2010, volume 11 #4. "Transport and Telecommunication". Журнал издательства TSI, ISSN 1407-6160, ISSN 1407-6179 | TSI

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2010, volume 11 #4. "Transport and Telecommunication". Журнал издательства TSI, ISSN 1407-6160, ISSN 1407-6179

NEW METHODS OF CALCULATING THE GENOME OF STRUCTURE AND THE FAILURE CRITICALITY OF THE COMPLEX OBJECTS’ ELEMENTS

E. A. Kopytov 1 A. N. Pavlov 2, V. A. Zelentsov 3

1Transport and Telecommunication Institute
Lomonosova 1, Riga, LV-1019, Latvia
Ph.: +371 67100669.
E-mail: kopitov@tsi.lv

2St. Petersburg Institute for Informatics and Automation of Russian Academy of Science
14th Line 39, St. Petersburg, 199178, Russia

Ph.: +7(812)3280103.
E-mail: pavlov62@list.ru

3St. Petersburg State University of Aerospace Instrumentation
Bolshaya Morskaya, 67, St. Petersburg, 190000, Russia
Ph.: +7(812)3280103.
E-mail: zvarambler@rambler.ru

There are considered two new methods of analysing the contribution of separate elements into the efficiency of a complex object. The first one is based on the introduction of a new notion – “the genome of structure” applied for calculating the structural significance of the monotonous and non-monotonous systems. The second method allows estimation of a more general indicator – failure criticality of the element. This method is based on a combined method of a fuzzy logic conclusion and on the methods of the experiment planning theory. The failure criticality of the complex objects’ elements is expressed by a vector property for which evaluating there is used a number of partial indicators, which may have both quantitative and qualitative character and for their measurement there may be used different types of scales. The resulting indicator of the element failure criticality is presented in the form of a polynomial which accounts both the influence of the separately taken indicators and the influence of the indicators’ aggregations (of 2, 3, etc.). Calculation of the polynomial coefficients is made on the basis of processing the expert information and the corresponding linguistic variables quantitatively measured by fuzzy numbers.

Keywords: genome of structure, failure criticality, complex object, multi-criteria analysis, theory of experiment planning, linguistic variable

 

APPROACH TO HARDWARE IMPLEMENTATION OF GENETIC ALGORITHM FOR INVERSE PROBLEM OF ROADWAY COVERAGE SUBSURFACE PROBING SOLUTION

A. Krainyukov, V. Kutev, D. Opolchenov

Transport and Telecommunications Institute
Lomonosova str. 1, Riga, LV-1019, Latvia
Ph.: +371 67100634. Fax: +371 67100660
E-mail: Aleksandrs.Krainukovs@tsi.lv, Valerijs.Kutev@tsi.lv, Daniil.Opolchenov@tsi.lv

This work has focused on the problem of approach to hardware implementation of genetic algorithm for inverse problem of roadway coverage subsurface radar probing solution. Iterative procedure to solve the inverse problem in frequency domain is used on base of aim function minimization. Genetic algorithm is used for search of global minimum of aim function. For hardware implementation of genetic algorithm it is necessary correctly to choose the values of arguments for aim function and parameters of genetic algorithm. The authors investigated two different kinds of aim functions. Estimation of possibility for genetic algorithm hardware implementation on base of field-programmable gate array (FPGA) is discussed.

Keywords: roadway radar monitoring, inverse problem, genetic algorithm, field-programmable devices, hardware implementation

 

SOME FEATURES OF THE HOP MODEL OF EARTH-IONOSPHERE WAVEGUIDE

Yury A. Krasnitsky

Transport and Telecommunication Institute
Lomonosova str. 1, Riga, LV-1019, Latvia
Ph.: +371 67100608.
Fax: +371 67100660.
E-mail: krasn@tsi.lv

The problem of electromagnetic pulse radiator location from single station observation is considered, based on the hop model of pulse propagation in spherical waveguide 'Earth-ionosphere'. Pulse characteristics both ground wave and hop (sky) waves of that waveguide are modelled as functions of the distance from radiation source. The waveguide parameters, namely, the distance from the radiator and the effective reflecting heights of the ionosphere, can be evaluated through the delays of the waves reflected by the ionosphere with respect to the ground wave. The errors in values of delays give rise to the errors in the waveguide parameters. These connections are investigated. It is demonstrated how the waveguide parameter errors depend on the distances and heights of reflections. A method to reinterpret the hop model features by using some equivalent antenna array conception is proposed.

Keywords: electromagnetic radiation, ionosphere, waveguide, hop model, distance, effective heights, delays, lightning discharge, atmospherics

 

COVERAGE ESTIMATION IN SINERGIC NETWORKED INTELLIGENT TRANSPORTATION SYSTEMS WITH NON-ISOTROPIC NODES

Victor Krebss1, Boris Tsilker2

1CPS, Ltd Skanstes str. 13, Riga, LV-1013, Latvia
Ph.: +371 29243923. E-mail: victor@cps.lv

2Transport and Telecommunication Institute
Lomonosova str.1, Riga, LV-1019, Latvia
Ph.: +371 67100604. Fax: +371 67100560.

Е-mail: tsilker@tsi.lv

Safety of road travel is of the most considerable tasks solvable by intelligent transportation systems (ITS). It can be solved by mutual interaction of nodes equipped by sensors forming a sensor network. The wireless sensor networks can be integrated into ITS as vehicles through vehicle-to-vehicle or infrastructure-to-vehicle communication models to monitor the road condition, construction sites or obstacles for driving safety and to announce such road. Wireless sensor networks also pose a number of challenging optimisation problems. Coverage problem was and remains a fundamental issue in construction of wireless networks. Most of known investigations, concerned with optimal (in sense of ensuring of necessary coverage level at every point in service area) deployment of networks’ nodes, i.e., with optimal network topology, study the problem on the assumption that wireless network service area is free from obstacles, impeding normal propagation of information signals [1-3]. As a result, suggested network topologies become far from optimal at presence of obstacles within serviced area. More realistic solution presumes taking into account of obstacles within the serviced area. Possible approaches for efficient placement of wireless network nodes on condition that service area contains obstacles are discussed at present work. Problem is examined from two points of view: as a probabilistic task, as well as a task of computational geometry. A probabilistic model is more realistic because the sensor design and environmental conditions are all stochastic in nature. Interference and noise in the environment can be modelled by stochastic processes. The investigation has resulted in some algorithms and considerations for near to optimal deployment of nodes within network service zone with obstacles.

Keywords: Intelligent Transportation System, anisotropic sensor, sensor network, coverage, service area

 

PATTERN-ORIENTED DECISIONS FOR LOGISTICS AND TRANSPORT SOFTWARE

Sergey Orlov, Andrei Vishnyakov

Transport and Telecommunication Institute
Lomonosova str.1, Riga, LV-1019, Latvia
E-mail: sorlov@tsi.lv, andrei.vishnyakov@gmail.com

Software architecture design and estimation play the key role for logistics and transport software development process. One of the design approaches is to reuse the architectural patterns, which express a fundamental structural organization of software systems and its behaviour. The usage of the proven and tested solutions allows us to increase the software quality and reduce potential risks. In this paper, the most suitable architectural patterns are chosen for the typical logistics and transport software. For the evaluation of architectural patterns the metrics such as Functional Points, Coupling and Cohesion are used. Based on these metrics the criterion of efficiency has been obtained, which helps us to evaluate and select the optimal architectural patterns for specified logistics or transport software.

Keywords: software architecture, architectural patterns, logistics and transport software, coupling, cohesion, FP-metrics

 

RELIABILITY OF AIRCRAFT AND AIRLINE

Yu. Paramonov, M. Hauka

Aviation Institute,
Riga Technical University
Lomonosova 1, Riga LV 1019, Latvia
Tel.: +371 67255394; fax: +371 67089990
E-mail yuri.paramonov@gmail.com, Maris.Hauka@ gmail.com

The reliability of aircraft (AC) and airline (AL) operation can be ensured by the implementation of a specific inspection program, which can be planned using full-scale fatigue test data and the theory of Markov Chains (MC) and a Semi-Markov process (SMP) with rewards. The process of the operation of aircraft is considered as absorbing MC with (4)n+ states. The states 121,,...,nEEE+ correspond to AC operation in time intervals 0112[,),[,),...,[,)nSLtttttt, where n is an inspection number, SLt is specified life (SL), i.e. AC retirement time. States 2nE+, 3nE+, and 4nE+ are absorbing states: AC is withdrawn from service when the SL is reached or fatigue failure (FF) or fatigue crack detection (CD) takes place. In the corresponding matrix for the operation processes of AL the states 2nE+, 3nE+ and 4nE+ are not absorbing, but correspond to the return of the MC to state 1E (AL operation returns to first interval). The problem of inspection planning is the choice of the sequence {}12,,...,,nSLtttt (in case of equal inspection intervals and fixed SLt, the choice of n) corresponding to the maximum of airline gain taking into account the limitations imposed by the intensity of AL fatigue failure (or AC failure probability). This paper considers the case when the parameters of the fatigue crack growth exponential model are known. Numerical examples are given.

Keywords: inspection program, Markov chains, reliability

 

COMPUTING EFFICIENCY METRICS FOR SYNERGIC INTELLIGENT TRANSPORTATION SYSTEMS

B. Tsilker1, S. Orlov2

Transport and Telecommunication Institute
Faculty of Computer Science and Electronics
Lomonosova str. 1, Riga, LV-1019, Latvia
E-mail: tsilker@tsi.lv1, sorlov@tsi.lv2

Considerable progress in computing and telecommunications opened new approaches for solving of transportation problems, affected in the concept of intelligent transportation systems (ITS). Technically such systems represent a set of interacting computational nodes with various sensors, and can be considered as distributed computer systems. Distributed nature of the ITS implies parallelization of solvable transportation tasks in conjunction with their distributed realization. Under efficiency of parallelized calculations we presuppose several aspects. Three of them are picked out in the work: calculation speed, efficiency of system scaling, and efficiency of parallel computations as compared to sequential ones. Typical metrics for numerical characterization of parallelized computations form three groups: index of parallelism and speedup (PI and S), efficiency and utilization (E and U), redundancy and compression (R and C). The main peculiarity of synergic intelligent transportation systems shows up in bulk of intercommunications, substantially affecting the indexes of the system. Present work focuses on influence of these communication overheads on overall efficiency of the synergic ITS.

Keywords: intelligent transportation system, parallelization, distributed systems, efficiency, performance metrics

 

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