The paper studies the complementarity of the methods from the field of traffic flow theory: methods of traffic flow intersecting intensity and the method for the at-grade intersection capacity analysis. Apart from checking mutual implications of these methods, the proportionality of mutual influences is assessed. Harmonized application of these methods acts efficiently on the entire traffic network, and not only on the intersections that are usually incorrectly represented as the only network operators. Theoretical considerations are illustrated by a practical example. KEY WORDS: traffic flow theory, theory of organization and direction of traffic flows, intersecting intensity of traffic flows, intersection capacity, optimization

This paper addresses the optimization possibilities of cargo operations onboard ship in order to minimize the operational costs through optimal structure of resources required. Since the setup model consists of composite objective function with several decision variables whose solution is constrained in the field Z+, the method for direct finding of optimal solution does not lead to satisfactory results. Therefore, for the solution of the problem a genetic algorithm has been developed, which yields an acceptable solution in a short time. In the given area of the possible solutions, the genetic algorithm, with variations of different crossover methods and mutation rates, gives a solution that coincides with the observed and expected results when operations of loading/unloading of general cargo ship are concerned. With the obtained structure of resources allocated in cargo operations, the minimum of operational costs is reached. KEY WORDS: ship, cargo operations, optimization, genetic algorithm

A simplified modelling approach to urban commuting patterns is achieved by focusing on daytime populations rather than on commuters, or on the commuting process itself. Whereas past studies were usually economic in nature, and viewed commuting as a process within the continuum of urban space and time, the approach addressing daytime populations transforms the modelling attempt into a demographic deliberation of a binary situation where switching of values between daytime and night-time indicators in each subarea throughout a metropolis is considered. The present study shows that such a focus on diurnal change as a binary concept offers a new paradigm in conceptualizing metropolitan commuting and transportation. Under certain assumptions, rooted in recent observations of metropolitan areas elsewhere, this study conjectures an analytic function for the estimation of daytime populations in small areas throughout the metropolitan region of Brno, Czech Republic. The conjectured relationship is a logistic function that utilizes as its independent variable the average household size in each of the subareas throughout the metropolitan region. Based on the data from the Czech census of 2001, the distributions of average household size and of residential populations throughout the metropolitan region are applied in a case study illustrating the utility of the proposed approach for the estimation of daytime populations throughout the region. The iterative procedure advanced here offers considerable potential for further applications elsewhere. KEY WORDS: metropolitan commuting, urban transportation, Brno, daytime population, average household size, logistic function, small area demography

In this paper, a solution is proposed for testing TCP congestion window process in a real-life network situation during stationary time intervals. With this respect, the architecture of hardware and expert-system-based distributed protocol analysis is presented that we used for data acquisition and testing, conducted on a major network with live traffic (Electronic Financial Transactions data transfer), as well as the appropriate algorithm for estimating the actual congestion window size from the measured data that mainly included decoding with precise time-stamps (100ns resolution locally and 1ms with GPS clock distribution) and expert-system comments, resulting from the appropriate processing of the network data, accordingly filtered prior to arriving to the special-hardware-based capture buffer. In addition, the paper presents the statistical analysis model that we developed for the evaluation whether the data belonged to the specific (in this case, normal) cumulative distribution function, or whether two data sets exhibit the same statistical distribution - the conditio sine qua non for a TCP-stable interval. Having identified such stationary intervals, it was found that the measured-data-based congestion window values exhibited very good fitting (with satisfactory statistical significance) to the truncated normal distribution. Finally, an appropriate model was developed and applied, for estimating the relevant parameters of the congestion window distribution: its mean value and the variance. KEY WORDS: protocol analysis, TCP-IP, testing, traffic congestion, statistical analysis, parameter estimation

This article is dealing with airline industry standards regarding reliability reporting and with practical aspects of reliability program deployment within an operator’s organization. Reliability program is a tool for monitoring the effectiveness of aircraft maintenance program. Apart from being an effective tool for maintenance program development, the reliability program can bring to light flaws in aircraft design, discrepant operational procedures, discrepancies in line and base maintenance. Reliability program is also considered to provide very valuable means for achieving better operational performance (through decreased maintenance-related problems in operation) and increased flight safety. For this reason, reliability programs are mandated by the regulations for all commercial operators. Even though there is a general industry standard regarding maintenance reliability programs, it still has to be customized and optimized by each operator in order to gain the most out of it. Organizational procedures will vary significantly from one operator to another, reflecting the size and structure of the monitored fleet, size of the operator and its engineering power. As maintenance reliability program involves the application of statistic methods in finding systematic negative trends, the bigger the size of the fleet, the more accurate and reliable results can be achieved. This work is outlining the existing airline industry standards and good practice in carrying out maintenance reliability program. KEY WORDS: aircraft maintenance program, maintenance reliability program, flight safety, small airline operator

International Civil Aviation Organization and other international aviation organizations regulate the safety in civil aviation. In the recent years the International Civil Aviation Organization has introduced the concept of the safety management system through several documents among which the most important is the 2006 Safety Management Manual. It treats the safety management system in all the segments of civil aviation, from carriers, aerodromes and air traffic control to design, construction and maintenance of aircraft, aerodromes, those who produce instruments, equipment and parts for the needs of civil aviation and others. This paper presents and partly deals with the documents from the safety management system domain and the system implementation in Croatia with special focus on the Croatia air navigation service provider, Croatia Control Ltd. KEY WORDS: safety management system, safety, air traffic control

In the existing legislative process, the Montenegrin judicature faces a series of questions imposed by the practice of arresting ships. Legislation tries to respond to them by innovating the current regulations, based on the 1977, i.e. 1998 Maritime and Inland Navigation Act (MINA), and by taking into consideration the achievements of foreign, similar jurisprudences and legislations, as well as of international conventions. The proposed solutions in the draft of the Maritime Navigation Act represent a certain change in legislative systematization of the legal institute of temporary measure of ships arrest. KEY WORDS: arrest of ships, national legislation, International Arrest Conventions

Air transport industry has gradually increased its share of global passenger and freight traffic, and this trend has accelerated in the last 40 years. For the past decade, air-freight traffic growth has outpaced air passenger traffic growth by 1-2% each year. In the past, air-freight sector offered limited services, with heavy reliance on several intermediaries and a significant dependence on air passenger operations. The sector can now be characterized as a sophisticated, innovative one, relying heavily on new electronic technologies, offering a wide range of transport and logistical products through dedicated specialist freight operators. With increasing emphasis on the globalization of trade and economic activity, air-freight growth is expected to continue to outpace air passenger traffic growth. The air-freight growth is expected to be greatest in the Asian markets (intra-Asia; North America-Asia; Europe-Asia and Australasia). The process of physical distribution of freight has become a highly sophisticated operation, with increasingly greater reliance being placed on the use of new technology to assist in the movement, storage, and tracking of consignments. But transport is just one component in this logistics chain. In this paper, air-freight sector is examined in terms of its structure, organization, its role in the supply chains, the main trends in the recent period, constraints facing the sector and the future prospects in air-freight sector. KEY WORDS: air freight organization, development, trends, forecast, logistics services