Articles

Access the latest knowledge in applied science, electrical engineering, computer science and information technology, education, and health.

Filter Icon

Filters article

Years

FAQ Arrow
0
0

Source Title

FAQ Arrow

Authors

FAQ Arrow

30,376 Article Results

System identification of batch milk cooling using output error models

10.12928/telkomnika.v24i1.27469
Rudy; University of Surabaya Agustriyanto , Aloisiyus; University of Surabaya Yuli Widianto , Edy; University of Surabaya Purwanto , Puguh; University of Surabaya Setyopratomo
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.
Volume: 24
Issue: 1
Page: 282-292
Publish at: 2026-02-01

Newchaos function from the composition of DTM and Gauss iterated map for digital image encryption

10.12928/telkomnika.v24i1.27551
Adrianus; Universitas Indonesia Yosia , Tokonyai Tawanda Jonathan; Universitas Indonesia Rabvemhiri , Suryadi; Universitas Indonesia MT
This manuscript introduces a novel chaotic discrete function, formulated through the composition of the dyadic transformation map (DTM) and the Gauss iterated map (GIM), and designated as DTGIM. The National Institute of Science and Technology (NIST) randomness test suite, bifurcation diagrams, and Lyapunov exponents are used to examine the chaotic characteristics of DTGIM. With ini tial condition x0 = 0.12345 and parameters α = −15 and β = 0.3, the func tion shows chaotic behavior in the bifurcation diagram and produces a positive Lyapunov exponent. Strong randomness is further confirmed by NIST tests, which achieve 100% for 32-bit binary sequences and 63.75% for 8-bit binary sequences. Additionally, we compare a number other chaotic discrete functions that also employ the composition method. These findings show that DTGIM is a viable option for applications involving chaos-based cryptography.
Volume: 24
Issue: 1
Page: 228-239
Publish at: 2026-02-01

Secure hybrid power-frequency multiple access in satellite terrestrial communication systems: a performance study

10.12928/telkomnika.v24i1.26892
Huu; Industrial University of Ho Chi Minh City Q. Tran , Viet-Thanh; Industrial University of Ho Chi Minh City Pham
This paper investigates a secure hybrid power–frequency multiple access (PFMA) framework for satellite–terrestrial communications. By integrating power- and frequency-domain multiplexing, PFMA achieves approximately 4 dB lower transmit signal-to-noise ratio (SNR) than non-orthogonal multiple access (NOMA) for the same connection outage probability (COP) at SNR > 0 dB, and it reduces the COP by up to 30% at low-to-medium SNRs. It further decreases the intercept probability (IP) by 20–25% at PS = 10 dBm. Closed-form COP and IP expressions are derived under shadowed-Rician fad ing with both internal and external eavesdroppers and validated via Monte Carlo simulations. Parameter analysis indicates that PFMA’s SNR gain can either ex tend coverage by 60% or save 37% energy, providing design guidelines for 6G, satellite IoT, and emergency communication systems. The single-cell assump tion points to future work on multi-cell and mobility scenarios.
Volume: 24
Issue: 1
Page: 14-21
Publish at: 2026-02-01

Optimizing blood cell classification: evaluating feature dimensionality and validation strategies

10.12928/telkomnika.v24i1.27269
Ruaa H. Ali; Northern Technical University Al-Mallah , Marwa Mawfaq; Northern Technical University Mohamedsheet Al-Hatab , Maysaloon; Northern Technical University Abed Qasim
Manual blood cell classification is time consuming and may lead to inconsistent results. This study aims to assist pathologists in diagnosing hematological disorders using machine learning (ML) techniques for automated classification of blood cells in multi-color test images, distinguishing red blood cells (RBCs) and white blood cells (WBCs). Features were extracted using the InceptionV3 network, and several ML models were evaluated for classifying blood cells into eight categories. Two validation strategies: a 66%–34% train–test split and 20-fold cross-validation were applied. The effect of dimensionality reduction through principal component analysis (PCA) was also examined, reducing the feature space from 2,048 to 100 components. Among all models, support vector machine (SVM) achieved highest performance, with 93.4% accuracy and an area under the curve (AUC) of 0.996 without PCA, and 90.1% accuracy with an AUC of 0.991 after PCA. Although PCA slightly reduced accuracy, it improved computational efficiency. Overall, SVM provided the most accurate, stable, and generalizable classification results for automated blood cell analysis.
Volume: 24
Issue: 1
Page: 359-370
Publish at: 2026-02-01

Performance evaluation of serverless cloud-native API deployment: a case study on a mobile health application

10.12928/telkomnika.v24i1.27261
Maulana Bintang; Politeknik Elektronika Negeri Surabaya Irfansyah , Bilal; Politeknik Elektronika Negeri Surabaya Waheed , Idris; Politeknik Elektronika Negeri Surabaya Winarno , Akhmad; Politeknik Elektronika Negeri Surabaya Alimudin
As software applications become increasingly complex, there is a growing need for scalable, flexible, and high-performance backend solutions. Cloud computing-based application programming interfaces (APIs) address these demands by enabling developers to offload resource-intensive tasks to the cloud while eliminating the burden of infrastructure management. This study presents a case study using Obesifix, a mobile health application for real time dietary monitoring and personalized nutrition recommendations. Two deployment models were evaluated: a traditional server-based architecture using Google Compute Engine (GCE) and a serverless approach using Google Cloud Run (GCR). Performance testing was conducted with Apache JMeter under simulated loads of 60, 120, and 180 users across four critical API endpoints (register, login, recommendation, prediction). Results show that GCR consistently achieved 20–30% lower response times and 15–20% higher throughput compared to GCE, while maintaining 0% error rate, lower memory consumption, and more balanced virtual central processing unit (vCPU) utilization. Time to first byte (TTFB) remained below 800 ms across all scenarios, confirming good server responsiveness. These findings highlight the scalability and efficiency benefits of serverless architectures for mobile health applications. Future research should explore asynchronous programming paradigms, autoscaling thresholds, and cost-performance trade-offs, as well as multi-cloud deployments to enhance system resilience and generalizability.
Volume: 24
Issue: 1
Page: 34-48
Publish at: 2026-02-01

Expert evaluation of a web-based grammatical competence module: Fuzzy Delphi method

10.11591/ijere.v15i1.35355
Nur Hidayah Md Yazid , Nur Ainil Sulaiman , Harwati Hashim
Web-based learning modules have been considered indispensable for English as a second language (ESL) learners to utilize autonomously. However, there are still not many reputable grammatical competence modules designed for the transition between secondary school and undergraduate levels. Thus, this study aimed to ascertain expert consensus on developing a web-based grammatical competence module for pre-university ESL learners. The Fuzzy Delphi method (FDM) was employed in this study to create the module. Four broad constructs, which are the design, technical aspects, content, pedagogy of the website were used as references in developing a survey as the instrument for the study. The features in the survey were evaluated by six selected experts based on established criteria for high-quality language learning websites. Data analysis was undertaken using a 5-point fuzzy scale and the Fuzzy Delphi approach Logic Software (FUDELO 1.0). Supported by the findings and a consensus rate of over 75%, a cut-off value (d) of ≤0.2, and a fuzzy score (A) of ≥α-cut value=0.5, expert consensus was reached for the four constructs. The findings support that the module is fitting for pre-university ESL learners and can be used as a supplementary grammar learning module. Empirical studies related to learner performance and engagement outcomes in the future must continue assessing the long-term effectiveness of the module and ensure its long-term efficacy in ESL learning.
Volume: 15
Issue: 1
Page: 784-794
Publish at: 2026-02-01

Performance enhancement of embedded object detection via neural hardware acceleration

10.12928/telkomnika.v24i1.27448
Alwin; STMIK Indonesia Mandiri Hartono Limaran , Agung; STMIK Indonesia Mandiri Wicaksono , Patah; STMIK Indonesia Mandiri Herwanto
This paper presents the first benchmarking of you only look once version 11 (YOLO11) on the Rockchip RK3566 neural processing unit (NPU) within the Orange Pi 3B platform. Performance was compared between the quad-core ARM Cortex-A55 CPU and the integrated NPU using the COCO2017 dataset, evaluating latency, energy, and accuracy. NPU acceleration achieved >80% latency reduction and ≈ 94% lower per-inference energy consumption, with speedup of up to 16.7× while maintaining accuracy within 0.03 mean average precision (mAP) of the baseline. Average power remained nearly constant (3.60 W central processing unit (CPU) vs. 3.59 W NPU), indicating that the efficiency gains stem from reduced inference time rather than lower wattage. Limitations included unstable INT8 quantization due to unsupported operators and calibration-range mismatch, as well as minor CPU-side overhead in preprocessing and non-maximum suppression. The findings confirm that the RK3566 NPU delivers substantial efficiency gains without accuracy loss, enabling compact and low-cost platforms to sustain modern object-detection workloads. This demonstrates that affordable NPUs can provide reliable, real time artificial intelligence (AI) inference for embedded vision, internet of things (IoT), and robotics applications.
Volume: 24
Issue: 1
Page: 126-141
Publish at: 2026-02-01

Anchovy-inspired filter algorithm: A bio-inspired optimization approach for high-dimensional benchmark functions

10.12928/telkomnika.v24i1.27594
Azrul; Politeknik Sultan Idris Shah Mahfurdz , Muhammad Muizz; Politeknik Sultan Idris Shah Mohd Nawawi , Sunardi; Universitas Ahmad Dahlan Sunardi , Mohd Azriq; Sapura Industrial Berhad, Bandar Baru Bangi Abd Aziz
This paper presents the anchovy-inspired filter algorithm (AFA), a novel bio-inspired metaheuristic optimization method motivated by the filter feeding behavior of anchovies. Unlike conventional swarm intelligence algorithms, AFA employs a filtering mechanism in which each agent generates multiple candidate solutions within a local sampling radius and selects the best, mimicking how anchovies filter microscopic prey from seawater. To evaluate its performance, AFA was benchmarked against particle swarm optimization (PSO) and genetic algorithm (GA) using six standard test functions: Sphere, Rosenbrock, Schwefel 1.2, Rastrigin, Griewank, and Ackley in 30-dimensional search spaces. Simulation results demonstrate that AFA consistently outperforms PSO and GA across unimodal and multimodal functions. For unimodal problems such as Sphere, Rosenbrock, and Schwefel 1.2, AFA achieved significantly lower best and mean fitness values, reflecting strong exploitation capability. For multimodal functions including Rastrigin, Griewank, and Ackley, AFA effectively avoided local minima, maintained robustness, and achieved stable convergence with lower variance. Convergence analysis further indicates that AFA steadily approaches near-global optima without premature stagnation. Overall, the results highlight the effectiveness of the filter-based exploitation mechanism in balancing exploration and exploitation. Future research will focus on adaptive filtering strategies, hybrid integration with other metaheuristics, and applications to real-world optimization problems.
Volume: 24
Issue: 1
Page: 271-281
Publish at: 2026-02-01

Deep learning-based power amplifier linearization in OFDM systems with unknown channel state information

10.12928/telkomnika.v24i1.27236
Meryem Mamia; University of Tlemcen Benosman , Mohammed Yassine; University of Tlemcen Bendimerad , Fethi Tarik; University of Tlemcen Bendimerad
This paper presents an end-to-end deep learning-based approach for orthogonal frequency-division multiplexing (OFDM) communication systems impaired by nonlinear power amplifiers (PAs) and channel fading. The PA nonlinearity is modeled using the modified Rapp model, and simulations are performed on a 64-subcarrier OFDM system with a cyclic prefix (CP) of 8 and 16-quadrature amplitude modulation (16-QAM). The proposed autoencoder-based OFDM–PA (AE-OFDM-PA) system jointly optimizes the transmitter and receiver through end-to-end learning, enabling simultaneous compensation of both PA nonlinearities and channel distortions without requiring explicit channel state information (CSI) estimation. Instead, the model leverages embedded pilot sequences to learn the implicit CSI representation directly from data, allowing the receiver to correct amplitude and phase distortions adaptively. Simulation results demonstrate that AE-OFDM-PA significantly outperforms conventional OFDM and OFDM-PA systems, achieving over 70× block error rate (BLER) improvement compared with the uncompensated OFDM-PA system at an input back-off (IBO) of 3 dB. Furthermore, the proposed method achieves approximately 11.5 dB adjacent channel leakage ratio (ACLR) improvement over the classical memory polynomial digital predistortion (DPD) technique, while slightly reducing the peak-to-average power ratio (PAPR). Overall, AE-OFDM-PA provides a robust, spectrally efficient, and low-complexity solution for nonlinear and fading environments with unknown or varying CSI.
Volume: 24
Issue: 1
Page: 1-13
Publish at: 2026-02-01

Optimizing planar micro-transformer performance

10.12928/telkomnika.v24i1.27276
Tahar; University of Science and Technology of Oran USTO-MB Alili , Fatima Zohra; University of Science and Technology of Oran USTO-MB Medjaoui , Azzedine; Nour El Bachir University Center Hamid , Abderahim; National Polytechnic School of Oran Maurice Audin Mokhefi , Yacine; Nour El Bachir University Center Guettaf , Hocine; Nour El Bachir University Center Guentri
Faced with new requirements for isolated switching power supplies with high efficiency and power density, planar transformer technology has emerged as a serious alternative to wound components. The work presented in this paper addresses the issue of developing planar transformers in the context of low-power electronics, where volume and weight constraints are paramount. The flat shape of the coils and the interlacing of the windings do not allow for control of magneto-thermal phenomena. Although scientific literature offers numerous simulation tools to aid in the design of such transformers, it must be noted that they do not allow for a rigorous account of these phenomena. In this paper, methods and a geometric and electrical sizing tool in planar technology are used for the design of flyback direct current to direct current (DC/DC) converters. Methods for dimensioning and estimating temperature rise are presented and compared in order to develop calculation tools for design purposes. This study enabled us to observe the distribution of the magnetic field, the role of ferrite, the distribution of currents and voltages in the coils, and the distribution of temperature in our device. It should be noted that conductive and convective heat transfer processes were considered in steady state.
Volume: 24
Issue: 1
Page: 313-328
Publish at: 2026-02-01

Distorted born iterative method reconstruction in high-noise environments using KNN-based machine learning denoising

10.12928/telkomnika.v24i1.27401
Nguyen Quang; Vietnam Academy of Science and Technology Huy , Nguyen Truong; Vietnam Academy of Science and Technology Thang
Ultrasound tomography reconstruction using the distorted born iterative method (DBIM) is sensitive to measurement noise, which degrades image fidelity and slows convergence. We propose integrating a k-nearest neighbors (KNN) denoising step within each DBIM iteration to suppress noise adaptively while preserving structural edges. Simulations with a circular cylindrical target and transmit/receive geometry (12×12) were conducted at signal-to-noise ratio (SNR) levels of 6 dB, 3 dB, and 1 dB. Compared with conventional DBIM employing Tikhonov regularization, the KNN-filtered DBIM reduces normalized reconstruction error by up to 57.2% at 1 dB and shows faster error decay over successive iterations. The method is training-free, computationally lightweight, and preserves fine structural details. These properties make KNN-filtered DBIM attractive for noisy or resource-constrained imaging environments. Future work will validate the approach on experimental data and explore adaptive K selection.
Volume: 24
Issue: 1
Page: 206-218
Publish at: 2026-02-01

Optimization and techno-economic analysis of hybrid renewable systems in Nigeria

10.12928/telkomnika.v24i1.27499
Lambe; Kwara State University Mutalub Adesina , Jamiu; Kwara State University Lawal , Olalekan; Kwara State University Ogunbiyi , Abdulwaheed; Kwara State University Musa , Bilkisu; Kwara State University Jimada Ojuolape , Monsurat; Kwara State University Omolara Balogun , Bashiru; Kwara State University Olalekan Ariyo
Rising electricity demand, fossil fuel depletion, and environmental concerns highlight the need for sustainable rural electrification. The Elenjere community in Kwara State, Nigeria, depends on costly diesel generation and limited grid access, creating an urgent demand for reliable and affordable alternatives. This study designs and optimizes a hybrid renewable energy system (HRES) for the community using hybrid optimization model for electric renewables (HOMER) Pro simulation. The proposed system combines photovoltaic (PV), wind turbines (WT), battery storage (BAT), inverter (INV), and a diesel generator (DG) as backup. Field data on load demand, solar radiation, and wind speed were used for realistic modeling. System performance was evaluated using levelized cost of energy (LCOE), net present cost (NPC), and system capital cost (SCC). Results show the PV/WT/BAT/INV/GEN configuration achieved the lowest LCOE of USD 0.455/kWh, an NPC of USD 2.98 million, and 86.2% renewable penetration, significantly reducing diesel use. Sensitivity analysis revealed that reducing battery costs and increasing PV capacity could lower the LCOE to USD 0.227–0.325/kWh. The study demonstrates how modest wind resources (4.19 m/s at 10 m) complement PV in low-wind regions while addressing inflation realism (25.5% discount rate, foreign exchange (FX) volatility). Future work will include dynamic control simulation and lifecycle analysis to enhance scalability and sustainability.
Volume: 24
Issue: 1
Page: 343-358
Publish at: 2026-02-01

Developing tuberculosis drug information system using a throwaway prototype: Udayana Hospital case study

10.12928/telkomnika.v24i1.27073
Rini; Udayana University Noviyani , Luh Arida Ayu; Udayana University Rahning Putri , I Nyoman; Udayana University Gede Budiana , Luh; Udayana University Gede Astuti , I Made; Udayana University Oka Widyantara , Ida Ayu; Udayana University Alit Widhiartini , Ida Bagus; Universitas Udayana Teaching Hospital Nyoman Maharjana , Sagung; Udayana University Chandra Yowani , I Gusti Ngurah; Udayana University Anom Cahyadi Putra
Tuberculosis (TB) remains a major health problem in Indonesia, and efficient drug management is essential to ensure continuous treatment and prevent resistance. At Udayana University Hospital, manual recording and reporting often caused delays and errors, while integration with the National Tuberculosis Information System (SITB) was limited. This study developed a TB drug information system using the throwaway prototype model to address these challenges and enhance hospital workflow efficiency. The system implementation demonstrated measurable improvements in operational performance, with data entry errors reduced by 83% and the average recording time per patient shortened by 35% compared to the previous manual process. User feedback confirmed improved usability, accuracy, and reliability in supporting hospital workflows and timely reporting. In conclusion, the proposed system effectively improved the accuracy and efficiency of TB drug management while addressing hospital level operational challenges. This study demonstrates the applicability of the throwaway prototype model in healthcare information-system development and provides insights for scaling and integration with national TB programs.
Volume: 24
Issue: 1
Page: 49-70
Publish at: 2026-02-01

Advancements in physical layer key generation: a review on channel reciprocity and IoT security techniques

10.12928/telkomnika.v24i1.27340
Syed Shafaq; Southeast University Ali Shah , Ajab; University of Science and Technology Bannu Noor , Ruiyue; Changchun University of Science and Technology Liang , Rahmat Ullah; FAST National University of Computer and Emerging Science Zadran
With the burgeoning internet of things (IoT), securing communication becomes paramount. Traditional cryptography does not meet computational needs and brute-force attacks. This review explores the state-of-the-art physical layer secret key generation (PLKG) that takes advantage of the inherent reciprocity and randomness of wireless channels. We investigate cutting-edge techniques such as feature extraction networks, domain adversarial training, and deep learning-based approaches, evaluating their effects on the security and efficiency of key generation. In addition to these methods, the review addresses real-world challenges such as multi-user scenarios, reconciliation overhead, and inconsistent channel measurement. We believe that improved key generation rates and security can be achieved through the use of millimeter wave technology and full-duplex communication. To strengthen the robustness of key generation, the paper concludes by suggesting future directions, such as incorporating more random sources, such as physiological signals and sensor data. This comprehensive overview offers deep insights into the state-of-the-art and paves the way for reliable communication in ever more complicated IoT settings.
Volume: 24
Issue: 1
Page: 196-205
Publish at: 2026-02-01

Comparison methods in a decision support system for determining JavaScript frameworks

10.12928/telkomnika.v24i1.27241
Rofif Aghna; Sunan Kalijaga State Islamic University Yogyakarta Fakhri Diya , Agus; Sunan Kalijaga State Islamic University Yogyakarta Mulyanto
The selection of an appropriate JavaScript framework in web-based software development often leads to errors when the chosen framework is incompatible with the design. The ability to make decisions quickly, accurately, and precisely is therefore a key factor in successful software design. Addressing this need, the present study analyzes the accuracy of the analytical hierarchy process-weight product (AHP-WP), analytical hierarchy process-technique for order preference by similarity to ideal solution (AHP TOPSIS), and analytical hierarchy process-simple multi-attribute rating technique (AHP-SMART) methods in determining the most suitable JavaScript framework according to the International Organization for Standardization (ISO) 9126 classification. To evaluate accuracy, the mean absolute percentage error (MAPE) was applied as a cost function to measure the error percentage of each method. The analysis was conducted on ten popular JavaScript frameworks selected based on their popularity and usage trends. The evaluation considered six quality criteria: functionality, reliability, usability, efficiency, maintainability, and portability. The results show the ranking of each alternative for all methods. Accuracy measurement using MAPE revealed that the AHP-WP method produced the smallest error percentage (37.77645%), compared to AHP-TOPSIS (47.12566%) and AHP-SMART (46.4041%). Accordingly, the AHP-WP method is recommended for decision support system (DSS) development.
Volume: 24
Issue: 1
Page: 95-110
Publish at: 2026-02-01
Show 78 of 2026

Discover Our Library

Embark on a journey through our expansive collection of articles and let curiosity lead your path to innovation.

Explore Now
Library 3D Ilustration