Поредното заседание на Общия семинар на секция "Анализ, геометрия и топология" ще се проведе на 15 октомври 2024 г. от 14:00 часа в зала 478 на ИМИ - БАН. Доклад на тема: Unimodality Preservation by Ratios of Functional Series and Integral Transforms ще изнесе Dmitrii Karp, Holon Institute of Technology, Holon, Israel. Поканват се всички интересуващи се. Резюме. Elementary, but very useful lemma due to Biernacki and Krzyz (1955) asserts that the ratio of two power series inherits monotonicity from that of the sequence of ratios of their corresponding coefficients. Over the last two decades it has been realized that, under some additional assumptions, similar claims hold for more general series ratios and integral transforms as well as for unimodality in place of monotonicity. [...]

На 15 октомври (вторник) от 14:00 ч. в зала 503 на ИМИ ще се състои сбирка на Семинара по Изследване на операциите. Доклад на тема Asymptotic covariance matrix of Capon’s Maximum likelihood estimator and application of steered response power phase alignment algorithm in seismic array data processing ще изнесе Александр Варипаев от секция ИОСВ. Абстракт: Capon’s estimator was originally developed for frequency-wavenumber power spectral density analysis. Theoretically, it can be treated as maximum likelihood estimator of unknown vector parameter of multidimensional linear system (MLS) model with one input and m outputs.  Practically important and non-trivial case is considered, when the number of nuisance parameters, which are values of input deterministic signal, tends to infinity. Under assumptions that MLS output signals distorted by random Gaussian stationary  [...]

Поредното заседание на Общия семинар на секция "Анализ, геометрия и топология" ще се проведе на 22 октомври 2024 г. от 14:00 часа в зала 478 на ИМИ - БАН. Доклад на тема: Higher order estimates for Monge-Ampere type equations motivated by quaternionic geometry ще изнесе Marcin Sroka, Jagiellonian University, Kraków, Poland. Поканват се всички интересуващи се. Резюме. In the talk I will discuss obstacles for obtaining higher order a priori estimates for equation introduced by Alesker and Verbitsky in 2010 on HKT manifolds in relation to Calabi type conjecture on those manifolds (and similar type PDEs studied since on hypercomplex manifolds). After presenting the state of art, I will focus on the key second order estimate. For the real Monge-Ampere equation on Riemannian manifolds [...]

На 22 октомври (вторник) от 14:00 ч. в зала 503 на ИМИ ще се състои сбирка на Семинара по Изследване на операциите. Доклад на тема Asymptotic covariance matrix of Capon’s Maximum likelihood estimator and application of steered response power phase alignment algorithm in seismic array data processing - част 2 ще изнесе Александр Варипаев от секция ИОСВ. Абстракт: Capon’s estimator was originally developed for frequency-wavenumber power spectral density analysis. Theoretically, it can be treated as maximum likelihood estimator of unknown vector parameter of multidimensional linear system (MLS) model with one input and m outputs.  Practically important and non-trivial case is considered, when the number of nuisance parameters, which are values of input deterministic signal, tends to infinity. Under assumptions that MLS output signals distorted by [...]

Поредната сбирка на семинара Дидактическо моделиране ще се проведе на 28.10.2024 г. от 14:30 ч. в зала 278 на ИМИ. Доклад на тема Старият (не)познат Logo: примери, идеи, пропускани възможности ще изнесe доц. Бойко Банчев.

Дата: Вторник, 29.10.2024 г., 15.00 ч. Място: Зала 278, ИМИ - БАН Докладчик: Verma Chaman, PhD Тема: Statistics and Machine Learning in Educational Informatics Поканени са всички заинтересовани. Линк за онлайн участие: https://meet.jit.si/imi-softis

Viability analysis in mathematical biology Докладчик: доц. д-р Петър Рашков, ИМИ - БАН Дата: 30.10.2024 г. Час: 14:00 ч. Място: зала 503 Резюме: Applications of control theory to mathematical biology are numerous. The study of control strategies happens most often in the context of optimal resource allocation or investigation of asymptotic convergence of solutions to equilibria with specific properties. The study of solutions of controlled systems which must respect some specific constraints has been pursued to a lesser extent. The ODE-based models I will present are subject to constraints on both the control and one or more phase variables. The mathematical task is to describe and compute the viability kernel associated to the constraints. This kernel is the set of those initial states for [...]

Публична академична лекция На 5 ноември 2024 г., вторник, от 12:00 часа в зала 503 на ИМИ-БАН, в рамките на Семинара на секция ИОВС, ще се проведе публична академична лекция на доц. д-р Асен Чорбаджиев на тема "Statistical inference for branching processes".   Резюме: It is usually expected that the development of branching processes depends on initial condition, law of branching and the method of measurement. However, usually the main problem of data analysis for branching processes is that either many of process' parameters are unknown or that the different stages of process development could not clearly distinguished. This is non-trivial problem and the analytical solutions usually are not available. The alternative approach to find solution for particular problems is also difficult. Constrained by [...]

Поредната сбирка на Националния семинар по стохастика ще се проведе на 13 ноември 2024 г. (сряда) от 15:00 часа в зала 503 на ИМИ - БАН. Доклад на тема Cancellable American options under negative discounting ще изнесе Zbigniew Palmowski (University of Wroclaw). Абстракт. In this talk we consider the McKean stochastic game for a geometric spectrally negative Lévy process of asset price which extends the American put option by introducing the possibility for the writer of the option to cancel the contract, at the expense of paying the intrinsic value plus an extra constant penalty. Additionally, we consider a negative discount rate which produces double continuation regions for writer and holder. This is then different from the scenario when the discount rate is positive which was [...]