avss
Layer Importance and Hallucination Analysis in Large Language Models via Enhanced Activation Variance-Sparsity
Song, Zichen, Huang, Sitan, Wu, Yuxin, Kang, Zhongfeng
Evaluating the importance of different layers in large language models (LLMs) is crucial for optimizing model performance and interpretability. This paper first explores layer importance using the Activation Variance-Sparsity Score (AVSS), which combines normalized activation variance and sparsity to quantify each layer's contribution to overall model performance. By ranking layers based on AVSS and pruning the least impactful 25\%, our experiments on tasks such as question answering, language modeling, and sentiment classification show that over 90\% of the original performance is retained, highlighting potential redundancies in LLM architectures. Building on AVSS, we propose an enhanced version tailored to assess hallucination propensity across layers (EAVSS). This improved approach introduces Hallucination-Specific Activation Variance (HSAV) and Hallucination-Specific Sparsity (HSS) metrics, allowing precise identification of hallucination-prone layers. By incorporating contrastive learning on these layers, we effectively mitigate hallucination generation, contributing to more robust and efficient LLMs(The maximum performance improvement is 12\%). Our results on the NQ, SciQ, TriviaQA, TruthfulQA, and WikiQA datasets demonstrate the efficacy of this method, offering a comprehensive framework for both layer importance evaluation and hallucination mitigation in LLMs.
AVSS: Layer Importance Evaluation in Large Language Models via Activation Variance-Sparsity Analysis
Song, Zichen, Wu, Yuxin, Huang, Sitan, Kang, Zhongfeng
Additionally, Zopf et al. [2] introduced The evaluation of layer importance in deep learning has been an Layer-wise Relevance Propagation (LRP), including its variants, active area of research, with significant implications for model to analyze the flow of information in complex neural networks, optimization and interpretability. Recently, large language models providing a more nuanced understanding of each layer's contribution (LLMs) have gained prominence across various domains, yet limited to the model's decisions. Furthermore, the work of Mencía studies have explored the functional importance and performance et al. [12] highlighted the significance of Contextual Importance contributions of individual layers within LLMs, especially from Measures(CIM), which integrate contextual information to dynamically the perspective of activation distribution. In this work, we propose evaluate the importance of each layer based on specific input the Activation Variance-Sparsity Score (AVSS), a novel metric conditions, thus overcoming the limitations of static assessment combining normalized activation variance and sparsity to assess methods. However, these approaches often struggle to fully capture each layer's contribution to model performance. By identifying and the intricate activation distributions and redundancy within large removing approximately the lowest 25% of layers based on AVSS, language models, limiting their effectiveness in identifying less we achieve over 90% of original model performance across tasks critical layers.
Efficient and Reliable Vector Similarity Search Using Asymmetric Encoding with NAND-Flash for Many-Class Few-Shot Learning
Chiang, Hao-Wei, Huang, Chi-Tse, Cheng, Hsiang-Yun, Tseng, Po-Hao, Lee, Ming-Hsiu, An-Yeu, null, Wu, null
While memory-augmented neural networks (MANNs) offer an effective solution for few-shot learning (FSL) by integrating deep neural networks with external memory, the capacity requirements and energy overhead of data movement become enormous due to the large number of support vectors in many-class FSL scenarios. Various in-memory search solutions have emerged to improve the energy efficiency of MANNs. NAND-based multi-bit content addressable memory (MCAM) is a promising option due to its high density and large capacity. Despite its potential, MCAM faces limitations such as a restricted number of word lines, limited quantization levels, and non-ideal effects like varying string currents and bottleneck effects, which lead to significant accuracy drops. To address these issues, we propose several innovative methods. First, the Multi-bit Thermometer Code (MTMC) leverages the extensive capacity of MCAM to enhance vector precision using cumulative encoding rules, thereby mitigating the bottleneck effect. Second, the Asymmetric vector similarity search (AVSS) reduces the precision of the query vector while maintaining that of the support vectors, thereby minimizing the search iterations and improving efficiency in many-class scenarios. Finally, the Hardware-Aware Training (HAT) method optimizes controller training by modeling the hardware characteristics of MCAM, thus enhancing the reliability of the system. Our integrated framework reduces search iterations by up to 32 times, and increases overall accuracy by 1.58% to 6.94%.
Accelerating Autonomy: Insights from Pro Racers in the Era of Autonomous Racing - An Expert Interview Study
Werner, Frederik, Oberhuber, René, Betz, Johannes
This research aims to investigate professional racing drivers' expertise to develop an understanding of their cognitive and adaptive skills to create new autonomy algorithms. An expert interview study was conducted with 11 professional race drivers, data analysts, and racing instructors from across prominent racing leagues. The interviews were conducted using an exploratory, non-standardized expert interview format guided by a set of prepared questions. The study investigates drivers' exploration strategies to reach their vehicle limits and contrasts them with the capabilities of state-of-the-art autonomous racing software stacks. Participants were questioned about the techniques and skills they have developed to quickly approach and maneuver at the vehicle limit, ultimately minimizing lap times. The analysis of the interviews was grounded in Mayring's qualitative content analysis framework, which facilitated the organization of the data into multiple categories and subcategories. Our findings create insights into human behavior regarding reaching a vehicle's limit and minimizing lap times. We conclude from the findings the development of new autonomy software modules that allow for more adaptive vehicle behavior. By emphasizing the distinct nuances between manual and autonomous driving techniques, the paper encourages further investigation into human drivers' strategies to maximize their vehicles' capabilities.