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The SP theory of intelligence: an overview

arXiv.org Artificial Intelligence

This article is an overview of the "SP theory of intelligence". The theory aims to simplify and integrate concepts across artificial intelligence, mainstream computing and human perception and cognition, with information compression as a unifying theme. It is conceived as a brain-like system that receives 'New' information and stores some or all of it in compressed form as 'Old' information. It is realised in the form of a computer model -- a first version of the SP machine. The concept of "multiple alignment" is a powerful central idea. Using heuristic techniques, the system builds multiple alignments that are 'good' in terms of information compression. For each multiple alignment, probabilities may be calculated. These provide the basis for calculating the probabilities of inferences. The system learns new structures from partial matches between patterns. Using heuristic techniques, the system searches for sets of structures that are 'good' in terms of information compression. These are normally ones that people judge to be 'natural', in accordance with the 'DONSVIC' principle -- the discovery of natural structures via information compression. The SP theory may be applied in several areas including 'computing', aspects of mathematics and logic, representation of knowledge, natural language processing, pattern recognition, several kinds of reasoning, information storage and retrieval, planning and problem solving, information compression, neuroscience, and human perception and cognition. Examples include the parsing and production of language including discontinuous dependencies in syntax, pattern recognition at multiple levels of abstraction and its integration with part-whole relations, nonmonotonic reasoning and reasoning with default values, reasoning in Bayesian networks including 'explaining away', causal diagnosis, and the solving of a geometric analogy problem.


Reconstructing subclonal composition and evolution from whole genome sequencing of tumors

arXiv.org Machine Learning

Tumors contain multiple, genetically diverse subclonal populations of cells that have evolved from a single progenitor population through successive waves of expansion and selection [1-3]. Reconstructing their evolutionary histories can help identify characteristic driver mutations associated with cancer development and progression [4, 5]; and can provide insight into how tumors might respond to treatment [6, 7]. In some cases, it is possible to genotype the subpopulations present in a tumor, while reconstructing its history, using the population frequencies of mutations that distinguish these subclonal populations [2, 8-21]. Increasingly, tumors are being characterized using whole genome sequencing (WGS) of bulk tumor samples [22] and few automated methods exist to reliably perform this reconstruction on the basis of these data. Subclonal reconstruction algorithms attempt to infer the population structure of heterogeneous tumors based on the measured variant allelic frequency (VAF) of their somatic mutations.


An Effective Semi-supervised Divisive Clustering Algorithm

arXiv.org Machine Learning

Diverse experimental data ranging from microarray gene expression data in biology to spectrum data in astronomy require to be clustered to signal meaningful correlation of the data. Massive documents or images on internet are also needed to be effectively organized so as to promote the efficiency of search engines. Clustering method as K-means (1) is popular for its simplicity, yet sensitive to noise and initialization and thus is limited by the lack of reliability. Hierarchical clustering (HC) (2) is simple and intuitive and thus widely used especially in biology (3), whereas it needs a large computation (4) and its result is variable to a set of similarity measures between clusters. Moreover, the cluster number for the above methods needs to be prespecified (e.g., K-means) or determined by a threshold (e.g., HC). Some other well-known algorithms either involve complex optimization and postprocessing (5), or have limited range of applications such as the distribution (6) or the attribute of data (7, 8). Although affinity propagation (AP) (9) has much better performance than K-means and the cluster number is determined automatically, it is not good at detecting nonspherical clusters (10). Recently, two effective clustering algorithms (10, 11) were proposed, which can together form a pool of clustering methods based on the in-tree structure (11). But they involve a free parameter.


Inverse Renormalization Group Transformation in Bayesian Image Segmentations

arXiv.org Machine Learning

Graduate School of Informatics, Kyoto University, 36-1 Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 Japan A new Bayesian image segmentation algorithm is proposed by combining a loopy belief propagation with an inverse real space renormalization group transformation to reduce the computational time. In results of our experiment, we observe that the proposed method can reduce the computational time to less than one-tenth of that taken by conventional Bayesian approaches. Bayesian segmentation modeling based on Markov random fields (MRF's) is one of the interesting research topics We consider an image as defined on a set of pixels arranged on a square grid graph (V,E). HereV { i i 1, 2,ยทยทยท, V } denotes the set of all the pixels andE is the set of all the nearest-neighbour pairs of pixels{ i,j} . The total numbers of elements in the setsV and E are denoted by V and E, respectively.


A generalization error bound for sparse and low-rank multivariate Hawkes processes

arXiv.org Machine Learning

Understanding the dynamics of social interactions is a challenging problem of fastly growing interest [11, 20, 9, 21] because of the large number of applications in web-advertisement and e-commerce, where large-scale logs of event history are available. A common supervised approach consists in the prediction of labels based on declared interactions (friendship, like, follower, etc.) However such supervision is not always available, and it does not always describe accurately the level of interactions between users. Labels are often only binary while a quantification of the interaction is more interesting, declared interactions are often deprecated, and more generally a supervised approach is not enough to infer the latent communities of users, as temporal patterns of actions of users are much more informative. A recent set of papers [32, 14, 10] consider an approach for recovering latent social groups directly based on the real actions or events of users, called also nodes in the following, that uses only the timestamps patterns of the considered events. The models assume a structure of data consisting in a sequence of independent cascades, containing timestamps for each nodes.


Concave Penalized Estimation of Sparse Gaussian Bayesian Networks

arXiv.org Machine Learning

We develop a penalized likelihood estimation framework to estimate the structure of Gaussian Bayesian networks from observational data. In contrast to recent methods which accelerate the learning problem by restricting the search space, our main contribution is a fast algorithm for score-based structure learning which does not restrict the search space in any way and works on high-dimensional datasets with thousands of variables. Our use of concave regularization, as opposed to the more popular $\ell_0$ (e.g. BIC) penalty, is new. Moreover, we provide theoretical guarantees which generalize existing asymptotic results when the underlying distribution is Gaussian. Most notably, our framework does not require the existence of a so-called faithful DAG representation, and as a result the theory must handle the inherent nonidentifiability of the estimation problem in a novel way. Finally, as a matter of independent interest, we provide a comprehensive comparison of our approach to several standard structure learning methods using open-source packages developed for the R language. Based on these experiments, we show that our algorithm is significantly faster than other competing methods while obtaining higher sensitivity with comparable false discovery rates for high-dimensional data. In particular, the total runtime for our method to generate a solution path of 20 estimates for DAGs with 8000 nodes is around one hour.


The Learnability of Unknown Quantum Measurements

arXiv.org Machine Learning

Quantum machine learning has received significant attention in recent years, and promising progress has been made in the development of quantum algorithms to speed up traditional machine learning tasks. In this work, however, we focus on investigating the information-theoretic upper bounds of sample complexity - how many training samples are sufficient to predict the future behaviour of an unknown target function. This kind of problem is, arguably, one of the most fundamental problems in statistical learning theory and the bounds for practical settings can be completely characterised by a simple measure of complexity. Our main result in the paper is that, for learning an unknown quantum measurement, the upper bound, given by the fat-shattering dimension, is linearly proportional to the dimension of the underlying Hilbert space. Learning an unknown quantum state becomes a dual problem to ours, and as a byproduct, we can recover Aaronson's famous result [Proc. R. Soc. A 463:3089-3144 (2007)] solely using a classical machine learning technique. In addition, other famous complexity measures like covering numbers and Rademacher complexities are derived explicitly. We are able to connect measures of sample complexity with various areas in quantum information science, e.g. quantum state/measurement tomography, quantum state discrimination and quantum random access codes, which may be of independent interest. Lastly, with the assistance of general Bloch-sphere representation, we show that learning quantum measurements/states can be mathematically formulated as a neural network. Consequently, classical ML algorithms can be applied to efficiently accomplish the two quantum learning tasks.


A Taxonomy of Big Data for Optimal Predictive Machine Learning and Data Mining

arXiv.org Machine Learning

Big data comes in various ways, types, shapes, forms and sizes. Indeed, almost all areas of science, technology, medicine, public health, economics, business, linguistics and social science are bombarded by ever increasing flows of data begging to analyzed efficiently and effectively. In this paper, we propose a rough idea of a possible taxonomy of big data, along with some of the most commonly used tools for handling each particular category of bigness. The dimensionality p of the input space and the sample size n are usually the main ingredients in the characterization of data bigness. The specific statistical machine learning technique used to handle a particular big data set will depend on which category it falls in within the bigness taxonomy. Large p small n data sets for instance require a different set of tools from the large n small p variety. Among other tools, we discuss Preprocessing, Standardization, Imputation, Projection, Regularization, Penalization, Compression, Reduction, Selection, Kernelization, Hybridization, Parallelization, Aggregation, Randomization, Replication, Sequentialization. Indeed, it is important to emphasize right away that the so-called no free lunch theorem applies here, in the sense that there is no universally superior method that outperforms all other methods on all categories of bigness. It is also important to stress the fact that simplicity in the sense of Ockham's razor non plurality principle of parsimony tends to reign supreme when it comes to massive data. We conclude with a comparison of the predictive performance of some of the most commonly used methods on a few data sets.


Automated Scheduling for NASA's Deep Space Network

AI Magazine

This article describes the DSN scheduling wngine (DSE) component of a new scheduling system being deployed for NASA's deep space network. The DSE provides core automation functionality for scheduling the network, including the interpretation of scheduling requirements expressed by users, their elaboration into tracking passes, and the resolution of conflicts and constraint violations. It has been integrated with a web application which provides DSE functionality to all DSN users through a standard web browser, as part of a peer-to-peer schedule negotiation process for the entire network. The system has been deployed operationally and is in routine use, and is in the process of being extended to support long-range planning and forecasting, and near-real-time scheduling.


Leveraging Multiple Artificial Intelligence Techniques to Improve the Responsiveness in Operations Planning: ASPEN for Orbital Express

AI Magazine

The challenging timeline for DARPA's Orbital Express mission demanded a flexible, responsive, and (above all) safe approach to mission planning. Mission planning for space is challenging because of the mixture of goals and constraints. These technologies had a significant impact on the success of the Orbital Express mission. Finally, we formulated a technique for converting procedural information to declarative information by transforming procedures into models of hierarchical task networks (HTNs).