Model of traffic access mode and railway station choice of suburban railway system in SloveniaGregor Rak
, Marjan Lep
, 2014, review article
Abstract: This article presents the establishment of a model of understanding the access mode and railway station choice of Slovenian passengers. Therefore, a model has been designed to predict the determination of existing decision making preferences of railway users about the access mode and railway station choice with a stated preference survey and face to face method. The target group in the survey were railway passengers in the suburban environment that use the rail for work and school purposes. The total number of respondents was 412. The survey showed that most passengers access the railway station with car (60,2%), by foot (26,2%), with public transport (bus – 8,3%) and with bike (5,3%). Average distance to the station is 4,9 km, average time of access is 10,5 min. Upon exit most passengers walk to the final destination (84,5%), use the public transport (bus – 14,1%), car (1,2%) or bike (0,2%). Average time from exit of the train to final destination is 13,1 min, average distance is 1,58 km.
Keywords: passenger transport, departure railway station choice, railway access mode choice
Published: 01.09.2017; Views: 23; Downloads: 0
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Discrete optimization with fuzzy constraintsPrimož Jelušič
, Bojan Žlender
, 2017, original scientific article
Abstract: The primary benefit of fuzzy systems theory is to approximate system behavior where analytic functions or numerical relations do not exist. In this paper, heuristic fuzzy rules were used with the intention of improving the performance of optimization models, introducing experiential rules acquired from experts and utilizing recommendations. The aim of this paper was to define soft constraints using an adaptive network-based fuzzy inference system (ANFIS). This newly-developed soft constraint was applied to discrete optimization for obtaining optimal solutions. Even though the computational model is based on advanced computational technologies including fuzzy logic, neural networks and discrete optimization, it can be used to solve real-world problems of great interest for design engineers. The proposed computational model was used to find the minimum weight solutions for simply-supported laterally-restrained beams.
Keywords: uncertainty, discrete optimization, neuro-fuzzy technique, structural optimization
Published: 09.08.2017; Views: 85; Downloads: 0
Full text (1,10 MB)
Urbanistično-arhitekturna delavnica kot priložnost za teoretsko refleksijoPeter Šenk
, Uroš Lobnik
, 2013, original scientific article
Abstract: V članku je predstavljena mednarodna urbanistično-arhitekturna delavnica Maribor-jug (2010-11), kot model "mariborskih" urbanistično-arhitekturnih delavnic, ki jih načrtovalci vrednotijo ter uporabljajo za usmerjanje urbanega razvoja in teoretske razprave. Predstavljeni interdisciplinarni projekt je raziskal možnosti za oblikovanje južnega roba mesta na območju, kjer je predvidena izgradnja južne obvoznice. Ob opisu primera delavnice, ki z definirano projektno osnovo - določenim območjem obdelave ter projektnim vprašanjem - razvije teoretsko polje skozi "praktično-projektni pristop", je v prispevku izpostavljena tudi priložnost za "teoretski pristop". Slednji ima za cilj, na podlagi generaliziranega prostorskega vprašanja, odpirati širši pogled v teoretsko polje, povezano z njim. S prvim pristopom izpostavljeno načrtovano usmerjanje urbanega razvoja na območjih izgrajevanja prometne infrastrukture, kot ene ključnih prioritet sodobnega urbanističnega načrtovanja ter trajnostnega preoblikovanja mesta, dobi v drugem, z obravnavo tem mobilnosti, prostora, kraja, mnogovrstnosti infrastruktur itd. sodobnega prostora razširjeno referenčno polje, ki pa se neposredno ne veže na projekt. Tako kot pri prvem, ob iskanju projektnih rešitev stremimo k teoretskemu osmišljanju, tako se pri drugem pristopu lahko posvetimo iskanju relacij med teoretskim konceptom in manifestacijami v realnem prostoru, vendar pristopa vselej ostajata ločena. Njuna operativnost je omogočena zgolj na ravni "kombinatornega mišljenja" in ostaja onkraj neposredne instrumentalnosti.
Keywords: arhitekturno-urbanistične delavnice, Maribor-jug, rob mesta, prometna infrastruktura, obvoznice, teoretska refleksija
Published: 09.08.2017; Views: 33; Downloads: 4
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Culture change in construction industry: from 2D toward BIM based constructionNenad Čuš Babič
, Danijel Rebolj
, 2016, original scientific article
Abstract: Building Information Modelling (BIM) has become accepted as an approach that should deliver substantial gains to all the stakeholders within the architecture, engineering and construction (AEC) industry. Recently, several researchers have pointed out the need for cultural changes as a necessary step for radically transforming the industry. In order to provide answers to these requests, the culture should be described in a more explicit way, and industry issues interpreted correctly. This paper via qualitative research of variety of sources explores the stability and persistence of a traditional 2D paper-based approach in the light of Institutional theory. The paper illustrates how the traditional approach is embedded within AEC culture by considering the regulative, normative, and cultural-cognitive aspects. These aspects support each other, thus providing even more stability and support for the existing values and ways of working. The aim of this work is to provide some insight into reasons for slower penetration of the BIM based construction. The paper also explains the local character of the industry, which slows down transference of best practices within the AEC industry. Understanding of existing patterns reveals new insights into how to make the transition easier and more functional, especially within the contexts of existing priorities and values.
Keywords: building information modelling, BIM, institutional theory, 2D paper based working
Published: 07.08.2017; Views: 59; Downloads: 0
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Financial aspects of a seismic base isolation system for a steel high-rack structureVojko Kilar
, Simon Petrovčič
, Simon Šilih
, David Koren
, 2013, original scientific article
Abstract: The paper deals with the effects and costs of implementing a base isolation system for the mitigation of the seismic risk of an existing steel rack structure. Different realistic distributions of the payload mass and occupancy levels, which form different plan asymmetric variants, have been analysed. The results obtained by the pushover analysis (N2 method) are presented as top floor envelopes and as plastic hinge damage patterns. In the presented cost study, the cost of the implementation of the proposed base isolation system is compared with the estimated costs of structural repairs to the damaged structural members of the superstructure, as well as with estimated expenses of the downtime period. The results have shown that base isolation is, in general, not economically feasible for lower ground motion intensities, whereas it could be of great benefit in the case of moderate and high intensities, especially if the downtime period is taken into account.
Keywords: rack structures, seismic behaviour, base isolation, cost efficiency, mass eccentricity, pushover analysis
Published: 07.08.2017; Views: 19; Downloads: 1
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Application of "Einstein's riddle" in solving construction machine allocation problemsBorna Dasović
, Marko Čorak
, Mario Galić
, Uroš Klanšek
, 2016, original scientific article
Abstract: “Einstein’s riddle” is a popular example of constraints satisfaction problem. Since its introduction, different forms and variations of the riddle have been presented. Regardless of the variant of the riddle, its solution is considered a tough challenge for humans. Researchers have developed and are still developing mathematical models, as well as computational simulation models for solving it. In this article, the authors have modified a previously published mathematical model and developed a computational spreadsheet model for solving the riddle, which provides a unique solution for the riddle. The model was also tested in a small and medium-scaled form for solving constraint satisfaction problems regarding the allocation of construction machines. The authors have also highlighted the model’s limitations for solving such problems and made suggestions regarding necessary modifications in the model to solve more complex problems in the same domain.
Keywords: Einstein's riddle, zebra riddle, construction, machine allocation, combinatorial optimization
Published: 02.08.2017; Views: 49; Downloads: 1
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Analysis of neural network responses in calibration of microsimulation traffic modelIrena Ištoka Otković
, Damir Varevac
, Matjaž Šraml
, 2015, original scientific article
Abstract: Microsimulation models are frequently used in traffic analysis. Various optimization methods are used in calibration, and the one method that has shown success is neural networks. This paper shows the responses of neural networks during calibration of a microsimulation traffic model. We analyzed two calibration methods by applying neural networks and comparing their neural network learning (according to their achieved correlation and the mean error of prediction) and their generalization ability (comparison of generalization results was analyzed in two steps). The best correlation between the microsimulation results and neural network prediction was 88.3%, achieved for the traveling time prediction, on which the first calibration method is based.
Keywords: microsimulation traffic models, calibration, response of neural networks, traveling time, queue parameters
Published: 02.08.2017; Views: 42; Downloads: 1
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The different methods of displacement monitoring at loading tests of bridges or different structuresBoštjan Kovačič
, Rok Kamnik
, Andrii Bieliatynskyi
, 2016, published scientific conference contribution
Abstract: By measuring the displacements and deformations at different structures we deal in the Faculty of Civil Engineering, transportation Engineering and Architecture in University of Maribor for about 20 years. At that time we measured over 600 structures. Most loading tests of bridges and Viaducts were made. The measurements of movements needed to be as precise and accurate as possible. To do that laboratory test of instruments were made to see which instrument gives us reliable results. Displacements can be determined by geodetic and physical methods, depends of the construction. The use of geodetic methods are still preferable. In the paper the measurements with the total station, the level and rotation level, photogrammetry and solutions on the field by physical methods with inductive transducers are presented. We need to measure displacements as quick as possible but efficiently because we can not repeat the measurements under the same conditions. Also the surveying on the bridge and in the lab with the comparison of methods is presented under the different hard terrain conditions - water beneath the construction, big height of the structure, unapproachability, large span structures.
Keywords: bridges, measurements, strain gauge, load test, deformation, strain, signal processing
Published: 02.08.2017; Views: 37; Downloads: 2
Full text (3,15 MB)
Risk assesment of an urban aquifer based on environmental tracersBranka Trček
, Primož Auersperger
, Albrecht Leis
, Jürgen Sültenfuss
, 2013, original scientific article
Abstract: Groundwater from a Pleistocene sandy-gravel aquifer is a drinking water resource for the Union brewery, located near the centre of Ljubljana (Slovenia). A large part of the aquifer recharge area is highly urbanized, which represents a great risk for the groundwater quality assurance. The groundwater dating techniques were used to study the contamination risk of this drinking-water resource. The application of chlorofluorocarbons (CFCs), sulphur hexafluoride (SF6) and tritium-helium-3 (3H-3He) age indicator was tested, as they haven’t been used in Slovene urban areas so far. The results reflect that the 3H-3He dating technique is the most suitable for a groundwater age determination in the study urban aquifer, since SF6 and particularly CFCs concentrations could be affected by the local contaminations. They indicated that average groundwater residence times range from 10 to 30 years. Boreholes that are more distant from the Šišenski hrib hill are more vulnerable to contamination due to flow of young groundwater from a direction of the main aquifer, which is exposed to the urban pollution. The presented results were supplemented with chemical investigations of groundwater organic pollutants. An unknown trace organic pollutant with a base ion mass-to-charge ratio 147 was put into focus. Its identification based on chromatographic separation and a mass spectrometric detection with GC-MS, LC-MS and LC-TOF MS techniques. The newly detected trace organic pollutant in sampled groundwater represents together with the 3H and 3He data a new technique to study the flow paths and contaminant transport in the urban aquifer in both, the lateral and vertical directions.
Keywords: urban area, intergranular aquifer, contamination risk, environmental tracers
Published: 24.07.2017; Views: 46; Downloads: 0
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On vulnerability measures of networksRija Erveš
, Darja Rupnik Poklukar
, Janez Žerovnik
, 2013, published scientific conference contribution
Abstract: As links and nodes of interconnection networks are exposed to failures, one of the most important features of a practical networks design is fault tolerance. Vulnerability measures of communication networks are discussed including the connectivities, fault diameters, and measures based on Hosoya- Wiener polynomial. An upper bound for the edge fault diameter of product graphs is proved.
Keywords: discrete optimization, communication network, vulnerability
Published: 21.07.2017; Views: 51; Downloads: 1
Full text (189,03 KB)