Oceania
Sequence-level Large Language Model Training with Contrastive Preference Optimization
Feng, Zhili, Ram, Dhananjay, Hawkins, Cole, Rawal, Aditya, Zhao, Jinman, Zha, Sheng
The next token prediction loss is the dominant self-supervised training objective for large language models and has achieved promising results in a variety of downstream tasks. However, upon closer investigation of this objective, we find that it lacks an understanding of sequence-level signals, leading to a mismatch between training and inference processes. To bridge this gap, we introduce a contrastive preference optimization (CPO) procedure that can inject sequence-level information into the language model at any training stage without expensive human labeled data. Our experiments show that the proposed objective surpasses the next token prediction in terms of win rate in the instruction-following and text generation tasks.
UniDyG: A Unified and Effective Representation Learning Approach for Large Dynamic Graphs
Xu, Yuanyuan, Zhang, Wenjie, Lin, Xuemin, Zhang, Ying
--Dynamic graphs, which capture time-evolving edges between nodes, are formulated in continuous-time or discrete-time dynamic graphs. They differ in temporal granularity: Continuous-Time Dynamic Graphs (CTDGs) exhibit rapid, localized changes, while Discrete-Time Dynamic Graphs (DTDGs) show gradual, global updates. This difference leads to isolated developments in representation learning for each type. T o advance dynamic graph representation learning, recent research attempts to design a unified model capable of handling both CTDGs and DTDGs, achieving promising results. However, it typically focuses on local dynamic propagation for temporal structure learning in the time domain, failing to accurately capture the underlying structural evolution associated with each temporal granularity and thus compromising model effectiveness. In addition, existing works-whether specific or unified-often overlook the issue of temporal noise, compromising the model's robustness. T o better model both types of dynamic graphs, we propose UniDyG, a unified and effective representation learning approach, which can scale to large dynamic graphs. Specifically, we first propose a novel Fourier Graph Attention (FGA T) mechanism that can model local and global structural correlations based on recent neighbors and complex-number selective aggregation, while theoretically ensuring consistent representations of dynamic graphs over time. Based on approximation theory, we demonstrate that FGA T is well-suited to capture the underlying structures in both CTDGs and DTDGs. We further enhance FGA T to resist temporal noise by designing an energy-gated unit, which adaptively filters out high-frequency noise according to the energy. Last, we leverage our proposed FGA T mechanisms for temporal structure learning and employ the frequency-enhanced linear function for node-level dynamic updates, facilitating the generation of high-quality temporal embeddings. Extensive experiments show that our UniDyG achieves an average improvement of 14. 4% over sixteen baselines across nine dynamic graphs while exhibiting superior robustness in noisy scenarios. YNAMIC graphs serve as a crucial data modality for representing time-evolving relationships (edges) between entities (nodes). Y uanyuan Xu and Wenjie Zhang are with the School of Computer Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia (e-mail: yuanyuan.xu@unsw.edu.au; Xuemin Lin is with Antai College of Economics and Management, Shanghai Jiao Tong University, Shanghai 200052, china (e-mail: xuemin.lin@gmail.com). Ying Zhang is with the School of Statistics and Mathematics, School of Computer Science, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China (e-mail: ying.zhang@zjgsu.edu.cn).
Personhood Credentials: Human-Centered Design Recommendation Balancing Security, Usability, and Trust
Building on related concepts, like, decentralized identifiers (DIDs), proof of personhood, anonymous credentials, personhood credentials (PHCs) emerged as an alternative approach, enabling individuals to verify to digital service providers that they are a person without disclosing additional information. However, new technologies might introduce some friction due to users misunderstandings and mismatched expectations. Despite their growing importance, limited research has been done on users perceptions and preferences regarding PHCs. To address this gap, we conducted competitive analysis, and semi-structured online user interviews with 23 participants from US and EU to provide concrete design recommendations for PHCs that incorporate user needs, adoption rules, and preferences. Our study -- (a)surfaces how people reason about unknown privacy and security guarantees of PHCs compared to current verification methods -- (b) presents the impact of several factors on how people would like to onboard and manage PHCs, including, trusted issuers (e.g. gov), ground truth data to issue PHC (e.g biometrics, physical id), and issuance system (e.g. centralized vs decentralized). In a think-aloud conceptual design session, participants recommended -- conceptualized design, such as periodic biometrics verification, time-bound credentials, visually interactive human-check, and supervision of government for issuance system. We propose actionable designs reflecting users preferences.
Supermarket-6DoF: A Real-World Grasping Dataset and Grasp Pose Representation Analysis
Toskov, Jason, Cosgun, Akansel
We present Supermarket-6DoF, a real-world dataset of 1500 grasp attempts across 20 supermarket objects with publicly available 3D models. Unlike most existing grasping datasets that rely on analytical metrics or simulation for grasp labeling, our dataset provides ground-truth outcomes from physical robot executions. Among the few real-world grasping datasets, wile more modest in size, Supermarket-6DoF uniquely features full 6-DoF grasp poses annotated with both initial grasp success and post-grasp stability under external perturbation. We demonstrate the dataset's utility by analyzing three grasp pose representations for grasp success prediction from point clouds. Our results show that representing the gripper geometry explicitly as a point cloud achieves higher prediction accuracy compared to conventional quaternion-based grasp pose encoding.
Understanding the Emergence of Multimodal Representation Alignment
Tjandrasuwita, Megan, Ekbote, Chanakya, Ziyin, Liu, Liang, Paul Pu
Multimodal representation learning is fundamentally about transforming incomparable modalities into comparable representations. While prior research primarily focused on explicitly aligning these representations through targeted learning objectives and model architectures, a recent line of work has found that independently trained unimodal models of increasing scale and performance can become implicitly aligned with each other. These findings raise fundamental questions regarding the emergence of aligned representations in multimodal learning. Specifically: (1) when and why does alignment emerge implicitly? and (2) is alignment a reliable indicator of performance? Through a comprehensive empirical investigation, we demonstrate that both the emergence of alignment and its relationship with task performance depend on several critical data characteristics. These include, but are not necessarily limited to, the degree of similarity between the modalities and the balance between redundant and unique information they provide for the task. Our findings suggest that alignment may not be universally beneficial; rather, its impact on performance varies depending on the dataset and task. These insights can help practitioners determine whether increasing alignment between modalities is advantageous or, in some cases, detrimental to achieving optimal performance. Code is released at https://github.com/MeganTj/multimodal_alignment.
Separated Contrastive Learning for Matching in Cross-domain Recommendation with Curriculum Scheduling
Chang, Heng, Gu, Liang, Hu, Cheng, Zhang, Zhinan, Zhu, Hong, Xu, Yuhui, Fang, Yuan, Chen, Zhen
Cross-domain recommendation (CDR) is a task that aims to improve the recommendation performance in a target domain by leveraging the information from source domains. Contrastive learning methods have been widely adopted among intra-domain (intra-CL) and inter-domain (inter-CL) users/items for their representation learning and knowledge transfer during the matching stage of CDR. However, we observe that directly employing contrastive learning on mixed-up intra-CL and inter-CL tasks ignores the difficulty of learning from inter-domain over learning from intra-domain, and thus could cause severe training instability. Therefore, this instability deteriorates the representation learning process and hurts the quality of generated embeddings. To this end, we propose a novel framework named SCCDR built up on a separated intra-CL and inter-CL paradigm and a stop-gradient operation to handle the drawback. Specifically, SCCDR comprises two specialized curriculum stages: intra-inter separation and inter-domain curriculum scheduling. The former stage explicitly uses two distinct contrastive views for the intra-CL task in the source and target domains, respectively. Meanwhile, the latter stage deliberately tackles the inter-CL tasks with a curriculum scheduling strategy that derives effective curricula by accounting for the difficulty of negative samples anchored by overlapping users. Empirical experiments on various open-source datasets and an offline proprietary industrial dataset extracted from a real-world recommender system, and an online A/B test verify that SCCDR achieves state-of-the-art performance over multiple baselines.
OrderSum: Semantic Sentence Ordering for Extractive Summarization
The sentence-level framework defines extractive summarization as an individual sentence selection problem, determining whether each sentence in a document should be included in the summary. However, the sentence-level framework often produces summaries that contain only general sentences or repeat important but similar sentences (Narayan et al., 2018b; Zhong et al., 2020). The summary-level framework overcomes this limitation by defining extractive summarization as a summary ranking problem rather than a sentence selection problem. The main idea of the summary-level framework is to generate a set of candidate summaries consisting of different sentences, and then rank them to select the best summary. By considering sentence composition at the entire summary level rather than sentence by sentence, this approach enables each sentence in the summary to convey different, specific information (Narayan et al., 2018b; Zhong et al., 2020). Previous work in both frameworks has primarily focused on improving which sentences to include in the summary, or in other words, sentence inclusion. However, to the best of our knowledge, the importance of sentence order in summaries has not been highlighted since the era of graph-based extractive summarization (Mihalcea and Ta-rau, 2004; Erkan and Radev, 2004). The sentence order of a text plays a crucial role not only in readability but also in its meaning (Yin et al., 2019; Lo-geswaran et al., 2018). Table 1 illustrates how the arXiv:2502.16180v1
Destroy and Repair Using Hyper Graphs for Routing
Li, Ke, Liu, Fei, Wang, Zhengkun, Zhang, Qingfu
Recent advancements in Neural Combinatorial Optimization (NCO) have shown promise in solving routing problems like the Traveling Salesman Problem (TSP) and Capacitated Vehicle Routing Problem (CVRP) without handcrafted designs. Research in this domain has explored two primary categories of methods: iterative and non-iterative. While non-iterative methods struggle to generate near-optimal solutions directly, iterative methods simplify the task by learning local search steps. However, existing iterative methods are often limited by restricted neighborhood searches, leading to suboptimal results. To address this limitation, we propose a novel approach that extends the search to larger neighborhoods by learning a destroy-and-repair strategy. Specifically, we introduce a Destroy-and-Repair framework based on Hyper-Graphs (DRHG). This framework reduces consecutive intact edges to hyper-edges, allowing the model to pay more attention to the destroyed part and decrease the complexity of encoding all nodes. Experiments demonstrate that DRHG achieves stateof-the-art performance on TSP with up to 10,000 nodes and shows strong generalization to real-world TSPLib and CVRPLib problems.
DUPRE: Data Utility Prediction for Efficient Data Valuation
Pham, Kieu Thao Nguyen, Sim, Rachael Hwee Ling, Nguyen, Quoc Phong, Ng, See Kiong, Low, Bryan Kian Hsiang
Data valuation is increasingly used in machine learning (ML) to decide the fair compensation for data owners and identify valuable or harmful data for improving ML models. Cooperative game theory-based data valuation, such as Data Shapley, requires evaluating the data utility (e.g., validation accuracy) and retraining the ML model for multiple data subsets. While most existing works on efficient estimation of the Shapley values have focused on reducing the number of subsets to evaluate, our framework, \texttt{DUPRE}, takes an alternative yet complementary approach that reduces the cost per subset evaluation by predicting data utilities instead of evaluating them by model retraining. Specifically, given the evaluated data utilities of some data subsets, \texttt{DUPRE} fits a \emph{Gaussian process} (GP) regression model to predict the utility of every other data subset. Our key contribution lies in the design of our GP kernel based on the sliced Wasserstein distance between empirical data distributions. In particular, we show that the kernel is valid and positive semi-definite, encodes prior knowledge of similarities between different data subsets, and can be efficiently computed. We empirically verify that \texttt{DUPRE} introduces low prediction error and speeds up data valuation for various ML models, datasets, and utility functions.
PLDR-LLMs Learn A Generalizable Tensor Operator That Can Replace Its Own Deep Neural Net At Inference
February 18, 2025 A BSTRACT We show that Large Language Model from Power Law Decoder Representations (PLDR-LLM) is a foundational model whose deductive outputs are invariant tensors up to a small perturbation. PLDR-LLM learns a singularity condition for the deductive outputs that enable the once-inferred energy-curvature tensor G LMto replace the deep neural network of power law graph attention (PLGA) generating the deductive outputs at inference. We demonstrate that a cache for G LM(G-cache) and KV -cache can be implemented in a straightforward manner to improve the inference time. The invariance and generalizable nature of deductive outputs is at a very high fidelity where deductive outputs have same RMSE and determinant values up to 15 decimal places after caching, and zero-shot benchmark scores remain unchanged. Ablation studies show that learned deductive outputs have distinct loss and accuracy characteristics from models pretrained with transferred, randomly initialized or identity tensors as a constant tensor operator and an LLM with scaled-dot product attention (SDP A) is a special case of PLDR-LLM where G LMis predefined as identity. The observed invariance characteristic introduces a novel asymmetry between training and inference phases with caching. We outline observed common characteristics of the deductive outputs for the learned singularity condition. We provide an implementation of a training and inference framework for PLDR-LLM with KV -cache and G-cache. 1 Introduction Large Language Model from Power Law Decoder Representations (PLDR-LLM) is a novel language model architecture with well-defined deductive and inductive outputs [Gokden, 2024]. It is composed of deep layers of decoders with multi-headed Power Law Graph Attention (PLGA) [Gokden, 2021, 2019]. The deductive outputs are intended to observe and regularize the model, while the inductive output is the next-token prediction of a language model. PLGA is a series of non-linear and linear transformations that attend to an input sentence that can be considered as a weighted graph G = ( V, E) where nodes are the tokens densely represented by an N-dimensional embedding space. The PLGA learns a metric tensor A LMof the embedding space after applying a custom fully connected layer and iSwiGLU, a positive semi-definite activation function, to the output A of a deep residual network of gated linear units (GLUs) whose input is a density matrix operator derived from the query.