2010, VOLUME 11 #2. "TRANSPORT AND TELECOMMUNICATION". ЖУРНАЛ ИЗДАТЕЛЬСТВА TSI, ISSN 1407-6160, ISSN 1407-6179 | TSI

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2010, VOLUME 11 #2. "TRANSPORT AND TELECOMMUNICATION". ЖУРНАЛ ИЗДАТЕЛЬСТВА TSI, ISSN 1407-6160, ISSN 1407-6179

CONSTRUCTION OF THE URBAN PUBLIC TRANSPORT SYSTEM’S QUALITY INDICATOR WITH MISSING DATA 

Irina Yatskiv1, Irina Pticina2

Transport and Telecommunication Institute
Lomonosova 1, Riga, LV-1019, Latvia 
1Ph.: +371 67100544. 
E-mail: ivl@tsi.lv 2Ph.: +371 67100596. 
E-mail: jurina@tsi.lv

The purpose of this investigation is the development of transport system’s quality indicator – UPTQI (urban public transport quality indicator) calculation methods where some values are missing in the data set. As a quality indicator, the indicator accumulating the information about urban public transport system – composite indicator is used. The algorithm described in [1] has been used for developing the composite indicator. The special accent is made on a choice of a missing data imputation method in an initial data set and on stability of results. It is not possible to make the unequivocal recommendation for use concrete method in the presence of a large number of offered methods. In many respects it depends on the initial data. The initial data concerning the cities of Europe were taken from EUROSTAT database [2]. The 8 sub-indicators for 2006 have been used for constructing the UPTQI. The research was divided into three stages. At first, artificial missing data was introduced, and investigated the influence of the 3 selected methods of missed data substitution (unconditional mean imputation, imputation by median and clustering-based imputation) upon the results of composite indicator calculation. In the next stage the cities with the missing data have been added (in total 62 European cities). The method which is chosen as the best for this problem during the first stage has been used to the missing data imputation. To calculate the weights and to aggregate the same variants of algorithm, as at the first stage were used. At the last the results of UPTQI constructing were analysed for uniformity.

Keywords: public transport, quality, composite indicator, weights, missing data, imputation

 

OPTIMISATION OF THE SUPPLY CHAIN PROCESS FOR THE LOGISTICS CENTRE 

Olga Girvica

Riga Technical University 
Kalku Str.1, Riga, LV-1658, Latvia 
Ph.: +371 29203422. 
E-mail: olga.girvica@rtu.lv

In this paper the problem of decision-making process for creation of the new supply and distribution channel of the Logistics centre is observed. The task consists in decision-making regarding the way selection from choosing the raw materials till final products creation that allows getting the maximum profit to the company. This task could be solved by using the method of dynamic programming. In this case it means to make decision for each unit individually. The solution of the real task for Logistics centre in Latvia is observed in this paper as the numerical sample of decision-making process for the new supply and sales channel development in order to get the maximum profit for the Logistics centre.

Keywords: decision-making, supply chain, dynamic programming

 

DEVELOPMENT OF SEGMENTATION METHOD BASED ON “MASS CENTRE” APPROACH FOR VIDEO SURVEILLANCE DATA OF TRANSPORT VEHICLES FLOW 

Alexander Grakovski, Alexander Murza

Transport and Telecommunication Institute 
Lomonosova 1, Riga, LV-1019, Latvia 
Ph.: +371 67100654. Fax: +371 67100535. 
E-mail: avg@tsi.lv

The increasing traffic in the European Union puts in the forefront the need to create intelligent transport systems of traffic control (ITS) at district, urban and regional scale. Structurally, such systems include a network of sensors of primary or indirect measurements of traffic flows, a control centre and a network of executive components (traffic lights, controlled traffic signs, reversible lanes, etc.). The wider the network of sensors, the more complete information is available for high quality of the intelligent control. Currently, video, laser, radio frequency, induction, and pressure sensors are mainly used as sensors of traffic flows’ parameters. The deployment of a network of such sensors requires significant financial resources, and sometimes also additional construction work. Installation, maintenance and protection of an expensive network of sensors and their channels of communication make the creation of full-scale ITS rather expensive, which is not affordable at all. The possibility of using mobile video detection system to measure traffic is discussed. This mobile system consists of a notebook and simple web-camera, which is the cheapest version of the video sensor. Video data processing is done by stages: detection, segmentation, classification and tracking. Algorithm for finding and identifying vehicles on each frame of video stream is proposed. Algorithm is based on finding “mass centre” of all “good features” on each video frame. This allows identifying vehicles and helps to escape noise and unwanted motions on the frame. Tracking of “mass centre” and other properties allows identifying transport vehicles during motion through the view port. Different cases of transport vehicle mutual intersection are processed.

Keywords: segmentation, computer vision, detection, tracking, transport vehicles

 

METHODOLOGICAL FEATURES REGARDING THE PROGNOSTICATION OF LITHUANIAN RAILWAY FREIGHT TRANSPORT VOLUMES FROM A LONG-TERM PERSPECTIVE 

Ausrine Griškevičiūtė-Gečienė1, Daiva Griškevičienė2, Algirdas Griškevičius31Vilnius Gediminas

Technical University, 
Department of Urban Engineering 
Sauletekio av. 11, LT-10223 Vilnius, Lithuania. 
E-mail: ausrine.griskeviciute@vgtu.lt 

2Vilnius Gediminas Technical University, 
Department of Transport Management 
Plytines st. 27, LT-10223 Vilnius, Lithuania.
E-mail: griskeviciene.daiva@gmail.com 

3Vilnius Gediminas Technical University, 
Department of Transport Management 
Plytines st. 27, LT-10223 Vilnius, Lithuania. 
E-mail: griskevicius.algirdas@gmail.com

The prognostication of Lithuanian Railway freight transport volumes from a long-term perspective is difficult methodological process even during a period of positive economic development. All sectors of National Economy have serious consequences of international crises and still are not recovered (did not climb out of economic recession). Therefore it is not a time to predict further optimistic development. Social sector having influence on a usage and a growth of its demand is still in more complicated situation. Despite of this unpleasant economic situation the processes of projection, strategic planning, and preparation of priority projects, investment planning and implementation continue to proceed. That determines urgent modelling of separate economic sectors, forecasting of specific activities and preparation of tactical plans. This attitude was a basis for the methodology regarding prognostication of railway freight and passenger transport volumes from a long-term perspective. Necessity of preparation of priority infrastructure projects and substantiation of their decision determines the period of perspective.

Keywords: railway freights volume, transport flows, DGP projections, providences of the economic development, influence of internal and external factors, forecast of macroeconomic indicators

 

LIGHTNING STROKE PASSIVE LOCATION BY ATMOSPHERICS ANALYSIS IN THE HOP MODEL FRAMES 

Yury A. Krasnitsky

Transport and Telecommunication Institute 
Lomonosova str., 1, Riga, LV-1019, Latvia
Ph.: +371 7100608. Fax: +371 7100660. 
E-mail: krasn@tsi.lv

The problem of lightning location from single station observation is considered based on the hop model of lightning electromagnetic radiation pulse propagation in spherical waveguide “Earth – ionosphere”. Some new methods are discussed to estimate the delays of the ionosphere reflected waves with respect to the ground wave. These delays give raise to the undetermined system of equations where unknown quantities are the distance and the effective reflecting heights of ionospheric waves. Some methods to remove the uncertainty based on approximation of difference of effective reflecting heights are considered. Program codes in Matlab to process atmospherics are developed. Proper examples concerning of really registered signals are carried out.

Keywords: thunderstorm, lightning, electromagnetic radiation, atmospherics, hop model, ionospheric waves, delays, distance evaluation

 

SIMULATION AT THE BRATISLAVA AIRPORT AFTER APPLICATION OF DIRECTIVE 2009/12/EC ON AIRPORT CHARGES 

Alena Novák Sedláčková1, Andrej Novák2

University of Zilina
Air Transport Department, 
Faculty of Operation and Economics of Transport and Communications
Univerzitná 1, 010 26 Žilina, Slovakia 
1 E-mail: alena.sedlackova@fpedas.uniza.sk 
2 E-mail: andrej.novak@fpedas.uniza.sk

The Directive on Airport Charges-Directive 2009/12/EC was issued in March 2009 by European Parliament and the Council. It is a common framework regulating the essential features of airport charges. EU presents the necessity of economic regulation of airports and airport charges in Europe, but is the economic regulation the right way for Bratislava Airport and airports in the similar position? This paper explains the situation of Slovak airports and their approach to economic regulation of airport charges. The paper describes the simulation of situation at the Airport Bratislava after application of a regulation formula of economic regulation of airport charges considered as the most appropriate for Slovak airports especially Airport Bratislava. The regulation formula is based on the research of the authors.

Keywords: directive of EU, airport charges, simulation, regulation formula, Slovak airports

 

EFFICIENCY OF ONBOARD COMPUTER SYSTEMS FOR SPACE VEHICLES AND STATIONS 

Sergey Orlov1, Boris Tsilker2

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

The technique of complex efficiency estimation for in space vehicles and stations used onboard computer systems is considered. A tooling for such estimation is offered: efficiency criteria and etalon vectors of operations rate, considering the specificity of onboard computer systems functioning and structure.

Keywords: efficiency, criterion of efficiency, control tasks and algorithms, instruction set, performance, average speed, etalon operations frequency vector

 

ESTIMATION OF MECHANICAL PROPERTIES OF THE ANISOTROPIC REINFORCED PLASTICS WITH APPLICATION OF THE METHOD OF ACOUSTIC EMISSION 

Alexander Urbach1, Mukharbiy Banov2, Yevhen Harbuz3, Vjacheslav Turko4, Jurij Feshchuk5, Nikolay Hodos6

1 The Riga Technical University,
Faculty of Transport and Mechanical Engineering 
Kaļķu Str.1, Riga, LV-1658, Latvia. Ph.: +371 67089948. 
E-mail: Aleksandrs.Urbahs@rtu.lv 

2 The Riga Technical University 
Kaļķu Str.1, Riga, LV-1658, Latvia. 
Ph.:+371 67089979. 
E-mail: muharbij@inbox.lv 

3 The Riga Technical University 
Kaļķu Str.1, Riga, LV-1658, Latvia. 
Ph.: +371 67089979. 
E-mail: Yevhen@inbox.lv 

4 Aviatest LNK, Ltd. 
Rezeknes Str.1, Riga, LV-1073, Latvia. 
Ph.: +371 67139102. 
E-mail: vladislav_turko@mail.ru 

5 The Riga Technical University 
Kaļķu Str.1, Riga, LV-1658, Latvia. 
Ph.: +371 67089979. 
E-mail: ndt_ae@inbox.lv 

6 InterSpecMet, Ltd.
Lielvardes Str., 103–13, Riga, Latvia. 
Ph.: +371 29611584. 
E-mail: nikmag@inbox.lv

In this paper the results of the estimation of composite material’s (the anisotropic reinforced plastics type) mechanical properties are presented. The test loadings are applied on specimens with the longitudinal in one case and cross-section in another case of the reinforced fibres orientation in relation to the load direction. The specimens for static tension tests are presented as squared shape band with the moulding fixed plates on the both ends for mounting into the test rig’s gapping jaws. The static test program consists of three - or six time specimen’s loading to the level making 20% of the ultimate load; after that the loading goes non-stop to the collapse of specimen. The possibility of the character and level of fibres and a matrix of composite specimen’s damages estimation by acoustic emission signals’ analysis is shown. The test performed have shown that the acoustic emission method can be used in practice to carry out the probes of responsible avia/space devices designed of anisotropic reinforced plastics.

Keywords: composite materials, static tests, acoustic emission, ultimate loads

 

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