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Kaile Wang

Publications and source records attributed to Kaile Wang.

30 records · Page 2Linked to original sources

Safe RLHF-V: Safe Reinforcement Learning from Multi-modal Human Feedback

Multimodal large language models (MLLMs) are essential for building general-purpose AI assistants; however, they pose increasing safety risks. How can we ensure safety alignment of MLLMs to prevent undesired behaviors? Going further, it is critical to explore how to fine-tune MLLMs to preserve capabilities while meeting safety constraints. Fundamentally, this challenge can be formulated as a min-max optimization problem. However, existing datasets have not yet disentangled single preference signals into explicit safety constraints, hindering systematic investigation in this direction. Moreover, it remains an open question whether such constraints can be effectively incorporated into the optimization process for multi-modal models. In this work, we present the first exploration of the Safe RLHF-V -- the first multimodal safety alignment framework. The framework consists of: $\mathbf{(I)}$ BeaverTails-V, the first open-source dataset featuring dual preference annotations for helpfulness and safety, supplemented with multi-level safety labels (minor, moderate, severe); $\mathbf{(II)}$ Beaver-Guard-V, a multi-level guardrail system to proactively defend against unsafe queries and adversarial attacks. Applying the guard model over five rounds of filtering and regeneration significantly enhances the precursor model's overall safety by an average of 40.9%. $\mathbf{(III)}$ Based on dual preference, we initiate the first exploration of multi-modal safety alignment within a constrained optimization. Experimental results demonstrate that Safe RLHF effectively improves both model helpfulness and safety. Specifically, Safe RLHF-V enhances model safety by 34.2% and helpfulness by 34.3%.

cs.LG↗

AI Alignment: A Comprehensive Survey

AI alignment aims to make AI systems behave in line with human intentions and values. As AI systems grow more capable, so do risks from misalignment. To provide a comprehensive and up-to-date overview of the alignment field, in this survey, we delve into the core concepts, methodology, and practice of alignment. First, we identify four principles as the key objectives of AI alignment: Robustness, Interpretability, Controllability, and Ethicality (RICE). Guided by these four principles, we outline the landscape of current alignment research and decompose them into two key components: forward alignment and backward alignment. The former aims to make AI systems aligned via alignment training, while the latter aims to gain evidence about the systems' alignment and govern them appropriately to avoid exacerbating misalignment risks. On forward alignment, we discuss techniques for learning from feedback and learning under distribution shift. On backward alignment, we discuss assurance techniques and governance practices. We also release and continually update the website (www.alignmentsurvey.com) which features tutorials, collections of papers, blog posts, and other resources.

cs.AI↗

Stream Aligner: Efficient Sentence-Level Alignment via Distribution Induction

The rapid advancement of large language models (LLMs) has led to significant improvements in their capabilities, but also to increased concerns about their alignment with human values and intentions. Current alignment strategies, including adaptive training and inference-time methods, have demonstrated potential in this area. However, these approaches still struggle to balance deployment complexity and capability across various tasks and difficulties. In this work, we introduce the Streaming Distribution Induce Aligner (Stream Aligner), a novel alignment paradigm that combines efficiency with enhanced performance in various tasks throughout the generation process. Stream Aligner achieves dynamic sentence-level correction by using a small model to learn the preferences of the suffix sentence, iteratively correcting the suffix sentence output by the upstream model, and then using the corrected sentence to replace the suffix sentence in subsequent generations. Compared to Aligner, our experiments demonstrate that Stream Aligner reduces reliance on the capabilities of additional models, enhances the reasoning abilities of LLMs, and decreases latency during user interaction. Specifically, Stream Aligner-2B model has achieved an improvement of 76.1% in helpfulness, 36.0% in harmlessness on the tested Llama2-70B-chat model, and Stream Aligner-8B has achieved an improvement of 3.5% on the math ability of the tested Llama3-70B-Instruct model.

cs.CL↗

Align Anything: Training All-Modality Models to Follow Instructions with Language Feedback

Reinforcement learning from human feedback (RLHF) has proven effective in enhancing the instruction-following capabilities of large language models; however, it remains underexplored in the cross-modality domain. As the number of modalities increases, aligning all-modality models with human intentions -- such as instruction following -- becomes a pressing challenge. In this work, we make the first attempt to fine-tune all-modality models (i.e. input and output with any modality, also named any-to-any models) using human preference data across all modalities (including text, image, audio, and video), ensuring its behavior aligns with human intentions. This endeavor presents several challenges. First, there is no large-scale all-modality human preference data in existing open-source resources, as most datasets are limited to specific modalities, predominantly text and image. Secondly, the effectiveness of binary preferences in RLHF for post-training alignment in complex all-modality scenarios remains an unexplored area. Finally, there is a lack of a systematic framework to evaluate the capabilities of all-modality models, particularly regarding modality selection and synergy. To address these challenges, we propose the align-anything framework, which includes meticulously annotated 200k all-modality human preference data. Then, we introduce an alignment method that learns from unified language feedback, effectively capturing complex modality-specific human preferences and enhancing the model's instruction-following capabilities. Furthermore, to assess performance improvements in all-modality models after post-training alignment, we construct a challenging all-modality capability evaluation framework -- eval-anything. All data, models, and code frameworks have been open-sourced for the community. For more details, please refer to https://github.com/PKU-Alignment/align-anything.

cs.AI↗

DMP_AI: An AI-Aided K-12 System for Teaching and Learning in Diverse Schools

The use of Artificial Intelligence (AI) has gained momentum in education. However, the use of AI in K-12 education is still in its nascent stages, and further research and development is needed to realize its potential. Moreover, the creation of a comprehensive and cohesive system that effectively harnesses AI to support teaching and learning across a diverse range of primary and secondary schools presents substantial challenges that need to be addressed. To fill these gaps, especially in countries like China, we designed and implemented the DMP_AI (Data Management Platform_Artificial Intelligence) system, an innovative AI-aided educational system specifically designed for K-12 education. The system utilizes data mining, natural language processing, and machine learning, along with learning analytics, to offer a wide range of features, including student academic performance and behavior prediction, early warning system, analytics of Individualized Education Plan, talented students prediction and identification, and cross-school personalized electives recommendation. The development of this system has been meticulously carried out while prioritizing user privacy and addressing the challenges posed by data heterogeneity. We successfully implemented the DMP_AI system in real-world primary and secondary schools, allowing us to gain valuable insights into the potential and challenges of integrating AI into K-12 education in the real world. This system will serve as a valuable resource for supporting educators in providing effective and inclusive K-12 education.

cs.CY↗

The individual abundance distributions of disc stars across birth radii in GALAH

Individual abundances in the Milky Way disc record stellar birth properties (e.g. age, birth radius ($R_{\rm birth}$)) and capture the diversity of the star-forming environments over time. Assuming an analytical relationship between ([Fe/H], [$α$/Fe]) and $R_{\rm birth}$, we examine the distributions of individual abundances [X/Fe] of elements C, O, Mg, Si, Ca ($α$), Al (odd-z), Mn (iron-peak), Y, and Ba (neutron-capture) for stars in the Milky Way. We want to understand how these elements might differentiate environments across the disc. We assign tracks of $R_{\rm birth}$ in the [$α$/Fe] vs. [Fe/H] plane as informed by expectations from simulations for $\sim 59,000$ GALAH stars in the solar neighborhood ($R\sim7-9$ kpc) which also have inferred ages. Our formalism for $R_{\rm birth}$ shows that older stars ($\sim$10 Gyrs) have a $R_{\rm birth}$ distribution with smaller mean values (i.e., $\bar{R}_{\mbox{birth}}$$\sim5\pm0.8$ kpc) compared to younger stars ($\sim6$ Gyrs; $\bar{R}_{\mbox{birth}}$$\sim10\pm1.5$ kpc), for a given [Fe/H], consistent with inside-out growth. The $α$-, odd-z, and iron-peak element abundances decrease as a function of $R_{\rm birth}$, whereas the neutron-capture abundances increase. The $R_{\rm birth}$-[Fe/H] gradient we measure is steeper compared to the present-day gradient (-0.067 dex/kpc vs -0.058 dex/kpc), which we also find true for $R_{\rm birth}$-[X/Fe] gradients. These results (i) showcase the feasibility of relating the birth radius of stars to their element abundances, (ii) the abundance gradients across $R_{\rm birth}$ are steeper than those over current radius, and (iii) offer an observational comparison to expectations on element abundance distributions from hydrodynamical simulations.

astro-ph.GA↗

Observation of Q-switched and continuous wave regimes with mode-hopping in Er-doped fiber lasers incorporating a dynamic population grating

Dynamic population gratings (DPGs) in rare-earth doped fibers are prevalent devices in fiber lasers for the production of single-longitudinal-mode emission, Q-switched pulses, and wavelength self-sweeping regimes. This study presents a transition from Q-switched state to continuous wave (CW) state, accompanying irregular mode-hopping, in an erbium-doped fiber laser with a heavily-doped DPG centered at 1549.95 nm. Our results demonstrate that the transition between these two states can be achieved by adjusting the pump power. The repetition frequency of the Q-switched pulse increases monotonically with the increasing pump power, while the pulse duration initially narrows and then expands because the reduced peak intensity weakens the nonlinear effect. Additionally, modulation peaks are evident on both the Q-switched pulse train and the CW background, which are induced by the irregular mode-hopping caused by the DPG. Furthermore, we observe that the central wavelength fluctuates within a range of 0.05 nm. These results provide valuable insight into the DPG effect in heavily-doped fibers.

physics.optics↗

The relationship between age, metallicity, and abundances for disk stars in a simulated Milky Way galaxy

Observations of the Milky Way's low-$α$ disk show that at fixed metallicity, [Fe/H], several element abundance, [X/Fe], correlate with age, with unique slopes and small scatters around the age-[X/Fe] relations. In this study, we turn to simulations to explore the age-[X/Fe] relations for the elements C, N, O, Mg, Si, S, and Ca that are traced in a FIRE-2 cosmological zoom-in simulation of a Milky Way-like galaxy, m12i, and understand what physical conditions give rise to the observed age-[X/Fe] trends. We first explore the distributions of mono-age populations in their birth and current locations, [Fe/H], and [X/Fe], and find evidence for inside-out radial growth for stars with ages < 7 Gyr. We then examine the age-[X/Fe] relations across m12i's disk and find that the direction of the trends agree with observations, apart from C, O, and Ca, with remarkably small intrinsic scatters, $σ_{int}$ (0.01-0.04 dex). This $σ_{int}$ measured in the simulations is also metallicity-dependent, with $σ_{int}$ $\approx$ 0.025 dex at [Fe/H]=-0.25 dex versus $σ_{int}$ $\approx$ 0.015 dex at [Fe/H]=0 dex, and a similar metallicity dependence is seen in the GALAH survey for the elements in common. Additionally, we find that $σ_{int}$ is higher in the inner galaxy, where stars are older and formed in less chemically-homogeneous environments. The age-[X/Fe] relations and the small scatter around them indicate that simulations capture similar chemical enrichment variance as observed in the Milky Way, arising from stars sharing similar element abundances at a given birth place and time.

astro-ph.GA↗

Self-sweeping ytterbium-doped fiber laser based on a fiber saturable absorber

Generally speaking, the self-sweeping effect relies on the dynamical grating formed in a gain fiber. Here, the normal self-sweeping was generated in a pump-free ytterbium-doped fiber which serves as a fiber saturable absorber and is introduced to the laser cavity by a circulator in this experiment. The sweeping rate and the sweeping range alter as usual, both of which can be controlled by the pump power. Further, a new self-pulse signal is observed and discussed in this work, which shows the difference of the self-sweeping effects between active fiber and fiber saturable absorber.

physics.optics↗

Narrow bandwidth Q-switched Erbium-doped fiber laser based on dynamic saturable absorption filtering effect

We proposed a narrow spectral bandwidth Erbium-doped fiber (EDF) laser Q-switched by a homemade saturable dynamic induced grating (SDIG) which is introduced via reforming the structure of a fiber saturable absorbers FSA with a piece of EDF and a fiber Bragg grating. The SDIG integrates both saturable absorption and spectral filtering effect simultaneously, which was confirmed through theoretical analysis and experimental results for the first time, to the best of our knowledge. Further study verified that the spectral width of the Q-switched emissions is decided by the length of the SDIG and the input power of the pump source. The Q-switched pulse with the narrowest spectral width of about 29.1 pm achieved in this work is the narrowest bandwidth pulse in the domain of the FSA Q-switched fiber lasers when the length of SDIG and pump power are 20 cm and 250 mW, respectively. Our method provides a simple way to obtain the Q-switched pulses with narrow bandwidths, which have promising applications for nonlinear frequency conversion, Doppler LIDAR and coherent beam combinations.

physics.optics↗

Discretized optical dynamics in one-dimensionally synthetic photonic lattice

Synthetic photonic lattice with temporally controlled potentials is a versatile platform for realizing wave dynamics associated with physical areas of optics and quantum physics. Here, discrete optics in one-dimensionally synthetic photonic lattice is investigated systematically, in which the light behavior is highly similar to those in evanescently coupled one-dimensional discrete waveguides. Such a synthetic dimension is constructed with position-dependent periodic effective gauge fields based on Aharonov-Bohm effect arising from the phase accumulations of the fiber loops. By tuning the phase accumulations and coupling coefficient of the coupler, the band translation and gap property can be modulated which further results in the impulse and tailored Gaussian wave packet responses as well as Talbot recurrences. In addition, Bloch oscillations and Anderson localization can also be obtained when the phase accumulations are linearly changed and weakly modulated in random, respectively. The periodic effective gauge fields configuration in our protocol enables SPL to be a research platform for one-dimensional dynamically modulated elements or even non-Hermitian waveguides.

physics.optics↗

Synthetic topological insulator with periodically modulated effective gauge fields

We study both theoretically and numerically the topological edge states in synthetic photonic lattice with finitely periodic gauge potentials. The effective gauge fields are implemented by tailoring the phase alternatively and periodically, which finally results in symmetric total reflection at two boundaries of the one-dimensional synthetic lattice. Further tuning the nearest-neighbor coupling anisotropically, topological edge states occur at the two boundaries. Our work provides a new way to study the topological physics of one-dimensional coupled waveguide arrays with synthetic photonic lattice.

physics.optics↗