LibreTimes

Search results for “метод наименьших квадратов”

45 results

Machine Learning 1. Lecture 12. Density Estimation and Bayesian Classification

2026LectureКонстантин Вячеславович Воронцов

Estimating a probability density from a sample: the maximum likelihood principle, the multivariate Gaussian density and its geometric meaning, multicollinearity and regularisation of the covariance matrix; separating a mixture of distributions, the EM algorithm as a method of simple iterations, the Gaussian mixture (GMM); the nonparametric Parzen–Rosenblatt estimate, the choice of kernel and window width; Bayesian classification theory: the generative and discriminative approaches, the optimal Bayes classifier, the Parzen window method, the quadratic discriminant, Fisher's linear discriminant, the radial basis function network and its training by the EM algorithm.
0
160

Machine Learning 2. Lecture 1. Deep Neural Networks

2026LectureКонстантин Вячеславович Воронцов

Reminder: the neuron model, the multilayer network, stochastic gradient, momentum, vanishing and exploding gradients, ReLU, dropout, batch normalisation; depth matters more than width; feature generation and end-to-end learning; convolutional neural networks: convolution and pooling layers, the standard CNN scheme, AlexNet and ImageNet, residual networks ResNet and Highway Networks; convolutional networks for speech, texts and games; recurrent neural networks, training by BPTT, long short-term memory networks LSTM, the peephole variant, GRU.
1
390

Machine Learning 2. Lecture 2. Neural Networks for Unsupervised Learning

2026LectureКонстантин Вячеславович Воронцов

Kohonen networks: clustering as a two-layer neural network, the hard (WTA) and soft (WTM) competition rules, self-organising Kohonen maps and their interpretation; autoencoders: the formulation of the problem, the linear autoencoder and the principal component method, sparse, denoising, contractive, relational and variational autoencoders, reparametrisation, autoencoders for supervised learning, multilayer autoencoders; joint training of several models: pre-training and transfer learning, multi-task learning and few-shot learning, self-supervised learning, distillation and surrogate modelling, learning using privileged information (LUPI), generative adversarial networks (GAN).
0
210

Machine Learning 1. Generalization Theory

2026LectureКонстантин Вячеславович Воронцов

The problem of estimating generalization ability; the error matrix and the probability of overfitting; the case of a single algorithm and the hypergeometric distribution; the principle of uniform convergence of frequencies and Boole's inequality; the Vapnik–Chervonenkis bound, the growth function and the capacity of a family of algorithms; inverting the bound and the complexity penalty; structural risk minimization; the splitting and similarity effects; the Occam's razor bound and its link to regularization.
0
140

Machine Learning 1. Bayesian Classification Theory

2026LectureКонстантин Вячеславович Воронцов

The probabilistic formulation of classification: prior and posterior class probabilities, class likelihood functions, the maximum a posteriori principle; the optimal Bayes classifier and losses from errors; empirical estimation of prior probabilities and class densities; the naive Bayes classifier, features with exponential-family densities and the linear naive Bayes classifier; a survey of Bayesian classifiers: the Parzen window method, the quadratic discriminant, Fisher's linear discriminant, Gaussian mixtures with diagonal covariance matrices, and the radial basis function network.
0
180

Machine Learning 1. Lecture 13. Clustering and Semi-Supervised Learning

2026LectureКонстантин Вячеславович Воронцов

The clustering problem and its ill-posedness, the aims of clustering, types of cluster structure, sensitivity to the choice of metric; the problem of semi-supervised learning and transductive learning, why it reduces neither to classification nor to clustering; criteria of clustering quality, the silhouette coefficient, the BCubed measures of precision and recall; the k-means method (Lloyd's algorithm) as a simplification of the EM algorithm for a mixture of Gaussians; the DBSCAN algorithm; agglomerative hierarchical clustering, the Lance–Williams formula and its special cases, the dendrogram, monotonicity, contracting and dilating distances, Ward's distance; semi-supervised learning based on classification: self-training, co-training, co-learning, the transductive SVM, expectation regularisation (XR).
0
280

Machine Learning 2. Lecture 3. Vector Representations of Texts and Graphs

2026LectureКонстантин Вячеславович Воронцов

Vector representations (embeddings) of texts and graphs: the distributional semantics hypothesis, syntagmatic and paradigmatic similarity of words, the CBOW and Skip-gram models of the word2vec program, hierarchical SoftMax on a Huffman tree, negative sampling (SGNS) and the connection of word2vec with the matrix factorisation of the PMI matrix, semantic analogies of words, the FastText model on character n-grams; texts as graphs; multidimensional scaling and the stress criterion, stochastic neighbour embedding SNE, perplexity, t-SNE; matrix factorisations of graphs, the random-walk models DeepWalk and node2vec; graph embedding methods as autoencoders, the generalised GraphEDM model, graph neural networks and message passing.
0
250

Machine Learning 2. Lecture 8. Association Rule Mining

2026LectureКонстантин Вячеславович Воронцов

Association rule mining as unsupervised learning: binary features, support and frequent itemsets, the association rule, minimum support MinSupp and minimum confidence MinConf; market basket analysis; the link between association rules and logical regularities; the anti-monotonicity of support; the APriori algorithm: breadth-first search for frequent itemsets and recursive extraction of rules; modifications: search on a random subsample, item hierarchies, incremental and decremental algorithms; the FP-growth algorithm: the prefix FP-tree, building it in one pass over the transaction database, computing the support of any itemset from the tree, the conditional FP-tree and recursive search for frequent itemsets; the speed of FP-growth compared with APriori.
0
160

Machine Learning. Additional Lecture 1. The Theory of Overfitting

2026LectureКонстантин Вячеславович Воронцов

The combinatorial theory of overfitting: the probability of overfitting and why the Vapnik–Chervonenkis bounds are loose; experiments with overfitting — a monotone chain of algorithms, the effect of splitting and connectivity of the family on the probability of overfitting and on the complete cross-validation estimate, overfitting of chains, the exact formula for the probability of overfitting when choosing between two algorithms; the splitting–connectivity graph of a family of algorithms, examples for linear classifiers, a monotone chain and a two-dimensional net; generating and forbidden sets, upper connectivity and inferiority of an algorithm; the splitting–connectivity upper bound, the idea of its proof and its properties.
1
220

Probability Theory. Lecture 1

2026LectureСтанислав Шапошников

The finite probability space and five properties of probability, a description of all probability measures on a finite set, equally likely outcomes and the choice of a model, classical paradoxes (two dice, the division of the stakes, Bertrand's paradox), conditional probability and the product rule, the law of total probability as a way to define a measure, Bayes' formula, independence of events.
0
170
Станислав Шапошников
@shaposhnikov

Станислав Валерьевич Шапошников — профессор кафедры математического анализа механико-математического факультета МГУ имени М. В. Ломоносова (с 2014 года) и профессор факультета математики НИУ ВШЭ (с 2013 года). Доктор физико-математических наук. Окончил мехмат МГУ в 2006 году. Кандидатская диссертация «Эллиптические уравнения для мер» (2009); докторская — «Качественные свойства стационарных распределений и переходных вероятностей диффузионных процессов» (2011), защищена в 27 лет. Специалист по уравнениям Фоккера–Планка–Колмогорова. Разработал метод перенормировки решений и в соавторстве решил задачу А. Н. Колмогорова о единственности вероятностных решений уравнений Фоккера–Планка–Колмогорова; предложил новый подход к регулярности решений эллиптических уравнений в дважды дивергентной форме. Лауреат премии имени А. Н. Колмогорова РАН (2018) за цикл работ «Стационарные уравнения Колмогорова», премии Правительства Москвы молодым учёным (2017) и премии имени И. И. Шувалова (2012) за докторскую диссертацию. Читает курсы анализа и теории вероятностей в МГУ и НИУ ВШЭ; в Независимом московском университете осенью 2026 года читает «Математический анализ-1» и «Теорию вероятностей».

Machine Learning 1. Lecture 9. Logical Classification Methods

2026LectureКонстантин Вячеславович Воронцов

The interpretability of models; decision trees and the greedy ID3 algorithm; the axioms of impurity, the entropy and Gini criteria; handling missing values; the merits and drawbacks of the greedy strategy; tree pruning (post-pruning); CART regression trees and Minimal Cost-Complexity Pruning; rule induction: logical regularities, families of rules (conjunctions, syndromes, half-planes, balls), search metaheuristics, a tree as a covering set of conjunctions; the Pareto front in (p,n) space, logical and statistical regularities, Fisher's exact test, informativeness criteria; building a classifier from regularities.
0
160

Machine Learning 2. Lecture 6. Learning to Rank

2026LectureКонстантин Вячеславович Воронцов

The learning-to-rank problem: recovering a partial order relation, the pointwise, pairwise and listwise approaches, the linear ranking model, applications; ordinal regression and the ordinal SVM (SVOR); the pairwise criterion, Ranking SVM, RankNet, the transition to the listwise method LambdaRank; ranking search results: query–document objects, assessor ratings, text, link and click features, TF-IDF and its probabilistic meaning, Okapi BM25, PageRank; quality criteria: precision and recall, MAP, the share of defective pairs and its link with AUC, DCG and NDCG, the pFound user behaviour model; the DSSM neural model: a siamese network, word hashing by letter trigrams, training on clicks with negative sampling.
0
130

Machine Learning 1. Lecture 8. Feature Selection, Model Evaluation and Model Selection

2026LectureКонстантин Вячеславович Воронцов

Measures of classification quality: type I and type II errors, the ROC curve and AUC, gradient maximization of AUC, log-loss, precision and recall, micro- and macro-averaging, the F-measure; internal and external criteria of generalization ability; hold-out, leave-one-out, q-fold and t×q-fold cross-validation, stratification; model consistency; regularization, AIC, BIC and the Vapnik–Chervonenkis bound; multi-criteria model selection; feature selection: full search, Add, Add-Del, depth-first search, beam search (GMDH), the genetic algorithm and random search with adaptation.
0
150

Topology 2. Lecture 1

2026LectureФёдор Вылегжанин

Why homology is needed — the fundamental group as a functor, homotopy groups, bordism and its combinatorial approximation; chain complexes and their homology; abstract simplicial complexes, geometric realisation and triangulations; the complex of simplicial chains, the proof of d2=0d^2 = 0, the simplicial homology of a segment, of two points and of the boundary of a triangle; reduced homology.

1
470
Константин Вячеславович Воронцов
@konstantin_vorontsov

Константин Вячеславович Воронцов — профессор РАН, доктор физико-математических наук. Заведующий кафедрой «Математические методы прогнозирования» ВМК МГУ, где с 2021 года — профессор; заведующий лабораторией «Машинное обучение и семантический анализ» Института искусственного интеллекта МГУ (с 2022 года); заведующий кафедрой «Машинное обучение и цифровая гуманитаристика» МФТИ (с 2021 года); заведующий кафедрой «Интеллектуальные системы» МФТИ (с 2022 года), на которой работает с 2004 года; главный научный сотрудник отдела «Интеллектуальные системы» ВЦ ФИЦ ИУ РАН, где работает с 2001 года. Окончил МФТИ (1994) и аспирантуру ВЦ РАН (1997). Кандидатская диссертация «Локальные базисы в алгебраическом подходе к проблеме распознавания» (1999, специальность 01.01.09); докторская диссертация «Комбинаторная теория надёжности обучения по прецедентам» (2010, специальность 05.13.17). Автор комбинаторной теории надёжности обучения по прецедентам, оценивающей вероятность переобучения с учётом эффектов расслоения и сходства в семействах алгоритмов; основное направление его исследований — теория и методы аддитивной регуляризации тематических моделей (ARTM). С 2014 года — научный руководитель разработки библиотеки тематического моделирования с открытым кодом BigARTM, с 2019 года — поисково-рекомендательной системы SciSearch. Один из идеологов и администраторов ресурса MachineLearning.ru (с 2008 года). Медаль РАН с премией для молодых учёных (1999, совместно с Е. В. Нарыжным); почётное звание профессора РАН (2015); юбилейная медаль РАН «300 лет Российской академии наук» (2024); премия Yandex ML Prize в номинации «Зал славы» (2025). Автор курсов «Вероятностные тематические модели», «Математические методы анализа текстов», «Прикладной статистический анализ данных» и спецкурса по теории надёжности обучения по прецедентам; в 2008–2020 годах преподавал в Школе анализа данных Яндекса. С 2004 года читает годовой курс «Машинное обучение» в МФТИ и ВМК МГУ.