Education
Weighted Sampling for Combined Model Selection and Hyperparameter Tuning
Sarigiannis, Dimitrios, Parnell, Thomas, Pozidis, Haris
The combined algorithm selection and hyperparameter tuning (CASH) problem is characterized by large hierarchical hyperparameter spaces. Model-free hyperparameter tuning methods can explore such large spaces efficiently since they are highly parallelizable across multiple machines. When no prior knowledge or meta-data exists to boost their performance, these methods commonly sample random configurations following a uniform distribution. In this work, we propose a novel sampling distribution as an alternative to uniform sampling and prove theoretically that it has a better chance of finding the best configuration in a worst-case setting. In order to compare competing methods rigorously in an experimental setting, one must perform statistical hypothesis testing. We show that there is little-to-no agreement in the automated machine learning literature regarding which methods should be used. We contrast this disparity with the methods recommended by the broader statistics literature, and identify the most suitable approach. We then select three popular model-free solutions to CASH and evaluate their performance, with uniform sampling as well as the proposed sampling scheme, across 67 datasets from the OpenML platform. We investigate the trade-off between exploration and exploitation across the three algorithms, and verify empirically that the proposed sampling distribution improves performance in all cases.
Sparse Canonical Correlation Analysis via Concave Minimization
Solari, Omid S., Brown, James B., Bickel, Peter J.
A new approach to the sparse Canonical Correlation Analysis (sCCA)is proposed with the aim of discovering interpretable associations in very high-dimensional multi-view, i.e.observations of multiple sets of variables on the same subjects, problems. Inspired by the sparse PCA approach of Journee et al. (2010), we also show that the sparse CCA formulation, while non-convex, is equivalent to a maximization program of a convex objective over a compact set for which we propose a first-order gradient method. This result helps us reduce the search space drastically to the boundaries of the set. Consequently, we propose a two-step algorithm, where we first infer the sparsity pattern of the canonical directions using our fast algorithm, then we shrink each view, i.e. observations of a set of covariates, to contain observations on the sets of covariates selected in the previous step, and compute their canonical directions via any CCA algorithm. We also introduceDirected Sparse CCA, which is able to find associations which are aligned with a specified experiment design, andMulti-View sCCA which is used to discover associations between multiple sets of covariates. Our simulations establish the superior convergence properties and computational efficiency of our algorithm as well as accuracy in terms of the canonical correlation and its ability to recover the supports of the canonical directions. We study the associations between metabolomics, trasncriptomics and microbiomics in a multi-omic study usingMuLe, which is an R-package that implements our approach, in order to form hypotheses on mechanisms of adaptations of Drosophila Melanogaster to high doses of environmental toxicants, specifically Atrazine, which is a commonly used chemical fertilizer.
Prediction of rare feature combinations in population synthesis: Application of deep generative modelling
Garrido, Sergio, Borysov, Stanislav S., Pereira, Francisco C., Rich, Jeppe
In population synthesis applications, when considering populations with many attributes, a fundamental problem is the estimation of rare combinations of feature attributes. Unsurprisingly, it is notably more difficult to reliably representthe sparser regions of such multivariate distributions and in particular combinations of attributes which are absent from the original sample. In the literature this is commonly known as sampling zeros for which no systematic solution has been proposed so far. In this paper, two machine learning algorithms, from the family of deep generative models,are proposed for the problem of population synthesis and with particular attention to the problem of sampling zeros. Specifically, we introduce the Wasserstein Generative Adversarial Network (WGAN) and the Variational Autoencoder(VAE), and adapt these algorithms for a large-scale population synthesis application. The models are implemented on a Danish travel survey with a feature-space of more than 60 variables. The models are validated in a cross-validation scheme and a set of new metrics for the evaluation of the sampling-zero problem is proposed. Results show how these models are able to recover sampling zeros while keeping the estimation of truly impossible combinations, the structural zeros, at a comparatively low level. Particularly, for a low dimensional experiment, the VAE, the marginal sampler and the fully random sampler generate 5%, 21% and 26%, respectively, more structural zeros per sampling zero generated by the WGAN, while for a high dimensional case, these figures escalate to 44%, 2217% and 170440%, respectively. This research directly supports the development of agent-based systems and in particular cases where detailed socio-economic or geographical representations are required.
AI Can Now Pass School Tests but Still Falls Short on the Turing Test
From winning at Go to passing eighth grade level multiple choice tests, AI is making rapid advances. But its creativity still leaves much to be desired. On September 4, 2019, Peter Clark, along with several other researchers, published "From'F' to'A' on the N.Y. Regents Science Exams: An Overview of the Aristo Project " The Aristo project named in the title is hailed for the rapid improvement it has demonstrated when it tested the way eighth-grade human students in New York State are tested for their knowledge of science. The researchers concluded that this is an important milestone for AI: "Although Aristo only answers multiple choice questions without diagrams, and operates only in the domain of science, it nevertheless represents an important milestone towards systems that can read and understand. The momentum on this task has been remarkable, with accuracy moving from roughly 60% to over 90% in just three years."
"Father of Machine Learning", the Chief AI Scientist of Squirrel AI Learning, Tom Mitchell Delivered an Opening Speech at the 2019 World Artificial Intelligence Conference(WAIC): AI for a Brighter World๏ผ
SHANGHAI, China, Sept. 16, 2019 (GLOBE NEWSWIRE) -- On August 29th, with the theme of "Intelligent Connectivity, Infinite Possibilities", the 2019 World Artificial Intelligence Conference (WAIC), co-sponsored by the National Development and Reform Commission, the Ministry of Science and Technology, the Ministry of Industry and Information Technology, National Internet Information Office, Chinese Academy of Sciences, Chinese Academy of Engineering and Shanghai Municipal People's Government, was solemnly held in Shanghai. More than 500 top universities, international organizations and the world's most influential scientists, entrepreneurs and investors in the field of artificial intelligence gathered in Shanghai. Turing Award winners Raj Reddy and Manuel Blum, former Dean of the School of Computer Science at CMU & Chief AI Scientist of Squirrel AI Learning Tom Mitchell, Nobel Prize winner George Smoot, "Father of Machine Learning", Finn E. Kydland, Swiss AI Lab IDSIA Scientific Director Jรผrgen Schmidhuber Co-founder and CEO of Tesla Elon Musk, Chairman of the Board of Directors and CEO of Tencent Pony (Huateng) Ma, Co-chairman of the United Nations High-level Group on Digital Cooperation Jack Ma etc., delivered brilliant speeches and conversations respectively. In the top-leader conversation session, Elon Musk, Co-founder and CEO of Tesla, conducted an in-depth conversation with Jack Ma, Co-chairman of the United Nations High-level Group on Digital Cooperation. When it comes to education, Musk said, "The lecture is the worst because it's too slow. It's hard to make fewer mistakes for us in predicting the future, but you have to try first, and then to adjust it according to the errors you have predicted before."
7 Effective Ways to Deal With a Small Dataset
Big data and data science are concepts often heard together. It is believed that nowadays there are large amounts of data and that data science can draw valuable insights from all these terabytes of information. However, in a practical scenario, you will often have limited data to solve a problem. Gathering a big dataset can be prohibitively expensive or simply impossible (e.g., only having records from a certain time period when doing time series analysis). As a result, there is often no choice but to work with a small dataset, trying to get as accurate predictions as possible.
Blaming video games for school shootings may reflect racist beliefs, study says
People have long blamed video games as a cause of school shootings, but a new study has found that this is more likely to be the case if the perpetrator is white. Researchers have found that video games are eight times more likely to be mentioned when the perpetrator was a white male than if the shooter were an African American male. Experts believe the public looks to find an explanation for this type of behavior if the act is carried out by someone who doesn't match the racial stereotype of a violent person. Although many politicians and media outlets point to violent video games as the cause of school shootings, experts have yet to find scientific evidence to support these claims. 'Video games are often used by lawmakers and others as a red herring to distract from other potential causes of school shootings,' said lead researcher Patrick Markey, PhD, a psychology professor at Villanova University.
Lab - ReadyAI
ReadyAI Lab believes that all students should have access to artificial intelligence, not only students with computer science backgrounds or those who attend schools with highly developed technology programs. At ReadyAI Lab, we want to make AI learning a reality and help students to be empowered to use AI to change the world. ReadyAI's curriculum sparks curiosity, builds confidence, and fosters teamwork. We emphasize both STEM education and the non-technical components of learning such as collaboration, teamwork, problem-solving, performing arts, and multimedia presentations. Create projects that use AI to help address society's greatest needs in healthcare, transportation, public safety, and many more areas.
Courses on AI for class 9 students must be according to industry needs: HRD Minister
Human Resource Development Minister Ramesh Pokhriyal'Nishank' instructed officials of his ministry to develop the syllabus on artificial intelligence introduced by the Central Board of Secondary Education (CBSE) for Class 9 students according to the needs of the industrial sector. The CBSE introduced artificial intelligence as an optional subject for Class 9 from this academic session. IIT Kharagpur too began a six-month course on it recently, the minister said. "The courses of Artificial Intelligence, from school education to higher education level should be designed according to the needs of the industrial sector. There is no dearth of talent among our students. Surely the best results will come out," Nishank said at the launch of two initiatives under the Department of Higher Education at Pravasi Bharatiya Kendra here.