TELKOMNIKA (Telecommunication Computing Electronics and Control)
Submitted papers are evaluated by anonymous referees by single blind peer review for contribution, originality, relevance, and presentation. The Editor shall inform you of the results of the review as soon as possible, hopefully in 10 weeks. Please notice that because of the great number of submissions that TELKOMNIKA has received during the last few months the duration of the review process can be up to 14 weeks. Communication Engineering, Computer Network and System Engineering, Computer Science and Information System, Machine Learning, AI and Soft Computing, Signal, Image and Video Processing, Electronics Engineering, Electrical Power Engineering, Power Electronics and Drives, Instrumentation and Control Engineering, Internet of Things (IoT)
Articles
3,452 Documents
Architecture and Fault Identification of Wide-area Protection System
Zhenxing Li Zhenxing Li;
Xianggen Yin Xianggen Yin;
Zhe Zhang Zhe Zhang;
Yuxue Wang
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 10, No 3: September 2012
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v10i3.822
Wide-area protection system (WAPS) is widely studied for the purpose of improving the performance of conventional backup protection. In this paper, the system architecture of WAPS is proposed and its key technologies are discussed in view of engineering projects. So a mixed structure-centralized-distributed structure which is more suitable for WAPS in limited power grid region, is obtained based on the advantages of the centralized structure and distributed structure. Furthermore, regional distance protection algorithm was taken as an example to illustrate the functions of the constituent units. Faulted components can be detected based on multi-source imformation fuse in the algorithm. And the algorithm cannot only improved the selectivity, the rapidity, and the reliability of relaying protection but also has high fault tolerant capability. A simulation of 220 kV grid systems in Easter Hubei province showed the effectiveness of the wide-area protection system presented by this paper.
A progressive learning for structural tolerance online sequential extreme learning machine
Sarutte Atsawaraungsuk;
Wasaya Boonphairote;
Kritsanapong Somsuk;
Chanwit Suwannapong;
Suchart Khummanee
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 21, No 5: October 2023
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v21i5.24564
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Measurement of information technology governance capability level: a case study of PT Bank BBS
Punto Widharto;
Zaldy Suhatman;
Rizal Fathoni Aji
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 20, No 2: April 2022
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v20i2.21668
The very close involvement of technology in the banking industry makes almost all banking activities and products currently dependent on information technology (IT). PT BPRS Bhakti Sumekar (PT BBS Bank) is one of the banks that realizes the importance of IT in the digital era and has included IT as part of the company's strategic plan. The company states that compliance with regulations, best practices, and standards is key to a successful IT implementation. In this study, the measurement of the capability level of corporate IT governance was conducted to determine what IT priorities were based on the company's strategic objectives and what recommendations could be given based on best practices to improve IT services in support of the company's strategic goals. The framework to be used is control objective for information and related technology (COBIT); the most widely used framework suitable for service-oriented organizations. The results of research using COBIT 2019 show how IT governance is needed by the company and what should be prioritized. The measurement results found that there is still a gap between management's expectations and the current level of capability and provide recommendations on what companies need to improve performance in order to meet expectations.
System identification of batch milk cooling using output error models
Rudy Agustriyanto;
Aloisiyus Yuli Widianto;
Edy Purwanto;
Puguh Setyopratomo
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 24, No 1: February 2026
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v24i1.27469
Accurate modelling of milk cooling dynamics is essential to maintain product quality and improve energy efficiency in small-scale dairy operations. This study aims to develop a dynamic model for a batch milk-cooling system used at Koperasi Unit Desa Sinau Andandani Ekonomi (KUD SAE) Pujon. Synthetic temperature data were generated under controlled perturbations reflecting actual process conditions, and the data were analysed using the output error (OE) identification method implemented in the MATLAB System Identification Toolbox. Several OE model structures were compared using statistical indicators, including the coefficient of determination (R²) and root mean square error (RMSE). The OE (2,2,1) model achieved the best performance with R² = 0.9923 and RMSE = 0.0600, accurately representing the first-order dynamics of the cooling process. The identified model provides a reliable foundation for process optimisation, controller design, and operator training in dairy systems. Although the validation is limited to simulated data, the proposed approach offers substantial potential for real-time implementation and can be extended to other temperature-sensitive food processes.
Automated classification of diseased cauliflower: a feature-driven machine learning approach
Mala Rani Barman;
Al Amin Biswas;
Marjia Sultana;
Aditya Rajbongshi;
Md. Sabab Zulfiker;
Tasnim Tabassum
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 22, No 4: August 2024
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v22i4.25812
Cauliflower is a popular winter crop in Bangladesh. However, cauliflower plants are vulnerable to several diseases that can reduce the cauliflowers’ productivity and degrade their quality. The manual monitoring of these diseases takes a lot of effort and time. Therefore, automatic classification of the diseased cauliflower through computer vision techniques is essential. This study has retrieved ten different statistical and gray-level co-occurrence matrix (GLCM)-based features from the cauliflower image dataset by implementing a variety of image processing techniques. Afterwards, the SelectKBest method with the analysis of variance f-value (ANOVA F-value) has been used to identify the most important attributes for classification of the diseased cauliflower. Based on the ANOVA F-value, the top N (5≤N ≤9) most dominant attributes is used to train and test five machine learning (ML) models for classification of diseased cauliflower. Finally, different performance metrics have been used for evaluating the effectiveness of the employed ML models. The bagging classifier achieved the highest accuracy of 82.35%. Moreover, this model has outperformed other ML classifiers in terms of other performance metrics also.
For improvements in chromatic scales and luminescent fluxes of white lights: developing a dual-layer remote phosphor structure
Van Liem Bui;
Nguyen Thi Phuong Loan;
Hai Minh Nguyen Tran
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 21, No 1: February 2023
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v21i1.24239
This study compares red-phosphor LaOF:Eu3+ impacts on a single-film remote phosphor configuration (SRPC) and a double-film remote phosphor configuration (DRPC). Mie theory is used to demonstrate the relationship between light flux and color quality. SRPC is a phosphor layer consisting of LaOF:Eu3+ particles mixed with YAG:Ce3+. Meanwhile, DRPC is two separate films of red and yellow phosphors. To increase scattering properties, we added 5% SiO2 into phosphor layers. The differences in structure affect significantly white light emitting diodes’ (WLEDs’) optical properties. Attained figures and statistics show that the color rendering indices (CRIs) increase along with the concentrations of both structures, and these numbers are approximately similar. However, DPRC exhibits a color quality scale (CQS) of 74 in all examined chromatic temperatures (5600 K - 8500 K), which is greater than SRPC’s 71 at 8500 K. Besides, the luminous efficiencies (LEs) in DRPC are more outstanding than that of SRPC, at given LaOF:Eu3+ concentration percentages (2%-14%). To summarize, DRPC offers greater benefits in luminous flux and color quality, compared to SRPC. Choosing the proper red light phosphor concentration, on the other hand, becomes a crucial aspect of achieving the ideal CQS and LEs.
Jacobian approximation of the Sum-Alpha stopping criterion
Aissa Ouardi
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 23, No 3: June 2025
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v23i3.25605
This article will report the development of new application of the SumAlpha stopping criterion to the case of log – maximum a posterioru LogMAP turbo decoding. It shows how to adapt Sum-Alphas quantities when using the Log-MAP algorithm and how to deduce a good decision threshold. We apply a logarithm to the quantity Sum-Alpha which is evaluated by the same Jacobian logarithm of the Log-MAP algorithm. We call this new adaptation Jacobian Approximation of Sum-Alpha (JASA) criterion. The simulation results demonstrate that the JASA criterion achieves comparable performance (in terms of bit error rate (BER) and frame error rate (FER)) to the Sum-Alpha and cross-entropy (CE) criteria, with the same average number of iterations.
A new multi-level key block cypher based on the Blowfish algorithm
Suhad Muhajer Kareem;
Abdul Monem S. Rahma
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 18, No 2: April 2020
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v18i2.13556
Blowfish is a block cypher algorithm used in many applications to enhance security, but it includes several drawbacks. For example, the mix between the key and data is limited. This paper presents a new modification to the Blowfish algorithm to overcome such problems realised through a multi-state operation instead of an XOR. Our proposed algorithm uses three keys in the encryption and decryption processes instead of one for controlling the variable block bits sizes (1, 2, 4, and 8) bits and for determining the state table numbers. These tables are formed from the addition in a Galois field GF (2n) based on block bit size to increase the complexity of the proposed algorithm. Results are evaluated based on the criteria of complexity, time encryption, throughout, and histogram, and show that the original Blowfish, those modified by other scholars, and our proposed algorithm are similar in time computation. Our algorithm is demonstrated to be the most complex compared with other well-known and modified algorithms. This increased complexity score for our proposed Blowfish makes it more resistant against attempts to break the keys.
Unified algorithms for generalized new Mersenne number transforms
Lujain S. Abdulla;
Abdulmuttalib A-Wahab Hussein;
Mounir Taha Hamood
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 21, No 6: December 2023
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v21i6.25253
The generalized new Mersenne number transforms (GNMNTs) have proved to be significant number theoretic transforms (NTTs) used to calculate convolutions and correlations accurately. In this paper, by applying the principles of the decimation-in-frequency (DIF) approach with appropriate relations in finite field modulo Mersenne primes, two new fast algorithms for computing odd NMNT (ONMNT) and odd-squared NMNT (O2NMNT) are introduced. Moreover, by formulating a unified index mapping scheme for data sequence, a close relationship between the structures of the developed algorithms has been established. As a result, it has been shown that only a single universal butterfly structure is adequate to execute both algorithms. Consequently, a unified implementation platform can be used to compute the ONMNT as well as the O2NMNT. The validity of the development has been checked via an example for fast calculations of different types of convolutions, using both the GNMNTs and the proposed algorithms.
A novel fern-like lines detection using a hybrid of pre-trained convolutional neural network model and Frangi filter
Heri Pratikno;
Mohd Zamri Ibrahim;
Jusak Jusak
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 20, No 3: June 2022
Publisher : Universitas Ahmad Dahlan
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DOI: 10.12928/telkomnika.v20i3.23319
Full ferning is the peak of the formation of a salt crystallization line pattern shaped like a fern tree in a woman’s saliva at the time of ovulation. The main problem in this study is how to detect the shape of the salivary ferning line patterns that are transparent, irregular and the surface lighting is uneven. This study aims to detect transparent and irregular lines on the salivary ferning surface using a comparison of 15 pre-trained convolutional neural network models. To detect fern-like lines on transparent and irregular layers, a pre-processing stage using the Frangi filter is required. The pre-trained convolutional neural network model is a promising framework with high precision and accuracy for detecting fern-like lines in salivary ferning. The results of this study using the fixed learning rate model ResNet50 showed the best performance with an error rate of 4.37% and an accuracy of 95.63%. Meanwhile, in implementing the automatic learning rate, ResNet18 achieved the best results with an error rate of 1.99% and an accuracy of 98.01%. The results of visual detection of fern-like lines in salivary ferning using a patch size of 34×34 pixels indicate that the ResNet34 model gave the best appearance