27 research outputs found
Fast algorithm for contactless partial discharge detection on remote gateway device
Detection of the high impedance fault caused by vegetation is one of the biggest challenges brought by the usage of covered conductors in medium voltage overhead power lines. One of the accompanying events of long-term contact of vegetation with the XLPE insulation is partial discharge which damages the insulation. Current systems for the detection of partial discharge have two major problems: the price and difficult installation. In this paper, an approach for the detection of the partial discharge from the data collected by the antenna is described. This approach is focused on the small computational demand and low false positive rate. Thanks to the small computational requirements, it can be run on the remote gateway devices which are collecting the data from the antenna. It is composed of four steps: outlier detection, outlier clustering, feature extraction, and classification. It is shown that this approach greatly improves the detection rate and lowers false positives compared to the previous algorithm used for partial discharge detection based on the data from an antenna, making it fit to use in the production environment.Web of Science3732130212
Prototype digital twin: recreation and biodiversity cultural ecosystem services
•Digital twin approaches have the potential to revolutionise usage, planning and management of cultural ecosystem services i.e. the non-material benefits people obtain from ecosystems, including recreation, tourism, intellectual development, spiritual enrichment, reflection and aesthetic experiences.
•Here, we outline our blueprint for a prototype digital twin (pDT) for cultural ecosystem services. The pDT consists of two modelling components; a recreation potential model to quantify the cultural ecosystem services of the physical landscape and species distribution models to quantify the biodiversity component.
•It is envisaged that the digital twin will be used primarily by two user types: 1. those who wanted to enjoy the area and potentially contribute to citizen science programmes and 2. people who want to inform or make evidence-based management decisions (land managers, policy-makers, researchers)
Alternative approaches of evaluating the 0–1 test for chaos
The 0-1 test for chaos is increasingly used in applications where it is important to distinguish between chaotic and regular dynamics of the deterministic dynamical system. This test consists of translating the time series into plane. Then the boundedness of the object created in the plane is inspected by computing mean square displacement and its growth rate. The computation of the mean square displacement for various lag has high computational complexity. In this paper, the inspection of the boundedness using bounding box and centre of gravity is proposed. This method has linear computational complexity and provides more control over the precision of the test through multiple input parameters.Web of Science1-252150
Aplikace operačního výskumu ve věřejném sektoru
Operations research in public sector is overshadowed by business sector. However it deals with a substantial amount of problems which concern whole population. Although it is not presented so much, a lot of research was made in many areas of the public sector. This thesis provide some basic information about where the operations research can be used. Then some approaches and model system used in energy policy modeling are presented. Lastly the use of operations research in water quality management is illustrated on a basic model minimizing the cost of water treatment
Aplikace operačního výskumu ve věřejném sektoru
Operations research in public sector is overshadowed by business sector. However it deals with a substantial amount of problems which concern whole population. Although it is not presented so much, a lot of research was made in many areas of the public sector. This thesis provide some basic information about where the operations research can be used. Then some approaches and model system used in energy policy modeling are presented. Lastly the use of operations research in water quality management is illustrated on a basic model minimizing the cost of water treatment.Operační výzkum ve veřejném sektoru je zastíněn sektorem soukromým, ačkoliv řeší velké množství problémů, které mají vliv na celou populaci. I když proběhly v mnoha oblastech veřejného sektoru četné výzkumy, nebývá to často zveřejňováno. Tato práce přináší základní informace o tom, kde může být operační výzkum aplikován. Poté jsou popsány některé postupy a modelové systémy využívané pro správu energetiky. Déle je na základním modelu minimalizace nákladů čištění vody ilustrováno použití operačního výzkumu v řízení kvality vody. Práce je zakončena shrnutím a poznámkami k jednotlivým kapitolám
Nástroje pro analýzu časových řad nelineárních dynamických systémů
Nonlinear dynamical systems analysis is a very important part of numerous areas of research. Study of deterministic chaos is a key tool to determine the dynamics of systems, which are hard to explain by classical methods. However, estimating dynamical properties of a system using the experimental data is a difficult task. Specifically, a computational complexity of many tools for the nonlinear analysis of dynamical system makes it impossible to estimate the results for the large datasets. This work focuses on parallelization and application of the computationaly expensive methods such as recurrence quantitative analysis and the 0-1 test for chaos. Comparison of these methods with the classical methods is made and the strengths and weaknesses of each method are discussed.Analýza nelineárních dynamických systémů je důležitou součástí mnoha vědních oborů. Studium deterministického chaosu je klíčovým nástrojem k vyšetření chování systémů, které je obtížné objasnit pomocí klasických metod. Odhad dynamických vlastností systémů z experimentálních dat je velmi komplikovaným úkolem. Předpověď výsledků pro rozsáhlá data znemožňuje zejména výpočetní náročnost mnohých nástrojů pro nelineární analýzu dynamických systémů. Tato práce se zabývá paralelizací a aplikací výpočetně náročných metod jako jsou kvantitativní rekurenční analýza a 0-1 test chaosu. Součástí práce je srovnání těchto metod s metodami klasickými a přehled výhod a nevýhod jednotlivých metod.96210 - Laboratoř pro náročné datové analýzy a simulacevyhově
Chaotic behavior of the CML model with respect to the state and coupling parameters
The main aim of this paper is the study of dynamical properties of the Laplacian-type coupled map lattice induced by the logistic family on a periodic lattice depending on two parameters: the state parameter of the logistic map and the coupling constant. For this purpose, tools like maximal Lyapunov exponent, approximate entropy, and the 0-1 test for chaos are introduced and applied to numerical simulations performed using a supercomputer.Web of Science5761681167
Automated Application of Inventory Optimization
Part 4: Optimization, TuningInternational audienceWe present automated application of inventory optimization based on sales forecast. Inventory stock optimization is very required issue by companies recent years, however inventory models are based on the sales expectation. Therefore, the problem of optimizing inventory stock is divided into two parts, sales forecast and setting optimal inventory. We describe an automated solution to model selection for sales forecast and the inventory setting based on those predictions. In the end, we present our validation of the system through historical simulation. We compare simulations results against real inventory levels. Due to the large number of different length time series, this simulation was run in parallel on cluster and was parallelized in R. The algorithms were developed and tested on inventory time series from real data sets of the K2 atmitec company (Sales forecasting and inventory optimization are parts of ERP solution K2, which is provided by K2 atmitec s.r.o. company, http://www.k2.cz/en/)
A survey of tools detecting the dynamical properties of one-dimensional families
One-dimensional dynamical systems attract researches for more than half a century and the topic was inspired by many real problems. Mainly piecewise linear and polynomial maps were considered and researched under several motivations from different scientific fields. As a main aim of the paper, the Logistic (polynomials of the second order) and the Tent (piecewise linear maps with two pieces) families are considered and studied. The dynamical properties of both families are derived using bifurcation diagrams, Lyapunov exponents, and newly established techniques like the 0-1 test for chaos and recurrence matrices
Highly scalable algorithm for computation of recurrence quantitative analysis
Recurrence plot analysis is a well-established method to analyse time series in numerous areas of research. However, it has exponential computational and spatial complexity. As the main result of this paper, a technique for the computation of recurrence quantitative analysis (RQA) is outlined. This method significantly reduces spatial complexity of computation by computing RQA directly from the time series, optimizing memory accesses and reducing computational time. Additionally, parallel implementation of this technique is tested on the Salomon cluster and is proved to be extremely fast and scalable. This means that recurrence quantitative analysis may be applied to longer time series or in applications with the need of real-time analysis.Web of Science7531186117