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On the Sample Complexity of Rank Regression from Pairwise Comparisons

arXiv.org Machine Learning

We consider a rank regression setting, in which a dataset of $N$ samples with features in $\mathbb{R}^d$ is ranked by an oracle via $M$ pairwise comparisons. Specifically, there exists a latent total ordering of the samples; when presented with a pair of samples, a noisy oracle identifies the one ranked higher with respect to the underlying total ordering. A learner observes a dataset of such comparisons and wishes to regress sample ranks from their features. We show that to learn the model parameters with $\epsilon > 0$ accuracy, it suffices to conduct $M \in \Omega(dN\log^3 N/\epsilon^2)$ comparisons uniformly at random when $N$ is $\Omega(d/\epsilon^2)$.


HASCO: Towards Agile HArdware and Software CO-design for Tensor Computation

arXiv.org Artificial Intelligence

Tensor computations overwhelm traditional general-purpose computing devices due to the large amounts of data and operations of the computations. They call for a holistic solution composed of both hardware acceleration and software mapping. Hardware/software (HW/SW) co-design optimizes the hardware and software in concert and produces high-quality solutions. There are two main challenges in the co-design flow. First, multiple methods exist to partition tensor computation and have different impacts on performance and energy efficiency. Besides, the hardware part must be implemented by the intrinsic functions of spatial accelerators. It is hard for programmers to identify and analyze the partitioning methods manually. Second, the overall design space composed of HW/SW partitioning, hardware optimization, and software optimization is huge. The design space needs to be efficiently explored. To this end, we propose an agile co-design approach HASCO that provides an efficient HW/SW solution to dense tensor computation. We use tensor syntax trees as the unified IR, based on which we develop a two-step approach to identify partitioning methods. For each method, HASCO explores the hardware and software design spaces. We propose different algorithms for the explorations, as they have distinct objectives and evaluation costs. Concretely, we develop a multi-objective Bayesian optimization algorithm to explore hardware optimization. For software optimization, we use heuristic and Q-learning algorithms. Experiments demonstrate that HASCO achieves a 1.25X to 1.44X latency reduction through HW/SW co-design compared with developing the hardware and software separately.


Implicit Regularization in Deep Tensor Factorization

arXiv.org Artificial Intelligence

Attempts of studying implicit regularization associated to gradient descent (GD) have identified matrix completion as a suitable test-bed. Late findings suggest that this phenomenon cannot be phrased as a minimization-norm problem, implying that a paradigm shift is required and that dynamics has to be taken into account. In the present work we address the more general setup of tensor completion by leveraging two popularized tensor factorization, namely Tucker and TensorTrain (TT). We track relevant quantities such as tensor nuclear norm, effective rank, generalized singular values and we introduce deep Tucker and TT unconstrained factorization to deal with the completion task. Experiments on both synthetic and real data show that gradient descent promotes solution with low-rank, and validate the conjecture saying that the phenomenon has to be addressed from a dynamical perspective.


A learning gap between neuroscience and reinforcement learning

arXiv.org Artificial Intelligence

Historically, artificial intelligence has drawn much inspiration from neuroscience to fuel advances in the field. However, current progress in reinforcement learning is largely focused on benchmark problems that fail to capture many of the aspects that are of interest in neuroscience today. We illustrate this point by extending a T-maze task from neuroscience for use with reinforcement learning algorithms, and show that state-of-the-art algorithms are not capable of solving this problem. Finally, we point out where insights from neuroscience could help explain some of the issues encountered.


Global Artificial Intelligence (AI) in BFSI Market Research Report 2021 โ€“ NeighborWebSJ

#artificialintelligence

Western Market Research-WMR Private Limited is a leading global consulting and market research company in India. We offer business intelligence and support to our client for business growth.We analyze the data and create an algorithm that provides specific insights, which are highly valued in the industry.WMR focus on strategies, future estimations, growth, opportunity analysis, and consumer survey by market experts.We care about the client data privacy and authenticity, Western Market Research has worked hard building our legacy of outstanding service, expertise, efficiency and integrity.


Looking at your phone makes other people do the same, study finds

Daily Mail - Science & tech

Looking at your phone makes other people nearby do the same in less than a minute, a new study reveals. Researchers in Italy investigated human'mimicry' or the'chameleon effect' โ€“ subconsciously replicating the physical actions of another human. Out of 184 people, half replicated the action of touching and looking at their phone 30 seconds after a subconscious trigger, researchers found. The experts say copying smartphone use is similar to the well-known'contagious yawning' phenomenon, when an individual yawns in response to someone else doing so. Mammals have evolved to subconsciously mimic each others' behaviour without knowing it.


NC State preparing students for artificial intelligence as tech companies come to Triangle

#artificialintelligence

It's something most people use without realizing it. From phones to search engines, social media, and smart devices in homes -- each uses artificial intelligence technology. "When we have our conversational assistance in our homes and we're talking with one of these and we're asking what's the weather going to be like or what's the capital of Tanzania. Those are kind of questions that are easy to answer," said North Carolina State University Distinguished Professor James Lester. Lester is also the Director of the Center for Educational Informatics where they conduct research on AI technologies for education.


Learning Good State and Action Representations via Tensor Decomposition

arXiv.org Machine Learning

The transition kernel of a continuous-state-action Markov decision process (MDP) admits a natural tensor structure. This paper proposes a tensor-inspired unsupervised learning method to identify meaningful low-dimensional state and action representations from empirical trajectories. The method exploits the MDP's tensor structure by kernelization, importance sampling and low-Tucker-rank approximation. This method can be further used to cluster states and actions respectively and find the best discrete MDP abstraction. We provide sharp statistical error bounds for tensor concentration and the preservation of diffusion distance after embedding.


Attention-augmented Spatio-Temporal Segmentation for Land Cover Mapping

arXiv.org Artificial Intelligence

The availability of massive earth observing satellite data provide huge opportunities for land use and land cover mapping. However, such mapping effort is challenging due to the existence of various land cover classes, noisy data, and the lack of proper labels. Also, each land cover class typically has its own unique temporal pattern and can be identified only during certain periods. In this article, we introduce a novel architecture that incorporates the UNet structure with Bidirectional LSTM and Attention mechanism to jointly exploit the spatial and temporal nature of satellite data and to better identify the unique temporal patterns of each land cover. We evaluate this method for mapping crops in multiple regions over the world. We compare our method with other state-of-the-art methods both quantitatively and qualitatively on two real-world datasets which involve multiple land cover classes. We also visualise the attention weights to study its effectiveness in mitigating noise and identifying discriminative time period.


An Examination of Fairness of AI Models for Deepfake Detection

arXiv.org Artificial Intelligence

Recent studies have demonstrated that deep learning models can discriminate based on protected classes like race and gender. In this work, we evaluate bias present in deepfake datasets and detection models across protected subgroups. Using facial datasets balanced by race and gender, we examine three popular deepfake detectors and find large disparities in predictive performances across races, with up to 10.7% difference in error rate between subgroups. A closer look reveals that the widely used FaceForensics++ dataset is overwhelmingly composed of Caucasian subjects, with the majority being female Caucasians. Our investigation of the racial distribution of deepfakes reveals that the methods used to create deepfakes as positive training signals tend to produce "irregular" faces - when a person's face is swapped onto another person of a different race or gender. This causes detectors to learn spurious correlations between the foreground faces and fakeness. Moreover, when detectors are trained with the Blended Image (BI) dataset from Face X-Rays, we find that those detectors develop systematic discrimination towards certain racial subgroups, primarily female Asians.