# Volume 35 (2015): Issue 1 (November 2015)

Journal Details
Format
Journal
eISSN
2083-4608
First Published
26 Feb 2008
Publication timeframe
4 times per year
Languages
English

18 Articles
Open Access

#### Stochastic Modelling Of The Repairable System

Published Online: 01 Dec 2015
Page range: 5 - 14

#### Abstract

All reliability models consisting of random time factors form stochastic processes. In this paper we recall the definitions of the most common point processes which are used for modelling of repairable systems. Particularly this paper presents stochastic processes as examples of reliability systems for the support of the maintenance related decisions. We consider the simplest one-unit system with a negligible repair or replacement time, i.e., the unit is operating and is repaired or replaced at failure, where the time required for repair and replacement is negligible. When the repair or replacement is completed, the unit becomes as good as new and resumes operation. The stochastic modelling of recoverable systems constitutes an excellent method of supporting maintenance related decision-making processes and enables their more rational use.

#### Keywords

• repairable system
• point process
• stochastic modelling
• Poisson process

#### Słowa kluczowe:

• system naprawialny
• proces punktowy
• modelowanie stochastyczne
• proces Poissona
Open Access

#### Realiability Of Heat Supply Subsystem

Published Online: 01 Dec 2015
Page range: 15 - 22

#### Abstract

The article presents the reliability analysis of subsystem of heat supply in the example of 47 thousand inhabitants’ city. The analysis was made on the basis of operational data made available by the Municipal Heating Company, between the years 2001 ÷ 2012. To describe the quantitative reliability of heat supply subsystem reliability indicators are used. Main times between failure and unitary failure rates including the month of their occurrence, type and diameter of the heating network, thermal power region were working out. Knowing the characteristics of the time to repair for the heating network, the reliability of heat supply subsystem for different thermal power region, considering the district heating system configuration can be determined.

#### Keywords

• reliability
• heat supply
• district heating

#### Słowa kluczowe:

• niezawodność
• dostawa ciepła
• miejski system ciepłowniczy
Open Access

#### Flight Safety In The Aspect Of Bird Strikes In Polish Air Force

Published Online: 01 Dec 2015
Page range: 23 - 34

#### Abstract

The paper presents analysis of bird strikes, that occurred in Polish Air Force. Data of Polish Air Force were used to analysis. Mentioned analysis concern such problems as time of day, height, kind of flight operation, severity of bird strikes. It is considered, that the results of researches can be used to determine bird strikes hazard and elaborate SMS in the context of bird strikes for military air bases.

#### Keywords

• flight safety
• bird strikes

#### Słowa kluczowe:

• bezpieczeństwo lotów
• kolizje statków powietrznych z ptakami
Open Access

#### Functional Analysis Of A Selected Airport’s System

Published Online: 01 Dec 2015
Page range: 35 - 42

#### Abstract

In this paper two selected airport’s systems (Flight Information System and Public Address Voice Annunciation) are defined and described. Then they are used to create an integrated unit, with the presentation of its way of functioning and a schematic picture. The author names main purposes of the integration process, serving to counteract negative consequences arising from implementation of the increasing number of systems on transport objects. In the following part of the article functional analysis of the integrated unit is carried out, defining system’s possible states of work and relations between them. Utilization of mathematical apparatus allows to calculate probabilities of system staying in the respective states, as well as system’s time indexes. Presented results are a fundament for the further analysis of this matter.

#### Keywords

• functional analysis
• integration
• airport

#### Słowa kluczowe:

• analiza funkcjonalna
• integracja
• port lotniczy
Open Access

#### Aspect Of Reliability In Airport Business Continuity Management

Published Online: 01 Dec 2015
Page range: 43 - 50

#### Abstract

The paper presents the issue of ensuring the continuity of the operation at the airport. Requirements and objectives relating to business continuity management have been defined in accordance with ISO 22301 international standard. Conducted a study of reliability issues operation of the airport. Defined the function of the reliability and operational readiness of the airport. Presented the concept of using function of operational readiness in the risk assessment for the continuity of the airport.

• airport

#### Słowa kluczowe:

• port lotniczy
• ciągłość działania
• gotowość operacyjna
Open Access

#### Reliability Of Routing Protocols

Published Online: 01 Dec 2015
Page range: 51 - 62

#### Abstract

The article refers to the impact of damage and dynamic variables on operation of routing protocols and consequently to the whole network. On this purpose, there was introduced the characteristic of the routing protocols and both an internal and an exterior gateway. Then, it was built the network architecture based on the TCP / IP stack. In the stack, there were created three autonomous systems and one of them was the backbone of the network. What is more, reliability tests, which have been performed, consisted of a resistance to physical damage to the network and dynamically changing parameters of the network as well as performance tests.

#### Keywords

• reliability
• routing
• network protocols

#### Słowa kluczowe:

• niezawodność
• routing
• protokoły sieciowe
Open Access

#### Analysis Of MPLS VPN Resistance To External Threats

Published Online: 01 Dec 2015
Page range: 63 - 72

#### Abstract

This article presents analysis and possible reactions of MPLS network on unauthorized access and on device’s failure. Five Cisco routers joined into a core network were used to conduct the project. The devices were connected into a classic reliability model with envelope shape. The key aspects of the research were incidents’ simulation in line with previously prepared scenarios as well as diagnosis of network’s reactions to a particular type of a device failure. These effects were modelled using special devices such as analysers and generators of data traffic. Additionally, the range of the project included measuring convergence time of the routing protocols acting inside the network combined with analysis of reactions to forced changes of route.

• MPLS
• security
• reliability

#### Słowa kluczowe:

• MPLS
• bezpieczeństwo
• niezawodność
Open Access

#### Evaluation Of The Safety Integrity Level (SIL) Due To The Guidelines Of EN 61508 And With The Use Of Markov Processes

Published Online: 01 Dec 2015
Page range: 73 - 84

#### Abstract

The methods of evaluation of the Probability of Failure on Demand (PFD) of safety systems were presented in the paper, assuming that the safety systems may be represented by the k out of n reliability structures. The results of the calculations obtained according to EN 61508 were compared with another results, this time obtained from the calculations done for these systems assuming that their failure-and-renewal process is a Markov process.

• reliability
• safety
• SIL

#### Słowa kluczowe:

• niezawodność
• bezpieczeństwo
• SIL
Open Access

#### Effect Of Selected Factors On The Safety Integrity Level (SIL)

Published Online: 01 Dec 2015
Page range: 85 - 98

#### Abstract

The presented paper concerns the functional safety problems of technical systems. The characteristics of safety assessment, described in IEC 61508 standard are an introduction to the problems associated with the methodology of the calculation of Safety Integrity Levels (SIL). The parameters obtained from reliability indicators, were calculated for the purpose of assessing the impact of repair time for the elements of a given system on the SIL. The calculated values of failure rate and the probability of dangerous failure show the sensitivity of the system at different time to repair values for various reliability-wise configurations. The indicators characterizing the safety level, calculated of the system with no repair time are the basis for demonstrating the influence of repair on the safety integrity level.

#### Keywords

• safety
• safety integrity levels (SIL)
• reliability-wise configuration
• repair time

#### Słowa kluczowe:

• bezpieczeństwo
• poziomy nienaruszalności SIL
• struktura niezawodnościowa
• czas odnowy
Open Access

#### Effectivness Of The Failure Rate On Maintenance Costs Of The City Buses

Published Online: 01 Dec 2015
Page range: 99 - 108

#### Abstract

The purpose of this paper was to present a failure rate and maintenance cost comparison for two types of city transport buses. The paper presents in detail a case study of well known bus brands used at Municipal Transport Company in Lublin. A failure index of all functional and constructional systems of the vehicles and their technical availability with regards to calendar time was determined. The paper also presents analysis of the factors related to maintenance costs of buses, including costs of fluids, repair costs and maintenance service. It has been demonstrated, that both analyzed buses generate similar maintenance costs, while their failures and technical availability differ significantly in operational practice. These differences are particularly evident in relation to the cumulative costs of repairs.

#### Keywords

• city transport buses
• failure index
• technical availability
• maintenance costs

#### Słowa kluczowe:

• autobusy komunikacji miejskiej
• wskaźniki uszkodzeń
• gotowość techniczna
• koszty utrzymania
Open Access

#### The Use Of Fuzzy Set Theory In Exploitation Management Process On The Water Supply Network

Published Online: 01 Dec 2015
Page range: 109 - 118

#### Abstract

Daily exploitation of the network, collected data base concerning the pipes failures and knowledge of employees forming the base of data using in effective failure removal process. The paper presents a methodology of assessment of technical condition of water pipes, based on ranking the failures and danger degree they present resulting the lack of water supply to the water consumers. Often decision making process take place under uncertainty conditions, therefore presented method is based on assessment of degree of danger pipe failure making by experts using fuzzy theory and fuzzy sets. In the paper a fuzzy graph including various types of failures causing lack of water supply was presented.

#### Keywords

• water supply network
• failure rate
• theory of fuzzy set

#### Słowa kluczowe:

• sieć wodociągowa
• awaryjność
• teoria zbiorów rozmytych
Open Access

#### The Concept Of Fuzzy Modeling Of Safety In Collective Water Supply Systems Using Bayesian Network

Published Online: 01 Dec 2015
Page range: 119 - 126

#### Abstract

The paper presents the use of fuzzy Bayesian network in safety modeling with regard to collective water supply system (CWSS). The theoretical basis of Bayesian networks and fuzzy modeling were presented. The paper presents failure events threatening the CWSS safety. The probability of the risk of lack of water supply to the city was designated. The model allows to determine the fuzzy probability of the risk at a given level.

#### Keywords

• collective water supply system
• Bayesian network

#### Słowa kluczowe:

• system zbiorowego zaopatrzenia w wodę
• sieć Bayesa
Open Access

#### Sources Of Incidental Events In Collective Water Supply System

Published Online: 01 Dec 2015
Page range: 127 - 136

#### Abstract

The publication presents the main types of incidental events in collective water supply system. The special attention was addressed to the incidental events associated with a decrease in water quality, posing a threat to the health and life of inhabitants. The security method against incidental contamination in the water source was described.

#### Keywords

• incidental events
• collective water supply system

#### Słowa kluczowe:

• zdarzenia incydentalne
• system zbiorowego zaopatrzenia w wodę
Open Access

#### Reliability And Maintenance Analysis Of CCTV Systems Used In Rail Transport

Published Online: 01 Dec 2015
Page range: 137 - 146

#### Abstract

CCTV systems are widely used across plethora of industrial areas including transport, where their function is to support transport telematics systems. Among others, they are used to ensure travel safety. This paper presented a reliability and maintenance analysis of CCTV. It led to building a relationships graph and then Chapman–Kolmogorov system of equations was derived to describe it. Drawing on those equations, relationships for calculating probability of system staying in state of full ability SPZ, state of the impendency over safety SZB1 as well as state of unreliability of safety SB were derived.

#### Keywords

• Closed Circuit Television
• reliability
• operation and maintenance

#### Słowa kluczowe:

• systemy monitoringu wizyjnego
• niezawodność
• eksploatacja
Open Access

#### Selected Methods For Increases Reliability The Of Electronic Systems Security

Published Online: 01 Dec 2015
Page range: 147 - 156

#### Abstract

The article presents the issues related to the different methods to increase the reliability of electronic security systems (ESS) for example, a fire alarm system (SSP). Reliability of the SSP in the descriptive sense is a property preservation capacity to implement the preset function (e.g. protection: fire airport, the port, logistics base, etc.), at a certain time and under certain conditions, e.g. Environmental, despite the possible non-compliance by a specific subset of elements this system. Analyzing the available literature on the ESS-SSP is not available studies on methods to increase the reliability (several works similar topics but moving with respect to the burglary and robbery (Intrusion.) Based on the analysis of the set of all paths in the system suitability of the SSP for the scenario mentioned elements fire events (device) critical because of security.

#### Keywords

• electronic security
• redundancy of
• reliability
• power

#### Słowa kluczowe:

• elektroniczne systemy bezpieczeństwa
• niezawodność
• zasilanie
Open Access

#### The Issue Of Water Resources Diversification In Water Supply Systems

Published Online: 01 Dec 2015
Page range: 157 - 168

#### Abstract

The aim of the paper is to present the methodology for determining the diversification degree of water resources in Collective Water Supply Systems (CWSS). Knowing the number of water supply sub-systems and their share in the total supply of water for CWSS, it is possible to calculate the dimensionless Pielou ratio. The paper presents the calculation of the diversification rate for 26 CWSS in Poland. The presented methodology makes it possible to compare CWSS with different water requirements.

#### Keywords

• collective water supply system
• diversification
• water recources

#### Słowa kluczowe:

• system zbiorowego zaopatrzenia w wodę
• dywersyfikacja
• zasoby wody
Open Access

#### Study Of Ceramic-Polymer Composites Reliability Based On The Bending Strength Test

Published Online: 01 Dec 2015
Page range: 169 - 178

#### Abstract

In this paper the reliability assessment of structural reliability of the selected light-cured dental composites based on the biaxial flexural strength test results has been presented. A two-parameter Weibull distribution was applied as a reliability model in order to estimate probability of strength maintenance in the analysed population. Weibull distribution parameters were interpreted as a characteristic material strength (scale parameter) and structural reliability parameter in terms of ability to maintain strength by each of specimen from the general population (shape parameter). 20 composite specimens underwent strength tests, including 2 “flow” type composites and 2 standard composites (with typical filler content). “Flow” type composites were characterized with lower characteristic strength and higher structural reliability comparing to other studied composites.

#### Keywords

• dental composites
• strength
• reliability analysis

#### Słowa kluczowe:

• kompozyty stomatologiczne
• wytrzymałość
• analiza niezawodności
Open Access

#### Use Of Bayesian Networks And Augmented Reality To Reliability Testing Of Complex Technical Objects

Published Online: 01 Dec 2015
Page range: 179 - 190

#### Abstract

This paper presents a methodology developed to support the tests of reliability of complex technical objects. The presented methodology covers the use of modern information technologies in the form of algorithmic models and effective visualization techniques in the form of augmented reality. The possibility of using a probabilistic Bayesian network. The method of determining the probabilities for specific nodes, and the total probability distribution of graph structures are presented. The structure of the model and its basic functions are shown. The results of the verification work for connecting data processing methods and visualization techniques based on augmented reality are presented.

#### Keywords

• Bayesian networks
• probabilistic networks
• augmented reality
• reliability

#### Słowa kluczowe:

• sieć Bayesa
• sieć probabilistyczna
• rzeczywistość rozszerzona
• niezawodność