaic system was sent into the electrical power grid using two or more H-bridge current source inverters operated in parallel. The proposed system is very suitable for large size photovoltaic system because of its some merits. The inverter circuits work generating sinusoidal output currents and controlling the power delivered into the grid. The test results of the new system showed that the system worked properly as interface between photovoltaic system and the electrical grid delivering high ac current with low harmonic distortion.
Volume: 9
Issue: 4
Page: 2220-2229
Publish at: 2019-08-01

Development of advanced automated test equipment for digital system by using FPGA

10.11591/ijeecs.v15.i2.pp661-670
Adharul Muttaqin , Zainul Abidin , Raden Arief Setyawan , Itsna Az Zahra
One of the fundamental devices in electronics, Integrated Circuit (IC), is usually applied in more complex devices. Before the IC is used, it has to pass some tests to guarantee that its function is in accordance with the specifications. Automated Test Equipment (ATE) is used to test many electronics devices, including ICs. Nowadays, with the rapid advance in electronics technology, the industry will need more advanced ATE to fulfill customers demand. One of the applicative solutions is improvement and integration of a standalone module in commercial ATE owned by the company. ASL 1000 Test System is one of the ATE that is still widely used in industry. ASL 1000 has one limitation in one of its module, Digital Driver and Detector (DDD). The limitation is how much vector pattern that can be saved in the memory. Based on the observation in DDD instrument, a standalone module that has similar specifications as DDD can be designed using Field Programmable Gate Array (FPGA) as its base component. In the standalone module plan, supporting circuits are used, these are interface circuit between FPGA and PC using RS-232 and ASIC as ATE drivers or comparators to connect FPGA and device under test (DUT). The result of the study shows that the designed module can receive and send 8-bit data at 19.200 baud rate. It can write and read 16-bit data from and to SDR SDRAM within 90 ns and 80 ns for one cycle. It can control DAC type AD5308 in standalone operation and DAC type AD5676 in daisy chain operation to generate specific voltage in specific channel. In behavioral simulation, main controller module has already worked in accordance with the desired specifications.
Volume: 15
Issue: 2
Page: 661-670
Publish at: 2019-08-01

Multi-function intelligent robotic in metals detection applications

10.12928/telkomnika.v17i4.11822
Nabeel Salih; University of Kufa Ali , Hakim Adil; University of Kufa Kadhim , Dheyaa Mohammed; University of Kufa Abdulsahib
Recent technologies for robotics have been offered an effective and efficient solution to safeguard workers from risks in their work environments. These risks involve radioactive, toxic, explosive and mines. In this paper, design and implement computer robot based on metal detection as well as avoiding obstacles automatically. The proposed wireless controlled robotic vehicle can be used in metal detection applications such as landmine detection, obstacles avoidance, selecting best routing without imposing human's harms and workforce aspects. The robotic wheel can sense the obstacles that positioning at ahead of its path, and also avoids the obstacles forward, left and right of its routes. The robot is controlled by using Bluetooth wireless communication to interface between the controller and the implemented robot. Furthermore, sensor IR (FC-03) for the metal detector and used ultrasonic sensor (HC-SR04) for objects or obstacles sensing. The presented controlled robotic designed for desert and dry soil that can replace the human role in avoiding obstacles and metal detection capabilities. The produced robot was useful due to it can detect metals and avoiding obstacles consecutively besides it was effective to select the best route based on the intelligent technique that adopted, the predefined metals by using an intelligent decision maker for route finder in a flat surface environment.
Volume: 17
Issue: 4
Page: 2058-2069
Publish at: 2019-08-01

Fingerprint indoor positioning based on user orientations and minimum computation time

10.12928/telkomnika.v17i4.12774
Firdaus; Universitas Islam Indonesia Firdaus , Noor Azurati; Universiti Teknologi Malaysia Ahmad , Shamsul; Universiti Teknologi Malaysia Sahibuddin
Indoor Positioning System (IPS) has an important role in the field of Internet of Thing. IPS works based on many existing radio frequency technologies. One of the most popular methods is WLAN Fingerprint because this technology has been installed widely inside buildings and it provides a high level of accuracy. The performance is affected by people who hold mobile devices (user) and also people around the users. This research aimed to minimize the computation time of kNN searching process. The results showed that when the value of k in kNN was greater, the computation time increased, especially when using Cityblock and Minkowski distance function. The smallest average computation time was 2.14 ms, when using Cityblock. Then the computational time for Euclidean and Chebychev were relatively stable, i.e. 2.2 ms and 2.23 ms, respectively.
Volume: 17
Issue: 4
Page: 1740-1749
Publish at: 2019-08-01
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