Ž. Đorđević, V. Vukadinović, ŽS ad, Beograd, Serbia M. Vasiljević, Traffi c faculty Doboj, B i H S. Vesković, Traffi c faculty, Beograd, Serbia S. Rajilić, Municipal Novi Grad, B i H Deformation of the wheels damage cars and rails and affect on vehicle stability and safety. Repair and replacement cause high costs and lack of wagons. Planning of maintenance of wagons can not be done without estimates of the number of wheels that will be replaced due to wear and deformation in a given period of time. There are many influencing factors, the most important are: weather conditions, quality of materials, operating conditions, and distance between the two replacements. The fuzzy logic model uses the collected data as input variables to predict the output variable number of deformed wheels for a certain type of vehicle in the defined period at a particular section of the railway.

The implications of large lepton-quark-leptoquark couplings for direct leptoquark searches at Large Hadron Collider (LHC) are addressed. It is shown that flavour physics constraints allow for sizeable couplings of leptoquarks to the Standard Model fermions if these interact exclusively with charged leptons and quarks of the same generation. The leptoquark production mechanisms at LHC are thoroughly discussed to demonstrate the importance of inclusion of a t-channel pair production and, in particular, a single leptoquark production if and when the leptoquark couplings are large. A recast of an existing CMS search at LHC for the second generation leptoquarks is accordingly presented. It is shown to yield the best direct limit to date on Yukawa coupling of a leptoquark that couples exclusively to a muon and a strange quark .