Ralph Gerard B. Sangalang
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Ralph Gerard B. Sangalang has a total of 68 co-authors. Here are the top co-authors by number of shared publications:
- Chua-Chin Wang
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung city, Taiwan
17 shared publications - Oliver Lexter July Alvarez Jose
Dept. of Electronics Engineering, Batangas State University, The National Engineering University, Batangas City, Philippines
10 shared publications - Lean Karlo Santos Tolentino
Electronics Engineering Department, Technological University of the Philippines, Manila, Philippines
7 shared publications - Antonette Villapando Chua
Dept. of Electronics Engineering, Batangas State University, The National Engineering University, Batangas City, Philippines
4 shared publications Oliver Lexter July A. Jose
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
4 shared publications- Anton Louise De Ocampo
Batangas State University, Philippines
3 shared publications
Latest Publications
- Open Access
- 31 October 2026
- Published by Elsevier in Journal of Engineering Research
A hybrid improved P&O-Model Predictive Control MPPT strategy for photovoltaic systems
- 31 October 2026
- Published by Elsevier in Journal of Engineering Research
Open AccessA hybrid improved P&O-Model Predictive Control MPPT strategy for photovoltaic systems
- 25 June 2026
- Published by Springer Nature in Signal, Image and Video Processing
- Vol. 20 (8) , 443
Edge-deployable residual-domain AE-CFAR for robust multi-target detection in automotive frequency-modulated continuous-wave (FMCW) radar
- 25 June 2026
- Published by Springer Nature in Signal, Image and Video Processing
- Vol. 20 (8) , 443
Edge-deployable residual-domain AE-CFAR for robust multi-target detection in automotive frequency-modulated continuous-wave (FMCW) radar
- Open Access
- 15 May 2026
- Published by JVE International Ltd. in Mathematical Models in Engineering
- Vol. 12 (2) , 125-146
Non-intrusive appliance health monitoring and remaining useful life prediction using a DRN-transformer model
This paper presents a high-performance embedded micro-sensing and processing integrated non-intrusive load monitoring system for real-time appliance health assessment and remaining useful life (RUL) prediction, with the core innovation focused on the design and implementation of an STM32H7-based embedded micro-system that realizes seamless integration of high-frequency signal acquisition, edge-side real-time preprocessing, and intelligent multi-task analysis on a single chip. Utilizing an STM32H7 microcontroller, it captures high-frequency voltage and current signals to detect appliance degradation features. Time-frequency preprocessing with FFT and STFT improves signal representation, enabling better feature extraction. The proposed DRN-Transformer model integrates deep residual networks and Transformer attention mechanisms to extract both local and long-range temporal features. Tested on four common household appliances (refrigerator, washing machine, air conditioner, microwave oven), the system achieved over 92 % accuracy in health classification (up to 97.8 % for washing machines) and a low error in RUL estimation with an average RMSE of 3.2 months and an average MAPE of 8.5 %, outperforming traditional machine learning baselines (SVM/RF) by more than 40 % in health classification accuracy and surpassing mainstream deep learning models (LSTM/Transformer/LSTM-VMD) by 15-20 % in RUL prediction precision. Furthermore, the proposed embedded micro-sensing platform explicitly considers hardware-level constraints such as on-chip memory capacity, computational complexity, and real-time inference latency. By optimizing model architecture and adopting lightweight deployment strategies, the system achieves efficient edge-side intelligence while maintaining compatibility with resource-constrained microcontroller platforms. The system outperformed traditional baseline models and showed good generalization across different brands. With low latency and power consumption, it is well-suited for smart home applications.
- 15 May 2026
- Published by JVE International Ltd. in Mathematical Models in Engineering
- Vol. 12 (2) , 125-146
Open AccessNon-intrusive appliance health monitoring and remaining useful life prediction using a DRN-transformer model
This paper presents a high-performance embedded micro-sensing and processing integrated non-intrusive load monitoring system for real-time appliance health assessment and remaining useful life (RUL) prediction, with the core innovation focused on the design and implementation of an STM32H7-based embedded micro-system that realizes seamless integration of high-frequency signal acquisition, edge-side real-time preprocessing, and intelligent multi-task analysis on a single chip. Utilizing an STM32H7 microcontroller, it captures high-frequency voltage and current signals to detect appliance degradation features. Time-frequency preprocessing with FFT and STFT improves signal representation, enabling better feature extraction. The proposed DRN-Transformer model integrates deep residual networks and Transformer attention mechanisms to extract both local and long-range temporal features. Tested on four common household appliances (refrigerator, washing machine, air conditioner, microwave oven), the system achieved over 92 % accuracy in health classification (up to 97.8 % for washing machines) and a low error in RUL estimation with an average RMSE of 3.2 months and an average MAPE of 8.5 %, outperforming traditional machine learning baselines (SVM/RF) by more than 40 % in health classification accuracy and surpassing mainstream deep learning models (LSTM/Transformer/LSTM-VMD) by 15-20 % in RUL prediction precision. Furthermore, the proposed embedded micro-sensing platform explicitly considers hardware-level constraints such as on-chip memory capacity, computational complexity, and real-time inference latency. By optimizing model architecture and adopting lightweight deployment strategies, the system achieves efficient edge-side intelligence while maintaining compatibility with resource-constrained microcontroller platforms. The system outperformed traditional baseline models and showed good generalization across different brands. With low latency and power consumption, it is well-suited for smart home applications.
- 6 May 2025
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Very Large Scale Integration (VLSI) Systems
- Vol. 33 (10) , 2620-2629
A 4.447 mW at 100 MHz and 49.62% Uniqueness XNOR–XOR RO PUF ASIC Using 180-nm CMOS Process for IoT Security Applications
Physical unclonable functions (PUFs) are increasingly recognized as a key technology for enhancing hardware and the Internet of Things (IoT) security. The IoT devices are often plagued by weak security measures, making them susceptible to various external threats. To address these vulnerabilities, robust and reliable security solutions are critical. This study introduces a highly reliable and low-power PUF application-specific integrated circuit (ASIC) design specifically designed for the IoT security applications. Initially, the proposed design is deployed on a Xilinx ZYNQ 7000 field-programmable gate array (FPGA) board operating at 100 MHz and later designed and fabricated using the Cadence Innovus in the 180-nm CMOS process on silicon. This work presents and evaluates a novel xnor–xor ring oscillator (RO) PUF with a configurable frequency. The design’s performance is analyzed using statistical metrics, including reliability, uniqueness, and uniformity. The xnor–xor RO PUF ASIC demonstrates max reliability of 91.92%, a uniqueness of 49.62%, and a uniformity of 50.19% on silicon.
- 6 May 2025
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Very Large Scale Integration (VLSI) Systems
- Vol. 33 (10) , 2620-2629
A 4.447 mW at 100 MHz and 49.62% Uniqueness XNOR–XOR RO PUF ASIC Using 180-nm CMOS Process for IoT Security Applications
Physical unclonable functions (PUFs) are increasingly recognized as a key technology for enhancing hardware and the Internet of Things (IoT) security. The IoT devices are often plagued by weak security measures, making them susceptible to various external threats. To address these vulnerabilities, robust and reliable security solutions are critical. This study introduces a highly reliable and low-power PUF application-specific integrated circuit (ASIC) design specifically designed for the IoT security applications. Initially, the proposed design is deployed on a Xilinx ZYNQ 7000 field-programmable gate array (FPGA) board operating at 100 MHz and later designed and fabricated using the Cadence Innovus in the 180-nm CMOS process on silicon. This work presents and evaluates a novel xnor–xor ring oscillator (RO) PUF with a configurable frequency. The design’s performance is analyzed using statistical metrics, including reliability, uniqueness, and uniformity. The xnor–xor RO PUF ASIC demonstrates max reliability of 91.92%, a uniqueness of 49.62%, and a uniformity of 50.19% on silicon.
- 28 April 2025
- Published by Taylor & Francis in International Journal of Electronics
- Vol. 113 (1) , 39-64
A 200 MHz 1.22 fJ/bit/search single-ended content addressable memory cell design in 45-nm CMOS technology
- 28 April 2025
- Published by Taylor & Francis in International Journal of Electronics
- Vol. 113 (1) , 39-64
A 200 MHz 1.22 fJ/bit/search single-ended content addressable memory cell design in 45-nm CMOS technology
- Open Access
- 7 February 2025
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Access
- Vol. 13, 28123-28134
A Power-Efficient 0.5668 TOPS/W Digital Logic Accelerator Implemented Using 40-nm CMOS Process for Underwater Object Recognition Usage
DNN (deep neural network) and CNN (convolution neural network) have been widely used in real-time artificial intelligent (AI) applications, particularly image or video recognitions, because they have been proved physically in many occasions. However, most prior AI hardware works are either suffered from high on-silicon area cost or low usage thereof. This investigation presents a power efficient and high performance implementation of a digital logic accelerator (DLA) for the underwater real-time underwater object recognition. The proposed DLA is also featured with 2-dimensional PE (processing element) array to increase the processing throughput by the enhancement of parallelism. The DLA design was realized and fabricated using TSMC 40-nm CMOS process. Not only the post-layout simulation results are shown, the on-silicon measurement outcome as well as the system validation in water are also demonstrated to prove the function correctness and the performance. The area efficiency (GOPS/mm2) is 4.562, and the power efficiency (TOPS/W) is 0.5668 on silicon, which both are the best to date.
- 7 February 2025
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Access
- Vol. 13, 28123-28134
Open AccessA Power-Efficient 0.5668 TOPS/W Digital Logic Accelerator Implemented Using 40-nm CMOS Process for Underwater Object Recognition Usage
DNN (deep neural network) and CNN (convolution neural network) have been widely used in real-time artificial intelligent (AI) applications, particularly image or video recognitions, because they have been proved physically in many occasions. However, most prior AI hardware works are either suffered from high on-silicon area cost or low usage thereof. This investigation presents a power efficient and high performance implementation of a digital logic accelerator (DLA) for the underwater real-time underwater object recognition. The proposed DLA is also featured with 2-dimensional PE (processing element) array to increase the processing throughput by the enhancement of parallelism. The DLA design was realized and fabricated using TSMC 40-nm CMOS process. Not only the post-layout simulation results are shown, the on-silicon measurement outcome as well as the system validation in water are also demonstrated to prove the function correctness and the performance. The area efficiency (GOPS/mm2) is 4.562, and the power efficiency (TOPS/W) is 0.5668 on silicon, which both are the best to date.
- 22 March 2024
- Published by Springer Nature in Circuits, Systems, and Signal Processing
- Vol. 43 (6) , 3376-3395
A 13.73 ns Input Time Range TDA Design Based on Adjustable Current Sources Using 40-nm CMOS Process
- 22 March 2024
- Published by Springer Nature in Circuits, Systems, and Signal Processing
- Vol. 43 (6) , 3376-3395
A 13.73 ns Input Time Range TDA Design Based on Adjustable Current Sources Using 40-nm CMOS Process
- 26 February 2024
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Very Large Scale Integration (VLSI) Systems
- Vol. 32 (5) , 972-976
A 6.25-MHz 3.4-mW Single Clock DPWM Technique Using Matrix Shift Array
Recent digital pulsewidth modulation (DPWM) researches use multiple clock inputs and long D flip-flop (DFF) arrays, which makes scaling to different DPWM frequencies challenging. This brief demonstrates a DPWM that utilizes a single clock and a Matrix shift array, allowing it to be scaled to any frequency and reducing the effects of clock skew. It has a clock gating technique that selects a specific row of DFFs based on the required % duty cycle. The DPWM design has a dead time generator to prevent shoot-throughs. The DPWM has been fabricated using UMC 180-nm CMOS process. The performance and functionality of the DPWM have been verified through the measured comparisons of % duty ratio, dead time ($T_{dt}$ ), and output frequency ($f_{\text {out}}$ ) at input clock frequency ($f_{\text {clk}_{\text {in}}}$ ) equal to 10$\sim $ 100 MHz. The DPWM design has a maximum % duty ratio of 90.6%,$T_{dt}$ = 1.8 ns, and$f_{\text {out}}$ = 6.25 MHz with 3.4-mW power consumption at$f_{\text {clk}_{\text {in}}}$ = 100 MHz.- 26 February 2024
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Very Large Scale Integration (VLSI) Systems
- Vol. 32 (5) , 972-976
A 6.25-MHz 3.4-mW Single Clock DPWM Technique Using Matrix Shift Array
Recent digital pulsewidth modulation (DPWM) researches use multiple clock inputs and long D flip-flop (DFF) arrays, which makes scaling to different DPWM frequencies challenging. This brief demonstrates a DPWM that utilizes a single clock and a Matrix shift array, allowing it to be scaled to any frequency and reducing the effects of clock skew. It has a clock gating technique that selects a specific row of DFFs based on the required % duty cycle. The DPWM design has a dead time generator to prevent shoot-throughs. The DPWM has been fabricated using UMC 180-nm CMOS process. The performance and functionality of the DPWM have been verified through the measured comparisons of % duty ratio, dead time ($T_{dt}$ ), and output frequency ($f_{\text {out}}$ ) at input clock frequency ($f_{\text {clk}_{\text {in}}}$ ) equal to 10$\sim $ 100 MHz. The DPWM design has a maximum % duty ratio of 90.6%,$T_{dt}$ = 1.8 ns, and$f_{\text {out}}$ = 6.25 MHz with 3.4-mW power consumption at$f_{\text {clk}_{\text {in}}}$ = 100 MHz.