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Publisher: Universitas Ahmad Dahlan   (Total: 16 journals)   [Sort by number of followers]

Showing 1 - 16 of 16 Journals sorted alphabetically
Ahmad Dahlan J. of English Studies     Open Access   (Followers: 2)
Bahastra     Open Access  
Berkala Fisika Indonesia     Open Access  
Bulletin of Electrical Engineering and Informatics     Open Access   (Followers: 8)
HUMANITAS (Jurnal Psikologi Indonesia)     Open Access   (Followers: 4)
Intl. J. of Advances in Intelligent Informatics     Open Access   (Followers: 7)
J. of Education and Learning     Open Access   (Followers: 11)
Jurnal Hukum Novelty     Open Access  
Jurnal Ilmiah AdMathEdu     Open Access  
Jurnal Informatika     Open Access   (Followers: 1)
Kes Mas : Jurnal Fakultas Kesehatan Masyarakat     Open Access   (Followers: 2)
Media Farmasi     Open Access  
Pharmaciana     Open Access  
Psikopedagogia : Jurnal Bimbingan dan Konseling     Open Access   (Followers: 2)
Spektrum Industri : Jurnal Ilmiah Pengetahuan dan Penerapan Teknik Industri     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 8, SJR: 0.265, CiteScore: 1)
Journal Cover
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)
Journal Prestige (SJR): 0.265
Citation Impact (citeScore): 1
Number of Followers: 8  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1693-6930 - ISSN (Online) 2302-9293
Published by Universitas Ahmad Dahlan Homepage  [16 journals]
  • Optimization a Scheduling Algorithm of CA in LTE Advanced system

    • Authors: Sarmad Khaleel Ibrahim, Nasser N Khamiss
      Abstract: Long Term Advancement Progressed (LTE-ADV) is the advancement of the long term evolution which created via 3GPP. LTE-ADVDV identified as International Mobile Telecommunications (IMT-Advanced) surpassed International Telecommunication Union (ITU prerequisites for 4 Generation (4G). This paper represents a study and an execution of carrier aggregation in LTE-ADV with a different scheduling algorithm are Proportional Fair, round robin, and my proposed algorithm and mapping model are Mutual Information Effective SINR Mapping (MIESM) and Exponential Effective SINR Mapping (EESM). The results show that throughput in my proposed algorithm with MIESM outperforms from others mapping and scheduling.
      PubDate: 2018-10-01
      DOI: 10.12928/telkomnika.v16i5.10054
      Issue No: Vol. 17, No. 1 (2018)
  • Secure Code Generation for Multi-Level Mutual Authentication

    • Authors: Gregor Alexander Aramice
      Abstract: Any secured system requires one or more logging policies to make that system safe. Static passwords alone cannot be furthermore enough for securing systems, even with strong passwords illegal intrusions occur or it suffers the risk of forgotten. Authentication using many levels (factors) might complicate the steps when intruders try to reach system resources. Any person to be authorized for logging-in a secured system must provide some predefined data or present some entities that identify his/her authority. Predefined information between the client and the system help to get more secure level of logging-in. In this paper, the user that aims to log-in to a secured system must provide a recognized RFID card with a mobile number, which is available in the secured systems database, then the secured system with a simple algorithm generates a One-Time Password that is sent via GSM Arduino compatible shield to the user announcing him/her as an authorized person.
      PubDate: 2018-08-14
      DOI: 10.12928/telkomnika.v17i1.10437
      Issue No: Vol. 17, No. 1 (2018)
  • AHP-TOPSIS for Analyze Job Performance with Factor Evaluation System and
           Process Mining

    • Authors: Gabriel Sophia, Riyanarto Sarno
      Abstract: Job performance is a combination of ability, effort and opportunity that can be judged based on work of employee.This research using  Factor Evaluation System method to analyze the job performance because this is one of popular method. FES has nine factor to analyze the employee, but the reality just nine factor is not enough. So we use process mining to improved the FES. Process mining help analysis of job performance becomes more details. In process mining there are event that has history of time stamp, case, activity, and resources of employee. So this method can be used continuously if we add weight for each factor. The weight are get from the Analytic Hierarchy Process-Technique for Order Preference by Similitary to Ideal Solution. The result show that AHP-TOPSIS is not compatible to use in this case when compared with the real work.
      PubDate: 2018-08-11
      DOI: 10.12928/telkomnika.v17i1.10408
      Issue No: Vol. 17, No. 1 (2018)
  • Proposed Model for Interference Estimation in Code Division Multiple

    • Authors: Dalal Kanaan Taher, Adheed Hassan Sallomi
      Abstract: Cellular CDMA systems are usually affected by interference experienced by users in adjacent cells that decrease the Quality of Services in wireless communication network. Hence, interference is the limiting factor of capacity in CDMA cellular and it is one of the problems fighting against the high efficiency of any mobile network. In this paper, a mathematical model to estimate the average number of users contributing in inter-cell interference at the busy hours of CDMA network is proposed.  As the power exponent value has significant effect on interferer signal attenuation and hence other-cells interference, measurements were carried through a drive test to determine the received power level at various distance from CDMA base stations at Baghdad. The results obtained show that the power exponent was 2.8. This value was applied in dual-slop path loss model to determine the expected interference factor, and the number of users that can be hold at each cell. Simulations showed that users at a boundary cell generate more interference than those close to the base station. Furthermore, it was denoted that greater number of users caused to increase the interference factor, and greater power exponent value result in interference factor reduction.
      PubDate: 2018-08-11
      DOI: 10.12928/telkomnika.v17i1.10330
      Issue No: Vol. 17, No. 1 (2018)
  • A Novel High Secure Buffer based Physical Unclonable Functions (PUF’s)
           for Device Authentication

    • Authors: Sadulla Shaik, Anil Kumar Kurra, A. Surendar
      Abstract: This paper presents a novel high secure buffer based Physical Unclonable Functions (PUF’s) for device authentication design for better uniqueness and reliability at low supply voltages. This is typically demanded in emerging Internet of Things (IoT) applications with stringent energy constraints. PUF is fast growing technology which utilizes the statistical variability of the manufacture variations acts as a finger print to the each device. It can be widely used in security applications such as device authentication, key generation and Intellectual Property (IP) protection. Due to the simplicity and low cost arbiter delay based PUFs have been mostly used as a cryptographic key in IoT devices. As conventional arbiter PUFs are suffers from less uniqueness and reliability and suffers from modeling attacks. The proposed new buffer based arbiter PUF architecture reduces the complexity of design and improves the PUF metrics. a set of  Monte-Carlo simulation were applied for delay variability of the PUFs. Buffer based PUF has 1.1 times better mean value and 99.1% lesser standard deviation values than delay based PUF with 150 samples at VDD range from 0V to 1.8V.  It has been demonstrated that experimental results of proposed buffer based arbiter PUF shows the considerable improvement in the uniqueness and
      PubDate: 2018-08-11
      DOI: 10.12928/telkomnika.v17i1.10436
      Issue No: Vol. 17, No. 1 (2018)
  • A Two-Stages Microstrip Power Amplifier for WiMAX Applications

    • Authors: Rachakh Amine, El Abdellaoui Larbi, Jamal Zbitou, Errkik Ahmed, Tajmouati Abdelali, Latrach Mohamed
      Abstract: Amplification is one of the most basic and prevalent microwave analog circuit functions. Wherefore power amplifiers are the most important parts of electronic circuits. This is why the designing of power amplifiers is crucial in analog circuit designing. The intent of this work is to present an analysis and design of a microwave broadband power amplifier by using two stages topology. A two stages power amplifier using a distributed matching network for WiMAX applications is based on ATF-21170 (GaAs FET). The configuration aims to achieve high power gain amplifier with low return loss over a broad bandwidth. The proposed BPA is designed with a planar structure on an epoxy (FR4) substrate. The planar structure is also utilized for getting the good matching condition. The advanced design system (ADS) software is used for design, simulation, and optimization the proposed amplifier. The complete amplifier achieves an excellent power gain; is changed between 28.5 and 20dB with an output power of 12.45dBm at 1dB compression point. For the input reflection coefficient (S11) is varied between -20 and -42dB. While the output reflection coefficient (S22) is varied between -10 and - 49dB over the wide frequency band of 3.2-3.8GHz.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.9338
      Issue No: Vol. 17, No. 1 (2018)
  • RS Codes Downlink LTE System over LTE-MIMO Channel

    • Authors: Ghasan Ali Hussain, Lukman Audah
      Abstract: Future applications require a modern generation of mobile communication systems; long term evolution (LTE) is a candidate to achieve this modern generation. One important challenge in wireless communications, including LTE systems, is the suitable techniques of controlling errors that degrade system performance in transmission systems over multipath fading channels. Different forward Error correction (FEC) techniques are required to improve the robustness of transmission channels. In this research, Reed-Solomon (RS) codes were used with a downlink LTE system over a LTE-MIMO channel. This research contributes by combining RS with a LTE-MIMO channel to improve downlink LTE system performance. The results show that this clearly improves system performance and thus decreases Bit Error Rates (BER) compared with Convolutional and Turbo codes. Lastly, the results show extra improvements of downlink LTE system performance by increasing the number of antennas of the LTE-MIMO channel.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.9177
      Issue No: Vol. 17, No. 1 (2018)
  • An Artificial Neural Network Approach for Detecting Skin Cancer

    • Authors: Sugiarti Sugiarti, Yuhandri Yuhandri, Jufriadif Na`am, Dolly Indra, Julius Santony
      Abstract: This study aims to present diagnose of melanoma skin cancer at an early stage. It applies feature extraction method of the first order for feature extraction based on texture in order to get high degree of accuracy with method of classification using artificial neural network (ANN). The method used is training and testing phases with classification of Multilayer Perceptron (MLP) neural network. The results showed that the accuracy of test image with 4 sets of training for image not suspected of melanoma and melanoma with the lowest accuracy of 80% and the highest accuracy of 88,88%, respectively.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.9547
      Issue No: Vol. 17, No. 1 (2018)
  • Image de-nosing in underwater colored noise using discrete wavelet
           transform and pre-whitening filter

    • Authors: Mohanad Najm Abdulwahed
      Abstract: Image denoising and improvement are essential processes in many underwater applications. Various scientific studies, including marine science and territorial defence, require underwater exploration. When it occurs underwater, noise power spectral density is inconsistent within a certain range of frequency, and the noise autocorrelation function is not a delta function. Therefore, underwater noise is characterised as coloured noise. In this study, a novel image denoising technique is proposed using discrete wavelet transform with different basis functions and a whitening filter, which converts coloured noise characteristics to white noise prior to the denoising process. Results of the proposed method depend on the following performance measures: peak signal-to-noise ratio (PSNR) and mean squared error. The results of different wavelet bases, such as Debauchies, biorthogonal and symlet, indicate that the denoising process that uses a pre-whitening filter produces more prominent images and better PSNR values than other methods.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.9236
      Issue No: Vol. 17, No. 1 (2018)
  • Filter Technique of Medical Image on Multiple Morphological Gradient (mMG)

    • Authors: Jufriadif Na'am
      Abstract: Filter technique is supportive for reducing image noise.  This paper presents a study on filtering medical images, i.e., CT-Scan, Chest X-ray and Panoramic X-ray collected from two of the most prominent public hospitals in Padang City, Indonesia. This study used Blur, Emboss, Gaussian, Laplacian, Roberts, Sharpen and Sobel techniques as pre-processing step. The filter process performed before edge detection and edge clarification.  mMG method used in this study to clarify the edge detection.  Based on the experiment,  this study found that Gaussian technique performs the best technique in reducing medical image noise and makes object observation in medical images,  such as infiltrates in the lungs, caries in teeth or hemorrhage in the brain. Thus, the results of this study preserved to reduce the doctor’s hesitation in diagnosing objects in x-ray medical images.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.9722
      Issue No: Vol. 17, No. 1 (2018)
  • A Novel Structure of A Low Cost Zero Bias Broadband Microstrip Power

    • Authors: Khalifa Echchakhaoui, Elhassane Abdelmounim, Jamal Zbitou, Hamid Bennis, Ahmed Errkik, Angel Mediavilla Sanchez
      Abstract: In this paper, a new broadband microwave microstrip power limiter is designed and realized. The Power Limiter is based on microstrip technology integrating a Zero Bias commercial Schottky diodes HSMS2820 [1].The power limiter is optimized and validated in two steps. The enhanced and achieved circuit is obtained by concatenating two basic structures. The final circuit was validated into simulation by using ADS solver. Finally this circuit was realized and tested. Simulation and measurement results are in a good agreement. The final circuit achieves a limiting rate of 15 dB with a threshold input power level of 0 dBm until a maximum input power level of 30 dBm.
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.8730
      Issue No: Vol. 17, No. 1 (2018)
  • Design of Dual Band Microstrip Antenna for Wi-Fi and WiMax Applications

    • Authors: Raad H. Thaher, Zainab S Jameel
      Abstract: In this paper, a dual band rectangular microstrip patch antenna with microstrip line is presented. The proposed antenna is designed on FR4 substrate with thickness 1.5mm and relative permittivity 4.3. The antenna is designed to operate at 2.4/5.8GHz bands for Wi-Fi/WiMax applications. The obtained return loss is -32.77dB at 2.4GHz with 7.4% bandwidth and -25.955dB at 5.8GHz with 8.17% bandwidth. The practical and simulation result are computed. It is noted that there is a good agreement between the simulation and measured result (using vector network analyzer (VNA)).     
      PubDate: 2018-08-10
      DOI: 10.12928/telkomnika.v17i1.10016
      Issue No: Vol. 17, No. 1 (2018)
  • Design and Analysis of broadband Elliptical Micro-strip Patch Antenna for
           Wireless Communication

    • Authors: Ali Khalid Jassim, Raad H. Thaher
      Abstract: In this paper presents the design and manufactured  of a new broadband elliptical patch antenna with microstrip feed line and optimum antenna  parameters. The antenna dimension of mm3 and fabricated on an FR-4 epoxy substrate having relative dielectric constant =4.3, loss tangent tan (δ) =0.002 and the feed line used has characteristic impedance of 50Ω.The designed antenna has the capability of operating in the bandwidth (6.95 - 30.94) GHz and the gain (6.8) dBi. The antenna performance was modified by inserting a slots in the ground plane to achieve impedance bandwidth (when S11  -10dB) and slots to patch to improve the gain. The modified antenna was designed to be used for fifth generation (5G) mobile communication. The simulation results are obtained using CST software.
      PubDate: 2018-08-05
      DOI: 10.12928/telkomnika.v17i1.9246
      Issue No: Vol. 17, No. 1 (2018)
  • Proposed P-shaped Microstrip antenna array for wireless communication

    • Authors: Noor Tamimi, Raad H. Thaher
      Abstract: In this paper a P-shaped microstip antenna array is proposed for X-band applications in the frequency range (8.1567-9.3811) GHz .The gain obtained in this frequency range is about 8.305dBi. The reflection coefficient is less than - 10 dB in the above frequency range. The simulation results were obtained for the optimum parameters using the CST software while the practical test was carried out using Vector Network Analyzer (VNA). The microstrip antenna was manufactured using FR-4 substrate with relative dielectric constant of 4.3 and loss tangent .The simulation and practical results were compared. The size of the antenna array is (33 70 1.6) . This array is suitable for satellite communication, radar application
      PubDate: 2018-12-01
      DOI: 10.12928/telkomnika.v16i6.10494
      Issue No: Vol. 16, No. 6 (2018)
  • Anomaly Detection Based on Control-flow Pattern of Parallel Business

    • Authors: Hendra Darmawan, Riyanarto Sarno, Adhatus Solichah Ahmadiyah, Kelly Rossa Sungkono, Cahyaningtyas Sekar Wahyuni
      Abstract: Company must have an audit trail that captures activities executed, named an event log. In executing the process, there are certain gap between what is expected and what is executed, called an anomaly. Anomaly have to be evaluated so it does not harm the company. Process mining is implemented to model actual workflow. Anomaly contained in the event log caused the low fitness and precision value. In this research, trace clustering is implemented to group the same trace into one cluster. Then, data filtering is done to filter traces which have a low frequency value. After that, the event log is modeled to form a new business process. The filtered business process model has higher fitness and precison value compared to unfiltered business process. The fitness and precision of unfiltered process model is 1 and 0.6446991. Meanwhile, the fitness and precision of filtered process model is 1 and 0.81481093.
      PubDate: 2018-12-01
      DOI: 10.12928/telkomnika.v16i6.10568
      Issue No: Vol. 16, No. 6 (2018)
  • Development of Low-Cost Fiber Optic Based Ammonia Detector for Fishpond

    • Authors: Budi Mulyanti, Yuski Maolid Rizki Faozan, Ajuni Budi Pantjawati, Roer Eka Pawinanto, Lilik Hasanah, Wahyu Sasongko Putro
      Abstract:  In this study aims to develop low-cost sensor based on fiber optic to detect ammonia substance for fishpond application. The simple design of detector leads it to move around   easily in the fishpond and to have a high accuracy in detecting ammonia substance during acid rain event. The testing result shows the maximum absorption loss with variation ammonia mass 1~5% with light source 1310 nm using Optical Spectrum Analyzer (OSA) and low-cost sensor ammonia detector (Photodiode FDS10X10) are 27.56 dBm and 25.86 dBm respectively. A good result over testing and validation process is states that the development of low-cost sensor has successful working with high accuracy.
      PubDate: 2018-12-01
      DOI: 10.12928/telkomnika.v16i6.10493
      Issue No: Vol. 16, No. 6 (2018)
  • Comparison of Raindrop Size Distribution Characteristics Across the
           Southeast Asia Region

    • Authors: Jafri Din
      Abstract: Satellite communication requires reliable estimates of the channel characteristics, especially with the future use of higher frequencies. Regardless of the rain rate, the shape of rain drop size distribution (DSD) start to considerably effect the specific attenuation. In this study DSDs are studied using ground-based two-dimensional video disdrometer measurements taken from Johor, Malaysia as well as two similar datasets from Gan and Manus, two equatorial islands. Integral rain parameters are studied to explain DSD variations across the southeast Asia region. Slightly higher raindrop concentrations and larger diameters were observed in Johor than in Gan or Manus, which is due to Johor being affected by not only oceanic rain- fall but land rainfall as well. The measured rainfall was classified into convective and stratiform precipitation types; the results showed that the Southeast Asia region is dominated by convective rain in terms of accumulated rainfall amount, but stratiform rain occurred more frequently. Further, seasonal variations observed in Johor were insignificant and the DSD variation was mostly due to changes in percentage occurrence of the precipitation types for each monsoon season.
      PubDate: 2018-12-01
      DOI: 10.12928/telkomnika.v16i6.10091
      Issue No: Vol. 16, No. 6 (2018)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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