Junn Yong Loo

dblp:248/5965 · also Junnyong Loo · DBLP profile ↗
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19ranked-venue papers
2as first author
19since 2021 · last 2026
0000-0001-9370-600XORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 7 · 7 since 2021Graphics, computer vision, multimedia, augmented reality and games · 7 · 7 since 2021Applied, interdisciplinary, general and emerging computing · 6 · 1 first-author · 6 since 2021Human-computer interaction and ubiquitous computing · 4 · 1 first-author · 4 since 2021Systems, architecture and hardware · 3 · 3 since 2021
YearPublicationVenuePosition
2026 A Deep Probabilistic Flow-Based Framework for Unsupervised Cross-Domain Soft Sensing
abstract
Industrial soft sensing is crucial for accurate process monitoring through reliable inference of dominant sensor variables. However, developing effective data-driven soft sensor models presents challenges, such as achieving domain adaptability, addressing incomplete sensor labels, and learning stochastic data variability. To overcome these challenges, we propose a deep variational potential flow (DVPF) framework for cross-domain soft sensor modeling, taking into account the lack of sensor labels in the target domain. Our framework introduces sequential variational Bayes with recurrent neural network (RNN) parameterization to address the maximum likelihood estimation problem that characterizes cross-domain soft sensing. Central to the framework is a potential flow that performs unsupervised Bayesian inference on the RNN-extracted features to obtain an exact representation of the intractable posterior distribution. Together, these DVPF components learn domain-adaptable features that effectively capture complex cross-domain process dynamics and data variability. We validate the proposed DVPF on a real industrial multiphase flow process across varying operating modes. The results show that the DVPF demonstrates superior performance in cross-domain soft sensing compared to existing deep feature-based domain adaptation methods.
Junn Yong Loo, Hwa Hui Tew, Fang Yu Leong, Ze Yang Ding, Vishnu Monn Baskaran, Chee-Ming Ting, Chee Pin Tan
IEEE Trans. Ind. Informatics1
2025 ST-HCSS: Deep Spatio-Temporal Hypergraph Convolutional Neural Network for Soft Sensing
abstract
Higher-order sensor networks are more accurate in characterizing the nonlinear dynamics of sensory time-series data in modern industrial settings by allowing multi-node connections beyond simple pairwise graph edges. In light of this, we propose a deep spatio-temporal hypergraph convolutional neural network for soft sensing (ST-HCSS). In particular, our proposed framework is able to construct and leverage a higher-order graph (hypergraph) to model the complex multi-interactions between sensor nodes in the absence of prior structural knowledge. To capture rich spatio-temporal relationships underlying sensor data, our proposed ST-HCSS incorporates stacked gated temporal and hypergraph convolution layers to effectively aggregate and update hypergraph information across time and nodes. Our results validate the superiority of ST-HCSS compared to existing state-of-the-art soft sensors, and demonstrates that the learned hypergraph feature representations aligns well with the sensor data correlations. The code is available at https://github.com/htew0001/ST-HCSS.git
Hwa Hui Tew, Gaoxuan Li, Junn Yong Loo, Chee-Ming Ting, Ze Yang Ding, Chee Pin Tan
ICASSP4
2025 Guided Diffusion For Class-Conditioned Synthesis & Classification Of Microscopic Blood Cell Images
abstract
Microscopic visualization of diseased cells plays a vital role in the diagnosis and understanding of various medical conditions. Recent advances in deep learning generative models have shown remarkable potential as formidable tools for generating high-quality medical images. However, training these models generally requires large, annotated datasets, which are often costly and time-consuming to obtain. To overcome this challenge, we propose a fast-sampling guided score-based diffusion model with a classifier-free guidance strategy for class-conditioned generation of microscopic peripheral blood cell images. Our model achieves a Fréchet Inception Distance (FID) score of 10.24, demonstrating its ability to generate realistic synthetic blood cell images. Furthermore, our experimental results show that augmenting training data with these synthetic images significantly improves classification accuracy compared to relying solely on real data, highlighting the potential of synthetic data augmentation in hematology.
Kar-Ee Hoh, Junn Yong Loo, Yee-Fan Tan, Raphael C.-W. Phan, Chee-Ming Ting
ICIP2
2025 Enhancing Autonomous Driving Perception Under Complex Weather Conditions Through Cyclegan-Based Driving Scene Generation
abstract
Complex and dynamic weather conditions pose significant challenges to the perception capabilities of autonomous driving systems. Existing datasets often lack sufficient cover-age of adverse weather scenarios, resulting in degraded performance of vision-based modules. To address this limitation, we propose a weather-aware driving scene generation framework based on CycleGAN. Our enhanced architecture integrates a multi-scale discriminator, feature matching loss, and channel-level structural similarity (SSIM) loss to generate high-fidelity driving images under various weather conditions. To evaluate the effectiveness of our approach, we perform cross-validation using three widely adopted detection models: YOLOv8, Faster R-CNN, and EfficientDet. The results demonstrate that the generated multi-weather images significantly improve detection accuracy and enhance the robustness and reliability of the perception system in complex environments. In addition to improving dataset diversity, our method preserves fine-grained structural details and enhances the visual quality of the generated scenes.
Litong Liu, Gaoxuan Li, Yaya Huang, Yixuan Dong, Chee-Ming Ting, Junn Yong Loo
ICIP6
2025 Conceptualizing Multi-scale Wavelet Attention and Ray-based Encoding for Human-Object Interaction Detection
abstract
Human-object interaction (HOI) detection is essential for accurately localizing and characterizing interactions between humans and objects, providing a comprehensive understanding of complex visual scenes across various domains. However, existing HOI detectors often struggle to deliver reliable predictions efficiently, relying on resource-intensive training methods and inefficient architectures. To address these challenges, we conceptualize a wavelet attention-like backbone and a novel ray-based encoder architecture tailored for HOI detection. Our wavelet backbone addresses the limitations of expressing middle-order interactions by aggregating discriminative features from the low- and high-order interactions extracted from diverse convolutional filters. Concurrently, the ray-based encoder facilitates multi-scale attention by optimizing the focus of the decoder on relevant regions of interest and mitigating computational overhead. As a result of harnessing the attenuated intensity of learnable ray origins, our decoder aligns query embeddings with emphasized regions of interest for accurate predictions. Experimental results on benchmark datasets, including ImageNet and HICO-DET, showcase the potential of our proposed architecture. The code is publicly available at [https://github.com/henrypay/RayEncoder].
Quan Bi Pay, Vishnu Monn Baskaran, Junn Yong Loo, Koksheik Wong, Simon See
IJCNN3
2025 SpaRTAN: Spatial Reinforcement Token-based Aggregation Network for Visual Recognition
abstract
The resurgence of convolutional neural networks (CNNs) in visual recognition tasks, exemplified by ConvNeXt, has demonstrated their capability to rival transformer-based architectures through advanced training methodologies and ViTinspired design principles. However, both CNNs and transformers exhibit a simplicity bias, favoring straightforward features over complex structural representations. Furthermore, modern CNNs often integrate MLP-like blocks akin to those in transformers, but these blocks suffer from significant information redundancies, necessitating high expansion ratios to sustain competitive performance. To address these limitations, we propose SpaRTAN, a lightweight architectural design that enhances spatial and channel-wise information processing. SpaRTAN employs kernels with varying receptive fields, controlled by kernel size and dilation factor, to capture discriminative multi-order spatial features effectively. A wave-based channel aggregation module further modulates and reinforces pixel interactions, mitigating channel-wise redundancies. Combining the two modules, the proposed network can efficiently gather and dynamically contextualize discriminative features. Experimental results in ImageNet and COCO demonstrate that SpaRTAN achieves remarkable parameter efficiency while maintaining competitive performance. In particular, on the ImageNet-1k benchmark, SpaRTAN achieves 77. 7% accuracy with only 3.8M parameters and approximately 1.0 GFLOPs, demonstrating its ability to deliver strong performance through an efficient design. On the COCO benchmark, it achieves 50.0% AP, surpassing the previous benchmark by 1.2% with only 21.5M parameters. The code is publicly available at [https://github.com/henry-pay/SpaRTAN].
Quan Bi Pay, Vishnu Monn Baskaran, Junn Yong Loo, Koksheik Wong, Simon See
IJCNN3
2025 Contrastive Denoising Variational Recurrent Neural Network for Noise-Agnostic State Modeling of Soft Robotic Systems
abstract
Soft robotic systems are highly susceptible to sensor noise arising from hardware imperfections, environmental disturbances, and the intrinsic compliance of soft materials. These noisy measurements can obscure essential state information and degrade performance in both perception and control tasks. In this paper, we introduce a Contrastive Denoising Variational Recurrent Neural Network (CD-VRNN) designed to address this challenge. The proposed model learns to decompose time-series data into clean signal and noise pathways, improving state estimation accuracy for soft robotic platforms. By incorporating a contrastive objective that enforces a separation between signal-related and noise-related latent representations, the proposed CD-VRNN more effectively isolates noise while retaining critical temporal features. In addition, we incorporate conditional flow-based priors for expressive, state-dependent distributions and skip-connected decoders that preserve subtle signal variations. Experimental results on a pneumatic soft robot and multiple public time-series datasets show that CD-VRNN consistently outperforms existing approaches for denoising and downstream task performance, demonstrating the model’s robustness and strong generalization capacity.
Shageenderan Sapai, Vishnu Monn Baskaran, Junn Yong Loo, Surya Girinatha Nurzaman, Chee Pin Tan
IJCNN3
2025 Contrastive Autoencoder for Robust State Modelling of Soft Robots in Incomplete and Noisy Environments
abstract
Soft robotic systems heavily depend on accurate sensor data for perception and control; however, this data is often corrupted by missing observations, due to partial sensor coverage, communication failures, or occlusions and noisy measurements stemming from hardware imperfections, environmental disturbances, and the intrinsic compliance of soft materials. Such corruption can obscure critical state information, causing unreliable modeling of soft robotics and degrading control accuracy. To address these challenges, we propose a Contrastive Dual-Latent Autoencoder (CDLAE) that jointly handles missing and noisy data in a single end-to-end framework. Our approach leverages an attention based autoencoder architecture with dual latent pathways, where one focuses on capturing the underlying clean signals while the other isolates noise-related components. A contrastive loss encourages strong separation between these pathways, enhancing the model’s ability to filter noise while reconstructing missing values. Additionally, the autoencoder is trained jointly with a downstream predictive network, ensuring that signal imputation is optimized with respect to the ultimate control task. Experimental evaluations on a pneumatic soft robot platform and multiple public time-series datasets demonstrate that CDLAE consistently outperforms existing methods in handling corrupted data, offering robust, high-fidelity reconstructions that significantly improve soft robot perception and control in real-world conditions.
Shageenderan Sapai, Vishnu Monn Baskaran, Junn Yong Loo, Surya Girinatha Nurzaman, Chee Pin Tan
IROS3
2025 T2I-Diff: fMRI Signal Generation via Time-Frequency Image Transform and Classifier-Free Denoising Diffusion Models
Hwa Hui Tew, Junn Yong Loo, Yee-Fan Tan, Hernando C. Ombao, Fuad Noman, Raphael C.-W. Phan, Chee-Ming Ting
MICCAI (3)2
2024 BrainFC-CGAN: A Conditional Generative Adversarial Network for Brain Functional Connectivity Augmentation and Aging Synthesis
abstract
Brain functional connectivity (FC) changes are associated with neuropsychiatric disorders and other underlying factors, such as age and gender. Due to small training sample, data augmentation has been increasingly used for deep learning-based classification of brain FC. Although deep generative models could generate brain FCs to enhance downstream classification, most existing methods neglect the underlying factors involved in the generation process and fail to preserve the subject identity. We propose a novel brain FC conditional Generative Adversarial Network (GAN) called BrainFC-CGAN with specialized layers and filters to preserve the symmetry property and topological structure of brain FCs. We design a FC generator that captures the complex variations between brain FCs, ages, and health statuses to generate synthetic FCs that preserve the subject identity. We categorized true brain FCs into different age groups; an augmented age-specific dataset generated from BrainFC-CGAN is combined with the training set for classification. Experimental results on major depressive disorder (MDD) resting-state functional magnetic resonance imaging data show that the proposed method synthesizes realistic brain FCs of different target age groups, significantly improving downstream classification performance over baseline without augmentation, and also outperforming several state-of-the-art GANs.
Yee-Fan Tan, Junn Yong Loo, Chee-Ming Ting, Fuad Noman, Raphael C.-W. Phan, Hernando C. Ombao
ICASSP2
2024 Deep Multi-Graph Embedded Clustering for Community Detection in FMRI Functional Brain Networks Across Individuals
abstract
Analyzing the community structure of brain networks provides new insights into human brain function. Existing studies broadly use conventional network clustering approaches. While graph neural networks have recently shown promise in modeling brain functional connectivity (FC) networks, their applications to brain community detection still need improvement and further refinement. Moreover, identifying common community structure while resolving the single-subject partitions across multiple individual networks remains underexplored. We propose a Deep Multi-Graph Embedded Clustering (DMGEC) framework to identify shared community partition in brain FC networks over a cohort of individuals. By incorporating the consensus information aggregated across network structures, DMGEC leverages a graph autoencoder to produce consensus-aware latent representations of individual networks, and applies deep embedded clustering on the multi-subject network representation to produce common community assignment of brain nodes. Simulations show superior community recovery by our method compared to conventional approaches, especially for networks with large number of communities. When applied to functional magnetic resonance imaging (fMRI) data, the DMGEC achieves outstanding alikeness over individual partitions, and uncovers group-level differences in brain community motifs between major depressive disorder patients and normal controls.
Kai-Jun See, Chee-Ming Ting, Fuad Noman, Junn Yong Loo, Yee-Fan Tan, Hernando C. Ombao, Raphael C.-W. Phan
ICIP4
2024 A Deep Probabilistic Spatiotemporal Framework for Dynamic Graph Representation Learning with Application to Brain Disorder Identification
Sin-Yee Yap, Junn Yong Loo, Chee-Ming Ting, Fuad Noman, Raphael C.-W. Phan, Adeel Razi, David L. Dowe
IJCAI2
2024 MDHA: Multi-Scale Deformable Transformer with Hybrid Anchors for Multi-View 3D Object Detection
abstract
Multi-view 3D object detection is a crucial component of autonomous driving systems. Contemporary query-based methods primarily depend either on dataset-specific initialization of 3D anchors, introducing bias, or utilize dense attention mechanisms, which are computationally inefficient and unscalable. To overcome these issues, we present MDHA, a novel sparse query-based framework, which constructs adaptive 3D output proposals using hybrid anchors from multi-view, multi-scale image input. Fixed 2D anchors are combined with depth predictions to form 2.5D anchors, which are projected to obtain 3D proposals. To ensure high efficiency, our proposed Anchor Encoder performs sparse refinement and selects the top-k anchors and features. Moreover, while existing multi-view attention mechanisms rely on projecting reference points to multiple images, our novel Circular Deformable Attention mechanism only projects to a single image but allows reference points to seamlessly attend to adjacent images, improving efficiency without compromising on performance. On the nuScenes val set, it achieves 46.4% mAP and 55.0% NDS with a ResNet101 backbone. MDHA significantly outperforms the baseline where anchor proposals are modelled as learnable embeddings. Code is available at https://github.com/NaomiEX/MDHA.
Michelle Adeline, Junn Yong Loo, Vishnu Monn Baskaran
IROS2
2024 Energy-Efficient Hybrid Model Predictive Trajectory Planning for Autonomous Electric Vehicles
abstract
To tackle the twin challenges of limited battery life and lengthy charging durations in electric vehicles (EV s), this paper introduces an Energy-efficient Hybrid Model Predictive Planner (EHMPP), which employs an energy-saving optimization strategy. EHMPP focuses on refining the design of the motion planner to be seamlessly integrated with the existing automatic driving algorithms, without additional hardware. It has been validated through simulation experiments on the Prescan, CarSim, and Matlab platforms, demonstrating that it can increase passive recovery energy by 11.74% and effectively track motor speed and acceleration at optimal power. To sum up, EHMPP not only aids in trajectory planning but also significantly boosts energy efficiency in autonomous EVs.
Xuewen Luo, Gaoxuan Li, Hwa Hui Tew, Junn Yong Loo, Wai Tong Chor, A. S. M. Bakibillah, Ziyuan Zhao, Zhiyu Tao
SMC5
2024 Cross-Domain Transfer Learning Using Attention Latent Features for Multi-Agent Trajectory Prediction
abstract
With the advancements of sensor hardware, traf-fic infrastructure and deep learning architectures, trajectory prediction of vehicles has established a solid foundation in intelligent transportation systems. However, existing solutions are often tailored to specific traffic networks at particular time periods. Consequently, deep learning models trained on one network may struggle to generalize effectively to unseen networks. To address this, we proposed a novel spatial-temporal trajectory prediction framework that performs cross-domain adaption on the attention representation of a Transformer-based model. A graph convolutional network is also integrated to construct dynamic graph feature embeddings that accurately model the complex spatial-temporal interactions between the multi-agent vehicles across multiple traffic domains. The proposed framework is validated on two case studies involving the cross-city and cross-period settings. Experimental results show that our proposed framework achieves superior trajectory prediction and domain adaptation performances over the state-of-the-art models.
Jia Quan Loh, Xuewen Luo, Hwa Hui Tew, Junn Yong Loo, Ze Yang Ding, Susilawati, Chee Pin Tan
SMC5
2024 KANS: Knowledge Discovery Graph Attention Network for Soft Sensing in Multivariate Industrial Processes
abstract
Soft sensing of hard-to-measure variables is often crucial in industrial processes. Current practices rely heavily on conventional modeling techniques that show success in improving accuracy. However, they overlook the non-linear nature, dynamics characteristics, and non-Euclidean dependencies between complex process variables. To tackle these challenges, we present a framework known as a Knowledge discovery graph Attention Network for effective Soft sensing (KANS). Unlike the existing deep learning soft sensor models, KANS can discover the intrinsic correlations and irregular relationships between the multivariate industrial processes without a predefined topology. First, an unsupervised graph structure learning method is introduced, incorporating the cosine similarity between different sensor embedding to capture the correlations between sensors. Next, we present a graph attention-based representation learning that can compute the multivariate data parallelly to enhance the model in learning complex sensor nodes and edges. To fully explore KANS, knowledge discovery analysis has also been conducted to demonstrate the interpretability of the model. Experimental results demonstrate that KANS significantly outperforms all the baselines and state-of-the-art methods in soft sensing performance. Furthermore, the analysis shows that KANS can find sensors closely related to different process variables without domain knowledge, significantly improving soft sensing accuracy.
Hwa Hui Tew, Gaoxuan Li, Xuewen Luo, Junn Yong Loo, Chee-Ming Ting, Ze Yang Ding, Chee Pin Tan
SMC5
2024 Sigma-Point Kalman Filter With Nonlinear Unknown Input Estimation via Optimization and Data-Driven Approach for Dynamic Systems
abstract
Most works on joint state and unknown input (UI) estimation require the assumption that the UIs are linear; this is potentially restrictive as it does not hold in many intelligent autonomous systems. To overcome this restriction and circumvent the need to linearize the system, we propose a derivative-free UI sigma-point Kalman filter (SPKF-nUI), where the SPKF is interconnected with a general nonlinear UI estimator that can be implemented via nonlinear optimization and data-driven approaches. The nonlinear UI estimator uses the posterior state estimate, which is less susceptible to state prediction error. In addition, we introduce a joint sigma-point transformation scheme to incorporate both the state and UI uncertainties in the estimation of SPKF-nUI. An in-depth stochastic stability analysis proves that the proposed SPKF-nUI yields exponentially converging estimation error bounds under reasonable assumptions. Finally, two case studies are carried out on a simulation-based rigid robot and a physical soft robot, i.e., the robots made of soft materials with complex dynamics, to validate the effectiveness of the proposed filter on nonlinear dynamic systems. Our results demonstrate that the proposed SPKF-nUI achieves the lowest state and UI estimation errors when compared to the existing nonlinear state-UI filters.
Junn Yong Loo, Ze Yang Ding, Vishnu Monn Baskaran, Surya Girinatha Nurzaman, Chee Pin Tan
IEEE Trans. Syst. Man Cybern. Syst.1
2023 Cross-domain Transfer Learning and State Inference for Soft Robots via a Semi-supervised Sequential Variational Bayes Framework
abstract
Recently, data-driven models such as deep neural networks have shown to be promising tools for modelling and state inference in soft robots. However, voluminous amounts of data are necessary for deep models to perform effectively, which requires exhaustive and quality data collection, particularly of state labels. Consequently, obtaining labelled state data for soft robotic systems is challenged for various reasons, including difficulty in the sensorization of soft robots and the inconvenience of collecting data in unstructured environments. To address this challenge, in this paper, we propose a semi-supervised sequential variational Bayes (DSVB) framework for transfer learning and state inference in soft robots with missing state labels on certain robot configurations. Considering that soft robots may exhibit distinct dynamics under different robot configurations, a feature space transfer strategy is also incorporated to promote the adaptation of latent features across multiple configurations. Unlike existing transfer learning approaches, our proposed DSVB employs a recurrent neural network to model the nonlinear dynamics and temporal coherence in soft robot data. The proposed framework is validated on multiple setup configurations of a pneumatic-based soft robot finger. Experimental results on four transfer scenarios demonstrate that DSVB performs effective transfer learning and accurate state inference amidst missing state labels.
Shageenderan Sapai, Junn Yong Loo, Ze Yang Ding, Chee Pin Tan, Raphael C.-W. Phan, Vishnu Monn Baskaran, Surya Girinatha Nurzaman
ICRA2
2023 A Zero-Shot Soft Sensor Modeling Approach Using Adversarial Learning for Robustness Against Sensor Fault
abstract
Soft sensors are widely used in many industrial systems to monitor key variables that are difficult to measure, using measurements from other available physical sensors. Because physical sensors are susceptible to faults, it is crucial for soft sensor models to be robust against them. Recently, deep learning has shown promising results in developing data-driven soft sensors for various applications. However, existing learning-based soft sensors are still vulnerable to sensor faults, which could deteriorate the performance of the models. In this article, we propose a deep learning-based modeling framework for developing soft sensor models that are robust to sensor faults. Due to the difficulty in obtaining datasets that cover all possible sensor fault characteristics, the proposed framework is developed to be zero-shot such that the model can be trained with only fault-free dataset without requiring any sensor fault patterns, thus greatly saving the time and resources needed to collect such data. Instead, adversarial examples are used as a proxy for faulty sensor inputs so that the model can learn to be adaptive through the proposed two-stage, uncertainty-aware recurrent neural network architecture. We demonstrate our approach to the TE benchmark process and a real industrial multiphase flow process and show that robustness is achieved as the accuracy does not degrade significantly when sensor faults are present during the model evaluation.
Ze Yang Ding, Junn Yong Loo, Surya Girinatha Nurzaman, Chee Pin Tan, Vishnu Monn Baskaran
IEEE Trans. Ind. Informatics2