Richard Cornelius Suwandi

I am a PhD student at CUHK-Shenzhen, advised by Prof. Feng Yin and Prof. Tsung-Hui Chang. Prior to my PhD, I obtained my BSc degree in Statistics from CUHK-Shenzhen. My current research explores:

Bayesian optimization for sample-efficient black-box optimization and sequential decision-making
Gaussian processes for probabilisitic modeling and uncertainty quantification
Foundation models for open-ended algorithm discovery and generative design in science & engineering

If you are interested in collaborating or discussing research ideas, feel free to reach out via email.

News

Dec 01, 2025

🛫 Flew to San Diego for NeurIPS 2025! If you are also attending, feel free to reach out to chat or grab a coffee

Nov 17, 2025

🏆 Selected as the recipient of the Guangdong Government Outstanding International Student Scholarship

Oct 09, 2025

✨ Invited to serve as a reviewer for ICASSP 2026!

Sep 24, 2025

✨ Invited to serve as a reviewer for ICLR 2026!

Sep 19, 2025

🎉 Our paper titled “Adaptive Kernel Design for Bayesian Optimization Is a Piece of CAKE with LLMs” has been accepted to NeurIPS 2025!

Sep 15, 2025

💻 Joined Dria as a Research Intern to work on evolutionary coding agents!

Jul 20, 2025

🏆 Won the 2nd prize award at the 2025 Doctoral Research and AI Innovation Conference held by CUHK-Shenzhen!

May 09, 2025

📚 Our latest work on grid spectral mixture product (GSMP) kernel has been featured in the “Machine Learning: From the Classics to Deep Networks, Transformers and Diffusion Models” book!

Jan 28, 2025

🎉 Our paper titled “Sparsity-Aware Distributed Learning for Gaussian Processes with Linear Multiple Kernel” has been accepted to IEEE TNNLS!

Sep 30, 2024

🏆 Selected as the recipient of the IEEE Signal Processing Society Scholarship!

Sep 10, 2024

📝 My blog post on “Optimize Your Signal Processing with Bayesian Optimization” has been published on IEEE SPS!

Sep 09, 2024

✨ Invited to serve as a reviewer for ICLR 2025!

Jul 17, 2024

🏆 Selected as the recipient of the Shenzhen Universiade International Scholarship Foundation Program!

Aug 14, 2023

🎓 Joined Bayesian Learning for Signal Processing Group as a PhD student!

May 04, 2022

🎉 Our paper titled “Gaussian Process Regression with Grid Spectral Mixture Kernel: Distributed Learning for Multidimensional Data” has been accepted to FUSION 2022!

Jan 30, 2021

🎉 Our paper titled “Demystifying Model Averaging for Communication-Efficient Federated Matrix Factorization” has been accepted to ICASSP 2021!

Selected Works

2025

ABSTRACT PAPER CODE POSTER

Adaptive Kernel Design for Bayesian Optimization Is a Piece of CAKE with LLMs

Richard Cornelius Suwandi, Feng Yin, Juntao Wang, 3 more authors

39th Conference on Neural Information Processing Systems (NeurIPS), 2025

Abstract

The efficiency of Bayesian optimization (BO) relies heavily on the choice of the Gaussian process (GP) kernel, which plays a central role in balancing exploration and exploitation under limited evaluation budgets. Traditional BO methods often rely on fixed or heuristic kernel selection strategies, which can result in slow convergence or suboptimal solutions when the chosen kernel is poorly suited to the underlying objective function. To address this limitation, we propose a freshly-baked Context-Aware Kernel Evolution (CAKE) to enhance BO with large language models (LLMs). Concretely, CAKE leverages LLMs as the crossover and mutation operators to adaptively generate and refine GP kernels based on the observed data throughout the optimization process. To maximize the power of CAKE, we further propose BIC-Acquisition Kernel Ranking (BAKER) to select the most effective kernel through balancing the model fit measured by the Bayesian information criterion (BIC) with the expected improvement at each iteration of BO. Extensive experiments demonstrate that our fresh CAKE-based BO method consistently outperforms established baselines across a range of real-world tasks, including hyperparameter optimization, controller tuning, and photonic chip design. Our code is publicly available at https://github.com/richardcsuwandi/cake.
2025

ABSTRACT PAPER CODE

Sparsity-Aware Distributed Learning for Gaussian Processes with Linear Multiple Kernel

Richard Cornelius Suwandi, Zhidi Lin, Feng Yin, 2 more authors Zhiguo Wang, Sergios Theodoridis

IEEE Transactions on Neural Networks and Learning Systems, 2025

Abstract

Gaussian processes (GPs) stand as crucial tools in machine learning and signal processing, with their effectiveness hinging on kernel design and hyper-parameter optimization. This paper presents a novel GP linear multiple kernel (LMK) and a generic sparsity-aware distributed learning framework to optimize the hyper-parameters. The newly proposed grid spectral mixture (GSM) kernel is tailored for multi-dimensional data, effectively reducing the number of hyper-parameters while maintaining good approximation capabilities. We further demonstrate that the associated hyper-parameter optimization of this kernel yields sparse solutions. To exploit the inherent sparsity property of the solutions, we introduce the Sparse LInear Multiple Kernel Learning (SLIM-KL) framework. The framework incorporates a quantized alternating direction method of multipliers (ADMM) scheme for collaborative learning among multiple agents, where the local optimization problem is solved using a distributed successive convex approximation (DSCA) algorithm. SLIM-KL effectively manages large-scale hyper-parameter optimization for the proposed kernel, simultaneously ensuring data privacy and minimizing communication costs. Theoretical analysis establishes convergence guarantees for the learning framework, while experiments on diverse datasets demonstrate the superior prediction performance and efficiency of our proposed methods.
2022

ABSTRACT PAPER CODE SLIDES

Gaussian process regression with grid spectral mixture kernel: Distributed learning for multidimensional data

Richard Cornelius Suwandi, Zhidi Lin, Yiyong Sun, 3 more authors Zhiguo Wang, Lei Cheng, Feng Yin

25th International Conference on Information Fusion (FUSION), 2022

Abstract

Kernel design for Gaussian processes (GPs) along with the associated hyper-parameter optimization is a challenging problem. In this paper, we propose a novel grid spectral mixture (GSM) kernel design for GPs that can automatically fit multidimensional data with affordable model complexity and superior modeling capability. To alleviate the computational complexity due to the curse of dimensionality, we leverage a multicore computing environment to optimize the kernel hyper-parameters in a distributed manner. We further propose a doubly distributed learning algorithm based on the alternating direction method of multipliers (ADMM) which enables multiple agents to learn the kernel hyper-parameters collaboratively. The doubly distributed learning algorithm is shown to be effective in reducing the overall computational complexity while preserving data privacy during the learning process. Experiments on various one-dimensional and multidimensional data sets demonstrate that the proposed kernel design yields superior training and prediction performance compared to its competitors.
2021

ABSTRACT PAPER POSTER

Demystifying model averaging for communication-efficient federated matrix factorization

Shuai Wang, Richard Cornelius Suwandi, Tsung-Hui Chang

46th IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2021

Abstract

Federated learning (FL) is encountered with the challenge of training a model in massive and heterogeneous networks. Model averaging (MA) has become a popular FL paradigm where parallel (stochastic) gradient descent (GD) is run on a small sampled subset of clients multiple times before uploading the local models to a server for averaging, which has been proven effective in reducing the communication cost for achieving a good model. However, MA has not been considered for the important matrix factorization (MF) model, which has vast signal processing and machine learning applications. In this paper, we investigate the federated MF problem and propose a new MA based algorithm, named FedMAvg, by judiciously combining the alternating minimization technique and MA. Through analysis, we show that gradually decreasing the number of local GD and only allowing partial clients to communicate with the server can greatly reduce the communication cost, especially in heterogeneous networks with non-i.i.d. data. Experimental results by applying FedMAvg to data clustering and item recommendation tasks demonstrate its efficacy in terms of both task performance and communication efficiency.

News

Selected Works

Adaptive Kernel Design for Bayesian Optimization Is a Piece of CAKE with LLMs

Abstract

Sparsity-Aware Distributed Learning for Gaussian Processes with Linear Multiple Kernel

Abstract

Gaussian process regression with grid spectral mixture kernel: Distributed learning for multidimensional data

Abstract

Demystifying model averaging for communication-efficient federated matrix factorization

Abstract

Media Coverage