rs 2
Parallel Sampling via Autospeculation
Anari, Nima, Baronio, Carlo, Chen, CJ, Haqi, Alireza, Koehler, Frederic, Li, Anqi, Vuong, Thuy-Duong
We present parallel algorithms to accelerate sampling via counting in two settings: any-order autoregressive models and denoising diffusion models. An any-order autoregressive model accesses a target distribution $μ$ on $[q]^n$ through an oracle that provides conditional marginals, while a denoising diffusion model accesses a target distribution $μ$ on $\mathbb{R}^n$ through an oracle that provides conditional means under Gaussian noise. Standard sequential sampling algorithms require $\widetilde{O}(n)$ time to produce a sample from $μ$ in either setting. We show that, by issuing oracle calls in parallel, the expected sampling time can be reduced to $\widetilde{O}(n^{1/2})$. This improves the previous $\widetilde{O}(n^{2/3})$ bound for any-order autoregressive models and yields the first parallel speedup for diffusion models in the high-accuracy regime, under the relatively mild assumption that the support of $μ$ is bounded. We introduce a novel technique to obtain our results: speculative rejection sampling. This technique leverages an auxiliary ``speculative'' distribution~$ν$ that approximates~$μ$ to accelerate sampling. Our technique is inspired by the well-studied ``speculative decoding'' techniques popular in large language models, but differs in key ways. Firstly, we use ``autospeculation,'' namely we build the speculation $ν$ out of the same oracle that defines~$μ$. In contrast, speculative decoding typically requires a separate, faster, but potentially less accurate ``draft'' model $ν$. Secondly, the key differentiating factor in our technique is that we make and accept speculations at a ``sequence'' level rather than at the level of single (or a few) steps. This last fact is key to unlocking our parallel runtime of $\widetilde{O}(n^{1/2})$.
- North America > United States > Arizona (0.04)
- North America > United States > Illinois > Cook County > Chicago (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
- (3 more...)
PAC Off-Policy Prediction of Contextual Bandits
Wan, Yilong, Li, Yuqiang, Wu, Xianyi
This paper investigates off-policy evaluation in contextual bandits, aiming to quantify the performance of a target policy using data collected under a different and potentially unknown behavior policy. Recently, methods based on conformal prediction have been developed to construct reliable prediction intervals that guarantee marginal coverage in finite samples, making them particularly suited for safety-critical applications. To further achieve coverage conditional on a given offline data set, we propose a novel algorithm that constructs probably approximately correct prediction intervals. Our method builds upon a PAC-valid conformal prediction framework, and we strengthen its theoretical guarantees by establishing PAC-type bounds on coverage. We analyze both finite-sample and asymptotic properties of the proposed method, and compare its empirical performance with existing methods in simulations.
- North America > United States > New York > New York County > New York City (0.04)
- North America > United States > Wisconsin > Dane County > Madison (0.04)
- North America > United States > District of Columbia > Washington (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
Reinforcement Learning with a Focus on Adjusting Policies to Reach Targets
Tsuboya, Akane, Kono, Yu, Takahashi, Tatsuji
The objective of a reinforcement learning agent is to discover better actions through exploration. However, typical exploration techniques aim to maximize rewards, often incurring high costs in both exploration and learning processes. We propose a novel deep reinforcement learning method, which prioritizes achieving an aspiration level over maximizing expected return. This method flexibly adjusts the degree of exploration based on the proportion of target achievement. Through experiments on a motion control task and a navigation task, this method achieved returns equal to or greater than other standard methods. The results of the analysis showed two things: our method flexibly adjusts the exploration scope, and it has the potential to enable the agent to adapt to non-stationary environments. These findings indicated that this method may have effectiveness in improving exploration efficiency in practical applications of reinforcement learning.
Bias-Corrected Joint Spectral Embedding for Multilayer Networks with Invariant Subspace: Entrywise Eigenvector Perturbation and Inference
In this paper, we propose to estimate the invariant subspace across heterogeneous multiple networks using a novel bias-corrected joint spectral embedding algorithm. The proposed algorithm recursively calibrates the diagonal bias of the sum of squared network adjacency matrices by leveraging the closed-form bias formula and iteratively updates the subspace estimator using the most recent estimated bias. Correspondingly, we establish a complete recipe for the entrywise subspace estimation theory for the proposed algorithm, including a sharp entrywise subspace perturbation bound and the entrywise eigenvector central limit theorem. Leveraging these results, we settle two multiple network inference problems: the exact community detection in multilayer stochastic block models and the hypothesis testing of the equality of membership profiles in multilayer mixed membership models. Our proof relies on delicate leave-one-out and leave-two-out analyses that are specifically tailored to block-wise symmetric random matrices and a martingale argument that is of fundamental interest for the entrywise eigenvector central limit theorem.
- North America > United States > Indiana (0.04)
- North America > United States > New York (0.04)
- North America > United States > District of Columbia > Washington (0.04)
- (2 more...)
- Information Technology > Data Science > Data Mining (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning (1.00)
- Information Technology > Communications > Networks (0.93)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning > Clustering (0.67)
Dynamics of spherical telescopic linear driven rotation robots
Zevering, Jasper, Borrmann, Dorit, Bredenbeck, Anton, Nuechter, Andreas
Lunar caves are promising features for long-term and permanent human presence on the moon. However, given their inaccessibility to imaging from survey satellites, the concrete environment within the underground cavities is not well known. Thus, to further the efforts of human presence on the moon, these caves are to be explored by robotic systems. However, a set of environmental factors make this exploration particularly challenging. Among those are the very fine lunar dust that damages exposed sensors and actuators and the unknown composition of the surface and obstacles within the cavity. One robotic system that is particularly fit to meet these challenges is that of a spherical robot, as the exterior shell completely separates the sensors and actuators from the hazardous environment. This work introduces the mathematical description in the form of a dynamic model of a novel locomotion approach for this form factor that adds additional functionality. A set of telescopic linearly extending rods moves the robot using a combination of pushing away from the ground and leveraging the gravitational torque. The approach allows the system to locomote, overcome objects by hoisting its center of gravity on top, and transform into a terrestrial laser scanner by using the rods as a tripod.
- North America > United States > Pennsylvania > Allegheny County > Pittsburgh (0.04)
- Europe > Netherlands > South Holland > Delft (0.04)
- Asia > India > Uttarakhand > Roorkee (0.04)
- Asia > China > Zhejiang Province > Hangzhou (0.04)
AI based mentor network Quantel ends FY23 with net revenue of Rs 2.1 crore; boasts of 1,000 mentors
The impact of a skilled mentor on one's life can be significant, potentially resulting in a successful career or business growth. Quantel, an AI-based mentor network platform, aims to offer mentorship opportunities to students from a diverse range of backgrounds, including government officers and corporate leaders, Lucky Rohilla, co-founder, Quantel, told FE Education. "We will bring on board mentors who possess exceptional capabilities and can effectively share their experiences with bright young minds who aspire to follow in their footsteps" Rohilla added. Incorporated in June 2020, Quantel is a recently established platform. The company ended FY22 with Rs 21.3 lakh from sales or supply of services, while net profit stood at Rs 30,324 as per regulatory filings accessed by business intelligence platform, Tofler.
Dual-constrained Deep Semi-Supervised Coupled Factorization Network with Enriched Prior
Zhang, Yan, Zhang, Zhao, Wang, Yang, Zhang, Zheng, Zhang, Li, Yan, Shuicheng, Wang, Meng
Nonnegative matrix factorization is usually powerful for learning the "shallow" parts-based representation, but it clearly fails to discover deep hierarchical information within both the basis and representation spaces. In this paper, we technically propose a new enriched prior based Dual-constrained Deep Semi-Supervised Coupled Factorization Network, called DS2CF-Net, for learning the hierarchical coupled representations. To ex-tract hidden deep features, DS2CF-Net is modeled as a deep-structure and geometrical structure-constrained neural network. Specifically, DS2CF-Net designs a deep coupled factorization architecture using multi-layers of linear transformations, which coupled updates the bases and new representations in each layer. To improve the discriminating ability of learned deep representations and deep coefficients, our network clearly considers enriching the supervised prior by the joint deep coefficients-regularized label prediction, and incorporates enriched prior information as additional label and structure constraints. The label constraint can enable the samples of the same label to have the same coordinate in the new feature space, while the structure constraint forces the coefficient matrices in each layer to be block-diagonal so that the enhanced prior using the self-expressive label propagation are more accurate. Our network also integrates the adaptive dual-graph learning to retain the local manifold structures of both the data manifold and feature manifold by minimizing the reconstruction errors in each layer. Extensive experiments on several real databases demonstrate that our DS2CF-Net can obtain state-of-the-art performance for representation learning and clustering.
- Europe > United Kingdom > England > East Sussex > Brighton (0.04)
- Asia > China > Guangdong Province > Shenzhen (0.04)
- Asia > China > Anhui Province > Hefei (0.04)
- (8 more...)
Wipro : Q2 net profit at Rs 2,070 crore; Gross Revenue grows 10% YoY 4-Traders
The company's total income has increased from Rs 13,198.6 crore for the quarter ended September 30, 2015 to Rs 14,407.3 The company has posted a net profit after taxes, minority interest and share of profit of associates of Rs 2070 crore for the quarter ended September 30, 2016 as compared to Rs 2241 crore for the quarter ended September 30, 2015. Total Income has increased from Rs 13198.6 crore for the quarter ended September 30, 2015 to Rs 14407.3 On a standalone bais, the company has posted a net profit of Rs 1932 crore for the quarter ended September 30, 2016 as compared to Rs 2153 crore for the quarter ended September 30, 2015. Total Income has increased from Rs 11725 crore for the quarter ended September 30, 2015 to Rs. 12101 crore for the quarter ended September 30, 2016.