The color-balanced spanning tree problem

summary:Suppose a graph $G=(V,E)$ whose edges are partitioned into $p$ disjoint categories (colors) is given. In the color-balanced spanning tree problem a spanning tree is looked for that minimizes the variability in the number of edges from different categories. We show that polynomiality of this problem depends on the number $p$ of categories and present some polynomial algorithm

Location Models for Two Different Applications

There has been a growing interest in location problems for their wide use in many areas, such as passive optical networks and logistics networks. However, as the papers appear in different literature, researchers usually do not take advantage of their mutual findings. We propose to bridge the gaps and therefore to propose efficient solutions schemes for two different applications. In the first application, our research goal is to investigate the FTTX (Fiber-to-the Home/Premises/Curb) passive optical network (PON) for the deployment of broadband access. We focus on designing the best possible architectures of FTTX hybrid PONs, which embraces both Time Division Multiplexing (TDM) and Wave Division Multiplexing (WDM) technology. A hybrid PON architecture is very efficient as it is not limited to any specific PON technology, rather it is flexible enough to deploy TDM/WDM technology depending on the type (i.e., unicast/multicast) and amount of traffic demand of the end-users. We investigate the optimized covering of a geographical area by a set of cost-effective hybrid PONs. We propose a novel network design optimization scheme for greenfield deployment of a set of hybrid PONs, in which all significant constraints are taken into account, e.g., type of traffic, attenuation, choice of splitting equipment. In the second application, we revisit the p-center location problem in the context of disruption events. We propose an optimized covering in the geographical area for a given number of customers and suppliers, ensuring each customer is assigned a primary supplier and a different backup supplier unless the primary supplier has a so-called fortified facility. However, the budget for facility fortification is limited and only few facilities can be fortified. We design an optimization model under the assumption of single event disruptions, and estimate accurately the required facility capacities while taking into account a sharing of the backup resources. We evaluate our proposed models and algorithms by a comprehensive set of numerical experiments, with some comparisons in each of these two applications. Conclusions are drawn in the last chapter

Multi-robot task allocation system to improve assistance in domestic scenarios

The AURORA project aims at developing new strategies to take assistive robotics a step further. In order to provide extended services to potential users, engaging a team of simpler robots is often preferable to using a unique, super-capable robot. In such multi-robot systems, the coordination for task execution is one of the major challenges to overcome. The present thesis proposes a solution to the specific issue of multi-robot task allocation within an heterogeneous team of robots, with additional inter-task precedence constraints. The main elements of the state of the art that support this project are reported, including useful taxonomies and existing methods. From the analyzed solutions, the one that better fits with the constraints of the project is an iterated auction-based algorithm able to manage precedence constraints, which has been modified to handle heterogeneity and partial scheduling. The selected solution has been designed and implemented with the particular purpose of being applied to the robotized kitchen setup of the AURORA project; it is however flexible and scalable and can therefore be applied to other use-cases, for instance vehicle-routing problems. Several evaluation scenarios have been tested, that demonstrate the good functioning and characteristics of the system, as well as the possibility to integrate humans into the task assignation process

Multi-Quality Auto-Tuning by Contract Negotiation

A characteristic challenge of software development is the management of omnipresent change. Classically, this constant change is driven by customers changing their requirements. The wish to optimally leverage available resources opens another source of change: the software systems environment. Software is tailored to specific platforms (e.g., hardware architectures) resulting in many variants of the same software optimized for different environments. If the environment changes, a different variant is to be used, i.e., the system has to reconfigure to the variant optimized for the arisen situation. The automation of such adjustments is subject to the research community of self-adaptive systems. The basic principle is a control loop, as known from control theory. The system (and environment) is continuously monitored, the collected data is analyzed and decisions for or against a reconfiguration are computed and realized. Central problems in this field, which are addressed in this thesis, are the management of interdependencies between non-functional properties of the system, the handling of multiple criteria subject to decision making and the scalability. In this thesis, a novel approach to self-adaptive software--Multi-Quality Auto-Tuning (MQuAT)--is presented, which provides design and operation principles for software systems which automatically provide the best possible utility to the user while producing the least possible cost. For this purpose, a component model has been developed, enabling the software developer to design and implement self-optimizing software systems in a model-driven way. This component model allows for the specification of the structure as well as the behavior of the system and is capable of covering the runtime state of the system. The notion of quality contracts is utilized to cover the non-functional behavior and, especially, the dependencies between non-functional properties of the system. At runtime the component model covers the runtime state of the system. This runtime model is used in combination with the contracts to generate optimization problems in different formalisms (Integer Linear Programming (ILP), Pseudo-Boolean Optimization (PBO), Ant Colony Optimization (ACO) and Multi-Objective Integer Linear Programming (MOILP)). Standard solvers are applied to derive solutions to these problems, which represent reconfiguration decisions, if the identified configuration differs from the current. Each approach is empirically evaluated in terms of its scalability showing the feasibility of all approaches, except for ACO, the superiority of ILP over PBO and the limits of all approaches: 100 component types for ILP, 30 for PBO, 10 for ACO and 30 for 2-objective MOILP. In presence of more than two objective functions the MOILP approach is shown to be infeasible

Switching Equipment Location/Allocation in hybrid PONs

Our research goal is to investigate the FTTX (Fiber-to-the Home/Premises/Curb) passive optical network (PON) for the deployment of BISAN (Broadband Internet Subscriber Access Network) to exploit the opportunities of optical fiber enabled technologies as well as of passive switching equipment. Indeed, the deployment of FTTX PON is the most OPEX-friendly scenario, because it allows for completely passive access networks through minimizing the number of active components in the network. Previously, most FTTX PON architectures are designed based on the principle of either time division multiplexing (TDM) technology or wavelength division multiplexing (WDM) technology. We focus on designing the best possible architectures of FTTX PON, specifically hybrid PONs, which embraces both TDM and WDM technology. A hybrid PON architecture is very efficient as it is not limited to any specific PON technology, rather it is flexible enough to deploy TDM/WDM technology depending on the type (i.e unicast/multicast) and amount of traffic demand of the end-users. The advantages of a hybrid PON are of two folds: (i) it can offer increased data rate to each user by employing WDM technology, (ii) it can provide flexible bandwidth utilization by employing TDM technology. In this thesis, we concentrate on determining the optimized covering of a geographical area by a set of cost-effective hybrid PONs. We also focus on the greenfield deployment of a single hybrid PON. It should be worthy to mention that while investigating the deployment of hybrid PONs, the research community around the world considers the specifications of either the physical layer or the optical layer. But an efficient planning for PON deployment should take into account the constraints of the physical and optical layers in order that both layers can work together harmoniously. We concentrate our research on the network dimensioning and the selection as well as the placement of the switching equipment in hybrid PONs with the intention of considering the constraints of both physical and optical layers. We determine the layout of an optimized PON architecture while provisioning wavelengths in a hybrid PON. We also propose to select the switching equipment depending on the type (unicast/multicast) of traffic demand. Finally, we determine the best set of hybrid PONs along with their cascading architecture, type and location of their switching equipment while satisfying the network design constraints such as the number of output ports of the switching equipment and maximum allowed signal power loss experienced at each end user’s premises. In this thesis, we propose two novel schemes for the greenfield deployment of a single hybrid PON. The first scheme consists of two phases in which a heuristic algorithm and a novel column generation (CG) based integer linear programming (ILP) optimization model are proposed in the 1st and 2nd phase respectively. In the second scheme, a novel integrated CG based ILP cross layer optimization model is proposed for the designing of a single hybrid PON. We also propose two novel schemes to deal with the greenfield deployment of multiple hybrid PONs in a given geographical area. These two schemes determine the best set of cost-effective hybrid PONs in order to serve all the end users in a given neighborhood. The first scheme executes in four phases in which two heuristic algorithms, a CG based ILP model and an ILP optimization model are proposed in the 1st, 2nd, 3rd and 4th phase respectively. In the second scheme, an ILP model as well as a CG based ILP model, another ILP model as well as another CG based ILP model, a CG based ILP model and an ILP optimization model are proposed during four consecutive phases. Our proposed scheme can optimize the design of a set of hybrid PONs covering a given geographic area as well as the selection of the best cascading architecture 1/2/mixedstage) for each selected PON. It minimizes the overall network deployment cost based on the location of the OLT and the ONUs while granting all traffic demands. The scheme emphasizes on the optimum placement of equipment in a hybrid PON infrastructure due to the critical dependency between the network performances and a proper deployment of its equipment, which, in turn depends on the locations of the users. It is a quite powerful scheme as it can handle data instances with up to several thousands ONUs. On the basis of the computational results, the proposed scheme leads to an efficient automated tool for network design, planning, and performance evaluation which can be beneficial for the network designers

Prospects for Research in Transport and Logistics on a Regional: Global Perspective (I: February 2009: İstanbul: Turkey)

"International Conference on Prospects for Research in Transport and Logistics on a Global - Regional Perspective" has undertaken the challenge to host very important experts and practitioners of Transport and Logistics from a large spectrum of countries. In our opinion, the conference has fulfilled the purpose of establishing an International Society; "Eurasian and Eastern Mediterranean Institute of Transportation and Logistics Association (EMIT)" that is expected to have a very promising role in the Eurasian and Eastern Mediterranean countries. The purpose of the Association is to contribute to establishing and developing the exchange of research work between all parts of the world in all fields of transportation and logistics. This proceedings book consists of 13 chapters, grouping the contributed papers into the following categories: Global Issues in Logistics and Transportation (3 papers), Regional Issues in Logistics and Transportation (2 papers), Education and Training in Logistics and Transportation (2 papers), Supply Chain Management (3 papers), Sustainable Transport Policies, Traffic Engineering (4 papers), Evaluation of Public Policies, Network Models and Environment (4 papers), Contemporary Topics in Transport and Logistics (7 papers), Transport Planning and Economics (3 papers), Planning, Operations, Management and Control of Transport and Logistics (3 papers), Transport Modeling (5 papers), Freight Transportation and Logistics Management (7 papers), Transport and Land Use (3 papers), Transport Infrastructure and Investment Appraisal (2 papers) It can be readily seen from this volume of selected papers that all papers do elaborate on rather timely problems in the fields of expertise related to Transport and Logistics, which have a considerable global importance.TÜBİTAK; Doğuş Üniversitesi ; Uluslararası Nakliyeciler Derneği ; İDO ; Tırsan ; Türk Hava YollarıCommittees, i -- Words of Welcome and Gratitude, ii -- Introduction, iii -- Chapter 1 Global Issues in Logistics and Transportation, 1 -- Potential to Reduce GHG through Efficient Logistic Concepts, 3 -- Werner Rothengatter -- A methodological framework for the evaluation and prioritisation of multinational transport projects: the Case of euro-asian transport linkages, 21 / Dimitrios TSAMBOULAS, Angeliki KOPSACHEILI -- Container port throughput performance - case study: Far east, north west european and mediterranean ports, 29 / Vesna DRAGOVIC-RADINOVIC, Branislav DRAGOVIC, Maja SKURIC, EmirĞIKMIROVlC and Ivan KRAPOVIC -- Chapter 2 Regional Issues in Logistics and Transportation, 35 -- Logistics service providers in turkey: A panel data analysis, 37 / Emel AKTAŞ, Füsun ÜLENGİN, Berrin AĞARAN, Şule ÖNSEL -- Milestones in the process of survey preparation for the logistics sector: case study for Istanbul, Turkey, 43 / Evren POSACI, Darçın AKIN -- Chapter 3 Education and Training in Logistics and Transportation, 51 -- Education in transport and logistics in an age of global economy, 53 / Yücel Candemlr -- The role of education and training in the supply chain sector, 59 / David Maunder -- Chapter 4 Supply Chain Management, 64 -- Modeling reverse flows in a closed -loop supply chain network, 67 / Vildan ÖZKIR, Önder ÖNDEMİR and Hüseyin BAŞLIGİL -- Strategic analysis of green supply chain management practices in T urkish automotive industry, 73 / Gülçin BÜYÜKÖZKAN and Alişan ÇAPAN -- A new framework for port competitiveness: the network approach, 79 / Marcella DE MARTINO, Alfonso MORVILLO -- Chapter 5 Sustainable Transport Policies, Traffic Engineering, 87 -- Clean transport: innovative solutions to the creation of a more sustainable urban transport system, 89 / Ela BABALIK-SUTCLIFFE -- Effects of urban bottlenecks on highway traffic congestion: case study of Istanbul, Turkey, 95 / Darçın AKIN and Mehtap ÇELİK -- Establishing an effective training module for IMDG code in MET institutions, 105 / Kadir CICEK, Metin CELIK -- An investment decision aid proposal towards choice of container terminal operating systems based on information axioms, 109 / Metin CELIK, Selcuk CEBI -- Chapter 6 Evaluation of Public Policies, Network Models and Environment, 115 -- Possibilistic linear programming approach for strategic resource planning, 117 / Özgür KABAK, Füsun ÜLENGİN -- A structural equation model for measuring service quality in passenger transportation, 125 / G.Nilay YÜCENUR and Nihan ÇETİN DEMİREL -- Analysis of potential gain from using hybrid vehicles in public transportation, 133 / İrem DÜZDAR and Özay ÖZAYDIN -- Optimization of e-waste management in Marmara region - Turkey, 141 / İlke BEREKETLİ, Müjde EROL GENEVOIS -- Chapter 7 Contemporary Topics in Transport and Logistics, 147 -- Future prospects on urban logistic research, 149 / Rosârio MACÂRIO, Vasco REIS -- An analyze of relationship between container ships and ports development, 155 / Branislav DRAGOVIC, Vesna Dragovic-Radinovic, Dusanka Jovovic, Romeo Mestrovic and Emir Ğikmirovic -- A holistic framework for performance measurement in logistics management, 161 / Yasemin Claire ERENSAL -- Heuristics for a generalization of tsp in the context of PCB assembly, 167 / Ali Fuat ALKAYA and Ekrem DUMAN -- Premium e-grocery: Exploring value in logistics integrated service solutions, 173 / Burçin BOZKAYA, Ronan De KERVENOAEL and D. Selcen Ö. AYKAÇ -- T ravelers response to VMS in the Athens area, 179 / Athena TSIRIMPA and Amalia POLYDOROPOULOU -- Regional airports and local development: the challenging balance between sustainability and economic growth, 189 / Rosârio MACÂRIO and Jorge SILVA -- Chapter 8 Transport Planning and Economics, 195 -- How financial constraints and non-optimal pricing affect the design of public transport services, 197 / Sergio R. Jara-Diaz and Antonio Gschwender -- Revenue management for returned products in reverse logistics, 203 / Mesut KUMRU -- Intra-city bus planning using computer simulation, 211 / Reza AZIMI and Amin ALVANCHI -- Chapter 9 Planning, Operations, Management and Control of Transport and Logistics, 217 -- A review of timetabling and resource allocation models for light-rail transportation systems, 219 / Selmin D. ÖNCÜL, D. Selcen Ö. AYKAÇ, Demet BAYRAKTAR and Dilay ÇELEBİ -- An approach of integrated logistics HMMS model under environment constraints and an application of time scale, 225 / Fahriye Uysal, Ömür Tosun, Orhan Kuruüzüm -- Freight transport planning with genetic algorithm based projected demand, 231 / Soner HALDENBILEN, Ozgur BASKAN, Huseyin CEYLAN and Halim CEYLAN -- Chapter 10 Transport Modeling, 239 -- Inverse model to estimate o-d matrix from link traffic counts using ant colony optimization, 241 / Halim CEYLAN, Soner HALDENBILEN, Huseyin CEYLAN, Ozgur BASKAN -- The impact of logistics on modelling commercial freight traffic, 251 / Ute IDDINK and Uwe CLAUSEN -- A comparative reviewof simulation-based behavior modeling for travel demand generation, 257 / Seda Yanık, Mehmet Tanyaş -- An efficiency analysis of turkish container ports using the analytic network process, 269 / Senay OĞUZTİMUR, Umut Rıfat TUZKAYA -- A multi-objective approach to designing a multicommudity supply chain distribution network with multiple capacities, 277 / Gholam Reza Nasiri, Hamid Davoudpour and B.Karimi -- Chapter 11 Freight Transportation and Logistics Management, 283 -- Evaluation of turkey’s freight transportation, 285 / Burcu KULELİ PAKand BaharSENNAROĞLU -- Short sea shipping, intermodality and parameters influencing pricing policies in the Mediterranean region: The Italian context, 291 / Monica GROSSO, Ana-Rita LYNCE, Anne SILLA, Georgios K. VAGGELAS -- Relevant strategic criteria when choosing a container port - the case of the port of Genoa, 299 / Monica Grosso, Feliciana Monteiro -- Determination of optimum fleet size and composition - A case study of retailer in Thailand, 307 / Terdsak RONGVIRIYAPANICH and Kawee SRIMUANG -- New container port development: forecasting future container throughput, 313 / Dimitrios TSAMBOULAS, Panayota MORAITI -- Sea port hinterland flows and opening hours: the way forward to make them match better 319 / Marjan BEELEN, Hilde MEERSMAN, Evy ONGHENA, Eddy VAN DE VOORDE and Thierry VANELSLANDER -- International road freight transport in Germany and the Netherlands driver costs analysis and French perspectives, 327 / Laurent GUIHERY -- Chapter 12 Transport and Land Use, 335 -- Land rent and new transport infrastructure: How to manage this relationship?, 337 / Elena SCOPEL -- Effects of pavement characteristics on the traffic noise levels, 345 / Aybike ONGEL and John HARVEY -- Fuzzy medical waste disposal facility location problem, 351 / Yeşim KOP, Müjde EROL GENEVOIS and H. Ziya ULUKAN -- Chapter 13 T ransport Infrastructure and Investment Appraisal, 357 -- Agents’ behavior in financing Italian transport infrastructures, 359 / Paolo BERIA -- Free trade agreements in the mediterranean region: a box-cox analysis, 367 / Matthew KARLAFTIS, Konstantinos KEPAPTSOGLOU and Dimitrios TSAMBOULA

Proceedings of the XIII Global Optimization Workshop: GOW'16

[Excerpt] Preface: Past Global Optimization Workshop shave been held in Sopron (1985 and 1990), Szeged (WGO, 1995), Florence (GO’99, 1999), Hanmer Springs (Let’s GO, 2001), Santorini (Frontiers in GO, 2003), San José (Go’05, 2005), Mykonos (AGO’07, 2007), Skukuza (SAGO’08, 2008), Toulouse (TOGO’10, 2010), Natal (NAGO’12, 2012) and Málaga (MAGO’14, 2014) with the aim of stimulating discussion between senior and junior researchers on the topic of Global Optimization. In 2016, the XIII Global Optimization Workshop (GOW’16) takes place in Braga and is organized by three researchers from the University of Minho. Two of them belong to the Systems Engineering and Operational Research Group from the Algoritmi Research Centre and the other to the Statistics, Applied Probability and Operational Research Group from the Centre of Mathematics. The event received more than 50 submissions from 15 countries from Europe, South America and North America. We want to express our gratitude to the invited speaker Panos Pardalos for accepting the invitation and sharing his expertise, helping us to meet the workshop objectives. GOW’16 would not have been possible without the valuable contribution from the authors and the International Scientific Committee members. We thank you all. This proceedings book intends to present an overview of the topics that will be addressed in the workshop with the goal of contributing to interesting and fruitful discussions between the authors and participants. After the event, high quality papers can be submitted to a special issue of the Journal of Global Optimization dedicated to the workshop. [...