Energy
ASKCOS: an open source software suite for synthesis planning
Tu, Zhengkai, Choure, Sourabh J., Fong, Mun Hong, Roh, Jihye, Levin, Itai, Yu, Kevin, Joung, Joonyoung F., Morgan, Nathan, Li, Shih-Cheng, Sun, Xiaoqi, Lin, Huiqian, Murnin, Mark, Liles, Jordan P., Struble, Thomas J., Fortunato, Michael E., Liu, Mengjie, Green, William H., Jensen, Klavs F., Coley, Connor W.
The advancement of machine learning and the availability of large-scale reaction datasets have accelerated the development of data-driven models for computer-aided synthesis planning (CASP) in the past decade. Here, we detail the newest version of ASKCOS, an open source software suite for synthesis planning that makes available several research advances in a freely available, practical tool. Four one-step retrosynthesis models form the basis of both interactive planning and automatic planning modes. Retrosynthetic planning is complemented by other modules for feasibility assessment and pathway evaluation, including reaction condition recommendation, reaction outcome prediction, and auxiliary capabilities such as solubility prediction and quantum mechanical descriptor prediction. ASKCOS has assisted hundreds of medicinal, synthetic, and process chemists in their day-to-day tasks, complementing expert decision making. It is our belief that CASP tools like ASKCOS are an important part of modern chemistry research, and that they offer ever-increasing utility and accessibility.
DFF: Decision-Focused Fine-tuning for Smarter Predict-then-Optimize with Limited Data
Yang, Jiaqi, Liang, Enming, Su, Zicheng, Zou, Zhichao, Zhen, Peng, Guo, Jiecheng, Ma, Wanjing, An, Kun
Decision-focused learning (DFL) offers an end-to-end approach to the predict-then-optimize (PO) framework by training predictive models directly on decision loss (DL), enhancing decision-making performance within PO contexts. However, the implementation of DFL poses distinct challenges. Primarily, DL can result in deviation from the physical significance of the predictions under limited data. Additionally, some predictive models are non-differentiable or black-box, which cannot be adjusted using gradient-based methods. To tackle the above challenges, we propose a novel framework, Decision-Focused Fine-tuning (DFF), which embeds the DFL module into the PO pipeline via a novel bias correction module. DFF is formulated as a constrained optimization problem that maintains the proximity of the DL-enhanced model to the original predictive model within a defined trust region. We theoretically prove that DFF strictly confines prediction bias within a predetermined upper bound, even with limited datasets, thereby substantially reducing prediction shifts caused by DL under limited data. Furthermore, the bias correction module can be integrated into diverse predictive models, enhancing adaptability to a broad range of PO tasks. Extensive evaluations on synthetic and real-world datasets, including network flow, portfolio optimization, and resource allocation problems with different predictive models, demonstrate that DFF not only improves decision performance but also adheres to fine-tuning constraints, showcasing robust adaptability across various scenarios.
CarbonChat: Large Language Model-Based Corporate Carbon Emission Analysis and Climate Knowledge Q&A System
Cao, Zhixuan, Han, Ming, Wang, Jingtao, Jia, Meng
As the impact of global climate change intensifies, corporate carbon emissions have become a focal point of global attention. In response to issues such as the lag in climate change knowledge updates within large language models, the lack of specialization and accuracy in traditional augmented generation architectures for complex problems, and the high cost and time consumption of sustainability report analysis, this paper proposes CarbonChat: Large Language Model-based corporate carbon emission analysis and climate knowledge Q&A system, aimed at achieving precise carbon emission analysis and policy understanding.First, a diversified index module construction method is proposed to handle the segmentation of rule-based and long-text documents, as well as the extraction of structured data, thereby optimizing the parsing of key information.Second, an enhanced self-prompt retrieval-augmented generation architecture is designed, integrating intent recognition, structured reasoning chains, hybrid retrieval, and Text2SQL, improving the efficiency of semantic understanding and query conversion.Next, based on the greenhouse gas accounting framework, 14 dimensions are established for carbon emission analysis, enabling report summarization, relevance evaluation, and customized responses.Finally, through a multi-layer chunking mechanism, timestamps, and hallucination detection features, the accuracy and verifiability of the analysis results are ensured, reducing hallucination rates and enhancing the precision of the responses.
Establishing baselines for generative discovery of inorganic crystals
Szymanski, Nathan J., Bartel, Christopher J.
Generative artificial intelligence offers a promising avenue for materials discovery, yet its advantages over traditional methods remain unclear. In this work, we introduce and benchmark two baseline approaches - random enumeration of charge-balanced prototypes and data-driven ion exchange of known compounds - against three generative models: a variational autoencoder, a large language model, and a diffusion model. Our results show that established methods such as ion exchange perform comparably well in generating stable materials, although many of these materials tend to closely resemble known compounds. In contrast, generative models excel at proposing novel structural frameworks and, when sufficient training data is available, can more effectively target properties such as electronic band gap and bulk modulus while maintaining a high stability rate. To enhance the performance of both the baseline and generative approaches, we implement a post-generation screening step in which all proposed structures are passed through stability and property filters from pre-trained machine learning models including universal interatomic potentials. This low-cost filtering step leads to substantial improvement in the success rates of all methods, remains computationally efficient, and ultimately provides a practical pathway toward more effective generative strategies for materials discovery.
ROLO-SLAM: Rotation-Optimized LiDAR-Only SLAM in Uneven Terrain with Ground Vehicle
Wang, Yinchuan, Ren, Bin, Zhang, Xiang, Wang, Pengyu, Wang, Chaoqun, Song, Rui, Li, Yibin, Meng, Max Q. -H.
LiDAR-based SLAM is recognized as one effective method to offer localization guidance in rough environments. However, off-the-shelf LiDAR-based SLAM methods suffer from significant pose estimation drifts, particularly components relevant to the vertical direction, when passing to uneven terrains. This deficiency typically leads to a conspicuously distorted global map. In this article, a LiDAR-based SLAM method is presented to improve the accuracy of pose estimations for ground vehicles in rough terrains, which is termed Rotation-Optimized LiDAR-Only (ROLO) SLAM. The method exploits a forward location prediction to coarsely eliminate the location difference of consecutive scans, thereby enabling separate and accurate determination of the location and orientation at the front-end. Furthermore, we adopt a parallel-capable spatial voxelization for correspondence-matching. We develop a spherical alignment-guided rotation registration within each voxel to estimate the rotation of vehicle. By incorporating geometric alignment, we introduce the motion constraint into the optimization formulation to enhance the rapid and effective estimation of LiDAR's translation. Subsequently, we extract several keyframes to construct the submap and exploit an alignment from the current scan to the submap for precise pose estimation. Meanwhile, a global-scale factor graph is established to aid in the reduction of cumulative errors. In various scenes, diverse experiments have been conducted to evaluate our method. The results demonstrate that ROLO-SLAM excels in pose estimation of ground vehicles and outperforms existing state-of-the-art LiDAR SLAM frameworks.
Dissecting a Small Artificial Neural Network
Yang, Xiguang, Arora, Krish, Bachmann, Michael
We investigate the loss landscape and backpropagation dynamics of convergence for the simplest possible artificial neural network representing the logical exclusive-OR (XOR) gate. Cross-sections of the loss landscape in the nine-dimensional parameter space are found to exhibit distinct features, which help understand why backpropagation efficiently achieves convergence toward zero loss, whereas values of weights and biases keep drifting. Differences in shapes of cross-sections obtained by nonrandomized and randomized batches are discussed. In reference to statistical physics we introduce the microcanonical entropy as a unique quantity that allows to characterize the phase behavior of the network. Learning in neural networks can thus be thought of as an annealing process that experiences the analogue of phase transitions known from thermodynamic systems. It also reveals how the loss landscape simplifies as more hidden neurons are added to the network, eliminating entropic barriers caused by finite-size effects.
Humanoid Locomotion and Manipulation: Current Progress and Challenges in Control, Planning, and Learning
Gu, Zhaoyuan, Li, Junheng, Shen, Wenlan, Yu, Wenhao, Xie, Zhaoming, McCrory, Stephen, Cheng, Xianyi, Shamsah, Abdulaziz, Griffin, Robert, Liu, C. Karen, Kheddar, Abderrahmane, Peng, Xue Bin, Zhu, Yuke, Shi, Guanya, Nguyen, Quan, Cheng, Gordon, Gao, Huijun, Zhao, Ye
Humanoid robots have great potential to perform various human-level skills. These skills involve locomotion, manipulation, and cognitive capabilities. Driven by advances in machine learning and the strength of existing model-based approaches, these capabilities have progressed rapidly, but often separately. Therefore, a timely overview of current progress and future trends in this fast-evolving field is essential. This survey first summarizes the model-based planning and control that have been the backbone of humanoid robotics for the past three decades. We then explore emerging learning-based methods, with a focus on reinforcement learning and imitation learning that enhance the versatility of loco-manipulation skills. We examine the potential of integrating foundation models with humanoid embodiments, assessing the prospects for developing generalist humanoid agents. In addition, this survey covers emerging research for whole-body tactile sensing that unlocks new humanoid skills that involve physical interactions. The survey concludes with a discussion of the challenges and future trends.
SMDP-Based Dynamic Batching for Improving Responsiveness and Energy Efficiency of Batch Services
Xu, Yaodan, Zhou, Sheng, Niu, Zhisheng
For servers incorporating parallel computing resources, batching is a pivotal technique for providing efficient and economical services at scale. Parallel computing resources exhibit heightened computational and energy efficiency when operating with larger batch sizes. However, in the realm of online services, the adoption of a larger batch size may lead to longer response times. This paper aims to provide a dynamic batching scheme that delicately balances latency and efficiency. The system is modeled as a batch service queue with size-dependent service times. Then, the design of dynamic batching is formulated as a semi-Markov decision process (SMDP) problem, with the objective of minimizing the weighted sum of average response time and average power consumption. A method is proposed to derive an approximate optimal SMDP solution, representing the chosen dynamic batching policy. By introducing an abstract cost to reflect the impact of "tail" states, the space complexity and the time complexity of the procedure can decrease by 63.5% and 98%, respectively. Numerical results showcase the superiority of SMDP-based batching policies across various parameter setups. Additionally, the proposed scheme exhibits noteworthy flexibility in balancing power consumption and latency.
Active Learning Enables Extrapolation in Molecular Generative Models
Antoniuk, Evan R., Li, Peggy, Keilbart, Nathan, Weitzner, Stephen, Kailkhura, Bhavya, Hiszpanski, Anna M.
Although generaIve models hold promise for discovering molecules with opImized desired properIes, they oNen fail to suggest synthesizable molecules that improve upon the known molecules seen in training. We find that a key limitaIon is not in the molecule generaIon process itself, but in the poor generalizaIon capabiliIes of molecular property predictors. We tackle this challenge by creaIng an acIve-learning, closed-loop molecule generaIon pipeline, whereby molecular generaIve models are iteraIvely refined on feedback from quantum chemical simulaIons to improve generalizaIon to new chemical space. Compared against other generaIve model approaches, only our acIve learning approach generates molecules with properIes that extrapolate beyond the training data (reaching up to 0.44 standard deviaIons beyond the training data range) and out-of-distribuIon molecule classificaIon accuracy is improved by 79%. By condiIoning molecular generaIon on thermodynamic stability data from the acIve-learning loop, the proporIon of stable molecules generated is 3.5x higher than the next-best model. More recently, generaIve or inverse-design models have been proposed as a new paradigm for materials discovery due to their ability to efficiently navigate chemical space beyond what is present in exisIng databases. The goal of property-constrained molecular generaIon is to generate novel molecules that possess desirable properIes for the applicaIon of interest. Typically, a ground-truth oracle funcIon is defined for each molecule design task to quanItaIvely assess how well the generated molecules meet the desired molecular properIes. As a means to quickly approximate this oracle funcIon, property predicIon models are used as a surrogate model. These property predicIon models are first trained on a pre-exisIng dataset of molecular properIes to learn the mapping between the chemical structure of the molecules and their target molecular properIes.
Grasping in Uncertain Environments: A Case Study For Industrial Robotic Recycling
Daniels, Annalena, Kerz, Sebastian, Bari, Salman, Gabler, Volker, Wollherr, Dirk
Autonomous robotic grasping of uncertain objects in uncertain environments is an impactful open challenge for the industries of the future. One such industry is the recycling of Waste Electrical and Electronic Equipment (WEEE) materials, in which electric devices are disassembled and readied for the recovery of raw materials. Since devices may contain hazardous materials and their disassembly involves heavy manual labor, robotic disassembly is a promising venue. However, since devices may be damaged, dirty and unidentified, robotic disassembly is challenging since object models are unavailable or cannot be relied upon. This case study explores grasping strategies for industrial robotic disassembly of WEEE devices with uncertain vision data. We propose three grippers and appropriate tactile strategies for force-based manipulation that improves grasping robustness. For each proposed gripper, we develop corresponding strategies that can perform effectively in different grasping tasks and leverage the grippers design and unique strengths. Through experiments conducted in lab and factory settings for four different WEEE devices, we demonstrate how object uncertainty may be overcome by tactile sensing and compliant techniques, significantly increasing grasping success rates.