Physical security has received increased attention after 9/11. However, access control to physical units has not been explored much. On the other hand, there is a rich literature on access control to information. These two areas appear converging as seen by recent products and studies. However, use of different notations and implementation details make this convergence harder. We need to try to...

During the last two decades the European airport industry is liberalised and turned to competitive market environment. This fact attracts an increasing scientific and practical interest to analysis of airport efficiency and its determinants, as well as different aspects of airport competition. This paper contains a critical review of existing researches in these two areas – airport efficiency a...

The Ground Delay Program (GDP) is an air traffic flow management mechanism used to decrease the rate of in-coming flights into an airport when it is projected that arrival demand will exceed capacity. Under a GDP, a set of flights destined for a single airport is assigned ground delays. In this paper we investigate how the set of flights to which delays are applied is defined. Specifically, we ...

Airport surface congestion results in significant increases in taxi times, fuel burn and emissions at major airports. This paper describes the field tests of a congestion control strategy at Boston Logan International Airport. The approach determines a suggested rate to meter pushbacks from the gate, in order to prevent the airport surface from entering congested states and to reduce the time t...

In a steam power plant, the temperature of the cooling water leaving the condenser for recyclingshould decrease. This is achieved in a cooling tower. The Heller cooling tower does not require waterfor operation, thus, it is a suitable system for use in thermal power plants throughout Iran. Wind is anenvironmental factor that unfavorably affects the performance of a cooling tower. Previous studi...

Design of a natural dry cooling tower has been accomplished in two sections: the design of heat exchangers and the numerical solution of flow through the tower. Heat exchanger (Heller type) has been simulated thermodynamically and then coupled with a computer program, which calculated the turbulent natural convection flow through the tower. The computer program developed for this purpose can be...

The paper presents a laboratory model of the 3D tower crane. The arm of the crane is approx 1.2m long and the model is approx. 1.5m heigh. The crane is equipped with three DC motors that control: the rotary movement of the tower, the movement of the trolley and up and down movement of the load. The model is equipped with an unique unit for measuring an angle position of the load. The paper cont...