Experimental Study of Phase Transition in Pedestrian Flow

The transition between low and high density phases is a typical feature of systems with social interactions. This contribution focuses on simple evacuation design of one room with one entrance and one exit; four passing-through experiments were organized and evaluated by means of automatic image processing. The phase of the system, determined by travel time and occupancy, is evaluated with respect to the inflow, a controlled boundary condition. Critical values of inflow and outflow were described with respect to the transition from low density to congested state. Moreover, microscopic analysis of travel time is provided.Comment: To appear in proceedings of Pedestrian and Evacuation Dynamics 2014, Transportation Research Procedia, Elsevie

Experimental Analysis of Two-Dimensional Pedestrian Flow in front of the Bottleneck

This contribution presents experimental study of two-dimensional pedestrian flow with the aim to capture the pedestrian behaviour within the cluster formed in front of the bottleneck. Two experiments of passing through a room with one entrance and one exit were arranged according to phase transition study in Ezaki et al. (2012), the inflow rate was regulated to obtain different walking modes. By means of automatic image processing, pedestrians' paths are extracted from camera records to get actual velocity and local density. Macroscopic information is extracted by means of virtual detector and leaving times of pedestrians. The pedestrian's behaviour is evaluated by means of density and velocity. Different approaches of measurement are compared using several fundamental diagrams. Two phases of crowd behaviour have been recognized and the phase transition was described.Comment: In proceedings of Traffic and Granullar Flow 2013, Springe

The Politics of Appointment of Top Civil Servants : Career Backgrounds and Civil Service Politicization in the Czech Republic

Th is contribution seeks to answer the question whether the new civil service legislation that entered into force in 2015 in the Czech Republic led to the depoliticization of the country’s ministerial bureaucracy. To that end, we compare the career backgrounds of top civil servants before and aft er the entry into force of the new Civil Service Act. Th e article examines the career backgrounds of the persons appointed as ministerial deputies between 2013 and 2018, focusing on their last “pre-deputy” jobs and considering a broader set of their career attributes. A focus on the previous job reveals that even before the law was introduced, bureaucrats constituted the largest share of appointees, and their share even increased with the new legislation. Th e incidence of deputies appointed directly from party-related jobs dropped considerably. However, when a broader set of career attributes is considered, the share of partisans among the pre-2015 deputies nearly matches that of the career bureaucrats. Ostensibly political careers among the post-2015 deputies declined but remain signifi cant. Hence, there has been a decline in the open politicization of the ministerial bureaucracy aft er 2015. Party political eff ects also matter, as the new ANO party, aft er entering the executive, has taken a diff erent approach to top bureaucratic appointments than the other major governing Czech parties. Typically, deputies appointed into the positions under the ANO’s control would not have links to the party itself but would be recruited via non-party channels, e.g. from pre-political networks of the ANO ministers and leaders. Consequently, though less politicized by party agents, the current Czech system is more a product of choices made by government ministers of the day than a stable arrangement resulting from fi rmly established norms and rules

Photogrammetry as efficient tool for documentation of actual realization of construction

Digital era brought to the discipline photogrammetry significant changes. In the past, only specialized and expensive equipment both on imaging and image processing could be used for metrical purposes and the operator had to have considerable expertise. It is now possible to use conventional digital cameras, image processing is implemented on the PC by software at affordable prices and the actual software is built to be "user friendly" to experts from other disciplines such as photogrammetry. Paper aims to bring the possibility of photogrammetry as a efficient measurement tool for variety of professions including forensic science.Digitálna doba priniesla aj do vednej disciplíny fotogrametrie významné zmeny. V minulosti bolo možné využívať na metrické účely len špecializované a drahé prístroje tak na snímkovanie ako aj na spracovanie snímok a spracovateľ musel disponovať nemalými odbornými vedomosťami. V súčasnosti je možné využívať bežné digitálne fotoaparáty, spracovanie snímok sa realizuje na PC softvérmi v dostupných cenách a samotné softvéry sú zostavené tak, aby boli „užívateľsky priateľské“ odborníkom aj z iných vedných disciplín ako je fotogrametria. Príspevok má za cieľ priblížiť možnosti fotogrametrie ako efektívneho meracieho nástroja pre rôzne profesie vrátane súdneho znalectva

Microscopic Travel Time Analysis of Bottleneck Experiments

This contribution provides a microscopic experimental study of pedestrian motion in front of the bottleneck. Identification of individual pedestrians in conducted experiments enables to explain the high variance of travel time by heterogeneity of the crowd. Some pedestrians are able to push effectively through the crowd, some get trapped in the crowd for significantly longer time. This ability to push through the crowd is associated with the slope of individual linear model of the dependency of the travel time on the number of pedestrians in front of the bottleneck. Further detailed study of the origin of such ability is carried out by means of the route choice, i.e. strategy whether to bypass the crowd or to walk directly through it. The study has revealed that the ability to push through the crowd is a combination of aggressiveness in conflicts and willingness to overtake the crowd.Comment: To appear in Transportmetrica A: http://www.tandfonline.com/doi/abs/10.1080/23249935.2017.141942

The effect of the type of sprayer bodies on the obtained coefficient of variation of sprayed liquid deposition

In this work, the study results of retention uniformity of sprayed liquid deposition obtained from three kinds of nozzles mounted in sprayer bodies of various constructions were presented. For the tests, a five-spray body with a rotation axis of a spigot parallel to the sprayed surface, a three-spray body with a retention axis perpendicular to the sprayed surface and one-spray body were used. Changes in individual spraying nozzles were done by three operators. It was stated that the biggest differences in repeatability and reproducibility of adjustments were noted for five-spray bodies, however, minimum changes not exceeding the value of one percentage point were noted for single bodies. For triple bodies repeatability of obtained CV regardless of mounted nozzles changed maximum up to 1,5 percentage point and reproducibility of measurement changed from 0,5 to 0,8 percentage point.In this work, the study results of retention uniformity of sprayed liquid deposition obtained from three kinds of nozzles mounted in sprayer bodies of various constructions were presented. For the tests, a five-spray body with a rotation axis of a spigot parallel to the sprayed surface, a three-spray body with a retention axis perpendicular to the sprayed surface and one-spray body were used. Changes in individual spraying nozzles were done by three operators. It was stated that the biggest differences in repeatability and reproducibility of adjustments were noted for five-spray bodies, however, minimum changes not exceeding the value of one percentage point were noted for single bodies. For triple bodies repeatability of obtained CV regardless of mounted nozzles changed maximum up to 1,5 percentage point and reproducibility of measurement changed from 0,5 to 0,8 percentage point

Game server security design

Tato diplomová práce se zabývá návrhem zabezpečení herního serveru, který je připojen do internetu. Na základě nynějšího zabezpečení a oskenování serveru nástroji k penetračnímu testování je navržena kompletní metodika pro napravení zjištěných bezpečnostních mezer.This master thesis focus on game server security which is connected directly to the internet. Based on current security and scanning the server with penetration testing tools, I designed complete methodology for fixing security issues and vulnerabilities.