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Budapest, Hungary

Tettamanti T.,BUTE | Varga I.,Hungarian Academy of Sciences
Periodica Polytechnica: Civil Engineering

The paper investigates a distributed control system scheme for urban road traffic management. The control algorithm is based on model predictive control (MPC) involving Jacobi iteration algorithm to solve constrained and nonlinear programming problem. The signal controllers of traffic network constitute a network of computers. They can distribute their computation realizing an efficient traffic control without any central management. However the optimal control inputs can be also calculated by a single traffic controller if the traffic network contains few intersections. The control aim is to relieve traffic congestion, reduce travel time and improve homogenous traffic flow in urban traffic area using distributed control architecture. The MPC based control strategy can be implemented in any urban transportation network but adequate measurement system and modern traffic controllers are needed. Theory, realization possibilities and simulation of the control method are also presented. The simulation results show that the system is able to ameliorate the network efficiency and reduce travel time. The distributed MPC based traffic control strategy proves the effectiveness by realizing a dependable control operation and creating optimal flow in the network subjected to control input constraints. © Periodica Polytechnica 2010. Source

Hajnal I.,BUTE
Procedia Engineering

One of the most apparent signs of the international real estate crisis is the many unfinished construction investments. The various states and professional organizations are attempting to mitigate investment risks with regulations and methodology instructions, and, thus inspiring new confidence, to kick-start financing, which is the engine driving the real estate market. New methods and approaches are necessary in the area of real estate appraisal also, to ensure that the market value of works in progress could be accurately determined at all times, thereby facilitating the management of risks and reinforcing the confidence of the investors. The author of the article reviews and evaluates the methods with which the value of works in progress can be estimated well, and which can replace the static, simplistic approach currently used by appraisers. While comparative methodology is not suitable to tackle the problem, as the first practical step, in the net replacement cost based valuation approach the Market Value of the land, as value-forming factor, must continuously be examined. The income-based calculation approach can easily be made suitable for the determination of the Market Value of works in progress. © 2015 The Authors. Published by Elsevier Ltd. Source

Szabo Z.,HAS BUTE Research Group on Dynamics of Machines and Vehicles | Zelei A.,HAS BUTE Research Group on Dynamics of Machines and Vehicles | Stepan G.,BUTE
Periodica Polytechnica, Mechanical Engineering

In this paper we investigated the dynamics of a thin, flat plate placed in potential planar flow and attached by springs to the wall. Furthermore, the centre of gravity of the plate was assumed to move only perpendicular to the direction of the flow. Thus, a two-degree-of-freedom oscillatory system was analysed, whose natural frequencies depend on the flow velocity. The equations of motion were derived for two cases: first, the flow forces acting on the plate were determined using a quasisteady approach; in the second case, we used the formulas derived by Theodorsen assuming unsteady potential flow. Finally, we obtained and compared the stability charts for the two cases. © Periodica Polytechnica 2012. Source

Devecseri G.,BUTE
Periodica Polytechnica: Civil Engineering

Asphalt is defined as a mixture of inert mineral matter, such as aggregate, mineral filler and bituminous binder in predeterminated portions. One of the most important properties of asphalt mixtures is the bitumen content. The most preferred way of asphalt binder analysis is extraction (with tricloroethylene). Because of environmental reasons extraction should be replaced with more environment friendly solution, this could be heating. But high temperatures can cause changes in the physical properties of mineral aggregates that are commonly used in asphalt mixtures causing faults in the results of the binder analysis. Eight different types (five andesites, one basalt, two dolomites) of Hungarian rocks have been tested in laboratory conditions to analyse the effect of heat on asphalt aggregates. 11/16mm fractions were heated at 480°C in an ignition furnace. The weight losses and grain distributions were recorded and compared. The physical parameters have shown that aggregates behave differently after burning on high temperature. As an additional result coloures and colour differences of aggregates were also observed after heating. © Periodica Polytechnica 2010. Source

Dudas A.,BUTE | Farkas L.,Aquaseal Ltd
Advanced Materials Research

Covering soil layer significantly reduces the heat loss of earth-sheltered building elements. Quantity of heat loss is highly influenced by the thickness of soil on examined building constructions. Based on the above mentioned facts an earth-sheltered sample building was designed. Ecological designing principles (recycled building materials and passive solar designing rules) were taken into consideration during planning of examined residential house. The building structures are general solutions, the earth-sheltered characteristic manifested by soil-covered elevations and green roof. The detailed energetic calculations are based on the linear heat transmission coefficient, which serves as a numerical definition of the heat bridge effect. Linear heat transmission coefficients were calculated as simulational results that can be derived from the finite element modelling of structural intersections. Detailed building simulations represent the advantages of soil covering. Hygrothermal analysis of building constructions based on their thermal simulations is essential. Due to the intensified waterproofing of earth-sheltered structures vapour diffusion is considerably reduced. At the same time environmentally conscious design prefers diffusion open orders of layers. Hygrothermal calculations of different waterproofing materials can categorise the environmental friendly solution of the protection. © (2014) Trans Tech Publications, Switzerland. Source

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