Statistical Learning
FlyingSquid: A Python Framework For Interactive Weak Supervision
In this research article, we will be discussing keypoints about FlyingSquid through the paper'Fast and Three-rious: Speeding Up Weak Supervision with Triplet Methods' published in 2020 by Stanford Researchers. Weak supervision is a common method for building machine learning models without relying on ground truth annotations. It generates probabilistic training labels by estimating the accuracy of multiple noisy labeling sources (e.g., heuristics). While it might seem like the easiest way to get started with ML, weak supervised training can be costly and time-consuming in practice. A group of computer science researchers from Stanford University shows that, for a class of latent variable models highly applicable to weak supervision, they could find an explicit closed-form solution obviating the need for iterative solutions like stochastic gradient descent (SGD). The research team used these insights to build the FlyingSquid framework, which is faster than previous weak supervision approaches and requires fewer assumptions.
Importance Of Artificial Intelligence In ECM - ONPASSIVE
Enterprise content management (ECM) technologies assist businesses in maximizing the value of structured and unstructured data. These systems are also known as Content Services Platforms, owing to their expanding breadth (CSPs). Most ECM systems still use rules-based techniques to extract, categorize, and enrich data, even though they used previous artificial intelligence technologies no longer labeled AI. Companies can execute standard ECM or CSP applications in a more automated manner with greater levels of compliance thanks to developments in artificial intelligence, machine learning, and intense learning. Traditional ECM firms are creating AI skills to catch up as new vendors emerge to supply these capabilities.
What is Artificial Intelligence?
Before we get on with the topic let me introduce myself!! Coz the reason you are here might be because you want to jump onto the AI bandwagon to make a carrier out it. My story, though incomplete, may encourage you to hop on or may persuade you to pursue some other stuff. I never was hard working, but always had interest in highly technical stuff. In my high-school or college I was interested in physics. I studied graduate level physics in high-school itself.
DXML: Distributed Extreme Multilabel Classification
As a big data application, extreme multilabel classification has emerged as an important research topic with applications in ranking and recommendation of products and items. A scalable hybrid distributed and shared memory implementation of extreme classification for large scale ranking and recommendation is proposed. In particular, the implementation is a mix of message passing using MPI across nodes and using multithreading on the nodes using OpenMP. The expression for communication latency and communication volume is derived. Parallelism using work-span model is derived for shared memory architecture. This throws light on the expected scalability of similar extreme classification methods. Experiments show that the implementation is relatively faster to train and test on some large datasets. In some cases, model size is relatively small.
OMB-Py: Python Micro-Benchmarks for Evaluating Performance of MPI Libraries on HPC Systems
Alnaasan, Nawras, Jain, Arpan, Shafi, Aamir, Subramoni, Hari, Panda, Dhabaleswar K
Python has become a dominant programming language for emerging areas like Machine Learning (ML), Deep Learning (DL), and Data Science (DS). An attractive feature of Python is that it provides easy-to-use programming interface while allowing library developers to enhance performance of their applications by harnessing the computing power offered by High Performance Computing (HPC) platforms. Efficient communication is key to scaling applications on parallel systems, which is typically enabled by the Message Passing Interface (MPI) standard and compliant libraries on HPC hardware. mpi4py is a Python-based communication library that provides an MPI-like interface for Python applications allowing application developers to utilize parallel processing elements including GPUs. However, there is currently no benchmark suite to evaluate communication performance of mpi4py -- and Python MPI codes in general -- on modern HPC systems. In order to bridge this gap, we propose OMB-Py -- Python extensions to the open-source OSU Micro-Benchmark (OMB) suite -- aimed to evaluate communication performance of MPI-based parallel applications in Python. To the best of our knowledge, OMB-Py is the first communication benchmark suite for parallel Python applications. OMB-Py consists of a variety of point-to-point and collective communication benchmark tests that are implemented for a range of popular Python libraries including NumPy, CuPy, Numba, and PyCUDA. We also provide Python implementation for several distributed ML algorithms as benchmarks to understand the potential gain in performance for ML/DL workloads. Our evaluation reveals that mpi4py introduces a small overhead when compared to native MPI libraries. We also evaluate the ML/DL workloads and report up to 106x speedup on 224 CPU cores compared to sequential execution. We plan to publicly release OMB-Py to benefit Python HPC community.
CIM-PPO:Proximal Policy Optimization with Liu-Correntropy Induced Metric
Guo, Yunxiao, Long, Han, Duan, Xiaojun, Feng, Kaiyuan, Li, Maochu, Ma, Xiaying
As an algorithm based on deep reinforcement learning, Proximal Policy Optimization (PPO) performs well in many complex tasks and has become one of the most popular RL algorithms in recent years. According to the mechanism of penalty in surrogate objective, PPO can be divided into PPO with KL Divergence (KL-PPO) and PPO with Clip function(Clip-PPO). Clip-PPO is widely used in a variety of practical scenarios and has attracted the attention of many researchers. Therefore, many variations have also been created, making the algorithm better and better. However, as a more theoretical algorithm, KL-PPO was neglected because its performance was not as good as CliP-PPO. In this article, we analyze the asymmetry effect of KL divergence on PPO's objective function , and give the inequality that can indicate when the asymmetry will affect the efficiency of KL-PPO. Proposed PPO with Correntropy Induced Metric algorithm(CIM-PPO) that use the theory of correntropy(a symmetry metric method that was widely used in M-estimation to evaluate two distributions' difference)and applied it in PPO. Then, we designed experiments based on OpenAIgym to test the effectiveness of the new algorithm and compare it with KL-PPO and CliP-PPO.
Iterated Block Particle Filter for High-dimensional Parameter Learning: Beating the Curse of Dimensionality
Ning, Ning, Ionides, Edward L.
Parameter learning for high-dimensional, partially observed, and nonlinear stochastic processes is a methodological challenge. Spatiotemporal disease transmission systems provide examples of such processes giving rise to open inference problems. We propose the iterated block particle filter (IBPF) algorithm for learning high-dimensional parameters over graphical state space models with general state spaces, measures, transition densities and graph structure. Theoretical performance guarantees are obtained on beating the curse of dimensionality (COD), algorithm convergence, and likelihood maximization. Experiments on a highly nonlinear and non-Gaussian spatiotemporal model for measles transmission reveal that the iterated ensemble Kalman filter algorithm (Li et al. (2020)) is ineffective and the iterated filtering algorithm (Ionides et al. (2015)) suffers from the COD, while our IBPF algorithm beats COD consistently across various experiments with different metrics.
Estimating Optimal Infinite Horizon Dynamic Treatment Regimes via pT-Learning
Zhou, Wenzhuo, Zhu, Ruoqing, Qu, Annie
Recent advances in mobile health (mHealth) technology provide an effective way to monitor individuals' health statuses and deliver just-in-time personalized interventions. However, the practical use of mHealth technology raises unique challenges to existing methodologies on learning an optimal dynamic treatment regime. Many mHealth applications involve decision-making with large numbers of intervention options and under an infinite time horizon setting where the number of decision stages diverges to infinity. In addition, temporary medication shortages may cause optimal treatments to be unavailable, while it is unclear what alternatives can be used. To address these challenges, we propose a Proximal Temporal consistency Learning (pT-Learning) framework to estimate an optimal regime that is adaptively adjusted between deterministic and stochastic sparse policy models. The resulting minimax estimator avoids the double sampling issue in the existing algorithms. It can be further simplified and can easily incorporate off-policy data without mismatched distribution corrections. We study theoretical properties of the sparse policy and establish finite-sample bounds on the excess risk and performance error. The proposed method is implemented by our proximalDTR package and is evaluated through extensive simulation studies and the OhioT1DM mHealth dataset.
Online non-parametric change-point detection for heterogeneous data streams observed over graph nodes
de la Concha, Alejandro, Kalogeratos, Argyris, Vayatis, Nicolas
Consider a heterogeneous data stream being generated by the nodes of a graph. The data stream is in essence composed by multiple streams, possibly of different nature that depends on each node. At a given moment $\tau$, a change-point occurs for a subset of nodes $C$, signifying the change in the probability distribution of their associated streams. In this paper we propose an online non-parametric method to infer $\tau$ based on the direct estimation of the likelihood-ratio between the post-change and the pre-change distribution associated with the data stream of each node. We propose a kernel-based method, under the hypothesis that connected nodes of the graph are expected to have similar likelihood-ratio estimates when there is no change-point. We demonstrate the quality of our method on synthetic experiments and real-world applications.