NetOPt2015: 4th Winter School on Network Optimization (1st announcement) The 4th edition of the Winter School on Network Optimization will take place at the Hotel Sana, Estoril, from the 12th to the 16th of January 2015. Its main objective is to provide an opportunity for PhD students to get together and attend high level courses in the field of Network Optimization. Non-PhD students are welcome to attend the school, but the number of participants is limited and priority will be given to PhD students. In this edition of the school, the lecturers and subjects to be addressed are: Bernard Gendron (Univ. Montréal): Decomposition methods for network design Adam Ouorou (Orange Labs): Robust optimization in telecommunications Gerhard Reinelt (Univ. Heidelberg): Ordering problems Giovanni Rinaldi (IASI): Maximum weight cuts in graphs and extensions Daniele Vigo (Univ. Bologna): Solution approaches for vehicle routing problems Since the first edition in 2009, the school has been part of the activities of the CIO (Centro de Investigação Operacional) University of Lisbon as well as of the ENOG(European Network Optimization Group). The event is also endorsed by the EURO (the Association of European Societies) and APDIO (the Portuguese OR society). Candidates are invited to submit their CVs to NetOpt2015@fc.ul.pt before 30th October 2014. After a short period of evaluation, the participants will be notified and be invited to register. More information is available at http:NetOpt2015.fc.ul.pt.