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Interested in Operations Reseach and Statistics applied to several fields.
The selection of porcine reproductive and respiratory syndrome (PRRS) resilient sows has been proposed as a strategy to control this disease. A discrete event-based simulation model was developed to mimic the outcome of farms with resilient or susceptible sows suffering recurrent PRRSV outbreaks. Records of both phenotypes were registered in a PRRSV-positive farm of 1500 sows during three years. The information was split in the whole period of observation to include a PRRSV outbreak that lasted 24 weeks (endemic/epidemic or En/Ep) or only the endemic phase (En). Twenty simulations were modeled for each farm: Resilient/En, Resilient/En_Ep, Susceptible/En, and Susceptible/En_Ep during twelve years and analyzed for the productive performance and economic outcome, using reference values. The reproductive parameters were generally better for resilient than for susceptible sows in the PRRSV En/Ep scenario, and the contrary was observed in the endemic case. The piglet production cost was always lower for resilient than for susceptible sows but showed only significant differences in the PRRSV En/Ep scenario. Finally, the annual gross margin by sow is significantly better for resilient than for susceptible sows for the PRRSV endemic (12%) and endemic/epidemic scenarios (17%). Thus, the selection of PRRSV resilient sows is a profitable approach for producers to improve disease control.
Gloria Abella; Adela Pagès-Bernaus; Joan Estany; Ramona Pena; Lorenzo Fraile; Lluis Plà-Aragonés. Using PRRSV-Resilient Sows Improve Performance in Endemic Infected Farms with Recurrent Outbreaks. Animals 2021, 11, 740 .
AMA StyleGloria Abella, Adela Pagès-Bernaus, Joan Estany, Ramona Pena, Lorenzo Fraile, Lluis Plà-Aragonés. Using PRRSV-Resilient Sows Improve Performance in Endemic Infected Farms with Recurrent Outbreaks. Animals. 2021; 11 (3):740.
Chicago/Turabian StyleGloria Abella; Adela Pagès-Bernaus; Joan Estany; Ramona Pena; Lorenzo Fraile; Lluis Plà-Aragonés. 2021. "Using PRRSV-Resilient Sows Improve Performance in Endemic Infected Farms with Recurrent Outbreaks." Animals 11, no. 3: 740.
This paper focuses on vertically integrated pig companies based on multi-farm systems. The aim is to address tactical decisions to plan production, increase flexibility, improve coordination and overall pig production under the uncertainty associated with future selling price. Decisions to purchase additional piglets and/or rent farms to adapt system capacity were considered. We propose a two-stage stochastic programming model with selling price as a stochastic parameter under a limited time horizon and a case study to illustrate their use. The model maximizes the net revenue of the system by considering a steady piglet production on sow farms and the corresponding animal flow according to growth stage throughout different farms such as breeding, rearing and fattening farms. All-in-all-out management and marketing time window to sell pigs to the abattoir were modeled on fattening farms. The stochastic solution for the case study provides an optimal first stage production plan regarding the purchase of 1016 piglets/week in addition to the 775 already produced beside the renting of rearing and fattening farms taking into account the different scenarios may happen in the future. The model is capable of identifying inefficiencies or bottlenecks in the system. We discuss the value of the stochastic solution of k€1683 compared to the deterministic solution, and concluding the valuable incorporation of uncertainty.
Esteve Nadal; Lluís M. Plà-Aragonès; Adela Pagès-Bernaus; Víctor M. Albornoz. A two-stage stochastic model for pig production planning in vertically integrated production systems. Computers and Electronics in Agriculture 2020, 176, 105615 .
AMA StyleEsteve Nadal, Lluís M. Plà-Aragonès, Adela Pagès-Bernaus, Víctor M. Albornoz. A two-stage stochastic model for pig production planning in vertically integrated production systems. Computers and Electronics in Agriculture. 2020; 176 ():105615.
Chicago/Turabian StyleEsteve Nadal; Lluís M. Plà-Aragonès; Adela Pagès-Bernaus; Víctor M. Albornoz. 2020. "A two-stage stochastic model for pig production planning in vertically integrated production systems." Computers and Electronics in Agriculture 176, no. : 105615.
Héctor Cancela; Andrew Higgins; Adela Pagès-Bernaus; Lluis Miquel Plà-Aragonès. Prologue – BigData and DSS in agriculture. Computers and Electronics in Agriculture 2019, 161, 1 -3.
AMA StyleHéctor Cancela, Andrew Higgins, Adela Pagès-Bernaus, Lluis Miquel Plà-Aragonès. Prologue – BigData and DSS in agriculture. Computers and Electronics in Agriculture. 2019; 161 ():1-3.
Chicago/Turabian StyleHéctor Cancela; Andrew Higgins; Adela Pagès-Bernaus; Lluis Miquel Plà-Aragonès. 2019. "Prologue – BigData and DSS in agriculture." Computers and Electronics in Agriculture 161, no. : 1-3.
This paper presents a bi-objective model for optimizing pig deliveries to the abattoir accounting for total revenue and CO 2 emissions. Fattening farms house the most important stage in pig production, and operations on farms must be coordinated with the rest of the pig supply chain when batch management is generally applied. The novelty of the model lies in the change of attitude in producers towards a greener production, which is becoming one of the major concerns in our society. In this context, we enrich the classical approach focused on revenues with the addition of the CO 2 emissions from the pigs on the fattening farms. Emissions derived from feeding and transportation are considered since they are the most important sources of CO 2 . The model is tested using parameters representing a typical integrated Spanish fattening farm. Our findings reveal the impact and the relationship between revenues and emissions, highlight that the break-even is reached achieving 459 kg of CO 2 per pig, which corresponds to a reduction of 6.05%. On the other hand, the profit is slightly reduced by 4.48% in favor of the environment.
Esteve Nadal-Roig; Adela Pagès-Bernaus; Lluís M. Plà-Aragonès. Bi-Objective Optimization Model Based on Profit and CO2 Emissions for Pig Deliveries to the Abattoir. Sustainability 2018, 10, 1782 .
AMA StyleEsteve Nadal-Roig, Adela Pagès-Bernaus, Lluís M. Plà-Aragonès. Bi-Objective Optimization Model Based on Profit and CO2 Emissions for Pig Deliveries to the Abattoir. Sustainability. 2018; 10 (6):1782.
Chicago/Turabian StyleEsteve Nadal-Roig; Adela Pagès-Bernaus; Lluís M. Plà-Aragonès. 2018. "Bi-Objective Optimization Model Based on Profit and CO2 Emissions for Pig Deliveries to the Abattoir." Sustainability 10, no. 6: 1782.
E‐Commerce activity has been increasing during recent years, and this trend is expected to continue in the near future. e‐Commerce practices are subject to uncertainty conditions and high variability in customers’ demands. Considering these characteristics, we propose two facility–location models that represent alternative distribution policies in e‐commerce (one based on outsourcing and another based on in‐house distribution). These models take into account stochastic demands as well as more than one regular supplier per customer. Two methodologies are then introduced to solve these stochastic versions of the well‐known capacitated facility–location problem. The first is a two‐stage stochastic‐programming approach that uses an exact solver. However, we show that this approach is not appropriate for tackle large‐scale instances due to the computational effort required. Accordingly, we also introduce a “simheuristic” approach that is able to deal with large‐scale instances in short computing times. An extensive set of benchmark instances contribute to illustrate the efficiency of our approach, as well as its potential utility in modern e‐commerce practices.
Adela Pagès-Bernaus; Helena Ramalhinho; Angel Juan; Laura Calvet. Designing e-commerce supply chains: a stochastic facility-location approach. International Transactions in Operational Research 2017, 26, 507 -528.
AMA StyleAdela Pagès-Bernaus, Helena Ramalhinho, Angel Juan, Laura Calvet. Designing e-commerce supply chains: a stochastic facility-location approach. International Transactions in Operational Research. 2017; 26 (2):507-528.
Chicago/Turabian StyleAdela Pagès-Bernaus; Helena Ramalhinho; Angel Juan; Laura Calvet. 2017. "Designing e-commerce supply chains: a stochastic facility-location approach." International Transactions in Operational Research 26, no. 2: 507-528.
L. Marí; N. Nabona; Adela Pagès Bernaus. Medium-term power planning in electricity markets with pool and bilateral contracts. European Journal of Operational Research 2017, 260, 432 -443.
AMA StyleL. Marí, N. Nabona, Adela Pagès Bernaus. Medium-term power planning in electricity markets with pool and bilateral contracts. European Journal of Operational Research. 2017; 260 (2):432-443.
Chicago/Turabian StyleL. Marí; N. Nabona; Adela Pagès Bernaus. 2017. "Medium-term power planning in electricity markets with pool and bilateral contracts." European Journal of Operational Research 260, no. 2: 432-443.
Rich Vehicle Routing Problems (RVRPs) refer to complex and realistic extensions of the classical Vehicle Routing Problem. They constitute a hot topic in logistics due to their high number of relevant applications. This work focuses on a RVRP with the following characteristics: (a) heterogeneous fleet of vehicles, (b) site-dependency, i.e., not all types of vehicle can reach all customers, (c) asymmetric costs, and (d) stochastic demands. We formally define the problem and describe real-life applications. Our main contribution is a simheuristic-based methodology including a Successive Approximations Method for solving it. A computational experiment is carried out to illustrate the proposed methodology. Moreover, the suitability of considering a simheuristic approach is analyzed.
Laura Calvet; Adela Pagès-Bernaus; Oriol Travesset-Baro; Angel A. Juan. A Simheuristic for the Heterogeneous Site-Dependent Asymmetric VRP with Stochastic Demands. Automata, Languages and Programming 2016, 408 -417.
AMA StyleLaura Calvet, Adela Pagès-Bernaus, Oriol Travesset-Baro, Angel A. Juan. A Simheuristic for the Heterogeneous Site-Dependent Asymmetric VRP with Stochastic Demands. Automata, Languages and Programming. 2016; ():408-417.
Chicago/Turabian StyleLaura Calvet; Adela Pagès-Bernaus; Oriol Travesset-Baro; Angel A. Juan. 2016. "A Simheuristic for the Heterogeneous Site-Dependent Asymmetric VRP with Stochastic Demands." Automata, Languages and Programming , no. : 408-417.
Smart cities represent rich and dynamic environments in which a multitude of smart mobile devices (SMDs) interact among them by sharing data. SMDs require from fast access to online services, but they offer limited computing capabilities and battery lifetime. SMDs make frequent use of computation offloading, delegating computing-intensive tasks to the cloud instead of performing them locally. In such a large-scale and dynamic environment, there might be thousands of SMDs simultaneously executing processes and, therefore, competing for the allotment of remote resources. This arises the need for a smart allocation of these resources. Accordingly, this paper proposes a biased-randomized algorithm to support efficient and fast link selection. This algorithm is able to provide “real-time” near-optimal solutions that outperform solutions obtained through existing greedy heuristics. Furthermore, it overcomes the responsiveness limitations of exact optimization methods.
Daniela Mazza; Adela Pagès Bernaus; Daniele Tarchi; Angel Juan; Giovanni Emanuele Corazza. Supporting Mobile Cloud Computing in Smart Cities via Randomized Algorithms. IEEE Systems Journal 2016, 12, 1598 -1609.
AMA StyleDaniela Mazza, Adela Pagès Bernaus, Daniele Tarchi, Angel Juan, Giovanni Emanuele Corazza. Supporting Mobile Cloud Computing in Smart Cities via Randomized Algorithms. IEEE Systems Journal. 2016; 12 (2):1598-1609.
Chicago/Turabian StyleDaniela Mazza; Adela Pagès Bernaus; Daniele Tarchi; Angel Juan; Giovanni Emanuele Corazza. 2016. "Supporting Mobile Cloud Computing in Smart Cities via Randomized Algorithms." IEEE Systems Journal 12, no. 2: 1598-1609.
Carlos L. Quintero-Araujo; Adela Pagès-Bernaus; Angel Juan; Oriol Travesset; Nicolas Jozefowiez. Planning Freight Delivery Routes in Mountainous Regions. Information Systems 2016, 123 -132.
AMA StyleCarlos L. Quintero-Araujo, Adela Pagès-Bernaus, Angel Juan, Oriol Travesset, Nicolas Jozefowiez. Planning Freight Delivery Routes in Mountainous Regions. Information Systems. 2016; ():123-132.
Chicago/Turabian StyleCarlos L. Quintero-Araujo; Adela Pagès-Bernaus; Angel Juan; Oriol Travesset; Nicolas Jozefowiez. 2016. "Planning Freight Delivery Routes in Mountainous Regions." Information Systems , no. : 123-132.
Production planning models are achieving more interest for being used in the primary sector of the economy. The proposed model relies on the formulation of a location model representing a set of farms susceptible of being selected by a grocery shop brand to supply local fresh products under seasonal contracts. The main aim is to minimize overall procurement costs and meet future demand. This kind of problem is rather common in fresh vegetable supply chains where producers are located in proximity either to processing plants or retailers. The proposed two-stage stochastic model determines which suppliers should be selected for production contracts to ensure high quality products and minimal time from farm-to-table. Moreover, Lagrangian relaxation and parallel computing algorithms are proposed to solve these instances efficiently in a reasonable computational time. The results obtained show computational gains from our algorithmic proposals in front of the usage of plain CPLEX solver. Furthermore, the results ensure the competitive advantages of using the proposed model by purchase managers in the fresh vegetables industry.
Jordi Mateo; Lluis M. Pla; Francesc Solsona; Adela Pagès. A production planning model considering uncertain demand using two-stage stochastic programming in a fresh vegetable supply chain context. SpringerPlus 2016, 5, 1 -16.
AMA StyleJordi Mateo, Lluis M. Pla, Francesc Solsona, Adela Pagès. A production planning model considering uncertain demand using two-stage stochastic programming in a fresh vegetable supply chain context. SpringerPlus. 2016; 5 (1):1-16.
Chicago/Turabian StyleJordi Mateo; Lluis M. Pla; Francesc Solsona; Adela Pagès. 2016. "A production planning model considering uncertain demand using two-stage stochastic programming in a fresh vegetable supply chain context." SpringerPlus 5, no. 1: 1-16.
Branch and Fix Coordination is an algorithm intended to solve large scale multi-stage stochastic mixed integer problems, based on the particular structure of such problems, so that they can be broken down into smaller subproblems. With this in mind, it is possible to use distributed computation techniques to solve the several subproblems in a parallel way, almost independently. To guarantee non-anticipativity in the global solution, the values of the integer variables in the subproblems are coordinated by a master thread. Scenario ‘clusters’ lend themselves particularly well to parallelisation, allowing us to solve some problems noticeably faster. Thanks to the decomposition into smaller subproblems, we can also attempt to solve otherwise intractable instances. In this work, we present details on the computational implementation of the Branch and Fix Coordination algorithm
Adela Pagès-Bernaus; Gerardo Pérez-Valdés; Asgeir Tomasgard. A parallelised distributed implementation of a Branch and Fix Coordination algorithm. European Journal of Operational Research 2015, 244, 77 -85.
AMA StyleAdela Pagès-Bernaus, Gerardo Pérez-Valdés, Asgeir Tomasgard. A parallelised distributed implementation of a Branch and Fix Coordination algorithm. European Journal of Operational Research. 2015; 244 (1):77-85.
Chicago/Turabian StyleAdela Pagès-Bernaus; Gerardo Pérez-Valdés; Asgeir Tomasgard. 2015. "A parallelised distributed implementation of a Branch and Fix Coordination algorithm." European Journal of Operational Research 244, no. 1: 77-85.
This paper presents a mathematical model for designing a carbon dioxide (CO2) value chain. Storage of CO2 in geological formations is recognized as an important alternative for carbon abatement. When CO2 is deposited in oil reservoirs it can sometimes be used to achieve additional oil production, enhanced oil recovery (EOR). The model determines an optimal CO2 value chain from a fixed set of CO2 emission points and a set of potential injection sites. It designs a transport network and chooses the best suited oil fields with EOR potential or other geological formations for storage. A net present value criterion is used. The model is illustrated by an example of a Norwegian case with 14 oil fields, two aquifers and five CO2 sources. A sensitivity analysis is performed on the most important parameters.
Ø. Klokk; P.F. Schreiner; A. Pagès-Bernaus; A. Tomasgard. Optimizing a CO2 value chain for the Norwegian Continental Shelf. Energy Policy 2010, 38, 6604 -6614.
AMA StyleØ. Klokk, P.F. Schreiner, A. Pagès-Bernaus, A. Tomasgard. Optimizing a CO2 value chain for the Norwegian Continental Shelf. Energy Policy. 2010; 38 (11):6604-6614.
Chicago/Turabian StyleØ. Klokk; P.F. Schreiner; A. Pagès-Bernaus; A. Tomasgard. 2010. "Optimizing a CO2 value chain for the Norwegian Continental Shelf." Energy Policy 38, no. 11: 6604-6614.
Carbon capture and sequestration is a possible technology for abating carbon dioxide emissions. This is costly and requires investment in capture, transportation and storage facilities, and compensation for possibly substantial operational cost at these facilities. On the other hand, this option avoids buying carbon offsets, and the CO2 may in some cases be used for enhanced oil recovery. Stochastic dynamic programming is applied to perform the underlying investment analysis, that is, to decide whether investment on a CO2 value chain is profitable, and if so, then when the decisions should be taken. The oil and CO2 prices are modelled as stochastic processes. As a case study we consider possible CO2 value chain investments on the Norwegian Continental Shelf.
Stein-Erik Fleten; Kristin Lien; Kristin Ljønes; Adela Pagès-Bernaus; Marte Aaberg. Value chains for carbon storage and enhanced oil recovery: optimal investment under uncertainty. Energy Systems 2010, 1, 457 -470.
AMA StyleStein-Erik Fleten, Kristin Lien, Kristin Ljønes, Adela Pagès-Bernaus, Marte Aaberg. Value chains for carbon storage and enhanced oil recovery: optimal investment under uncertainty. Energy Systems. 2010; 1 (4):457-470.
Chicago/Turabian StyleStein-Erik Fleten; Kristin Lien; Kristin Ljønes; Adela Pagès-Bernaus; Marte Aaberg. 2010. "Value chains for carbon storage and enhanced oil recovery: optimal investment under uncertainty." Energy Systems 1, no. 4: 457-470.