The article presents a system approach to air traffic operationand control. A mathematical model of the system has beendeveloped, for the case when the input/output functions are discreterandom processes. A solution for a special example of inputfunctions has been calculated and analysed.

Full implementation of the final phase of EATCHIP isplanned for the beginning of the 21' century. It will re-define theEuropean system of air traffic regulation and control. The integrationof a great number of ATC systems into a unique operativenetwork is supported by the technical modernisation andstandardisation of the communication, navigation and radardevices. Integration of Croatia into the European air trafficcontrol system assumes its active participation in the cun·entprojects, implementation of relevant technical standards andthe national air traffic development strategy within the contextof Euro-atlantic integration.

The article deals with the problem of network facilities locationin the low-pressure networks. It is a 'general m-median'problem. The demand of gas is defined both in the nodes andalong the edge. The problem is solved by a heuristic algorithm.It searches for the optimal location of supply facilities in thenetwork using Mini-sum criterion. The continuous demand oneach link is replaced by a concentrated demand in the middlepoint of the link.

Traffic counts or statistical evidence of the traffic processare often a characteristic of time-series data. In this paper fundamentalproblem of estimating deterministic and stochasticcomponents of a traffic process are considered, in the context of'generalised traffic modelling'. Different methods for identificationand/or elimination of the trend and seasonal componentsare applied for concrete traffic counts. Further investigationsand applications of ARIMA models, Hilbert space formulationsand state-space representations are suggested.

The majority of network services provision (postal and telecommunicationsservices, rail transport, air transport, etc.)were traditionally considered as natural monopoly. New scenarioof the liberalised national market and 'Open NetworkProvision' require precise and concrete economic evaluationbefore implementation itselfThis paper considers the methodology for the application ofnatural monopoly with the concept of cost sub-additivity. It ispointed out that the scale and scope economies, associatedwith 'plant (network) sub-additivity' is not sufficient to justifythe monopoly in every service provision in the traffic system andits subsystems. The paper considers and analyses the possiblemarket configuration with various degrees of competition fortelecommunication subsystem. The asymmetric competition inthe telecommunication subsystem by means of the dominantorganisation model has been analysed.

The paper shows the maritime system of the Republic ofSlovenia and its weakpoints, mainly as a result of the transitionand gaining of independence. The second heading describes researchactivities in the area of the maritime system of the Republicof Slovenia during the period from 1992 to 1995. Thethird heading gives a brief review of the EU maritime policy anddescription of Research & Development projects that are intendedas guidelines of the EU maritime policy. In conclusion,the author presents a proposal of the themes and procedures ofscientific research projects in the area of maritime activities ofthe Republic of Slovenia.

The European cities are faced today by the phenomenon ofexpanding everyday activities, affecting directly the traffic development.Physical expansion, the growing number of cars androad networks explain the increase in car utilisation in all typesof travelling in the range of 75 to 90%.Due to the adverse effects on the environment caused bysuch growing motorisation, the efforts are made in order to establishenvironmentally friendlier traffic. The paper considersthe concept of environmentally friendly individual trafficthrough MCC (Micro Compact Car) and MCC- mobility .systemwhich will provide its linking with other traffic participants,which may have a long-term positive influence on the quality ofurban life.

This paper describes the applications of an enhanced neuralnetwork and genetic algorithm for bus tickets sales forecasting.The proposed approach has several significant advantagesover conventional prediction methods. The major advantage ofthe approach is that no assumptions need to be made about theunderlying function or model, since the neural network is ableto extract hidden infonnation from the historical data. Althoughneural networks represent a promising altemative forforecasting, the problem of network design remains and couldimpair widespread applications in practice. The genetic algorithmis used to evolve neural network architectures automatically,thus eliminating the pitfalls associated with human engineeringapproach.

Internet information traffic becomes greater and moreimportant. With increasing growth of information importancerequirement for its security becomes indispensable. Theinformation security problem especially affect large and smallcompanies whose prosperity is depending on Internet presence.This affecting the three areas of Internet commerce: credit cardtransactions, virtual private networks and digital certification.To ensure information traffic it is necessary to find a solution,in a proper way, for three major problems: frontier problem,market problem and government problem. While the eventualemergence of security standards for Internet transactions isexpected, it will not automatically result in secure Internettransactions. In future, there is a wealth of security issues thatwill continue to require attention: internal security, continuedhacking, social engineering, malicious code, reliability andperformance, skills shortages and denial of se1vice attacks.

The paper presents a model of a detector-controlled trafficlight intersection as a complex traffic system. By analysing thekey factors of safety, the preliminary guidelines are given for theimplementation of the presented solution. The special emphasisis on defining the safety intervals as significant safety factorsin passing through an intersection.

The work describes some biologically regenerative fuels andcomments on the possibility of their application. Regarding theEuropean conditions, the most acceptable biologically regenerativefuel has proven to be the one based on rape. The characteristicssignificant for the combustion have been compared tothe conventional (fossil) fuels. Also, the impact of biologicallyregenerative fuels on the emission of harmful exhaust gases hasbeen described, and a favourable influence on the emission ofcarbon dioxide (CO2) and other harmful exhaust gases hasbeen determined.

The paper first describes the invention and introduction ofmobile telephony in the world and in Croatia. Then the basiccharacteristics are compared as well as the possibilities of certaingenerations of the mobile radio telephone systems with emphasison certain advantages. Finally, the prospects of furtherdevelopment of the mobile telephones are discussed, and theadequate conclusions made.

The development of fast railway results in an increased applicationof Trailer Train bimodal system transportation. Thetraffic costs are multiply reduced, particularly the variablecosts. On the other hand the environmental pollution from exhaustgases is also reduced. Therefore, by the year 2010 cargotransport should be preponderant~v used which would be characterisedby fast electric trains producing less noise, at lowercosts and with clean environment.

Air supply can be performed in two ways: by transportingthe technical equipment by transport aircraft or helicopters,and unloading upon landing and by air-dropping. The airdropcan be performed by dropping without parachutes, with parachutesand by low altitude cargo extraction. In the USA- CADS(Controlled Aerial Delivery System) has been developed providingcontrol of the falling cargo via a remote controller.