2011, volume 12 #3. "Transport and Telecommunication". Журнал издательства TSI, ISSN 1407-6160, ISSN 1407-6179
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Motor Transport Institute, Management and Transport Telematics Centre
Jagiellońska 80, 03–301 Warsaw, Poland, Phone +48 228113231 ex. 134
The paper refers to the implementation problems of Intelligent Transport System (ITS) in Member States of the European Union. The autonomous systems implemented in Member States of EU are not interoperable due to some reasons, especially lack of cooperation capability. European Commission has taken steps in the mentioned issue (directive 2010/40/EU, M/453, decision 2011). Furthermore the paper discussed assumptions and test results of NATCS Pilot Project developed by Motor Transport Institute, Autoguard SA, and Fela Management AG. Legislation steps were taken at the EC level because of interoperability problems of European Electronic Tolling Service (EETS) in the EU. Commission has urged the member states to conduct studies and pilot projects concerning these issues. Motor Transport Institute has taken up a challenge by developing and testing the pilot project – the functional structure of the NATCS. System has some requirements of EC legislation and it is interoperable with other DSRC and GPS/GSM based systems implemented in the member states of the European Union. Test results have shown a high accuracy and efficacy of the system.
Keywords: Intelligent Transport Systems (ITS), interoperability, the European Electronic Toll Service (EETS), the National Automatic Toll Collection System (NATCS), eCall
Transport and Telecommunication Institute
Lomonosova str. 1, LV-1019, Riga, Latvia
This paper presents the standard rules formulated for the allocation of resources in mesoscopic flow models. In terms of level of detail, the underlying mesoscopic simulation approach is situated between the prevalent approaches to continuous and discrete event simulation. Mesoscopic models use piecewise constant flow rates to represent the logistics flow processes. The resulting linearity of the cumulative flows facilitates event scheduling and the use of mathematical formulae to recalculate the system state variables at every simulation time step. Multichannel funnels are a mesoscopic model main component because they represent properly the processes of parallel or sequential processing and storage of several product types and product portions in a real area of operations. The identical types of resources that are arbitrarily allocable among the funnel different channels are labelled homogenous resources. The paper describes a mesoscopic simulation model of the passenger check-in processes on an airport. Resource allocation strategies based on mathematical formulae are an important part of the model.
Keywords: simulation, material flow, logistics systems, mesoscopic models
Jacek Mazurkiewicz, Tomasz Walkowiak
Institute of Computer Engineering, Control and Robotics
Wroclaw University of Technology
ul. Janiszewskiego 11/17, 50-372 Wroclaw, Poland
E-mails: Jacek.Mazurkiewicz@pwr.wroc.pl, Tomasz.Walkowiak@pwr.wroc.pl
The paper presents the formal model of discrete transportation systems (DTS). The modelling methodology is based on the system functional behaviour. Monte Carlo approach is used as a simulation tool. The actual DTS situation is measured by the global metric called availability. The proposed solution is very useful for the system owner and manager. The critical situations are caused by reliability, functional and human origin. Absence of restrictions on the system structure and on the kind of distribution describing the system functional and reliability parameters is the main advantage of the approach. The exemplar DTS driven into critical situation is presented in the final part. The results show and discuss different ways to restore the normal operating point. The proposed solution seems to be essential for the owner and administrator of the transportation systems.
Keywords: reliability, discrete transportation system, Monte-Carlo simulation, critical sets
Sergey Orlov, Andrei Vishnyakov
Today logistics and transport systems are complex and expensive, so it is necessary to use modern metric suits for their development process, which takes into account the characteristics of such systems. It is very important to choose a metric suite on the early development stages and the choice should be based on objective facts and experience. To choose the optimal metric suite it is necessary to use a technique that contains a number of steps. At each step, a specific criterion should be used to make a selection from the available metric suites. As long as the metric suite is chosen it is necessary to perform its improvement. To do so each metric in the suite should be considered separately and replaced if the analogous metrics provides a better criteria matching. In the end we obtain the modified metric suite, which is optimal according to the requirements.
Keywords: metric suite, object oriented design metrics, metrics selection algorithm, logistics and transport software, Chidamber & Kemerer's metrics suite, software package metrics, metrics for object oriented design, LCOM
Daniil Opolchenov, Valery Kutev
Transport and Telecommunications Institute
Lomonosova str. 1, Riga, LV-1019, Latvia
Ph.: +371 67100634. Fax: +371 67100660.
E-mails: Daniil.Opolchenov@tsi.lv, Valerijs.Kutevs@tsi.lv
Ph.: +421-41-513 3535. E-mail: firstname.lastname@example.org
This work has focused on the development of approach to estimation of the automatic vehicle location system functionality which is determined by system technical parameters. The work examines the main elements of the automatic vehicle location systems and options for their implementation on the basis of modern technical means. To estimate system functionality it is necessary to choose correctly the set of the main parameters able to provide the possibility of the system comparison with other ones. We propose to use “weigh” estimation of system functionality for performing such comparison. Some results of the comparative analysis for the “on-line” as well as “off-line” automatic vehicle location systems are presented. On this basis a new approach to the estimation of its functionality is proposed.
Keywords: transportation, transport monitoring systems, automatic vehicle location system, system architecture, efficiency, functionality
Victor Krebss1, Boris Tsilker2
1CPS Ltd, Skanstes 13, Riga, LV 1013, Latvia
Ph: +371 29243923, e-mail: email@example.com
2Transport and Telecommunication Institute
Lomonosova str.1, Riga, LV 1019, Latvia
Ph: +371 67100604, fax: +371 67100560, е-mail: firstname.lastname@example.org
Most of modern vehicle navigation and safety applications suppose availability of precise vehicle coordinates. Occasionally the only way for getting of these coordinates is vehicle self-localization. The ability of a vehicle to determine its own location, is vital for many aspects of Intelligent Transportation Systems (ITS) and telematics. Localization might be realized in two ways, geometric methods (trilateration, triangulation, hyperbolic methods) and fingerprinting methods (signal mapping). The accuracy localization based on distance measurements may be degraded by noise. The impact of the ranging error usually depends on the estimation algorithm, the bandwidth of pulses, application scenarios, etc. Additionly the position information provided by some anchor nodes may be inaccurate.. It is clear that a single localization technique is not enough to meet requirements of critical applications at the same time, such as being available anywhere and anytime, with highly accurate and reliable position computations. As a result, Data-fusion techniques to combine different localization methods and protocols in a single localization system are required, such as moving average, least squares, Kalman, particle filters Bayesian inference and Dempster-Shafer methods. In order to improve the localization precision several statistical based approaches have been proposed in [1, 2]. However, the statistical methods may not be able to provide enough accuracy if the data quantity is not sufficient. There is also the probabilistic approach considered in order to improve the localization precision. The inaccuracies are characterized by modeling the range measurements as a set of probability density functions. These functions can be used to compute the probabilistic constraints that reduce the uncertainties of the nodes positions. This approach can lead to significant enhancements in the localization accuracy compared to the least squares estimate.
Keywords: Intelligent Transportation System, sensor network, localization, cooperative positioning, data fusion