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Matematika na pozadí geografických informačních systémů
Pászto, Vít; Marek, Lukáš
Czech
V posledních letech se stává geoinformatika a její nástroje (zejména GIS - geografcký informační systém, materiály DPZ - dálkový průzkum Země, GPS - Global positioning system, mapové servery, aj.) samozřejmou součástí života lidí na celém světě. Mnohdy si ani uživatel neuvědomí, že právě geoinformatika v daný moment slouží k jeho lepšímu rozhodování. Příkladem může být navigace řidiče vozidla po silniční síti pro dosažení svého cíle. Aniž by to bylo zřejmé, tak onen řidič používá dohromady hned několik (geo)informačních technologií - samotný přístroj s GPS čipem, mapové podklady, vektorové vrstvy silniční sítě, letecký či družicový snímek, či 3D modely budov. Avšak na pozadí všeho je správná síťová analýza pro nalezení nejkratší/nejrychlejší cesty, jež využívá matematických algoritmů, jelikož se jedná o optimalizační úlohy v orientovaném a ohodnoceném grafu. A obdobně každá GIS analýza využívá matematického aparátu, ať jednoduchého nebo složitého. Účelem tohoto příspěvku není představení nových matematických formulí pro řešení prostorových analýz, ale ukázat použití základních matematických principů v nejrůznějších aplikacích. Autoři chtějí přiblížit čtenářům geoinformatiku jakožto aplikační vědní disciplínu, a podnítit tak jejich zájem o interdisciplinární spolupráci.
Available in a digital repository NRGL
Matematika na pozadí geografických informačních systémů
V posledních letech se stává geoinformatika a její nástroje (zejména GIS - geografcký informační systém, materiály DPZ - dálkový průzkum Země, GPS - Global positioning system, mapové servery, aj.) ...
Analysis of local moisture increase of timber constructions on ice arena roof
Žák, Antonín; Trcala, Miroslav; Šikula, Ondřej
English
Dřevo je díky nízké hmotnosti a velmi dobrým mechanickým vlastnostem jedním z nejčastěji využívaných materiálů na vytvoření zastřešení zimních stadionů. Nízká teplota, vysoká relativní vlhkost vnitřního vzduchu a přítomnost ledové plochy, snižující vzájemným sáláním povrchové teploty konstrukcí i pod teplotu rosného bodu, jsou rizikovým faktorem nejen z pohledu snížení únosnosti konstrukce v čase, ale také z hlediska biokoroze. V blízkosti jednotlivých prvků střešní konstrukce se vytváří specifické tepelně-vlhkostní mikroklima odlišné od parametrů vzduchu v hale. Nově vyvinutým matematicko-fyzikálním modelem a využitím CFD simulace bylo simulováno tepelně-vlhkostní namáhání částí dřevěné střešní konstrukce zimního stadionu, které nezanedbatelně ovlivňuje kvalitu, užitné vlastnosti a životnost dřevěných prvků střechy. Výsledky byly srovnány s experimenty na konkrétním zimním stadionu. Timber is one of the most used materials for roofing of ice arena because of its very good mechanical properties and low weight. High relative humidity of internal air, low temperature and ice rink presence, which cause fall of surface temperatures of constructions under the dew point due
to radiation, are risky factors not only from structural point of view, when load bearing capacity of construction in time is reduced, but also from the view point of bio corrosion. Specific hygrothermal microclimate, different from air parameters in the ice arena, is formatted close to the
individual members of roof construction. Newly developed mathematical and physical model using CFD simulation is used for simulation of hygrothermal stress in chosen part of the ice arena roof construction, which substantially affects quality, utility properties and life time of timber roof components. Results are compared with experiments in specific ice rink.
Available in a digital repository NRGL
Analysis of local moisture increase of timber constructions on ice arena roof
Dřevo je díky nízké hmotnosti a velmi dobrým mechanickým vlastnostem jedním z nejčastěji využívaných materiálů na vytvoření zastřešení zimních stadionů. Nízká teplota, vysoká relativní vlhkost ...
Warehouse Modeling Using Graphical User Interface
Rajnoha, Martin
Slovak
This paper describes a new algorithm which enable efficient conversion of graphical representation of warehouse into graph theory representation and consequently accelerates estimation for route costs. The proposed algorithm computes route distances between any place in warehouses and does so significantly faster than traditional approaches. For this purpose an algorithm based on Breadth first search, image processing “skeletonization” and Dijkstra algorithm was proposed. Using the proposed algorithm it is possible to search routes in a warehouse effectively and fast using precomputed routing table. Searching time is approximately hundreds of microseconds using routing table and even it is independent on size of warehouse instead of using Dijkstra algorithm.
Keywords:
warehouse; GUI; skeletonization; graph; searching; paths; routing; table
Available in a digital repository NRGL
Warehouse Modeling Using Graphical User Interface
This paper describes a new algorithm which enable efficient conversion of graphical representation of warehouse into graph theory representation and consequently accelerates estimation for route ...
Sparse Signal Recovery via Convex Optimization
Novosadová, Michaela
English
We propose recovering 1D piecewice linear signal using a sparsity-based method consisting of two steps. The first step is signal segmentation via optimization algorithms solving sparsity based model. Second step consists of applying an ordinary mean square method on each detected segment of the signal. We show results of our experiments on two types of the signal.
Keywords:
convex optimization; Douglas-Rachford algorithm; Forward-Backward algorithm; signal recovery; signal segmentation
Available in a digital repository NRGL
Sparse Signal Recovery via Convex Optimization
We propose recovering 1D piecewice linear signal using a sparsity-based method consisting of two steps. The first step is signal segmentation via optimization algorithms solving sparsity based model. ...
Rules for Determination of Expected P Wave Type in ECG Signals
Maršánová, Lucie
English
The aim of this work is to improve existing possibilities of automatic detection of pathological P wave in electrocardiogram. For detection of different types of P wave is crucial to choose suitable algorithm. In this paper, establishing of rules for determining which P wave type is in given situation probably present is done. This rules are derived from positions of QRS complexes. Therefore, accurate QRS detector based on a signal filtering by bandpass filter and finding the maximum in a moving window is designed.
Keywords:
P wave; detection of QRS; P wave type; P wave detector
Available in a digital repository NRGL
Rules for Determination of Expected P Wave Type in ECG Signals
The aim of this work is to improve existing possibilities of automatic detection of pathological P wave in electrocardiogram. For detection of different types of P wave is crucial to choose suitable ...
Control Platform for Multiphase Motors
Kozovský, Matúš
English
This article focuses on the design and subsequent implementation platform for controlling multi-phase motors. Article describes the functionality of the assembled platform and the possibility of its usage to control either the individual motors or a single multi-phase motor. Platform is able to control Maximum nine-phases motor. The platform uses the three core AURIX TriCore microcontroller TC275. This paper also describes the distribution control program to initialization of device and separated control application generated by the Simulink automatic code generation. Finally interconnection these partial programs into a single control application.
Keywords:
TC275; AURIX; TriCore; nine-phases power stage
Available in a digital repository NRGL
Control Platform for Multiphase Motors
This article focuses on the design and subsequent implementation platform for controlling multi-phase motors. Article describes the functionality of the assembled platform and the possibility of its ...
Verification and numerical simulation of advanced composite inlet in compliance of airworthiness impact requirements
Doubrava, Radek; Oberthor, Martin; Raška, Jan; Bělský, Petr; Doubrava, Karel; Dvořák, Milan
English
Bird or hail stone strikes are an important phenomenon which must be considered during aircraft design. Most of major bird or hail strike incidents result from engine ingestion. As engines are the sole thrust providing mechanisms of an aircraft, it is critical to investigate and mitigate the effects of bird or hail strikes on engine inlets and systems to the greatest extent possible. The article presents application of test verified numerical simulation for design and full-scale test verification of advanced composite air inlet for new generation of jet trainer aircraft from point of view of high speed impact resistance. The physical bird and hail impact tests were performed at the Czech Aerospace Research Centre (VZLÚ) according to airworthiness requirements. The measurement during impact test were performed by high-speed camera, Fiber Bragg Grating (FGB) sensors and strain gauges in cooperation with Czech Technical University (CTU) in Prague. The results from full-scale bird and hail strike tests were compared with numerical simulation.
Keywords:
bird; hail; air inlet; FEM; impact
Available in a digital repository NRGL
Verification and numerical simulation of advanced composite inlet in compliance of airworthiness impact requirements
Bird or hail stone strikes are an important phenomenon which must be considered during aircraft design. Most of major bird or hail strike incidents result from engine ingestion. As engines are the ...
Reduction in the pilot’s stress during the landing maneuver by providing accurate height information
Šplíchal, Miroslav
English
The article is focused on pilot stress reduction during landing by providing accurate height information. It is based on the results of the completed project TA04030510 – Assistance systems supporting the pilot’s right decisions increasing the safety of operating small civil aircraft. The landing is the most critical phase of a flight. Accidents occurring during approach and landing phases generally represent up to 40 % of all aircraft accidents. A frequent cause of these accidents is a pilot error. During project development, 112 accidents of ultralight aircraft and 152 accidents of small GA aircraft that happened from 2005 to 2015 were analyzed. In total, 48 aircraft landing-related accidents and 22 accidents in ultralight aircraft were found. Landing accidents represent 26.5% of all investigated accidents.
Keywords:
landing; stress measurement; heart rate variability
Available in a digital repository NRGL
Reduction in the pilot’s stress during the landing maneuver by providing accurate height information
The article is focused on pilot stress reduction during landing by providing accurate height information. It is based on the results of the completed project TA04030510 – Assistance systems supporting ...
Integrated method utilizing graph theory and fuzzy logic for safety and reliability assessment of airborne systems
Janhuba, Luboš; Hlinka, Jiří; Koštial, Rostislav
English
This paper presents integrated algorithm for airborne system safety and reliability assessment. In general aviation (mostly up to EASA CS-23) and non-military unmanned aerial vehicles industry, safety and reliability assessment process still relays almost exclusively on human judgment. Recommended practices define processes for system modelling and safety assessing are based on analyst understanding of a particular system. That is difficult and time-consuming process. Commercial computation aids are extremely expensive with restricted (or closed) access to the solution algorithms. Together with this problem, rapid development of modern airborne systems, their increasing complexity, elevates level of interconnection. Therefore, safety and reliability analyses have to continuously evolve and adapt to the extending complexity. Growing expansion brings in the field of unnamed aerial vehicles systems which consist of items without relevant reliability testing. Presented algorithm utilizes graph theory and fuzzy logic in order to develop integrated computerized mean for reliability analysis of sophisticated, highly interconnected airborne systems. Through the usage of graph theory, it is possible to create model of particular systems and its sub-systems in the form of universal data structure. Algorithm is conceived as fuzzy expert system, that emulates decision making of a human expert. That brings opportunity to partially quantify system attributes and criticality. Criticality evaluation increases level of assessment correlation with real state of system and its attributes.
Keywords:
Reliability; Airborne; Systems; Airplane; Graph theory; Fuzzy logic; Criticality
Available in a digital repository NRGL
Integrated method utilizing graph theory and fuzzy logic for safety and reliability assessment of airborne systems
This paper presents integrated algorithm for airborne system safety and reliability assessment. In general aviation (mostly up to EASA CS-23) and non-military unmanned aerial vehicles industry, safety ...
Teaching aircraft design through a blended learning method in a higher education
Kwiek, Agnieszka
English
A blended learning is a method which combines a few teaching methods. Usually it is a mix of classic teaching approach with using of online tools. A Nearpod is technology enhanced learning (TEL) tool which allows for creating an interactive presentation which can be delivered in a real time session or in a self-paced mode. The presentation can be displayed on a student’s computer or mobile phone. This paper presents how students experience can be enhanced by the implementation of a blended learning in aircraft design lectures. And how a Nearpod can be integrated into those lectures to help students develop such skills as creativity, critical thinking and problem solving, which are vital for aircraft design project and students’ further career in the aerospace sector. This study focuses on aeronautical students studying at the University of Brighton in School of Computing Engineering and Mathematics. Students group includes BEng., MEng. and BSc. Top-Up students who were enrolled in level 6 module - ME351 Aircraft Design and Management Project. Results reveal that students' attendance is higher than traditional lectures and the most favorite and helpful activities are quizzes & polls, draw it and fill blanks. Aerospace engineering students prefer Nearpod activities where they can choose an answer or draw it rather than writing it.
Keywords:
Aircraft design education; blended learning; Nearpod; higher education
Available in a digital repository NRGL
Teaching aircraft design through a blended learning method in a higher education
A blended learning is a method which combines a few teaching methods. Usually it is a mix of classic teaching approach with using of online tools. A Nearpod is technology enhanced learning (TEL) tool ...
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