Digital Signal Processing
Mel-Frequency Cepstral Coefficients · Fast Fourier Transform

Robotics Engineer · Jakarta
Engineering intelligent systems for the real world
I’m Charles, an Automotive and Robotics Engineering student with a strong interest in robotics, autonomous systems, industrial automation, and software development. I enjoy building things that connect the physical and digital worlds — whether it’s an autonomous drone, a robotic welding system, a mecanum rover, or a manufacturing dashboard. My work often takes me across different fields, from embedded systems and control engineering to machine learning and full-stack development. I like learning by building, experimenting, and solving real engineering problems.
What I work with
Mel-Frequency Cepstral Coefficients · Fast Fourier Transform
Rover · Manipulator
Object detection · Inverse Perspective Mapping
Support Vector Machine · Naive Bayes · Logistic Regression · Hyperparameter tunning
Selected work
Focused on clean interfaces, strong technical foundations, and details that make a difference in use.
View all projectsPublished projects will appear here.
Recent publications
A short selection of published writing and technical documentation.
View all publicationsThis study explores next-day gold price direction prediction using supervised machine learning. Daily Indonesian gold price data are transformed into features such as log returns, moving-average ratios, and short-term volatility, then classified using Naïve Bayes, Logistic Regression, and Support Vector Machine. Among the evaluated models, Logistic Regression achieved the strongest overall performance, with an F1-score of 0.737 and accuracy of 58.3%, showing the potential of engineered financial features for short-term directional forecasting.
This research presents an embedded system for early sleep apnea screening by combining physiological monitoring with audio-based snoring detection. The system uses MFCC feature extraction and a Convolutional Neural Network (CNN) to classify snoring sounds, while sensors connected to an ESP32 and Raspberry Pi monitor parameters such as SpO₂, heart rate, respiratory activity, and body movement. The optimized CNN achieved 99.38% training accuracy and 98.50% testing accuracy, demonstrating the system’s potential as a portable, non-invasive solution for preliminary sleep apnea monitoring outside clinical environments.
V-AIR (Voice-Activated Intelligent Remote) is a voice-based UAV control system designed to make drone operation more intuitive and accessible. The system uses Mel-Frequency Cepstral Coefficients (MFCC) for speech feature extraction and an SVM with an RBF kernel to recognize six basic flight commands: takeoff, land, forward, backward, left, and right. The developed model achieved 98.66% training accuracy and 85.23% testing accuracy, demonstrating the potential of voice commands as a practical hands-free alternative to conventional UAV controllers.
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