Wan Du

Dr. Wan Du

Department of Computer Science and Engineering, School of Engineering, The University of California, Merced, CA, USA

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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17 August 2018 in IEEE Transactions on Multimedia
Verified
Journal Article
Open access
ZSZhenfeng Shao
Zhenfeng Shao
WWWenjing Wu
Wenjing Wu
Zhongyuan WangZhongyuan Wang
Zhongyuan Wang
Wan DuWan Du
Wan Du
CLChengyuan Li
Chengyuan Li
In this paper, we introduce a new large-scale dataset of ships, called SeaShips, which is designed for training and evaluating ship object detection algorithms. The dataset currently consists of 31 455 images and covers six common ship types (ore carrier, bulk cargo carrier, general cargo ship, container ship, fishing boat, and passenger ship). All of the images are from about 10 080 real-world video segments, which are acquired by the monitoring cameras in a deployed coastline video surveillance system. They are carefully selected to mostly cover all possible imaging variations, for example, different scales, hull parts, illumination, viewpoints, backgrounds, and occlusions. All images are annotated with ship-type labels and high-precision bounding boxes. Based on the SeaShips dataset, we present the performance of three detectors as a baseline to do the following: 1) elementarily summarize the difficulties of the dataset for ship detection; 2) show detection results for researchers using the dataset; and 3) make a comparison to identify the strengths and weaknesses of the baseline algorithms. In practice, the SeaShips dataset would hopefully advance research and applications on ship detection.

25 October 2019 in IEEE Communications Surveys & Tutorials
Verified
Journal Article
Closed access
JSJothi Prasanna Shanmuga Sundaram
Jothi Prasanna Shanmuga Sundaram
Wan DuWan Du
Wan Du
Zhiwei ZhaoZhiwei Zhao
Zhiwei Zhao

7 February 2019 in IEEE Transactions on Circuits and Systems for Video Technology
Verified
Journal Article
Closed access
ZSZhenfeng Shao
Zhenfeng Shao
LWLinggang Wang
Linggang Wang
Zhongyuan WangZhongyuan Wang
Zhongyuan Wang
Wan DuWan Du
Wan Du
WWWenjing Wu
Wenjing Wu
Real-time detection of inshore ships plays an essential role in the efficient monitoring and management of maritime traffic and transportation for port management. Current ship detection methods which are mainly based on remote sensing images or radar images hardly meet real-time requirement due to timeliness of image acquisition. In this paper, we propose to use visual images captured by an on-land surveillance camera network to achieve real-time detection. However, due to the complex background of visual images and the diversity of ship categories, the existing convolution neural network (CNN) based methods are either inaccurate or slow. To achieve high detection accuracy and real-time performance simultaneously, we propose a saliency-aware CNN framework for ship detection, comprising comprehensive ship discriminative features, such as deep feature, saliency map and coastline prior. This model uses CNN to predict the category and the position of ships, and uses the global contrast based salient region detection to correct the location. We also extract coastline information and respectively incorporate it into CNN and saliency detection to obtain more accurate ship locations. We implement our model on Darknet under CUDA 8.0 and CUDNN V5 and use a real-world visual image dataset for training and evaluation. The experimental results show that our model outperforms representative counterparts (Faster R-CNN, SSD, and YOLOv2) in terms of accuracy and speed.

12 November 2023
Verified
Conference Paper
Open access
XDXianzhong Ding
Xianzhong Ding
LCLe Chen
Le Chen
MEMurali Emani
Murali Emani
CLChunhua Liao
Chunhua Liao
PLPeihung Lin
Peihung Lin
Wan DuWan Du
Wan Du
Large Language Models (LLMs), including the LLaMA model, have exhibited their efficacy across various general-domain natural language processing (NLP) tasks. However, their performance in high-performance computing (HPC) domain tasks has been less than optimal due to the specialized expertise required to interpret the model’s responses. In response to this challenge, we propose HPC-GPT, a novel LLaMA-based model that has been supervised fine-tuning using generated QA (Question-Answer) instances for the HPC domain. To evaluate its effectiveness, we concentrate on two HPC tasks: managing AI models and datasets for HPC, and data race detection. By employing HPC-GPT, we demonstrate comparable performance with existing methods on both tasks, exemplifying its excellence in HPC-related scenarios. Our experiments on open-source benchmarks yield extensive results, underscoring HPC-GPT’s potential to bridge the performance gap between LLMs and HPC-specific tasks. With HPC-GPT, we aim to pave the way for LLMs to excel in HPC domains, simplifying the utilization of language models in complex computing applications.

8 July 2024 in ACM Transactions on Sensor Networks
Verified
Journal Article
Open access
XDXianzhong Ding
Xianzhong Ding
Wan DuWan Du
Wan Du
Agricultural irrigation is a significant contributor to freshwater consumption. However, the current irrigation systems used in the field are not efficient. They rely mainly on soil moisture sensors and the experience of growers but do not account for future soil moisture loss. Predicting soil moisture loss is challenging because it is influenced by numerous factors, including soil texture, weather conditions, and plant characteristics. This article proposes a solution to improve irrigation efficiency, which is called DRLIC (deep reinforcement learning for irrigation control). DRLIC is a sophisticated irrigation system that uses deep reinforcement learning (DRL) to optimize its performance. The system employs a neural network, known as the DRL control agent, which learns an optimal control policy that considers both the current soil moisture measurement and the future soil moisture loss. We introduce an irrigation reward function that enables our control agent to learn from previous experiences. However, there may be instances in which the output of our DRL control agent is unsafe, such as irrigating too much or too little. To avoid damaging the health of the plants, we implement a safety mechanism that employs a soil moisture predictor to estimate the performance of each action. If the predicted outcome is deemed unsafe, we perform a relatively conservative action instead. To demonstrate the real-world application of our approach, we develop an irrigation system that comprises sprinklers, sensing and control nodes, and a wireless network. We evaluate the performance of DRLIC by deploying it in a testbed consisting of six almond trees. During a 15-day in-field experiment, we compare the water consumption of DRLIC with a widely used irrigation scheme. Our results indicate that DRLIC outperforms the traditional irrigation method by achieving water savings of up to 9.52%.

14 June 2024 in IEEE Transactions on Automation Science and Engineering
Verified
Journal Article
Closed access
XDXianzhong Ding
Xianzhong Ding
ACAlberto Cerpa
Alberto Cerpa
Wan DuWan Du
Wan Du
The application of reinforcement learning in controlling Heating, Ventilation, and Air Conditioning (HVAC) systems has been extensively researched. Existing studies primarily focus on Model-Free Reinforcement Learning (MFRL), which involves trial-and-error interactions with real buildings to train the agent. However, MFRL encounters a significant challenge: it requires a large amount of training data to achieve satisfactory performance. While simulation models have been used to generate training data and expedite the training process, they necessitate high-fidelity building models that are difficult to calibrate. As a result, Model-Based Reinforcement Learning (MBRL) has been employed for HVAC control. Although MBRL demonstrates remarkable sample efficiency, it often falls short in terms of asymptotic control performance, particularly in achieving substantial energy savings while ensuring occupants’ thermal comfort. In this study, we conduct experiments to analyze the limitations of current MBRL-based HVAC control methods, focusing on model uncertainty and controller effectiveness. Leveraging the insights gained from these experiments, we develop, an innovative MBRL-based HVAC control system that combines high control performance with exceptional sample efficiency. learns the dynamics of the building by employing an ensemble of environment-conditioned neural networks and utilizes a novel control method called Model Predictive Path Integral (MPPI) for HVAC control. MPPI generates candidate action sequences using an importance sampling weighted algorithm, which is well-suited for multi-zone buildings with high state and action dimensions. We evaluate using EnergyPlus simulations in a five-zone office building, and the results demonstrate that achieves 8.23% higher energy savings compared to the state-of-the-art MBRL solution while maintaining comparable thermal comfort. Moreover, significantly reduces the required training data set by an order of magnitude (10.52 $\times$ ) while delivering performance on par with MFRL approaches. Note to Practitioners —Our research addresses a critical challenge in HVAC control, offering an innovative solution to enhance the data efficiency of HVAC systems while optimizing energy usage. Traditional approaches, such as Model-Free Reinforcement Learning, often require a large volume of real-world data. Our primary focus is improving the effectiveness of HVAC control, a vital aspect of building management that directly affects energy consumption and occupant well-being. We introduce, a Model-Based Reinforcement Learning system designed to significantly improve energy savings while maintaining thermal comfort. achieves remarkable results, offering exceptional sample efficiency and substantially reducing the required training data. Our research leverages an ensemble of environment-conditioned neural networks and employs Model Predictive Path Integral in HVAC control. While presents notable benefits, it also has limitations. Further research and development are required to optimize its performance across different building environments and specific use cases. Future directions should focus on addressing the safety challenges associated with real-world deployment. Beyond HVAC control, the principles and methods explored in this research have potential applications in various automation domains, such as robotics, industrial automation, and manufacturing processes.