Volume 24 (2012): Edizione 1 (December 2012)

The permanent increase of the ship’s traffic density causes the growth of collision probability. Therefore, the probability evaluation of ship-ship collision is a very important topic. In the paper the method using theory of cellular automata is applied for maritime traffic safety evaluation. There are considered two types of traffic schemes: classical routes crossing and roundabout. The proposed model is implemented and computational results are obtained with the respect to ships safety prediction. The dependency analysis of the traffic flow structure and parameters on the ships safety is preformed. Finally, the results are summarized and a conclusion regarding future developments are given.

Application of the theory of using fuzzy fault trees is the first attempt to be used in collective water supply systems safety assessment in Poland. The paper presents a method of fault tree using fuzzy set theory. Fuzziness of basic logic gates used in the fault tree method is presented. The paper contains an application example of the method.

Presently, as a result of the technical progress, more and more complicated machines are being used in our everyday life. This is even more the case in relation to technology used at sea, where highly specialised services are needed. Sophisticated marine devices require special diagnostic methods that take into account the specific conditions of use of this type of machinery. In this paper we present the diagnostic systems elaborated to support the exploitation of the vessel power. Marine engine is a complex technical object. For the purpose of diagnostics it is convenient to divide the engine into several units - subsystems such as: piston -crank assembly; working medium exchange system, fuel supply system, lubricating system, cooling system, starting up - reversing system; combustion chamber, etc. The organization of the marine engine and auxiliary machinery diagnostic process can usually come down to two stages, general diagnostics and damage location. Most popular in marine engine diagnostics have been the periodic run analyzers, called pressure analyzers, electronic indicators. The diagnostic system of marine engine is able to assess the current engine condition and give forecast concerning its future operation in a complex way with the use of computer technology. Working out operating decision was based on proper preparation of operational parameters which were processed in a computer according to defined algorithms.

The paper presents an example of qualitative and quantitative application of a method for assessing component importance of a reliability structure in the case of a complex technical system based on the example of the subsystem of a marine power plant, that is, a lube oil system for sealing a stern tube. An example of the importance of the analysis considered in terms of not only reliability but also safety (impact of a component failure on human, machine and the environmental safety). Safety is usually analyzed in terms of quality, so the approach of trying to combine quantitative and qualitative estimation has been called a qualitative and quantitative method. A two - criteria importance of components according to the reliability criteria and safety criteria have been determined. The directions for further research have been outlined.

The paper provides justification for the necessity to define reliability of diagnosing systems (SDG) in order to develop a diagnosis on state of any technical mechanism being a diagnosed system (SDN). It has been shown that the knowledge of SDG reliability enables defining diagnosis reliability. It has been assumed that the diagnosis reliability can be defined as a diagnosis property which specifies the degree of recognizing by a diagnosing system (SDG) the actual state of the diagnosed system (SDN) which may be any mechanism, and the conditional probability p(S*/K*) of occurrence (existence) of state S* of the mechanism (SDN) as a diagnosis measure provided that at a specified reliability of SDG, the vector K* of values of diagnostic parameters implied by the state, is observed. The probability that SDG is in the state of ability during diagnostic tests and the following diagnostic inferences leading to development of a diagnosis about the SDN state, has been accepted as a measure of SDG reliability. The theory of semi-Markov processes has been used for defining the SDG reliability, that enabled to develop a SDG reliability model in the form of a seven-state (continuous-time discrete-state) semi-Markov process of changes of SDG states.

In a paper an application of the architecture evaluation method used for prediction the effects of incidents for information security which is inside of Information and Communication Technology (ICT) system is described. As a base, the ATAM method is taken. During the analysis there is shown, that direct use of the ATAM technique is impossible, because it use only one set of data. Use just one view of ICT system is not adequate for measure the influence of incident on information security, which is inside ICT system. A tool which is useful for assessment effects of incidents, is an incidence matrix that presents logical connections between elements of ICT system. Knowledge of logical connections and structures of the messages being exchanged enables an assessment of operation the elements which receive modified messages.

During the period of the structural changes in the processes of the European integration and regionalisation, the issue of the water services quality standards, which is associated with the social, economic and demographic development of the country, becomes more and more important. A properly functioning collective water supply system (CWSS) should ensure a continuous water supply to the recipients, with a suitable quality and adequate quantity (required pressure), at a specific time. These parameters must be maintained at the required level, which in reality is not so simple. Also indicators used for assess water services reliability for recipients are proposed. These indicators clearly evaluates the consequences of failures and at the same time retains the simplicity of estimation, which allows for its widespread usage in risk management.

This paper presents the computer simulation technique related to the reliability of an object under variable operation conditions. The Monte Carlo simulation is performed and, consequently, the unknown parameters for the considered object operation process and its main reliability characteristics are identified. The optimal transient probabilities of the object operation process at the particular operation states and its optimal unconditional reliability function are determined.

Are researched methods of text model interpretation in case of their use to describe social objects. Are considered peculiarities of their use for modeling objects which are hard to formally describe by theoretical means at the level of their detalization which will ensure necessary level of analytical possibilities for research and control of objects being modeled. In the research are proposed and developed methods of text model analysis based on use of semantic parameters which describe text model which itself is some text description in user language. As some elements of social objects accept information as its text description, so semantic coherence of texts with social object’s text description characterizes a level of its perception.

Transport telematic systems related issues are discussed in the paper. Most focused on were highway emergency response systems. Their structure and operational characterisation were described. Methods of assessing their reliability were also presented.

Town of Krosno is supplied with water by 3 intakes: Sieniawa, Iskrzynia and Szczepańcowa. After the treatment water flows in water mains to the water network in Krosno. The aim of his paper is qualitative risk analysis of the water main Sieniawa failures. The consequences of the failure: pressure value in the network and its duration, were described for different conditions of failures: time of failure, water demand and water storage tanks initial filling. For simulations of pipe failure water network model made in Epanet 2 program was used. The model was verified both during operation of water network and during the failure, where field data were used. The results of the simulations are corresponding to observations made during the real failures. Negative consequences appear only after emptying the water storage tanks, it results from two features of the storage tanks: they stabilize pressure in the network and for some time can provide water to the network. The time of emptying the storage tanks varies according to water demand their initial filling, it is at least 3 hours. During this time the are no sign of failure. When the storage tanks are empty reduction of pressure an shortage of water are observed on prevailing area of Krosno.

With regard to drinking water consumers, safety is understood as a probability to avoid threat arising from the consumption of water inconsistent with quality standards or the lack of water. Accordance with the Regulation of the Minister of Health water is safe for human health, if it is free from pathogenic microorganisms and parasites in the amount constituting a potential threat to human health, any substances in quantities hazardous to health and has no aggressive corrosive properties. Water supply reliability means providing stable conditions allowing to meet current and future demand for water in sufficient quantity and with required quality, in convenient time for water consumers and also at a price acceptable by them. In this study consumer (individual) risk r_K was defined as the sum of the first kind of risk r_KI, associated with possibility of interruptions in water supply and the second kind of risk r_KII associated with possibility of consumption of water inconsistent with quality standards. Three-parameter matrix of risk was proposed. For presented method was made an application example based on exploitation data of collective water supply system, which may help to increase safety of water consumers.

In this research, the effect of the European regional differences on the risk of been killed in road accident in these regions is investigated. Factors which differentiate regions can be described as automotive, economic, infrastructural, demographic, geographic. Analyzed risk, counted as regional fatality rate was modeled by the Poisson model. Because of regional diversity of Poisson distribution parameters, the Poisson distribution was adopted. The multivariate multilevel model was developed, in order to asses combined effects of different factors on road safety level in regions. Such models could be helpful to forecast such risk on the regional level and focus safety actions precisely for region, because the national actions and their results differentiate in regions so far.

This paper presents an application of the FMEA (Failure mode and effects analysis) to evaluate the operational risk in railway transport. The methodology developed by the Department of Rail Transport (KTS), including approval thresholds for risk adopted, the model forms (hazard record, FMEA form) were adopted in the Polish railways as a standard to evaluate the operational risk for operators and infrastructure managers. Reacting to the development of requirements for security management - Regulation EC No 445 of 2011 - Department of Rail Transport proposed the standard RAMS - PN - EN 50126 to oversee rail vehicles. This solution is currently being implemented in several entities building maintenance management systems (MMS) for the wagons. This article is dedicated to the people who deal with issues of safety management both in the transport of goods and people as well as the maintenance of rail vehicles.

Modern ship’s navigation support systems relay mainly on GNSS technology, as prime source of position. The advantages of such solution are obvious and undeniable. On the other hand in critical situations the dependency of the one system presents a great deal of risk. Taking above into consideration the idea of building GNSS independent Pilot Navigation and Docking System (PNDS) was put into practice. PNDS utilizes the range measurements between laser head and ship’s side to determine the ship’s horizontal plane presented on the screen. The study comprises the case in which three networked rangefinders were deployed on the berth side in a line. Such location of sensors causes uncertainty in determining of ship’s outline contour and speed in relation to assigned coordinate reference system. The final algorithm presented in the article, taking into account all underdetermined conditions, has been tested in PNDS system constructed in Maritime University in Szczecin.