Passenger number dependent traffic control in signalized intersections

The paper investigates a novel approach to the traffic control problem of signalized junction with bus priority. In road traffic engineering practice, adaptive control algorithms are generally used for maximizing the traffic flow of intersections. The adaptive strategies aim to calculate optimal signal splits for the traffic lights. The calculation is usually based on the number of vehicles measured by appropriate detection methods and may also depend on public transport priority actions (e.g. “green call” by buses). The main drawback of these methods is that the number of vehicle passengers is not taken into consideration. Unlike the common approaches the presented control strategy considers weighted passenger number exclusively (by using the assumption that the number of passengers can be measured in all vehicles). Hence, the control aim is to maximize the number of weighted passenger number capable to cross the intersection. The proposed control method is based on two factors: the number of passengers in road vehicles and their temporal distance measured from the stop line. The strategy does not apply priority measures for public transport directly. At the same time, the vehicles carrying numerous passengers (i.e. buses) acquire preference

Examination of 2D and 3D surface roughness parameters of face milled aluminium surfaces

Material removal with a rotating cutting tool has a series of special characteristics due to the movement relations. For face milling, looped cycloids occur, which also affects the roughness characteristics of the machined surface. This article analyses how the values of 2D and 3D roughness parameters change in symmetrical milling of flat surfaces of aluminium parts in planes parallel to the feed direction

Expansion of the sharp-snouted rock lizard (Dalmatolacerta oxycephala) in the southern part of the island of Cres

In 2005, a new lizard species, the sharp-snouted rock lizard (Dalmatolacerta oxycephala) appeared on the island of Cres, probably due to anthropogenic transfer. Before that, only the Dalmatian wall lizard (Podarcis melisellensis) had inhabited the town of Osor, where the new species was discovered. In areas where the two species live sympatrically, P. melisellensis is competitively superior to D. oxycephala; however, in Osor, D. oxycephala appeared in parts of the town where P. melisellensis had been present before. Since 2005, there has been no systematic survey to assess how the distribution of the two species has changed in Osor and, the aim of this study is to investigate how far D. oxycephala has spread and what happened to the distribution of the native P. melisellensis after the new species appeared. Here we show that in 16 years, the native Dalmatian wall lizard was outcompeted by the sharp-snouted rock lizard, and there was no observation of the two species together at the same locations. Despite the new species preferring high stone walls, specimens were also found on shorter stone walls alongside the road towards Lošinj. According to our findings, the further spread of the sharp-snouted rock lizard cannot be excluded in the upcoming years in Cres, which could negatively affect the native Dalmatian wall lizard, but further research is needed to reveal the causes of our observations and to monitor the changes in the distribution of the two species

Application of models with different complexity for a stirred tank reactor

Engineering problem solving such as process design, process optimization, safety analysis, etc.; relies widely on mathematical models of the process. To solve various engineering problems various models with different complexity are needed. A stirred tank reactor with a highly exothermic reaction is studied in this work, because in the modern chemical technologies mixing is one of the most important operations, and stirred reactors are widely used in industrial applications. The stirring system of a mixed tank is always an important aspect of the design, because the involved processes (such as reactions, heat and component transport) usually require proper contact and homogeneity of the existing phases. For the suitable homogeneity the design and the size of the moving parts are also important problems. In certain situations attachment of static parts to a stirred tank (such as baffles) may have an important effect too. The primary goal of this study is to create models with different level of complexity and determine which model is the best suited for solving different engineering tasks such as process design, scale-up, or optimisation. etc. To determine which model fits best for a problem, mathematical models were created and compared to find out, how the information can be extracted from these models and be applied to solve engineering problems. Three types of models have been developed: perfectly mixed reactor model, compartment model, and Computational Fluid Dynamics (CFD) models with different dimensions. The reaction of hydrogen peroxide with sodium thiosulphate in a continuously stirred tank reactor is analysed as a case study. The perfectly mixed vessel models and compartment models were solved in MATLAB/SIMULINK program package. The CFD models were implemented in COMSOL Multiphysics

SDR mint lehetséges drónzavaró eszköz = SDR as a Potential Jamming Tool

Napjainkban a drónok felhasználása és alkalmazása szinte az életünk minden területén megjelenik. A felhasználási intenzitás növekedése egyre nagyobb, akár katonai, akár civil vonatkozásban. A drón alkalmazása egy bizonyos nézőpontból lehet „hasznos”, az emberiség és társadalom fejlődését elősegítő, és lehet „káros” is. Az adott nézőpontból „hasznos” kategóriába sorolt drónt és annak küldetésteljesítését meg kell védeni, míg a „káros” kategóriába sorolt működését és küldetésvégrehajtását korlátozni kell. Cikkünkben a drónok tájékozódását segítő műholdas navigációs rendszer kiiktathatóságát és zavarhatóságát vizsgáljuk. Vizsgálatainkhoz szoftverdefiniált rádiót (SDR) használunk. Nowadays, the use and application of drones appear in almost every area of our lives. The intensity of use is increasing in both military and civilian contexts. From a certain point of view, the use of drones can be “useful” for the development of humanity and society, and it can also be “harmful”. From a given point of view, a drone classified in the “useful” category and its mission performance must be protected, while the operation and mission performance of a “harmful” category must be limited. In our article, we examine the discontinuity and interference of the satellite navigation system that helps with drone orientation. We use software defined radio (SDR) for our tests