Jacek Leśkow – författare

This book covers a new and innovative approach to the issue of investment portfolio efficiency from the perspective of a large institutional investor. It discusses the challenges relating to changes in returns on the international stock market, with particular emphasis on investments.

Instead of focusing on just one designated market, the book examines four diversified, developed markets, and models the Polish market as a representative of emerging markets. The authors argue that the current market for available financial instruments, mainly derivatives, may be an example of a partially complete market. With such assumptions, they test selected markets, assuming that a representative investor, such as an investment fund, makes rational decisions and uses all available financial instruments. The research conducted in the book is unique in its assumption that investors form portfolios that consider the structure of the company''s financial results. The significant impact that the financial crisis in the United States since 2007, the COVID-19 pandemic, and Russia''s aggression against Ukraine have had on investors'' decisions is also discussed.

The book will find an audience among researchers, scholars, and students specialising in finance and capital market investments.

This book covers a new and innovative approach to the issue of investment portfolio efficiency from the perspective of a large institutional investor. It discusses the challenges relating to changes in returns on the international stock market, with particular emphasis on investments.

Instead of focusing on just one designated market, the book examines four diversified, developed markets, and models the Polish market as a representative of emerging markets. The authors argue that the current market for available financial instruments, mainly derivatives, may be an example of a partially complete market. With such assumptions, they test selected markets, assuming that a representative investor, such as an investment fund, makes rational decisions and uses all available financial instruments. The research conducted in the book is unique in its assumption that investors form portfolios that consider the structure of the company''s financial results. The significant impact that the financial crisis in the United States since 2007, the COVID-19 pandemic, and Russia''s aggression against Ukraine have had on investors'' decisions is also discussed.

The book will find an audience among researchers, scholars, and students specialising in finance and capital market investments.

This book offers an overview of current and recent methods for the analysis of the nonstationary processes, focusing on cyclostationary systems that are ubiquitous in various application fields. Based on the 13th Workshop on Nonstationary Systems and Their Applications, held on February 3-5, 2020, in Grodek nad Dunajcem, Poland, the book merges theoretical contributions describing new statistical and intelligent methods for analyzing nonstationary processes, and applied works showing how the proposed methods can be implemented in practice and do perform in real-world case studies. A significant part of the book is dedicated to nonstationary systems applications, with a special emphasis on those in condition monitoring. 

In the last decade the research in signal analysis was dominated by models that encompass nonstationarity as an important feature. This book presents the results of a workshop held in Grodek—Poland in February 2013 which was dedicated to the investigation of cyclostationary signals. Its main objective is to highlight the strong interactions between theory and applications of cyclostationary signals with the use of modern statistical tools.

An important application of cyclostationary signals is the analysis of mechanical signals generated by a vibrating mechanism. Cyclostationary models are very important to perform basic operations on signals in both time and frequency domains. One of the fundamental problems in diagnosis of rotating machine is the identification of significant modulating frequencies that contribute to the cyclostationary nature of the signals. The book shows that there are modern tools available for analyzing cyclostationary signals without the assumption of gaussianity. Those methods are based on the ideas of bootstrap, subsampling and Fraction-of-time (FOT) models. The book is organised in two parts. The first part will be dedicated to pure theory on cyclostationarity. Applications are presented in the second part including several mechanical systems such as bearings, gears, with or without damages.

This book reports on the latest advances in the analysis of non-stationary signals, with special emphasis on cyclostationary systems. It includes cutting-edge contributions presented at the 7th Workshop on “Cyclostationary Systems and Their Applications,” which was held in Gródek nad Dunajcem, Poland, in February 2014. The book covers both the theoretical properties of cyclostationary models and processes, including estimation problems for systems exhibiting cyclostationary properties, and several applications of cyclostationary systems, including case studies on gears and bearings, and methods for implementing cyclostationary processes for damage assessment in condition-based maintenance operations. It addresses the needs of students, researchers and professionals in the broad fields of engineering, mathematics and physics, with a special focus on those studying or working with nonstationary and/or cyclostationary processes.

This book gathers contributions presented at the 9th Workshop on Cyclostationary Systems and Their Applications, held in Gródek nad Dunajcem, Poland in February 2016. It includes both theory-oriented and practice-oriented chapters. The former focus on heavy-tailed time series and processes, PAR models, rational spectra for PARMA processes, covariance invariant analysis, change point problems, and subsampling for time series, as well as the fraction-of-time approach, GARMA models and weak dependence. In turn, the latter report on case studies of various mechanical systems, and on stochastic and statistical methods, especially in the context of damage detection. The book provides students, researchers and professionals with a timely guide to cyclostationary systems, nonstationary processes and relevant engineering applications.