Proof-Theoretic Analysis of the Quantified Argument Calculus

This article investigates the proof theory of the Quantified Argument Calculus (Quarc) as developed and systematically studied by Hanoch Ben-Yami [3, 4]. Ben-Yami makes use of natural deduction (Suppes-Lemmon style), we, however, have chosen a sequent calculus presentation, which allows for the proofs of a multitude of significant meta-theoretic results with minor modifications to the Gentzen's original framework, i.e., LK. As will be made clear in course of the article LK-Quarc will enjoy cut elimination and its corollaries (including subformula property and thus consistency).Peer reviewe

A Two-Phase VIKOR Model for Track Layout Evaluation of Passenger Rail Stations

Passenger stations are transit hubs where several railway lines interchange. They have important roles in providing train operations and passenger services. Interrelations between track layouts and technological performances are important for reducing bottleneck effects and raising the operational effectiveness of rail networks. To the best of our knowledge, in previous research the assessment of track layouts has not been considered with respect to various technological aspects including railway operations, safety, and passenger services but rather as a single criterion for analysis of different individual performance indicators. We propose a new two-phase decision making approach for the complex evaluation of track layout alternatives. The first phase model is a VIKOR method for ranking track layouts by criteria related to: railway capacity, safety issue, and passenger-pedestrian fluctuations. Next, in the second phase, we use marginal analysis to find Pareto front and compare the alternatives ratings by calculating performance-benefit coefficients. To show the applicability of the proposed model, we employ an illustrative example of a passenger rail station and evaluate six different track layout alternatives. The effectiveness of the proposed model is demonstrated comparing the proposed two-phase model with traditional VIKOR

Fuzzy renewal theory about forecasting mistakes done by a locomotive driver: a serbian railway case study

The human factor is one of the most dominant causes of railway accidents. For example, human impact appears to be the main reason for 44% of railway accidents in the Republic of Serbia. Thus, a remarkable effort is undertaken to investigate human factors. Therefore, plenty of researchers have analyzed a human influence on railway accidents. This paper develops a model for forecasting the number of railway accidents caused by the human factor. The proposed model is based on the renewal theory and assumes that working time between the faults of a locomotive driver has exponential distribution (or another Erlang distribution of a higher order) characterized by parameter λ that is treated as a fuzzy dependant variable and considered as a function of job complexity, the exposure of locomotive drivers (i.e. time spent in driving) and a tendency of locomotive drivers to make mistakes. The application of the model to the population of 777 Serbian railway locomotive drivers provided encouraging results in predicting the number of railway accidents

Fuzzy multicriteria decision-making in railway infrastructure planning and design

U radu je prikazan pristup neizrazitog višekriterijskog odlučivanja u procesu planiranja i projektiranja željezničke infrastrukture koji omogućava cjelovito i sustavno rješavanje problema postojanja faktora neizvjesnosti i neodređenosti prilikom procjene vrijednosti kriterijskih funkcija. Predloženi pristup višekriterijskog odlučivanja je predstavljen u okviru metodologije za izbor najpovoljnije trase dvokolosiječne željezničke pruge. Za vrednovanje varijantnih rješenja trase u radu su upotrebljeni trouglasti neizraziti brojevi, a za rangiranje je primijenjena neizrazita VIKOR metoda.A fuzzy multicriteria approach in the railway infrastructure planning and design, enabling an integrated and systematic solving of uncertainty and indeterminacy problems in the evaluation of criteria functions, is presented in paper. The proposed multicriteria decision making approach is presented in the scope of the methodology for selecting the most favourable route of a double track railway. Triangular fuzzy numbers are used to evaluate variant solutions, while the VIKOR fuzzy method is used for route ranking

Analysis of simulation model application to forecast the railway workers failures

In this paper the idea of treating the operational service workers as the elements of technique systems is suggested and the renewal theory is used to forecast the number of accidents caused by human factor. The analytical model is presented and limitations for its application are quoted. Furthermore, the simulation model is developed and the conditions for its use are given. The model observes each worker separately and establishes the exact time of arisen failures, the number of failures at some moment t, time tn, to the nth failure, inconsistency of failure number and total number of failures of the observed population. The model is tested on the sample of 348 engine drivers in PE "Serbian Railways" who have made at leas one accident, in order to research the parameters necessary for using the renewal theory and simulation.

Group decision making process for early stage evaluations of infrastructure projects using extended VIKOR method under fuzzy environment

Abstract Purpose This paper considers the evaluations of project alternatives at the early stages of infrastructure project developments. Although it is expected to make important decisions at project early stages, it is rarely possible to obtain reliable data for exact evaluations. To deal with low quality data and the existence of uncertainties, this paper extends the evaluation problem to the fuzzy environment. Methods We propose group decision making process for early stage evaluations of infrastructure projects. The evaluation approach utilizes combination weighting and compromise ranking. We integrate subjective and objective weighting methods to specify criteria weights. Afterwards, we use the VIKOR method to rank alternatives in the presence of conflicting criteria. Results As a case study, we illustrate the evaluation problem within a railway line reconstruction project. Specifically, the proposed approach is efficiently applied to evaluate and rank several route alternatives considered within the reconstruction project of the regional line Pančevo – Vršac at Serbian railway network. Conclusions The provided example illustrates the applicability of the proposed approach to deal with the evaluations at the early stage of the railway line reconstruction. The existence of uncertainties at early stages of project developments is common, so the proposed method is also applicable for other linear infrastructure in transport sector

Track properties for formation of pick-up trains

U ovom radu razmatran je problem kolosijeka za formiranje sabirnih vlakova s analizom I prijedlogom mogucih rješenja. Predložena rješenja zasnovana su na rezultatima provedenih simulacija ciju osnovu predstavljaju podaci dobiveni iz ranžirnih kolodvora Beograd i Lapovo. Procesi koji se realiziraju u tim kolodvorima pokazali su se diskretnim sa stohastickim elementima te su i simulacijski modeli izabrani za rješavanje ovog problema prilagođeni istom, primjenjivi i ucinkoviti. Dobiveni rezultati pokazuju da dosadašnja praksa rješavanja ovog problema nije bila dobra, da ne daje dobre rezultate i da je treba mijenjati.The problem of tracks for formation of pick-up trains, with the analysis and proposal of possible solutions, is considered in the paper. Proposed solutions are derived from the results of simulations, which are based on the information obtained from the Belgrade and Lapovo marshalling yards. it was established that processes realized in these train stations are discrete with stochastic elements, and so the simulation models selected for solving this problem have been adapted accordingly, and have proven to be implementable and efficient. The results obtained show that the current practice in solving this issue has not been appropriate, that it does not provide good results and, hence, that it has to be changed

Analysis of impact of meteorological conditions on human factors in estimating the risk of railway accidents

This paper explores the accidents that occurred in the railway system of Serbian Railways from 2006 to 2012. The total number of the sample observed includes 3983 accidents, of which 2725 or 68.41% were caused by the human factor. One of the major contemporary problems – global climate change and the increase of average temperatures – has not yet been considered in the context of external factors for increasing the risk of accidents. The air pressure has become accepted as an external factor, in addition to the air temperature. It is assumed that temperature and air pressure have a significant impact on the risk of railway accidents occurrence (taking only accidents caused by a human factor into account). This assumption was made based on reduced cognitive abilities of railway staff as a result of extreme differences in temperature and air pressure. In this paper, the emphasis is put on Railway Crossings (RC) as sites where two forms of traffic intersect, since it is noticed that certain weather conditions have a significant effect on occurrence of accidents. The analysis of the observed sample of 266 accidents that occurred on RC shows that the risk of accident occurrence is significantly higher at low temperatures (from –10 to 0 °C) and high air pressures (p > 1010 mbar), the risk being 2.17, that is 2.41 times higher than in standard (average) weather conditions. Additionally, in the case of high temperatures (above 20 °C) and low air pressures (p < 1010 mbar) the risk rises to 2.07 in comparison to average weather conditions. The absolute risk of railway accident occurrence appears at temperatures below –10 °C and air pressures higher than 1010 mbar, as well as at high temperatures (T > 25 °C) and air pressures lower than 1010 mbar. First Published Online: 31 Aug 201