Title Participants Abstract "Selective backhauls in truck transport with risk mitigation : large Belgian retailer case study" "Kenneth Stoop, Mario Pickavet, Didier Colle, Pieter Audenaert" "In this work the problem of selective backhauls in the transport of fresh products is investigated for the case of a large Belgian grocery retailer. Explicit measures for estimating the risk involved in certain route - vendor backhauling combinations, which emerge from the uncertainties involved in over road transport and unforeseen waiting and loading/unloading times at the depot or stores, are constructed. Two different models are proposed: an integer linear program with chance constraints, and a stochastic linear program. The chance constraints in the first model are based on the intuition and experience of the people in planning and dispatching. In the second model, the balance between risk and potential profit is directly incorporated into the objective function. For this study, the largest of all transport companies working for the studied retailer is considered for reference and data. The stochastic linear program proved to be superior. Moreover, we demonstrate that, even if only considering a small part of the fleet, the potential profits and reduction in empty kilometers due to the selected backhauls are considerable." "Simulation analysis of an adjusted gravity model for hospital admissions robust to incomplete data" "Timo Latruwe, Marlies Van der Wee, Pieter Vanleenhove, Kwinten Michielsen, Sofie Verbrugge, Didier Colle" "BackgroundGravity models are often hard to apply in practice due to their data-hungry nature. Standard implementations of gravity models require that data on each variable is available for each supply node. Since these model types are often applied in a competitive context, data availability of specific variables is commonly limited to a subset of supply nodes.MethodsThis paper introduces a methodology that accommodates the use of variables for which data availability is incomplete, developed for a health care context, but more broadly applicable. The study uses simulated data to evaluate the performance of the proposed methodology in comparison with a conventional approach of dropping variables from the model.ResultsIt is shown that the proposed methodology is able to improve overall model accuracy compared to dropping variables from the model, and that model accuracy is considerably improved within the subset of supply nodes for which data is available, even when that availability is sparse.ConclusionThe proposed methodology is a viable approach to improve the performance of gravity models in a competitive health care context, where data availability is limited, and especially where a the supply nodes with complete data are most relevant for the practitioner." "Hedging risks in the C-ITS road-side unit investment case for Flanders : a real options approach" "Thibault Degrande, Didier Colle, Sofie Verbrugge" "Cooperative intelligent transport systems (C-ITS) deployments for vehicle-to-infrastructure communication require substantial investments from European Member States in road-side units (RSUs) and in central traffic management systems. The promise of numerous societal benefits should justify these public investments. However, C-ITS uptake in passenger cars, and thus the subsequent societal benefits, are highly uncertain. Therefore, here, a case study of Flanders is presented in which real option analysis) is used to help road authorities assess the RSU investment opportunity. The framework combines a detailed cost and benefit model and includes managerial options for the road authority. This technique aims to incorporate the value of the flexibility that is available during the deployment to reduce risk exposure, and as such more accurately appraise the investment. C-ITS uptake in passenger cars was modelled as the major source of uncertainty, as it is the primary driver of societal benefits. While a static RSU investment analysis for Flanders, Belgium, was found to be negative, embedding the option to defer the investment decision to further study C-ITS uptake results in a positive average net present value. The results are useful for any road authority aspiring to roll out C-ITS road-side infrastructure." "Routing protocols exploiting queue information for deterministic networks" "Jakob Miserez, Gourav Prateek Sharma, Wouter Tavernier" "On the network design and control of an optical network : interconnecting multiple chips on a wafer" "Ziyue Zhang, Didier Colle, Wouter Tavernier, Mario Pickavet" "In this paper, we propose a network architecture for a multi-chip optical network-on-wafer (NoW); we concentrate on the research of its control mechanisms and control algorithms. Our proposed optical NoW aims at providing dynamically controlled terabytes-per-second unidirectional bandwidth for every chip module in a multi-chip processor. This architecture is promising in achieving low energy consumption and high aggregated bandwidth, providing a competitive idea for the next generation of optical-connected multi-chip computing systems. A synchronous network control scheme with a network control algorithm is proposed for slowly varying traffic patterns. Moreover, an edge coloring algorithm is an important part of our network control algorithm; we propose improved edge coloring algorithms modified from existing edge coloring algorithms. We show that our improved edge coloring algorithm has lower time complexity and also achieves faster execution in our experiments than the existing methods." "Deployment of cooperative intelligent transport system infrastructure along highways : a bottom-up societal benefit analysis for Flanders" "Thibault Degrande, Frederic Vannieuwenborg, Sofie Verbrugge, Didier Colle" "Improving inpatient and daycare admission estimates with gravity models" "Timo Latruwe, Marlies Van der Wee, Pieter Vanleenhove, Kwinten Michielsen, Sofie Verbrugge, Didier Colle" "Growing healthcare costs have been accompanied by increased policymakers' interest in the efficiency of healthcare systems. Network formation by hospitals as a vehicle for consolidation and achieving economies of scale has emerged as an important topic of conversation among academics and practitioners. Within networks, consolidation of particular specialties or entire campuses is expected and encouraged to take place. This paper describes the main findings of an effort to build gravity-type models to describe patient choices in inpatient and daycare hospital facilities. It analyzes the distance decay effects as a function of car travel times and great-circle distance, and it offers a method for inclusion of university hospitals. Additionally, it reviews the impact of driving and transit accessibility on hospital attraction and reviews the differences in distance decay for patient age groups and hospitalization types. In the described application, the best models achieve a Mean Absolute Percentage Error of around 10% in non-metropolitan areas, and 14.5% across different region types. Results in metropolitan areas suggest that latent factors unrelated to proximity and size have a significant role in determining hospital choices. Furthermore, the effects of relative driving and transit accessibility are found to be small or non-existent." "The reality of data-driven ecosystems : how do theoretic benefits hold true in practice?" "Maarten de Mildt, Sofie Verbrugge, Didier Colle" "Photonic network-on-wafer for multichiplet GPUs" "Shiqing Zhang, Ziyue Zhang, Mahmood Naderan-Tahan, Seyyed Hossein SeyyedAghaei Rezaei, Xin Wang, Lionel Hertzog, Senbiao Qin, Didier Colle, Guy Torfs, Mario Pickavet, Johan Bauwelinck, Günther Roelkens, Lieven Eeckhout" "Techno-economic analysis of MEC clustering models for seamless CCAM service provision" "Asma Chiha Ep Harbi, Benoit Denis, Sofie Verbrugge, Didier Colle" "The latency requirements of delay-sensitive applications such as cooperative, connected, and automated mobility (CCAM) services challenge the capabilities of traditional vehicular radio access technologies (i.e., IEEE 802.11P and cellular networks). To this end, the 5G cellular network is adopting the multi-access edge computing (MEC) paradigm. However, the use of this technology comes with several challenges. In this article, MEC placement challenges and their impact on network deployment costs are studied. We propose three MEC clustering models and compare them from a cost perspective. Results show that all the MEC clustering models outperform the non-clustering approach. In addition, the conditions in which specific clustering models yield the most optimal results are analyzed. Results aim to provide insights into cost-effective MEC deployment models."