Wenny Ramadha

Ms. Wenny Ramadha

PhD Student and Researcher
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 February 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Yung-Hui LiYung-Hui Li
Yung-Hui Li
Wenny RamadhaWenny Ramadha
Wenny Ramadha
Muhammad Saqlain AslamMuhammad Saqlain Aslam
Muhammad Saqlain Aslam
CCChing-Chun Chang
Ching-Chun Chang
Iris segmentation plays an important and significant role in the iris recognition system. The prerequisite for accurate iris recognition is the correctness of iris segmentation. However, the efficiency and robustness of traditional iris segmentation methods are severely challenged in a non-cooperative environment because of unfavorable factors, for instance, occlusion, blur, low resolution, off-axis, motion, and specular reflections. All of the above factors seriously reduce the accuracy of iris segmentation. In this paper, we present a novel iris segmentation algorithm that localizes the outer and inner boundaries of the iris image. We propose a neural network model called “Interleaved Residual U-Net” (IRUNet) for semantic segmentation and iris mask synthesis. The K-means clustering is applied to select saliency points set in order to recover the outer boundary of the iris, whereas the inner border is recovered by selecting another set of saliency points on the inner side of the mask. Experimental results demonstrate that the proposed iris segmentation algorithm can achieve the mean IOU value of 98.9% and 97.7% for inner and outer boundary estimation, respectively, which outperforms the existing approaches on the challenging CASIA-Iris-Thousand database.

9 March 2022 in Sensors
Verified
Journal Article
Open access
PDF file
Wenny RamadhaWenny Ramadha
Wenny Ramadha
SLShen-Hsuan Liu
Shen-Hsuan Liu
Muhammad Saqlain AslamMuhammad Saqlain Aslam
Muhammad Saqlain Aslam
Yung-Hui LiYung-Hui Li
Yung-Hui Li
Chin-Chen ChangChin-Chen Chang
Chin-Chen Chang
JWJia-Ching Wang
Jia-Ching Wang
Iris segmentation plays a pivotal role in the iris recognition system. The deep learning technique developed in recent years has gradually been applied to iris recognition techniques. As we all know, applying deep learning techniques requires a large number of data sets with high-quality manual labels. The larger the amount of data, the better the algorithm performs. In this paper, we propose a self-supervised framework utilizing the pix2pix conditional adversarial network for generating unlimited diversified iris images. Then, the generated iris images are used to train the iris segmentation network to achieve state-of-the-art performance. We also propose an algorithm to generate iris masks based on 11 tunable parameters, which can be generated randomly. Such a framework can generate an unlimited amount of photo-realistic training data for down-stream tasks. Experimental results demonstrate that the proposed framework achieved promising results in all commonly used metrics. The proposed framework can be easily generalized to any object segmentation task with a simple fine-tuning of the mask generation algorithm.

4 July 2024 in Sensors
Verified
Journal Article
Open access
JWJianHong Wang
JianHong Wang
PLPhuong Thi Le
Phuong Thi Le
WBWeng-Sheng Bee
Weng-Sheng Bee
Wenny RamadhaWenny Ramadha
Wenny Ramadha
Ming-Hsiang SuMing-Hsiang Su
Ming-Hsiang Su
JWJia-Ching Wang
Jia-Ching Wang
In recent years, embedded system technologies and products for sensor networks and wearable devices used for monitoring people’s activities and health have become the focus of the global IT industry. In order to enhance the speech recognition capabilities of wearable devices, this article discusses the implementation of audio positioning and enhancement in embedded systems using embedded algorithms for direction detection and mixed source separation. The two algorithms are implemented using different embedded systems: direction detection developed using TI TMS320C6713 DSK and mixed source separation developed using Raspberry Pi 2. For mixed source separation, in the first experiment, the average signal-to-interference ratio (SIR) at 1 m and 2 m distances was 16.72 and 15.76, respectively. In the second experiment, when evaluated using speech recognition, the algorithm improved speech recognition accuracy to 95%.

17 October 2025 in Sensors
Verified
Journal Article
Open access
PDF file
JHJi-Long He
Ji-Long He
YCYing-Hua Chen
Ying-Hua Chen
Wenny RamadhaWenny Ramadha
Wenny Ramadha
CHChung-I Huang
Chung-I Huang
Ming-Hsiang SuMing-Hsiang Su
Ming-Hsiang Su
JWJia-Ching Wang
Jia-Ching Wang
The field of autonomous driving has seen continuous advances, yet achieving higher levels of automation in real-world applications remains challenging. A critical requirement for autonomous navigation is accurate map construction, particularly in novel and unstructured environments. In recent years, Simultaneous Localization and Mapping (SLAM) has evolved to support diverse sensor modalities, with some implementations incorporating machine learning to improve performance. However, these approaches often demand substantial computational resources. The key challenge lies in achieving efficiency within resource-constrained environments while minimizing errors that could degrade downstream tasks. This paper presents an enhanced ORB-SLAM2 (Oriented FAST and Rotated BRIEF Simultaneous Localization and Mapping, version 2) algorithm implemented on a Raspberry Pi 3 (ARM A53 CPU) to improve mapping performance under limited computational resources. ORB-SLAM2 comprises four main stages: Tracking, Local Mapping, Loop Closing, and Full Bundle Adjustment (BA). The proposed improvements include employing a more efficient feature descriptor to increase stereo feature-matching rates and optimizing loop-closing parameters to reduce accumulated errors. Experimental results demonstrate that the proposed system achieves notable improvements on the Raspberry Pi 3 platform. For monocular SLAM, RMSE is reduced by 18.11%, mean error by 22.97%, median error by 29.41%, and maximum error by 17.18%. For stereo SLAM, RMSE decreases by 0.30% and mean error by 0.38%. Furthermore, the ROS topic frequency stabilizes at 10 Hz, with quad-core CPU utilization averaging approximately 90%. These results indicate that the system satisfies real-time requirements while maintaining a balanced trade-off between accuracy and computational efficiency under resource constraints.

27 February 2026 in Electronics
Verified
Journal Article
Open access
PDF file
KLKai-Wen Liang
Kai-Wen Liang
Wenny RamadhaWenny Ramadha
Wenny Ramadha
WLWei-Hung Liu
Wei-Hung Liu
YLYen-Ting Lai
Yen-Ting Lai
BPBach-Tung Pham
Bach-Tung Pham
PCPao-Chi Chang
Pao-Chi Chang
Wind noise is a pervasive and non-stationary form of interference in outdoor audio recordings, posing a significant challenge for speech enhancement systems. To address this problem, this paper proposes a speech separation-based wind noise reduction framework termed Dual-mask permutation-invariant training (DMPIT). Building upon the dual-masking concept, the key contribution of DMPIT lies in embedding the dual-mask structure within a permutation-invariant training (PIT) framework and reformulating the loss function to better align with speech-oriented noise reduction objectives. Specifically, two supervised masks are jointly optimized: a speech mask that directly estimates the target speech from the mixture and a noise mask that isolates the wind noise component. Assuming that the mixture consists solely of speech and wind noise, the training process computes the loss using both estimated components and the corresponding clean speech. Since wind noise is not a signal of interest, the estimated noise is subtracted from the mixture to obtain a residual speech signal, which is then used to refine the direct speech estimate. The final enhanced speech output is produced by fusing the direct and residual speech estimates through a weighted combination. The experimental results demonstrate that DMPIT consistently outperforms conventional single-mask and single-channel wind noise reduction methods in terms of speech quality and noise suppression.

1 October 2026 in IEEE Sensors Journal
Verified
Journal Article
Closed access
Wenny RamadhaWenny Ramadha
Wenny Ramadha
SYShih-Tsung Yang
Shih-Tsung Yang
BPBach-Tung Pham
Bach-Tung Pham
PCPo-Cheng Chan
Po-Cheng Chan
ADAn Dang
An Dang
JWJia-Ching Wang
Jia-Ching Wang