Modelling public transport accessibility with Monte Carlo stochastic simulations: A case study of Ostrava

Activity-based micro-scale simulation models for transport modelling provide better evaluations of public transport accessibility, enabling researchers to overcome the shortage of reliable real-world data. Current simulation systems face simplifications of personal behaviour, zonal patterns, non-optimisation of public transport trips (choice of the fastest option only), and do not work with real targets and their characteristics. The new TRAMsim system uses a Monte Carlo approach, which evaluates all possible public transport and walking origin-destination (O-D) trips for k-nearest stops within a given time interval, and selects appropriate variants according to the expected scenarios and parameters derived from local surveys. For the city of Ostrava, Czechia, two commuting models were compared based on simulated movements to reach (a) randomly selected large employers and (b) proportionally selected employers using an appropriate distance-decay impedance function derived from various combinations of conditions. The validation of these models confirms the relevance of the proportional gravity-based model. Multidimensional evaluation of the potential accessibility of employers elucidates issues in several localities, including a high number of transfers, high total commuting time, low variety of accessible employers and high pedestrian mode usage. The transport accessibility evaluation based on synthetic trips offers an improved understanding of local situations and helps to assess the impact of planned changes.Web of Science1124art. no. 709

Factors influencing walking distance to the preferred public transport stop in selected urban centres of Czechia

One of the ways of improving the attractiveness of public transport is to bring it closer to its potential users. A long walking distance from a stop is often one of the critical factors limiting its more frequent and extensive use. Studies dealing with the accessibility of transport networks usually work only with the closest stop. This article analyses the actual walking distance from the place of residence to the preferred stop. The survey used a questionnaire method and was conducted in two cities in the Czech Republic-Ostrava and Olomouc. Based on the results of the study, the average walking distance was assessed and the impact of demographic characteristics (gender, age, education, number of members in the household, economic activity, the presence of a child in the household, and car ownership), transport behavior (preferred mode of transportation, car convenience and opinions on public transport), and urban characteristics (prevailing housing type) on the walking distance were analyzed. The main findings prove a significant impact on walking distance by a number of these factors, but the preferred use of a car for commuting or unemployment does not significantly affect walking distance. Highlights for public administration, management and planning: The public transport stop reported as being closest to a respondent's residence was used by only 51% of all respondents in the survey. Another 20% of residents used the second closest stop, 11% the third stop. Travellers select the stop based on number of connections; seamless connection; the speed of connection; potential delays; equipment of stops and nearby areas; the comfort of the vehicle; avoiding overcrowded stop; other personal factors. The average walking distance to the preferred stop is 568 metres in Ostrava while only 439 metres in Olomouc. Significantly shorter distances refer to the female population in Ostrava, retired and unemployed. Assumption of the negative influence of the higher number of family members, higher salaries, car ownership and worse education (blue collar) was not proved.Web of Science131301

Granular Materials, Contact Problems, DVI, MPRGP

Active-set algorithm for solving inner optimization problem in multi-body dynamics is presented. The efficiency of our algorithm is demonstrated on the solution of simple simulation with thousands of moving spherical particles and static box obstacles. We discuss the solvability and the uniqueness of solution of the problem and the influence of solution to resulting velocity during time-stepping schema

Design of meander RFID antenna

Tato práce pojednává o problematice RFID tagů. V první části je prezentován celkový přehled existujících RFID systémů se zaměřením na pasivní UHF tagy a jejich přínos při využití v logistickém řetězci. Následuje popis elektromagnetických simulátorů CST Studio Microwave a IE3D Zeland použitých pro návrh meadrovitých antén. Antény jsou navrženy na různých substrátech pro kmitočtová pásma 867 MHz a 2,4 GHz. Navržené antény lze rozdělit do dvou kategorií bez reflektoru a antény doplněné o reflektor, které mohou být umístěny na kovové povrchy. Vyrobené antény byly experimentálně odzkoušeny v podniku METRA Blansko a.s., kde byla zkoumána jedna z nejdůležitějších vlastností pasivních tagů – jejich maximální čtecí vzdálenost.This thesis deals with RFID tags. In the first part of the thesis, the general overviews of the present-day RFID systems are presented. This part of the thesis is focused on the passive back-scatter UHF tags and the advantages of their application in supply chain usage. Subsequently, the electromagnetic simulators CST Microwave Studio and IE3D Zeland are described. These simulators were used to design loaded meander antennas. The antennas were designed for different materials and frequency bands of 867 MHz and 2.4 GHz. The designed antennas were made without as well as with the reflector which allows using the antennas in the vicinity of metals. Produced antennas were experimentally tested in the company METRA Blansko Inc, where one of the most significant characteristics of passive RFID tags – the read range was observed.

Wildfires identification: Semantic segmentation using support vector machine classifier

summary:This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR channels, we proceed with a normalized reflectance over 152 days so that such time series is assigned to each pixel. We compare models associated with $\mathcal{l}1$-loss and $\mathcal{l}2$-loss functions and stopping criteria based on a projected gradient and duality gap in the presented benchmarks

Kotvení předpjaté frp výztuže pro betonové konstrukce

Předpětí FRP výztuže v betonových konstrukcích eliminuje její negativní vlastnost, kterou je nízký modul pružnosti. Článek popisuje vyvinutý způsob kotvení, který požívá FRP materiály i pro kotevní oblast. Základní princip návrhu je popsán v textu. Výsledky analytického návrhu jsou porovnány s experimenty, které byly provedeny v rámci řešení výzkumného projektu AdMaS.Non-metallic reinforcement has many advantages, but there are some areas of application that need to be resolved to improve the usage of FRP reinforcement in real conditions. One of the disadvantages of FRP reinforcement is its lower modulus of elasticity, which leads to greater deflections of structures and can also cause early propagation of cracks. The paper deals with the possibility of eliminating this problem by prestressing the reinforcement. It covers several problems related to anchoring and current anchoring methods used world-wide. The paper also mentions some drawbacks of these methods. In an effort to bypass these drawbacks a new anchoring method has been developed. It differs in the way longitudinal forces are transferred from the bar to the surrounding concrete. Basically, it is based on the addition of an additional anchoring member (cylinder) on the surface. This member is made of polymers so the whole system remains completely steel-free and very simple to produce. Before using the system in real structures a series of tests were performed and the results are presented. Also, some prestressed test panels were prepared and compared with standard panels

The energy consumption optimization of the BLAS routines

The paper deals with the energy consumption evaluation of selected Sparse and Dense BLAS Level 1, 2 and 3 routines. Authors employed AXPY, Sparse Matrix-Vector, Sparse Matrix-Matrix, Dense Matrix-Vector, Dense Matrix-Matrix and Sparse Matrix-Dense Matrix multiplication routines from Intel Math Kernel Library (MKL). The measured characteristics illustrate the different energy consumption of BLAS routines, as some operations are memory-bounded and others are compute-bounded. Based on their recommendations one can explore dynamic frequency switching to achieve significant energy savings up to 23%

Non-monotone projected gradient method in linear elasticity contact problems with given friction

We are focusing on the algorithms for solving the large-scale convex optimization problem in linear elasticity contact problems discretized by Finite Element method (FEM). The unknowns of the problem are the displacements of the FEM nodes, the corresponding objective function is defined as a convex quadratic function with symmetric positive definite stiffness matrix and additional non-linear term representing the friction in contact. The feasible set constraints the displacement subject to non-penetration conditions. The dual formulation of this optimization problem is well-known as a Quadratic Programming (QP) problem and can be considered as a most basic non-linear optimization problem. Understanding these problems and the development of efficient algorithms for solving them play the crucial role in the large-scale problems in practical applications. We shortly review the theory and examine the behavior and the efficiency of Spectral Projected Gradient method modified for QP problems (SPG-QP) on the solution of a toy example in MATLAB environment.Web of Science1220art. no. 867