This special issue contains selected papers of three scientific meetings: the VOCAL-2014, the XXXI. Hungarian Operations Research Conference, and the EURO Summer Institute on Online Algorithms.
VOCAL-2014 (Veszprém Optimization Conference: Advanced Algorithms) took place at Veszprém, December 14–17, 2014. The chairman of the organizing committee was Botond Bertók. The number of participants was around 70. VOCAL-2014 had 3 plenary speakers, 2 plenary tutorial talks and over 60 contributed talks in two parallel sessions. More information can be found at the home page http://vocal.dcs.uni-pannon.hu.
The XXXI. Hungarian Operations Research Conference was held in Cegléd, 10–12 June, 2015. The primary organizer of the meeting was the Hungarian Society for Economic Modeling, collaborating with the Hungarian Operations Research Society and the János Bolyai Mathematical Society. The number of participants was around 100. The scientific program of the meeting included three plenary talks and 75 contributed presentations in two parallel sessions. The language of this conference was Hungarian, for further details see http://www.opkut.hu/konferencia/. It is already the eights special issue of CEJOR devoted to the Hungarian Conferences of Operations Research, and we hope that this tradition provides values for the OR community in Central Europe and beyond. The scope of the conference involved several aspects of operations research: a good mixture of theoretical results and successful applications were presented.
The EURO Summer Institute on Online Algorithms was held in Szeged, 15–27 June, 2015. The program had 17 senior and 18 regular talks. The conference home page (http://www.eswi.u-szeged.hu/) has more details on the meeting.
We have received eighteen submissions for this volume. Sorting out the best papers of the conferences, the aim of this special volume is to demonstrate the strength of the Hungarian operations research community. The manuscripts went through the usual refereeing process according to the policy of CEJOR: each manuscript was reviewed by at least two anonymous reviewers, and after some rounds of peer reviewing, twelve papers have been accepted. The editors of the special issue thank the referees for their efforts with which they contributed to the quality of this volume.
The composition of the special issue reflects more or less the versatility of the conference subjects. We have five papers mostly on methodological issues: those written by Csató (2017), Filatovas et al. (2016), Foroughi and Shureshjani (2017), Pál (2017) and Tar et al. (2017). A contribution by Berlinger et al. (2017) considers a financial problem. The online algorithm related papers are those by Dávid and Krész (2017), Dunke and Nickel (2017) and Renault (2017). Application motivated optimization problems were analysed by Csehi and Farkas (2017), Fleiner et al. (2017) and Kosztyán et al. (2017). Finally, the paper by Vinkó and Gelle (2017) considers a novel technique from network theory to global optimization. Our special issue is similar to that of the Czech Society for Operations Research, CEJOR issue 2 of volume 24(2016). The closest papers there are by Fiala on games in economic modelling (Fiala 2016), the Kramulova and Jablonsky article on the AHP methodology for preference analysis (2016), and the article on the application of MILP methods (Zouharová et al. 2016).
Budapest and Szeged, June, 2017