Publications

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Publications and open acccess preprints of my publications are listed below. Click on [Abstract] to obtain more information. Bibliographical information is available by clicking on [BibTeX].

You can search in the abstracts using the quicksearch box below. The official publication pages can be accessed through the link given [DOI]. If a preprint version is available it can be found by clicking on [URL]. Links to press coverage are listed under [Comment].

A list of my publications is also available on Google Scholar.


Kaandorp C, van de Giesen N and Abraham E (2021), "The water use of heating pathways to 2050: analysis of national and urban energy scenarios", Environmental Research Letters.
Abstract: Sustainable energy systems can only be achieved when reducing both carbon emissions and water use for energy generation. Although the water use for electricity generation has been well studied, integrated assessments of the water use by low-carbon heat systems are lacking. In this paper we present an analysis of the water use of scenarios for heat and electricity production for the year 2050 for the Netherlands and its capital, Amsterdam. The analysis shows that (i) the water withdrawal for heating can increase up to the same order of magnitude as the current water withdrawal of thermoelectric plants due to the use of Aquifer Thermal Energy Storage (ATES), (ii) the virtual water use for heating can become higher than the operational water consumption for heating, and (iii) the water use for electricity production becomes a relevant indicator for the virtual water use for heat generation because of the increase of Power-to-Heat applications.
BibTeX:
@article{heatingTrasition2021a,
  author = {Chelsea Kaandorp and Nick van de Giesen and Edo Abraham},
  title = {The water use of heating pathways to 2050: analysis of national and urban energy scenarios},
  journal = {Environmental Research Letters},
  year = {2021},
  url = {http://iopscience.iop.org/article/10.1088/1748-9326/abede7}
}
Abraham E, Verbart J and van der Hoek J (2020), "Smart solutions for intermittent supply systems", The Source -- The magazine of the International Water Association., December, 2020. Vol. 21, pp. 24-28.
Abstract: Intermittent operation of water supply networks is widespread, including in sub-Saharan Africa. Edo Abraham, Joost Verbart and Jan Peter van der Hoek look at the opportunities to use digital technologies to improve management.
BibTeX:
@article{abrahamsmartintermittent2020,
  author = {E. Abraham and J.J.G.M. Verbart and van der Hoek, J.P.},
  title = {Smart solutions for intermittent supply systems},
  journal = {The Source -- The magazine of the International Water Association},
  year = {2020},
  volume = {21},
  pages = {24--28},
  note = {Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ -- Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.},
  url = {https://www.thesourcemagazine.org/smart-solutions-for-intermittent-supply-systems/}
}
Steffelbaeur D, Blokker M, Buchberger S, Knobe A and Abraham E (2021), "Dynamic Time Warping Clustering to Discover Socioeconomic Characteristics in Smart Water Meter Data", Journal of Water Resources Planning and Management. Vol. 147(6), pp. 04021026.
Abstract: Socioeconomic characteristics are influencing the temporal and spatial variability of water demand, which are the biggest source of uncertainties within water distribution system modeling. Improving current knowledge of these influences can be utilized to decrease demand uncertainties. This paper aims to link smart water meter data to socioeconomic user characteristics by applying a novel clustering algorithm that uses a dynamic time warping metric on daily demand patterns. The approach is tested on simulated and measured single-family home data sets. It is shown that the novel algorithm performs better compared with commonly used clustering methods, both in finding the right number of clusters as well as assigning patterns correctly. Additionally, the methodology can be used to identify outliers within clusters of demand patterns. Furthermore, this study investigates which socioeconomic characteristics (e.g., employment status and number of residents) are prevalent within single clusters and, consequently, can be linked to the shape of the cluster's barycenters. In future, the proposed methods in combination with stochastic demand models can be used to fill data gaps in hydraulic models.
BibTeX:
@article{DTWSmartMeterData2021,
  author = {David Steffelbaeur and Mirjam Blokker and Steven Buchberger and Arno Knobe and Edo Abraham},
  title = {Dynamic Time Warping Clustering to Discover Socioeconomic Characteristics in Smart Water Meter Data},
  journal = {Journal of Water Resources Planning and Management},
  year = {2021},
  volume = {147},
  number = {6},
  pages = {04021026},
  url = {https://doi.org/10.1061/(ASCE)WR.1943-5452.0001360},
  doi = {10.1061/(ASCE)WR.1943-5452.0001360}
}
Aydin BoranEkin, Essink GualbertHPOude, Delsman J, van de Giesen N and Abraham E (2020), "Nonlinear Model Predictive Control of Salinity and Water Level in Polder Networks", Under Review.
BibTeX:
@article{Aydin2020,
  author = {Aydin, Boran Ekin and Essink, Gualbert H.P.Oude and Joost Delsman and van de Giesen, Nick and Edo Abraham},
  title = {Nonlinear Model Predictive Control of Salinity and Water Level in Polder Networks},
  journal = {Under Review},
  year = {2020},
  note = {Under Review}
}
Burger R and Abraham E (2020), "Maximizing Water--Food--Energy Nexus Synergies at Basin Scale", In Frontiers in Water-Energy-Nexus: Nature-Based Solutions, Advanced Technologies and Best Practices for Environmental Sustainability. , pp. 67-70. Springer.
BibTeX:
@incollection{Burger2020,
  author = {Rogier Burger and Edo Abraham},
  editor = {Naddeo V. and Balakrishnan M. and Choo KH.},
  title = {Maximizing Water--Food--Energy Nexus Synergies at Basin Scale},
  booktitle = {Frontiers in Water-Energy-Nexus: Nature-Based Solutions, Advanced Technologies and Best Practices for Environmental Sustainability},
  publisher = {Springer},
  year = {2020},
  pages = {67--70},
  url = {https://link.springer.com/chapter/10.1007/978-3-030-13068-8_16}
}
Chang N-B, Hossain U, Valencia A, Qiu J, Zheng QP, Gu L, Chen M, Lu J-W, Pires A, Kaandorp C, Abraham E, ten Veldhuis M-C, van de Giesen N, Molle B, Tomas S, Ait-Mouheb N, Dotta D, Declercq R, Perrin M, Conradi L and Molle G (2020), "Integrative technology hubs for urban food-energy-water nexuses and cost-benefit-risk tradeoffs (I): Global trend and technology metrics", Critical Reviews in Environmental Science and Technology. Vol. 0(0), pp. 1-46. Taylor & Francis.
BibTeX:
@article{doi:10.1080/10643389.2020.1759328,
  author = {Ni-Bin Chang and Uzzal Hossain and Andrea Valencia and Jiangxiao Qiu and Qipeng P. Zheng and Lixing Gu and Mengnan Chen and Jia-Wei Lu and Ana Pires and Chelsea Kaandorp and Edo Abraham and Marie-Claire ten Veldhuis and Nick van de Giesen and Bruno Molle and Severine Tomas and Nassim Ait-Mouheb and Deborah Dotta and Rémi Declercq and Martin Perrin and Léon Conradi and Geoffrey Molle},
  title = {Integrative technology hubs for urban food-energy-water nexuses and cost-benefit-risk tradeoffs (I): Global trend and technology metrics},
  journal = {Critical Reviews in Environmental Science and Technology},
  publisher = {Taylor & Francis},
  year = {2020},
  volume = {0},
  number = {0},
  pages = {1-46},
  url = {https://doi.org/10.1080/10643389.2020.1759328},
  doi = {10.1080/10643389.2020.1759328}
}
Chang N-B, Hossain U, Valencia A, Qiu J, Zheng QP, Gu L, Chen M, Lu J-W, Pires A, Kaandorp C, Abraham E, ten Veldhuis M-C, van de Giesen N, Molle B, Tomas S, Ait-Mouheb N, Dotta D, Declercq R, Perrin M, Conradi L and Molle G (2020), "Integrative technology hubs for urban food-energy-water nexuses and cost-benefit-risk tradeoffs (II): Design strategies for urban sustainability", Critical Reviews in Environmental Science and Technology. Vol. 0(0), pp. 1-51. Taylor & Francis.
Abstract: AbstractThe Food-Energy-Water (FEW) nexus for urban sustainability needs to be analyzed via an integrative rather than a sectoral or silo approach, reflecting the ongoing transition from separate infrastructure systems to an integrated social-ecological-infrastructure system. As technology hubs can provide food, energy, water resources via decentralized and/or centralized facilities, there is an acute need to optimize FEW infrastructures by considering cost-benefit-risk tradeoffs with respect to multiple sustainability indicators. This paper identifies, categorizes, and analyzes global trends with respect to contemporary FEW technology metrics that highlights the possible optimal integration of a broad spectrum of technology hubs for possible cost-benefit-risk tradeoffs. The challenges related to multiscale and multiagent modeling processes for the simulation of urban FEW systems were discussed with respect to the aspects of scaling-up, optimization process, and risk assessment. Our review reveals that this field is growing at a rapid pace and the previous selection of analytical methodologies, nexus criteria, and sustainability indicators largely depended on individual FEW nexus conditions disparately, and full-scale cost-benefit-risk tradeoffs were very rare. Therefore, the potential full-scale technology integration in three ongoing cases of urban FEW systems in Miami (the United States), Marseille (France), and Amsterdam (the Netherlands) were demonstrated in due purpose finally.
BibTeX:
@article{doi:10.1080/10643389.2020.1761088,
  author = {Ni-Bin Chang and Uzzal Hossain and Andrea Valencia and Jiangxiao Qiu and Qipeng P. Zheng and Lixing Gu and Mengnan Chen and Jia-Wei Lu and Ana Pires and Chelsea Kaandorp and Edo Abraham and Marie-Claire ten Veldhuis and Nick van de Giesen and Bruno Molle and Severine Tomas and Nassim Ait-Mouheb and Deborah Dotta and Rémi Declercq and Martin Perrin and Léon Conradi and Geoffrey Molle},
  title = {Integrative technology hubs for urban food-energy-water nexuses and cost-benefit-risk tradeoffs (II): Design strategies for urban sustainability},
  journal = {Critical Reviews in Environmental Science and Technology},
  publisher = {Taylor & Francis},
  year = {2020},
  volume = {0},
  number = {0},
  pages = {1-51},
  url = {https://doi.org/10.1080/10643389.2020.1761088},
  doi = {10.1080/10643389.2020.1761088}
}
Farrokhzadeh S, Hashemi Monfared SA, Azizian G, Sardar Shahraki A, Ertsen MW and Abraham E (2020), "Sustainable Water Resources Management in an Arid Area Using a Coupled Optimization-Simulation Modeling", Water. Vol. 12(3), pp. 885. Multidisciplinary Digital Publishing Institute.
BibTeX:
@article{farrokhzadeh2020sustainable,
  author = {Farrokhzadeh, Siamak and Hashemi Monfared, Seyed Arman and Azizian, Gholamreza and Sardar Shahraki, Ali and Ertsen, Maurits W and Abraham, Edo},
  title = {Sustainable Water Resources Management in an Arid Area Using a Coupled Optimization-Simulation Modeling},
  journal = {Water},
  publisher = {Multidisciplinary Digital Publishing Institute},
  year = {2020},
  volume = {12},
  number = {3},
  pages = {885},
  url = {https://www.mdpi.com/2073-4441/12/3/885},
  doi = {10.3390/w12030885}
}
van der Heijden T, Lugt D, van Nooyen R, Palensky P and Abraham E (2020), "Multi-market demand response from open canal systems: an economic MPC approach for pump scheduling"
BibTeX:
@article{heidenAbraham2019,
  author = {T.J.T. van der Heijden and D. Lugt and R.R.P. van Nooyen and P. Palensky and Edo Abraham},
  title = {Multi-market demand response from open canal systems: an economic MPC approach for pump scheduling},
  year = {2020},
  note = {Under Review}
}
Kassing R, de Schutter B and Abraham E (2020), "Optimal Control for Precision Irrigation of a Large-Scale Plantation: Closed-loop analysis with AquaCrop-OS", Water Resources Research, AGU. Vol. e2019WR026989
BibTeX:
@article{Kassing2020wrr,
  author = {Ruud Kassing and Bart de Schutter and Edo Abraham},
  title = {Optimal Control for Precision Irrigation of a Large-Scale Plantation: Closed-loop analysis with AquaCrop-OS},
  journal = {Water Resources Research, AGU},
  year = {2020},
  volume = {e2019WR026989},
  url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019WR026989},
  doi = {10.1029/2019WR026989}
}
Kassing R, de Schutter B and Abraham E (2020), "Optimal seasonal water allocation and model predictive control for precision irrigation", In EGU General Assembly Conference Abstracts., 12, 2020.
BibTeX:
@conference{KassingetalEGU2020,
  author = {Ruud Kassing and Bart de Schutter and Edo Abraham},
  title = {Optimal seasonal water allocation and model predictive control for precision irrigation},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-11270.html}
}
Khan Z, Abraham E and Byers E (2020), "Multi-scale water-energy-land nexus planning to manage socio-economic, climatic, and technological change", In EGU 2020 Scientific Sessions, Convened Session.
Abstract: The world's energy, water, and land systems are in transition and rapidly integrating, driven by forces such as socioeconomic, demographic, climatic, and technological changes as well as policies intended to meet Sustainable Development Goals (SDGs) and other societal priorities. These dynamics weave across spatial scales, connecting global markets and trends to regional and sub-regional economies. At the same time, resources are often locally managed under varying administrative jurisdictions closely tied to inherent characteristics of each commodity such as river basins for water, grid regions for electricity and land-use boundaries for agriculture. Local decisions in turn are critical in deciding the aggregate success and consequences of national and global policies. Thus, there is a growing need to better characterize the energy-water-land nexus to guide robust and consistent decision making across these scales. This session invites abstracts exploring energy-water-land dynamics, trade patterns, policy interventions, infrastructure planning and uncertainty characterization across variable spatial boundaries.

Keys: Integrated Assessment Modelling, Water-Energy-Food Nexus, Infrastructure Decisions, Urbanization, Climate Change</td> </tr>

BibTeX:
@inproceedings{KhanAbrahamByers2020,
  author = {Zarrar Khan and Edo Abraham and Edward Byers},
  title = {Multi-scale water-energy-land nexus planning to manage socio-economic, climatic, and technological change},
  booktitle = {EGU 2020 Scientific Sessions, Convened Session},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/session/35928}
}
Paez. DA, Filion Y, ..., Deuerlein J, Gilbert D, Abraham E, Piller O, ..., Savic D and Walski T (2020), "The Battle of Post-Disaster Response and Restoration (BPDRR)", Journal of Water Resources Planning and Management.
BibTeX:
@article{Paezeatal2020,
  author = {Diego Alejandro Paez.; Yves Filion; ... ;Jochen Deuerlein; Denis Gilbert; Edo Abraham ; Olivier Piller; ... ; Dragan Savic; Thomas Walski},
  title = {The Battle of Post-Disaster Response and Restoration (BPDRR)},
  journal = {Journal of Water Resources Planning and Management},
  year = {2020},
  note = {Accepted}
}
Sakomoto T, Lutaaya M and Abraham E (2020), "Managing Water Quality in Intermittent Supply Systems: The Case of Mukono Town, Uganda", Water. Vol. 12(3), pp. 806. Multidisciplinary Digital Publishing Institute.
BibTeX:
@article{sakomoto2020managing,
  author = {Sakomoto, Takuya and Lutaaya, Mahmood and Abraham, Edo},
  title = {Managing Water Quality in Intermittent Supply Systems: The Case of Mukono Town, Uganda},
  journal = {Water},
  publisher = {Multidisciplinary Digital Publishing Institute},
  year = {2020},
  volume = {12},
  number = {3},
  pages = {806},
  doi = {10.3390/w12030806}
}
van Steen J, Steffelbauer D, Balkema S, van der Hoek JP and Abraham E (2020), "Fantastic leaks and where to find them", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{Steen2020,
  author = {Jip van Steen and David Steffelbauer and Sijbrand Balkema and Jan Peter van der Hoek and Edo Abraham},
  title = {Fantastic leaks and where to find them},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-8305.html}
}
Steffelbauer D, Blokker M, Knobbe A and Abraham E (2020), "DASH of Water -- water distribution system modelling in the age of smart water meters", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{SteffelbaueretalEGU2020,
  author = {David Steffelbauer and Mirjam Blokker and Arno Knobbe and Edo Abraham},
  title = {DASH of Water -- water distribution system modelling in the age of smart water meters},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2020},
  url = {https://meetingorganizer.copernicus.org/EGU2020/EGU2020-13439.html}
}
Aydin B, Tian X, Delsman J, Oude Essink GualbertHP, Rutten M and Abraham E (2019), "Optimal salinity and water level control of water courses using Model Predictive Control", Environmental Modelling & Software., 2, 2019. Vol. 112, pp. 36-45. Elsevier.
Abstract: Worldwide, delta areas are under stress due to climate change. With rising sealevels and decreasing freshwater availability, surface water salinization due togroundwater exfiltration is expected to increase in these low-lying areas. Tocounteract surface water salinization, freshwater diverted from rivers is used to flush agricultural ditches. In this paper, we demonstrate a Model Predictive Control (MPC) scheme to control salinity and water levels in a water course while minimizing freshwater usage. A state space description of the discretized De Saint Venant and advection-dispersion equations for water and salt transport, respectively, is used as the internal model of the controller. The developed MPC scheme is tested using groundwater exfiltration data from two different representative Dutch polders. The tests demonstrate that water levels and salinity concentrations can successfully be controlled within set limits while minimizing the freshwater used.
BibTeX:
@article{0a25d27b09884d21830f6b76e07277b1,
  author = {Boran Aydin and Xin Tian and Joost Delsman and Oude Essink, Gualbert H.P. and Martine Rutten and Edo Abraham},
  title = {Optimal salinity and water level control of water courses using Model Predictive Control},
  journal = {Environmental Modelling & Software},
  publisher = {Elsevier},
  year = {2019},
  volume = {112},
  pages = {36--45},
  doi = {10.1016/j.envsoft.2018.11.010}
}
Odriozola M, Abraham E, Lousada-Ferreira M, Spanjers H and van Lier JulesB (2019), "Identification of the methanogenesis inhibition mechanism using comparative analysis of mathematical models", Frontiers in Bioengineering and Biotechnology. Vol. 7
Abstract: The application of cationic polymers to enhance membrane fluxes in anaerobic membrane bioreactors has been proposed by several authors. However, literature shows contradictory results on the influence of those chemicals on the biological activity. In this research, we studied the effect of a cationic polymer on the production of methane from acetate by acetoclastic methanogens. We assessed the effect of polymer concentration on the accumulated methane production (AMP) and the specific methanogenic activity (SMA) in batch tests. Batch tests results showed lower SMA values at higher concentrations of polymer and no effect on the final AMP. Different inhibition models were calibrated and compared to find the best fit and to hypothesize the prevailing inhibition mechanisms. The assessed inhibition models were: competitive (M1a), non-competitive (M2a), un-competitive (M3a), biocide-linear (M4a), and biocide-exponential (M5a). The parameters in the model related to the polymer characteristics were adjusted to fit the experimental data. M2a and M3a were the only models that fitted both experimental SMA and AMP. Although M1a and M4a adequately fitted the experimental SMA, M1a simulations slightly deviated from the experimental AMP, and M4a considerably underpredicted the AMP at concentrations of polymer above 0.23 gCOD L-1. M5a did not adequately fit either experimental SMA and AMP results. We compared models a (M1a to M5a), which consider the inhibition by the concentration of polymer in the bulk liquid, with models b (M1b to M5b) considering the inhibition being caused by the total concentration of polymer in the reactor. Results showed that the difference between a and b models' simulations were negligible for all kinetic models considered (M1, M2, M3, M4, and M5). Therefore, the models that better predicted the experimental data were the non-competitive (M2a and M2b) and un-competitive (M3a and M3b) inhibition models, which are biostatic inhibition models. Consequently, the decreased methanogenic activity caused by polymer additions is presumably a reversible process.
BibTeX:
@article{6ee0fab4e8ec493aa97749f9bc266443,
  author = {Magela Odriozola and Edo Abraham and Maria Lousada-Ferreira and Henri Spanjers and van Lier, Jules B.},
  title = {Identification of the methanogenesis inhibition mechanism using comparative analysis of mathematical models},
  journal = {Frontiers in Bioengineering and Biotechnology},
  year = {2019},
  volume = {7},
  doi = {10.3389/fbioe.2019.00093}
}
Abraham E, Pecci F and Stoianov I (2019), "A multi-objective framework for managing self-cleaning capacity and leakage: application to a real network model,", In Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI). Exeter, UK, Septermber, 2019.
BibTeX:
@inproceedings{Abraham2019,
  author = {Edo Abraham and Filippo Pecci and Ivan Stoianov},
  title = {A multi-objective framework for managing self-cleaning capacity and leakage: application to a real network model,},
  booktitle = {Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  year = {2019}
}
Abraham E, Khan Z and Pande S (2019), "Integrated Assessment of water -- food -- energy nexuses", In EGU 2019 Scientific Sessions, Convened Session.
Abstract: Developing a sustainable future requires the optimal integration and synergising of energy, agriculture and water sectors. As developing economies grow with rapid urbanisation, access to modern energy and water services should grow sustainably. Quantitative tools for planning and assessing national and basin scale infrastructure planning are essential for this. Issues of access and the challenges of biophysical and socioeconomic dynamics involved therein are often poorly reflected in plans. Integrated Assessment Modeling (IAMs) can allow for studying interactions between the economy, water use, energy use, and the environment. IAMs enable investigating long-term transition pathways in the context of climate change and shared socioeconomic pathways.

Most IAMs, however, are mainly global and at best regional, and as such do not adequately represent socio-hydrological mechanisms at smaller scale. On the other hand, basin scale studies often poorly reflect national and regional drivers. One of the main bottlenecks is the intrinsic difficulty in bridging the high-level system-oriented approach of IAMs with the strong dependency of the efficacy of plans on local socioeconomic and hydrological drivers. We invite contributions connecting fundamental and applied research for policy making, concepts and case studies to better understand how IAMs can be better utilised in infrastructure decisions at regional, country or basin scales.

Keys: Integrated Assessment Modelling, Water-Energy-Food Nexus, Infrastructure Decisions, Urbanization, Climate Change</td> </tr>

BibTeX:
@inproceedings{abrahamKhanEGU2019,
  author = {Edo Abraham and Zarrar Khan and Saket Pande},
  title = {Integrated Assessment of water -- food -- energy nexuses},
  booktitle = {EGU 2019 Scientific Sessions, Convened Session},
  year = {2019},
  note = {Convened Session},
  url = {https://meetingorganizer.copernicus.org/EGU2019/session/30354}
}
Aydin BE, Hagedooren H and Abraham E (2019), "A Heuristic Approach to Effective Sensor Placement for Salinity State Reconstruction in a Low-Lying Polder", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{Aydin2019,
  author = {Aydin, Boran Ekin and Hagedooren, Hugo and Abraham, Edo},
  title = {A Heuristic Approach to Effective Sensor Placement for Salinity State Reconstruction in a Low-Lying Polder},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2019}
}
Aydin BoranEkin, Hagedooren H, Rutten MartineM, Delsman J, Essink GualbertHPOude, van de Giesen N and Abraham E (2019), "A greedy algorithm for optimal sensor placement to estimate salinity in polder networks", Water. Vol. 11(5) Multidisciplinary Digital Publishing Institute (MDPI).
BibTeX:
@article{Aydin2019a,
  author = {Aydin, Boran Ekin and Hugo Hagedooren and Rutten, Martine M. and Joost Delsman and Essink, Gualbert H.P.Oude and van de Giesen, Nick and Edo Abraham},
  title = {A greedy algorithm for optimal sensor placement to estimate salinity in polder networks},
  journal = {Water},
  publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},
  year = {2019},
  volume = {11},
  number = {5},
  doi = {10.3390/w11051101}
}
Pecci F, Abraham E and Stoianov I (2019), "Model Reduction and Outer Approximation for Optimizing the Placement of Control Valves in Complex Water Networks", Journal of Water Resources Planning and Management. Vol. 145(5) American Society of Civil Engineers (ASCE).
Abstract: The optimal placement and operation of pressure control valves in water distribution networks is a challenging engineering problem. When formulated in a mathematical optimization framework, this problem results in a nonconvex mixed integer nonlinear program (MINLP), which has combinatorial computational complexity. As a result, the considered MINLP becomes particularly difficult to solve for large-scale looped operational networks. We extend and combine network model reduction techniques with the proposed optimization framework in order to lower the computational burden and enable the optimal placement and operation of control valves in these complex water distribution networks. An outer approximation algorithm is used to solve the considered MINLPs on reduced hydraulic models. We demonstrate that the restriction of the considered optimization problem on a reduced hydraulic model is not equivalent to solving the original larger MINLP, and its solution is therefore sub-optimal. Consequently, we investigate the trade-off between reducing computational complexity and the potential sub-optimality of the solutions that can be controlled with a parameter of the model reduction routine. The efficacy of the proposed method is evaluated using two large scale water distribution network models.
BibTeX:
@article{db80276b5de9451ba60787d414f19d66,
  author = {Filippo Pecci and Edo Abraham and Ivan Stoianov},
  title = {Model Reduction and Outer Approximation for Optimizing the Placement of Control Valves in Complex Water Networks},
  journal = {Journal of Water Resources Planning and Management},
  publisher = {American Society of Civil Engineers (ASCE)},
  year = {2019},
  volume = {145},
  number = {5},
  note = {Accepted Author Manuscript},
  doi = {10.1061/(ASCE)WR.1943-5452.0001055}
}
Farrokhzadeh S, Abraham E and Ertsen M (2019), "A Multi-Objective Approach for the Analysis of a Water-Food-Ecosystems Nexus at Basin Scale", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{Farrokhzadeh2019,
  author = {Farrokhzadeh, Siamak and Abraham, Edo and Ertsen, Maurits},
  title = {A Multi-Objective Approach for the Analysis of a Water-Food-Ecosystems Nexus at Basin Scale},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2019},
  url = {https://www.egu2019.eu/}
}
van der Heijden T, Lugt D, van Nooyen R, Palensky P and Abraham E (2019), "Demand response from pumping infrastructure in the Dutch Delta", In International Conference on Applied Energy., August, 2019.
BibTeX:
@inproceedings{Heijden2019a,
  author = {T.J.T. van der Heijden and D. Lugt and R.R.P. van Nooyen and P. Palensky and E. Abraham},
  title = {Demand response from pumping infrastructure in the Dutch Delta},
  booktitle = {International Conference on Applied Energy},
  year = {2019}
}
van der Heijden T, Klopstra D and Abraham E (2019), "Optimising water system operations, blue storage and the green energy transition", TU Delft DeltaLinks.
Kaandorp C, van de Giesen N and Abraham E (2019), "Water security: threats and opportunities of a heat transition", LIRS symposium 2019. Heerlen, Netherlands
BibTeX:
@conference{Kaandorp2019,
  author = {Kaandorp, Chelsea and van de Giesen, Nick and Edo Abraham},
  title = {Water security: threats and opportunities of a heat transition},
  journal = {LIRS symposium 2019},
  year = {2019}
}
Kaandorp C, van de Giesen N and Abraham E (2019), "Spatio-temporal modelling of urban water flows related to the integration of energy technologies in Amsterdam, the Netherlands.", EGU General Assembly 2019., In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{Kaandorp2019a,
  author = {Kaandorp, Chelsea and van de Giesen, Nick and Edo Abraham},
  title = {Spatio-temporal modelling of urban water flows related to the integration of energy technologies in Amsterdam, the Netherlands.},
  booktitle = {EGU General Assembly Conference Abstracts},
  journal = {EGU General Assembly 2019},
  year = {2019}
}
LageLand G, Abraham E and Esfahani P (2019), "Active Leak Localisation in a Water Distribution Network through pressure driven models and bayesian classification", IEEE Transactions on Control Systems Technology. Vol. Working Paper
BibTeX:
@article{LageLand2019,
  author = {Gert LageLand and Edo Abraham and PeymanMohajerin Esfahani},
  title = {Active Leak Localisation in a Water Distribution Network through pressure driven models and bayesian classification},
  journal = {IEEE Transactions on Control Systems Technology},
  year = {2019},
  volume = {Working Paper}
}
Pecci F, Abraham E and Stoianov I (2019), "Tight convex relaxations for optimal design and control problems in water supply networks", In Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI). Exeter, UK, Septermber, 2019.
BibTeX:
@inproceedings{Pecci2019,
  author = {Filippo Pecci and Edo Abraham and Ivan Stoianov},
  title = {Tight convex relaxations for optimal design and control problems in water supply networks},
  booktitle = {Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  year = {2019}
}
Pecci F, Abraham E and Stoianov I (2019), "Global optimality bounds for the placement of control valves in water supply networks", Optimization and Engineering. Vol. 20(2), pp. 457-495. Springer.
Abstract: In this article, a comprehensive review of existing methods is presented and computationally efficient sparse null space algorithms are proposed for the hydraulic analysis of water distribution networks. The linear systems at each iteration of the Newton method for nonlinear equations are solved using a null space algorithm. The sparsity structure of these linear equations, which arises from the sparse network connectivity, is exploited to reduce computations. A significant fraction of the total flops in the Newton method are spent in computing pipe head losses and matrix-matrix multiplications involving flows. Because most flows converge after a few iterations, a novel partial update of head losses and matrix products is used to further reduce computational complexity. Convergence analyses are also presented for the partialupdate formulas. A new heuristic for reducing the number of pressure head computations of a null space method is proposed. These savings enable fast near-real-time control of large-scale water networks. It is often observed that the linear equations that arise in solving the hydraulic equations become ill-conditioned due to hydraulic solutions with very small and zero flows. The condition numbers of the Newton equations are bounded using a regularization technique with insignificant computational overheads. The convergence properties of all proposed algorithms are analyzed by posing them as an inexact-Newton method. Small-scale to large-scale models of operational water networks are used to evaluate the proposed algorithms.
BibTeX:
@article{pecci2019global,
  author = {Pecci, Filippo and Abraham, Edo and Stoianov, Ivan},
  title = {Global optimality bounds for the placement of control valves in water supply networks},
  journal = {Optimization and Engineering},
  publisher = {Springer},
  year = {2019},
  volume = {20},
  number = {2},
  pages = {457--495},
  doi = {10.1007/s11081-018-9412-7}
}
Sakomoto T, Lutaaya M and Abraham E (2019), "Managing water quality in intermittent supply systems: the case of Mukono Town, Uganda", In Proceedings of IWA-ASPIRE Conference., November, 2019.
BibTeX:
@inproceedings{Sakomoto2019,
  author = {Takuya Sakomoto and Mahmood Lutaaya and Edo Abraham},
  title = {Managing water quality in intermittent supply systems: the case of Mukono Town, Uganda},
  booktitle = {Proceedings of IWA-ASPIRE Conference},
  year = {2019}
}
Steffelbauer D, Blokker M, Knobbe A and Abraham E (2019), "Stochastic drinking water demand model parameterisation with smart meter data and data science algorithms", In Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI). Exeter, UK, Septermber, 2019.
BibTeX:
@inproceedings{Steffelbauer2019,
  author = {David Steffelbauer and Mirjam Blokker and Arno Knobbe and Edo Abraham},
  title = {Stochastic drinking water demand model parameterisation with smart meter data and data science algorithms},
  booktitle = {Proc. 17th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  year = {2019}
}
van der Heijden T, Lugt D, van Nooyen R, Palensky P and Abraham E (2019), "Energy markets and sustainable water management: pumping and demand response in the Dutch delta.", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{T2019,
  author = {T.J.T. van der Heijden and D. Lugt and R.R.P. van Nooyen and P. Palensky and E. Abraham},
  title = {Energy markets and sustainable water management: pumping and demand response in the Dutch delta.},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2019}
}
Authors: Yacob Mulugetta (UCL), Pablo E. Carvajal (IRENA), James Haselip (UNEP DTU), Thomas Spencer (TERI) and Contributing authors: Edo Abraham (TU Delft), Simon Batchelor (Gamos Ltd), Brigitte Knopf (Mercator) (2019), "Bridging the Gap: Global Transformation of the Energy System", In Bridging the Gap -- Enhancing Mitigation Ambition and Action at G20 Level and Globally. United Nations Environment Programme.
BibTeX:
@techreport{UCL2019,
  author = {Authors: Yacob Mulugetta (UCL), Pablo E. Carvajal (IRENA), James Haselip (UNEP DTU), Thomas Spencer (TERI) and Contributing authors: Edo Abraham (TU Delft), Simon Batchelor (Gamos Ltd), Brigitte Knopf (Mercator) },
  editor = {Höhne, N and Fransen, T and Hans, F and Bhardwaj, A and Blanco, G and den Elzen, M and Hagemann, M and Henderson, C and Keesler, D and Kejun, J and others},
  title = {Bridging the Gap: Global Transformation of the Energy System},
  booktitle = {Bridging the Gap -- Enhancing Mitigation Ambition and Action at G20 Level and Globally},
  publisher = {United Nations Environment Programme},
  year = {2019},
  url = {https://wedocs.unep.org/bitstream/handle/20.500.11822/30797/EGR2019.pdf?sequence=1&isAllowed=y}
}
Abraham E, Blokker E and Stoianov I (2018), "Decreasing the Discolouration Risk of Drinking Water Distribution Systems through Optimised Topological Changes and Optimal Flow Velocity Control", Journal of Water Resources Planning and Management., 2, 2018. Vol. 144(10) American Society of Civil Engineers (ASCE).
Abstract: In this paper, a new mathematical framework is proposed for maximizing the self-cleaning capacity (SCC) of drinking water distribution systems by controlling the diurnal peak flow velocities in the pipes under normal operation. This is achieved through an optimal change of the network connectivity (topology). This paper proposes an efficient algorithm for the network analysis of valve closures, which allows enforcing favorable changes in the flow velocities for maximizing the SCC by determining an optimal set of links to isolate in the forming of a more branched network, while concurrently satisfying the hydraulic and regulatory pressure constraints at the demand nodes. Multiple stochastic demands from an end-use demand model are generated to test the robustness in the improved SCC for the modified network connectivity under changing demand. An operational network model is used to demonstrate the efficacy of the proposed approach.
BibTeX:
@article{40f6e7dfec4240a980dccc4735caaaaa,
  author = {Edo Abraham and EJM Blokker and Ivan Stoianov},
  title = {Decreasing the Discolouration Risk of Drinking Water Distribution Systems through Optimised Topological Changes and Optimal Flow Velocity Control},
  journal = {Journal of Water Resources Planning and Management},
  publisher = {American Society of Civil Engineers (ASCE)},
  year = {2018},
  volume = {144},
  number = {10},
  doi = {10.1061/(ASCE)WR.1943-5452.0000878}
}
Aydin B, Rutten M and Abraham E (2018), "Model Predictive Control of Salinity and Water Level in a Hypothetical Polder Ditch: Is it Possible to Use the Discretized Linearized Physical Equations for Optimization", In EPiC Series in Engineering., 9, 2018. Vol. 3, pp. 117-122. EasyChair.
Abstract: Surface water salinization in deltaic areas due to saline groundwater exfiltration is an important issue. Fresh water diverted from the rivers is used for flushing the canals and the ditches in coastal areas to remove the low quality saline surface water mixed with saline groundwater. Worldwide, deltaic areas are under stress due to climate change, sea level increase and decrease in fresh water availability. The current fresh water management strategies in polders to overcome the salinization problem solely depends on uncontrolled freshwater use. However, this operation will not be effective during a scarce freshwater availability scenario and has to be revised for efficient management possibilities. With the advances in real time measurement of salinity and water level measurements, using a Model Predictive Control (MPC) scheme for the operation of a polder system is gaining popularity. MPC is a powerful control tool that can handle multiple objectives, consider the constraints and the uncertainties of the system. However, a MPC scheme requires a simple and reliable internal model that will be used to calculate the optimum control actions. The internal model should be robust, should reflect the system behaviour with enough detail and should not be computationally costly. In this paper, a MPC scheme is proposed using the discretized linearized De Saint Venant (SV) and Advection-Diffusion (AD) equations as the internal model of the controller. The proposed scheme will be able to control salinity and water level at any discretization point by manipulating the flushing and outflow discharges. This is an ongoing research with tests continuing on a realistic test case.
BibTeX:
@inproceedings{Aydin2018,
  author = {Boran Aydin and Martine Rutten and Edo Abraham},
  editor = {La Loggia,  Goffredo and Gabriele Freni and Valeria Puleo and De Marchis, Mauro},
  title = {Model Predictive Control of Salinity and Water Level in a Hypothetical Polder Ditch: Is it Possible to Use the Discretized Linearized Physical Equations for Optimization},
  booktitle = {EPiC Series in Engineering},
  publisher = {EasyChair},
  year = {2018},
  volume = {3},
  pages = {117--122},
  doi = {10.29007/rpmp}
}
Deuerlein J, Gilbert D, Abraham E and others (2018), "A Greedy Scheduling of Post-Disaster Response and Restoration using Pressure-Driven Models and Graph Segment Analysis", In WDSA/CCWI Joint Conference Proceedings. Kingston, Ontario, Canada, July, 2018. Vol. 1
BibTeX:
@inproceedings{Deuerlein2018,
  author = {Deuerlein, J and Gilbert, D and Abraham, E and others},
  title = {A Greedy Scheduling of Post-Disaster Response and Restoration using Pressure-Driven Models and Graph Segment Analysis},
  booktitle = {WDSA/CCWI Joint Conference Proceedings},
  year = {2018},
  volume = {1},
  url = {https://ojs.library.queensu.ca/index.php/wdsa-ccw/article/view/12180}
}
Stoianov I, Abraham E and Pecci F (2018), "Management of liquid conduit systems", #December#, 2018. Google Patents.
BibTeX:
@patent{Stoianov2018,
  author = {Stoianov, Ivan and Abraham, Edo and Pecci, Filippo},
  title = {Management of liquid conduit systems},
  publisher = {Google Patents},
  year = {2018},
  note = {US Patent App. 16/061,276}
}
Gilbert D, Abraham E, Montalvo I and Piller O (2017), "Iterative Multistage Method for a Large Water Network Sectorization into DMAs under Multiple Design Objectives", Journal of Water Resources Planning and Management. Vol. 143(11) American Society of Civil Engineers (ASCE).
Abstract: This paper considers the sectorization of a large water distribution network into district metered areas (DMAs) and simultaneously optimizes rehabilitation of the network with new pipes, control valves, and storage tanks. Since the available water resources are much smaller in the dry season, both the design and operational settings are optimized to satisfy water demand, water quality and pressure constraints, and efficiency indices under stringent conditions. Because of the heterogeneity of the multiple decision variables and the complicated way they interact through the multiple objectives (some complimentary and some conflicting), it is not possible to fully automize the simultaneous sectorization, rehabilitation and operational optimization. Therefore, we employ a multi-stage approach where engineering judgement and network graph simplification and visualization tools are employed to find a good feasible solution that is used as a first guess for further optimization of sectors and operational settings, to achieve feasible solutions with better cost of implementation, demand similarity among DMAs and better pressure uniformity in operations. A multi-objective Agent Swarm Optimization framework is used to iteratively change the sectors at the boundaries. For the final configuration, sequential linear programming is used to find optimal valve and pump settings.
BibTeX:
@article{223101b1f1a244a6861d47c119936a4e,
  author = {Denis Gilbert and E. Abraham and Idel Montalvo and Olivier Piller},
  title = {Iterative Multistage Method for a Large Water Network Sectorization into DMAs under Multiple Design Objectives},
  journal = {Journal of Water Resources Planning and Management},
  publisher = {American Society of Civil Engineers (ASCE)},
  year = {2017},
  volume = {143},
  number = {11},
  doi = {10.1061/(ASCE)WR.1943-5452.0000835}
}
Pecci F, Abraham E and Stoianov I (2017), "Penalty and relaxation methods for the optimal placement and operation of control valves in water supply networks", Computational Optimization and Applications., 5, 2017. Vol. 67(1), pp. 201-223. Springer Netherlands.
Abstract: In this paper, we investigate the application of penalty and relaxation methods to the problem of optimal placement and operation of control valves in water supply networks, where the minimization of average zone pressure is the objective. The optimization framework considers both the location and settings of control valves as decision variables. Hydraulic conservation laws are enforced as nonlinear constraints and binary variables are used to model the placement of control valves, resulting in a mixed-integer nonlinear program. We review and discuss theoretical and algorithmic properties of two solution approaches. These include penalty and relaxation methods that solve a sequence of nonlinear programs whose stationary points converge to a stationary point of the original mixed-integer program. We implement and evaluate the algorithms using a benchmarking water supply network. In addition, the performance of different update strategies for the penalty and relaxation parameters are investigated under multiple initial conditions. Practical recommendations on the numerical implementation are provided.
BibTeX:
@article{6b59e43d71c64deaa0aee9fdf1cd487a,
  author = {Filippo Pecci and Edo Abraham and Ivan Stoianov},
  title = {Penalty and relaxation methods for the optimal placement and operation of control valves in water supply networks},
  journal = {Computational Optimization and Applications},
  publisher = {Springer Netherlands},
  year = {2017},
  volume = {67},
  number = {1},
  pages = {201--223},
  doi = {10.1007/s10589-016-9888-z}
}
Abraham E (2017), "Sustainable Management of Water Distribution Systems Using Model-based Optimization Tools and Renewable Energy", In JDS International Seminar. Tsukuba University, January, 2017.
BibTeX:
@conference{Abraham2017,
  author = {Edo Abraham},
  title = {Sustainable Management of Water Distribution Systems Using Model-based Optimization Tools and Renewable Energy},
  booktitle = {JDS International Seminar},
  year = {2017}
}
Aydin B, Rutten M, Abraham E, Oude Essink G and Delsman J (2017), "Model Predictive Control of Salinity in a Polder Ditch under High Saline Groundwater Exfiltration Conditions: A Test Case", In 20h World Congress of the International Federation of Automatic Control (IFAC), 2017. Netherlands Vol. 50(1), pp. 3160-3164. Elsevier.
Abstract: Surface water salinization in deltaic areas due to saline groundwater exfiltration is an important issue. Saline surface water will not be appropriate for drinking water production, agricultural and industrial use, and therefore, freshwater diverted from rivers is used for flushing the canals and ditches in coastal areas. The effects of climate change, sea level increase and fresh water availability increases the stress on deltaic areas resulting in questioning current fresh water management strategies. In this paper, a Model Predictive Control (MPC) scheme is developed and tested for combined salinity and water level control of a polder ditch. The MPC scheme is coupled with Rapid Saline Groundwater Exfiltration Model (RSGEM) developed for fast calculation of exfiltration flux and concentration in a low-lying polder. For the test case presented in this paper, real data from Lissertocht catchment in Netherlands is used for RSGEM to see the performance of the MPC scheme for a real scenario. With open space for further research, results presented on this paper show that MPC of salinity in polders is capable of dealing with saline groundwater exfiltration modeled by RSGEM.
BibTeX:
@inproceedings{Aydin2017,
  author = {Boran Aydin and Martine Rutten and Edo Abraham and Oude Essink, GHP and Joost Delsman},
  editor = {D. Dochain and D. Henrion and D. Peaucelle},
  title = {Model Predictive Control of Salinity in a Polder Ditch under High Saline Groundwater Exfiltration Conditions: A Test Case},
  booktitle = {20h World Congress of the International Federation of Automatic Control (IFAC), 2017},
  publisher = {Elsevier},
  year = {2017},
  volume = {50},
  number = {1},
  pages = {3160--3164},
  edition = {1},
  url = {https://doi.org/10.1016/j.ifacol.2017.08.335},
  doi = {10.1016/j.ifacol.2017.08.335}
}
Pecci F, Abraham E and Stoianov I (2017), "Quadratic head loss approximations for optimisation problems in water supply networks", Journal of Hydroinformatics. Vol. 19(4), pp. 493-506. IWA Publishing.
Abstract: This paper presents a novel analysis of the accuracy of quadratic approximations for the Hazen--Williams (HW) head loss formula, which enables the control of constraint violations in optimisation problems for water supply networks. The two smooth polynomial approximations considered here minimise the absolute and relative errors, respectively, from the original non-smooth HW head loss function over a range of flows. Since quadratic approximations are used to formulate head loss constraints for different optimisation problems, we are interested in quantifying and controlling their absolute errors, which affect the degree of constraint violations of feasible candidate solutions. We derive new exact analytical formulae for the absolute errors as a function of the approximation domain, pipe roughness and relative error tolerance. We investigate the efficacy of the proposed quadratic approximations in mathematical optimisation problems for advanced pressure control in an operational water supply network. We propose a strategy on how to choose the approximation domain for each pipe such that the optimisation results are sufficiently close to the exact hydraulically feasible solution space. By using simulations with multiple parameters, the approximation errors are shown to be consistent with our analytical predictions.
BibTeX:
@article{d2d1cdecc94241ddb088e46421a8e075,
  author = {Filippo Pecci and Edo Abraham and Stoianov I},
  title = {Quadratic head loss approximations for optimisation problems in water supply networks},
  journal = {Journal of Hydroinformatics},
  publisher = {IWA Publishing},
  year = {2017},
  volume = {19},
  number = {4},
  pages = {493--506},
  doi = {10.2166/hydro.2017.080}
}
Menke R, Kadehjian K, Abraham E and Stoianov I (2017), "Investigating trade-offs between the operating cost and green house gas emissions from water distribution systems", Sustainable Energy Technologies and Assessments. Vol. 21, pp. 13-22. Elsevier.
Abstract: For electricity grids with an increasing share of intermittent renewables, the power generation mix can have significant daily variations. This leads to time-dependent emission intensities and volatile electricity prices in the day-ahead and spot market tariffs that can be better utilised by energy intensive industries such as water supply utilities. A multi-objective optimisation method for scheduling the operation of pumps is investigated in this paper for the reduction of both electricity costs and greenhouse gas emissions for a benchmark water distribution system. A set of energy supply scenarios has been formulated based on future projections from National Grid plc (UK) in order to investigate the range of cost savings and emission reductions that could be possibly achieved. Pump scheduling options with fixed time-of-use and day ahead market tariffs are analysed in order to compare potential reduction tradeoffs for both electricity costs and greenhouse gas emissions using Pareto optimality. The presented analysis concludes that the explicit inclusion of greenhouse gas emission reductions in optimising the scheduling of pumps operation in water distribution systems could provide considerable benefits; however, more compelling fiscal and regulatory incentives are needed.
BibTeX:
@article{d663c13fccd649b39445ec06c8052618,
  author = {Ruben Menke and K Kadehjian and Edo Abraham and Ivan Stoianov},
  title = {Investigating trade-offs between the operating cost and green house gas emissions from water distribution systems},
  journal = {Sustainable Energy Technologies and Assessments},
  publisher = {Elsevier},
  year = {2017},
  volume = {21},
  pages = {13--22},
  doi = {10.1016/j.seta.2017.03.002}
}
Pecci F, Abraham E and Stoianov I (2017), "Scalable Pareto set generation for multiobjective co-design problems in water distribution networks: a continuous relaxation approach", Structural and Multidisciplinary Optimization., 3, 2017. Vol. 55(3), pp. 857-869. Springer Verlag.
Abstract: In this paper, we study the multiobjective co-design problem of optimal valve placement and operation in water distribution networks, addressing the minimization of average pressure and pressure variability indices. The presented formulation considers nodal pressures, pipe flows and valve locations as decision variables, where binary variables are used to model the placement of control valves. The resulting optimization problem is a multiobjective mixed integer nonlinear optimization problem. As conflicting objectives, average zone pressure and pressure variability can not be simultaneously optimized. Therefore, we present the concept of Pareto optima sets to investigate the trade-offs between the two conflicting objectives and evaluate the best compromise. We focus on the approximation of the Pareto front, the image of the Pareto optima set through the objective functions, using the weighted sum, normal boundary intersection and normalized normal constraint scalarization techniques. Each of the three methods relies on the solution of a series of single-objective optimization problems, which are mixed integer nonlinear programs (MINLPs) in our case. For the solution of each single-objective optimization problem, we implement a relaxation method that solves a sequence of nonlinear programs (NLPs) whose stationary points converge to a stationary point of the original MINLP. The relaxed NLPs have a sparse structure that come from the sparse water network graph constraints. In solving the large number of relaxed NLPs, sparsity is exploited by tailored techniques to improve the performance of the algorithms further and render the approaches scalable for large scale networks. The features of the proposed scalarization approaches are evaluated using a published benchmarking network model.
BibTeX:
@article{e534a5ac07da4755ac270c91f3083f97,
  author = {Filippo Pecci and Edo Abraham and Ivan Stoianov},
  title = {Scalable Pareto set generation for multiobjective co-design problems in water distribution networks: a continuous relaxation approach},
  journal = {Structural and Multidisciplinary Optimization},
  publisher = {Springer Verlag},
  year = {2017},
  volume = {55},
  number = {3},
  pages = {857--869},
  doi = {10.1007/s00158-016-1537-8}
}
Ekin Aydin B, Rutten M, Oude Essink GH, Delsman J and Abraham E (2017), "Smart Salinity Management in Low-lying Deltaic Areas: A Model Predictive Control Scheme Applied to a Test Canal", In EGU General Assembly Conference Abstracts.
BibTeX:
@conference{EkinAydin2017,
  author = {Ekin Aydin, Boran and Rutten, Martine and Oude Essink, Gualbert HP and Delsman, Joost and Abraham, Edo},
  title = {Smart Salinity Management in Low-lying Deltaic Areas: A Model Predictive Control Scheme Applied to a Test Canal},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = {2017},
  url = {https://meetingorganizer.copernicus.org/EGU2017/EGU2017-14448.pdf}
}
Pecci F, Abraham E and Stoianov I (2017), "Outer approximation methods for the solution of co-design optimisation problems in water distribution networks", In IFAC-PapersOnLine. Netherlands Vol. 50(1), pp. 5373-5379. Elsevier.
Abstract: In the present manuscript, we red investigate and demonstrate the use of outer approximation methods for simultaneously optimising the placement and operation of control valves in water distribution networks. The problem definition results in a mixed-integer nonlinear program with nonconvex constraints. We simplify the formulation, compared to previous literature, in order to reduce the degree of nonlinearity in the constraints and decrease the total problem size. We then red formulate the application of outer approximation based methods for the generation of good quality local optimal solutions for red the considered co-design problem. Finally, we present the results of applying the developed techniques to two case studies, and also comparing the performances of the outer approximation approaches with those of other local mixed integer nonlinear programming solution methods.
BibTeX:
@inproceedings{Pecci2017,
  author = {Filippo Pecci and Edo Abraham and Ivan Stoianov},
  editor = {D. Peaucelle and D. Dochain and D. Henrion},
  title = {Outer approximation methods for the solution of co-design optimisation problems in water distribution networks},
  booktitle = {IFAC-PapersOnLine},
  publisher = {Elsevier},
  year = {2017},
  volume = {50},
  number = {1},
  pages = {5373--5379},
  edition = {1},
  doi = {10.1016/j.ifacol.2017.08.1069}
}
Abraham E and Stoianov I (2016), "Constraint preconditioned inexact Newton method for hydraulic simulation of large-scale water distribution networks", IEEE Transactions on Control of Network Systems. , pp. 610-619. IEEE Control Systems Society.
Abstract: Many sequential mathematical optimization methods and simulation-based heuristics for optimal control and design of water distribution networks rely on a large number of hydraulic simulations. In this paper, we propose an efficient inexact subspace Newton method for hydraulic analysis of water distribution networks. By using sparse and well-conditioned fundamental null space bases, we solve the nonlinear system of hydraulic equations in a lower-dimensional kernel space of the network incidence matrix. In the inexact framework, the Newton steps are determined by solving the Newton equations only approximately using an iterative linear solver. Since large water network models are inherently badly scaled, a Jacobian regularization is employed to improve the condition number of these linear systems and guarantee positive definiteness. After presenting a convergence analysis of the regularised inexact Newton method, we use the conjugate gradient (CG) method to solve the sparse reduced Newton linear systems. Since CG is not effective without good preconditioners, we propose tailored constraint preconditioners that are computationally cheap because they are based only on invariant properties of the null space linear systems and do not change with flows and pressures. The preconditioners are shown to improve the distribution of eigenvalues of the linear systems and so enable a more efficient use of the CG solver. Since contiguous Newton iterates can have similar solutions, each CG call is warm-started with the solution for a previous Newton iterate to accelerate its convergence rate. Operational network models are used to show the efficacy of the proposed preconditioners and the warm-starting strategy in reducing computational effort.
BibTeX:
@article{014cf92e004445749e636362c8641492,
  author = {Edo Abraham and Ivan Stoianov},
  title = {Constraint preconditioned inexact Newton method for hydraulic simulation of large-scale water distribution networks},
  journal = {IEEE Transactions on Control of Network Systems},
  publisher = {IEEE Control Systems Society},
  year = {2016},
  pages = {610--619},
  doi = {10.1109/TCNS.2016.2548418}
}
Herrera M, Abraham E and Stoianov I (2016), "A Graph-Theoretic Framework for Assessing the Resilience of Sectorised Water Distribution Networks", Water Resources Management., 3, 2016. Vol. 30(5), pp. 1685-1699. Springer Netherlands.
Abstract: Water utilities face a challenge in maintaining a good quality of service under a wide range of operational management and failure conditions. Tools for assessing the resilience of water distribution networks are therefore essential for both operational and maintenance optimization. In this paper, a novel graph-theoretic approach for the assessment of resilience for large scale water distribution networks is presented. This is of great importance for the management of large scale water distribution systems, most models containing up to hundreds of thousands of pipes and nodes. The proposed framework is mainly based on quantifying the redundancy and capacity of all possible routes from demand nodes to their supply sources. This approach works well with large network sizes since it does not rely on precise hydraulic simulations, which require complex calibration processes and computation, while remaining meaningful from a physical and a topological point of view. The proposal is also tailored for the analysis of sectorised networks through a novel multiscale method for analysing connectivity, which is successfully tested in operational utility network models made of more than 100,000 nodes and 110,000 pipes.
BibTeX:
@article{324cb064c566405e8aafd4f9ceb33f9c,
  author = {Manuel Herrera and Edo Abraham and Ivan Stoianov},
  title = {A Graph-Theoretic Framework for Assessing the Resilience of Sectorised Water Distribution Networks},
  journal = {Water Resources Management},
  publisher = {Springer Netherlands},
  year = {2016},
  volume = {30},
  number = {5},
  pages = {1685--1699},
  doi = {10.1007/s11269-016-1245-6}
}
Menke R, Abraham E, Parpas P and Stoianov I (2016), "Exploring Optimal Pump Scheduling in Water Distribution Networks with Branch and Bound Methods", Water Resources Management., 11, 2016. Vol. 30(14), pp. 5333-5349. Springer Netherlands.
Abstract: Water utilities can achieve significant savings in operating costs by optimising pump scheduling to improve efficiency and shift electricity consumption to low-tariff periods. Due to the complexity of the optimal scheduling problem, heuristic methods that cannot guarantee global optimality are often applied. This paper investigates formulations of the pump scheduling problem solved using a branch and bound method. Piecewise linear component approximations outperform non-linear approximations within application driven accuracy bounds and demand uncertainties. It is shown that the reduction of symmetry through the grouping of pumps significantly reduces the computational effort, whereas loops in the network have the opposite effect. The computational effort of including convex, non-linear pump operating, and maintenance cost functions is investigated. Using case studies, it is shown that linear and fixed-cost functions can be used to find schedules which, when simulated in a full hydraulic simulation, have performances that are within the solver optimality gap and the uncertainty of demand forecasts.
BibTeX:
@article{47b984b1a03648ba983550edcb685aa0,
  author = {Ruben Menke and Edo Abraham and Panos Parpas and Ivan Stoianov},
  title = {Exploring Optimal Pump Scheduling in Water Distribution Networks with Branch and Bound Methods},
  journal = {Water Resources Management},
  publisher = {Springer Netherlands},
  year = {2016},
  volume = {30},
  number = {14},
  pages = {5333--5349},
  doi = {10.1007/s11269-016-1490-8}
}
Abraham E and Stoianov I (2016), "An efficient null space inexact Newton method for hydraulic simulation of water distribution networks", ArXiv.org.
BibTeX:
@article{4bf764cbf53f41ee9b73bb14b1575ba4,
  author = {Edo Abraham and Ivan Stoianov},
  title = {An efficient null space inexact Newton method for hydraulic simulation of water distribution networks},
  journal = {ArXiv.org},
  year = {2016},
  url = {https://arxiv.org/abs/1602.02630}
}
Abraham E, Blokker E and Stoianov I (2016), "Network Analysis, Control Valve Placement and Optimal Control of Flow Velocity for Self-Cleaning Water Distribution Systems", In 18th Conference on Water Distribution System Analysis., 7, 2016. Vol. 186, pp. 576-583. Elsevier.
Abstract: In this paper, we consider the proactive control of flow velocities to maximise the self-cleaning capacity of the drinking water distribution systems under normal operations both through a change of the network topology and through an optimal control of pressure reducing valve (PRV) settings. Inspired by line outage flow distribution in electrical networks, we show how a fast network graph analysis of link closures can be used to estimate the potential changes in flow velocities, which are then used to determine the most favourable pipes for closure. Where closing of pipes cannot be used because of other conflicting objectives, we consider the optimal control of PRVs to maximise self-cleaning at peak demand periods. We formulate a novel optimisation problem to maximise the network operations for increased self-cleaning capacity, while satisfying hydraulic and regulatory pressure constraints at demand nodes. A new smooth objective function approximation for cleaning capacity of the network is proposed along with a scalable sequential convex programming method to solve the resulting valve optimization problems. We use a published benchmark network as a case study to show the efficacy of these new approaches.
BibTeX:
@inproceedings{Abraham2016a,
  author = {Edo Abraham and EJM Blokker and Ivan Stoianov},
  title = {Network Analysis, Control Valve Placement and Optimal Control of Flow Velocity for Self-Cleaning Water Distribution Systems},
  booktitle = {18th Conference on Water Distribution System Analysis},
  publisher = {Elsevier},
  year = {2016},
  volume = {186},
  pages = {576--583},
  doi = {10.1016/j.proeng.2017.03.272}
}
Menke R, Abraham E, Parpas P and Stoianov I (2016), "Demonstrating demand response from water distribution system through pump scheduling", Applied Energy., 5, 2016. Vol. 170, pp. 377-387. Elsevier.
Abstract: Significant changes in the power generation mix are posing new challenges for the balancing systems of the grid. Many of these challenges are in the secondary electricity grid regulation services and could be met through demand response (DR) services. We explore the opportunities for a water distribution system (WDS) to provide balancing services with demand response through pump scheduling and evaluate the associated benefits. Using a benchmark network and demand response mechanisms available in the UK, these benefits are assessed in terms of reduced green house gas (GHG) emissions from the grid due to the displacement of more polluting power sources and additional revenues for water utilities. The optimal pump scheduling problem is formulated as a mixed-integer optimisation problem and solved using a branch and bound algorithm. This new formulation finds the optimal level of power capacity to commit to the provision of demand response for a range of reserve energy provision and frequency response schemes offered in the UK. For the first time we show that DR from WDS can offer financial benefits to WDS operators while providing response energy to the grid with less greenhouse gas emissions than competing reserve energy technologies. Using a Monte Carlo simulation based on data from 2014, we demonstrate that the cost of providing the storage energy is less than the financial compensation available for the equivalent energy supply. The GHG emissions from the demand response provision from a WDS are also shown to be smaller than those of contemporary competing technologies such as open cycle gas turbines. The demand response services considered vary in their response time and duration as well as commitment requirements. The financial viability of a demand response service committed continuously is shown to be strongly dependent on the utilisation of the pumps and the electricity tariffs used by water utilities. Through the analysis of range of water demand scenarios and financial incentives using real market data, we demonstrate how a WDS can participate in a demand response scheme and generate financial gains and environmental benefits.
BibTeX:
@article{b5221f0acdbc45c4aca2b336ee5e1095,
  author = {Ruben Menke and Edo Abraham and Panos Parpas and Ivan Stoianov},
  title = {Demonstrating demand response from water distribution system through pump scheduling},
  journal = {Applied Energy},
  publisher = {Elsevier},
  year = {2016},
  volume = {170},
  pages = {377--387},
  doi = {10.1016/j.apenergy.2016.02.136}
}
Abraham E and Kerrigan EricC (2015), "Lower-order H∞ filter design for bilinear systems with bounded inputs", IEEE Transactions on Signal Processing., 2, 2015. Vol. 63(4), pp. 895-906. IEEE.
Abstract: We propose an optimization-based method for designing a lower order Luenberger-type state estimator, while providing L2-gain guarantees on the error dynamics when the estimator is used with the higher order system. Suitable filter parameters can be computed by modelling the bilinear system as a linear differential inclusion and solving a set of bilinear matrix inequality constraints. Since these constraints are nonconvex, in general, we also show that one can solve a suitably defined semi-definite program to compute a bound on the level of suboptimality. The design method also allows one to explicitly take account of linear parameter uncertainties in order to provide a priori robustness guarantees. The H-infinity estimator not only has lower real-time computational requirements compared with a Kalman filter, but also does not require knowledge of the noise spectrum. For a numerical example, we consider the estimation of the radiation force for a wave energy converter, where a low-order model is used to approximate the radiation dynamics.
BibTeX:
@article{41c4365d75f54e2ab7d1546ada1aec3b,
  author = {Edo Abraham and Kerrigan, Eric C.},
  title = {Lower-order H∞ filter design for bilinear systems with bounded inputs},
  journal = {IEEE Transactions on Signal Processing},
  publisher = {IEEE},
  year = {2015},
  volume = {63},
  number = {4},
  pages = {895--906},
  doi = {10.1109/TSP.2014.2385656}
}
Wright R, Abraham E, Parpas P and Stoianov I (2015), "Control of water distribution networks with dynamic DMA topology using strictly feasible sequential convex programming", Water Resources Research., 12, 2015. Vol. 51(12), pp. 9925-9941. American Geophysical Union.
Abstract: The operation of water distribution networks (WDN) with a dynamic topology is a recently pioneered approach for the advanced management of District Metered Areas (DMAs) that integrates novel developments in hydraulic modeling, monitoring, optimization, and control. A common practice for leakage management is the sectorization of WDNs into small zones, called DMAs, by permanently closing isolation valves. This facilitates water companies to identify bursts and estimate leakage levels by measuring the inlet flow for each DMA. However, by permanently closing valves, a number of problems have been created including reduced resilience to failure and suboptimal pressure management. By introducing a dynamic topology to these zones, these disadvantages can be eliminated while still retaining the DMA structure for leakage monitoring. In this paper, a novel optimization method based on sequential convex programming (SCP) is outlined for the control of a dynamic topology with the objective of reducing average zone pressure (AZP). A key attribute for control optimization is reliable convergence. To achieve this, the SCP method we propose guarantees that each optimization step is strictly feasible, resulting in improved convergence properties. By using a null space algorithm for hydraulic analyses, the computations required are also significantly reduced. The optimized control is actuated on a real WDN operated with a dynamic topology. This unique experimental program incorporates a number of technologies set up with the objective of investigating pioneering developments in WDN management. Preliminary results indicate AZP reductions for a dynamic topology of up to 6.5% over optimally controlled fixed topology DMAs.
BibTeX:
@article{667431ff20fa41d689de001441ebe739,
  author = {Robert Wright and Edo Abraham and Panos Parpas and Ivan Stoianov},
  title = {Control of water distribution networks with dynamic DMA topology using strictly feasible sequential convex programming},
  journal = {Water Resources Research},
  publisher = {American Geophysical Union},
  year = {2015},
  volume = {51},
  number = {12},
  pages = {9925--9941},
  doi = {10.1002/2015WR017466}
}
Abraham E and Stoianov I (2015), "Efficient preconditioned iterative methods for hydraulic simulation of large scale water distribution networks", Procedia Engineering., In Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI). Vol. 119w(1), pp. 623-632. Elsevier.
Abstract: In this paper, we consider the use of an efficient null space algorithm for hydraulic analysis that employs preconditioned conjugate gradient (PCG) methods for solving the Newton linear equations. Since large water network models are inherently badly conditioned, a Jacobian regularization is employed to improve the condition number to some degree, this resulting in an inexact Newton method whose analyses is presented. Based on this analysis, constraint preconditioners are used to improve the condition number further for more efficient use of CG solvers. Operational networks are used to study the computational properties of the various approaches.
BibTeX:
@inproceedings{Abraham2015,
  author = {Edo Abraham and Ivan Stoianov},
  title = {Efficient preconditioned iterative methods for hydraulic simulation of large scale water distribution networks},
  booktitle = {Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  journal = {Procedia Engineering},
  publisher = {Elsevier},
  year = {2015},
  volume = {119w},
  number = {1},
  pages = {623--632},
  doi = {10.1016/j.proeng.2015.08.915}
}
Herrera M, Abraham E and Stoianov I (2015), "Graph-theoretic surrogate measures for analysing the resilience of water distribution networks", Procedia Engineering., In Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI). Vol. 119(1), pp. 1241-1248. Elsevier.
Abstract: Hydraulic resilience can be formulated as a measure of the ability of a water distribution network to maintain a minimum level of service under operational and failure conditions. This paper explores a hybrid approach to bridge the gap between graph-theoretic and hydraulic measures of resilience. We extend the concept of geodesic distance of a pipeline by taking into account energy losses associated with flow. New random-walk algorithms evaluate hydraulically feasible routes and identify nodes with different levels of hydraulic resilience. The nodes with the lowest scores are further analysed by considering the availability and capacity of their supply routes.
BibTeX:
@inproceedings{Herrera2015,
  author = {Manuel Herrera and Edo Abraham and Ivan Stoianov},
  title = {Graph-theoretic surrogate measures for analysing the resilience of water distribution networks},
  booktitle = {Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  journal = {Procedia Engineering},
  publisher = {Elsevier},
  year = {2015},
  volume = {119},
  number = {1},
  pages = {1241--1248},
  doi = {10.1016/j.proeng.2015.08.985}
}
Wright R, Abraham E, Parpas P and Stoianov I (2015), "Optimized control of pressure reducing valves in water distribution networks with dynamic topology", Procedia Engineering., In Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI). Vol. 119(1), pp. 1003-1011. Elsevier.
Abstract: A dynamic topology aggregates zones in water distribution networks (WDNs) for improved pressure management and resilience to failure. Based on a sequential convex programming (SCP) approach, we propose an optimization method for the control of pressure reducing valves (PRV) in WDNs with dynamic topology. By restricting the SCP iterations to the feasible search space, we show that reliable convergence of the method is achieved. Using an experimental study in a large operational network, the optimization of PRV settings with a dynamic topology is shown to result in pressure reductions of 3.7% compared to optimized PRVs in a closed DMA structure.
BibTeX:
@inproceedings{Wright2015,
  author = {Robert Wright and E. Abraham and Panos Parpas and Ivan Stoianov},
  title = {Optimized control of pressure reducing valves in water distribution networks with dynamic topology},
  booktitle = {Proc. 13th Int. Conference on Computing and Control in the Water Industry (CCWI)},
  journal = {Procedia Engineering},
  publisher = {Elsevier},
  year = {2015},
  volume = {119},
  number = {1},
  pages = {1003--1011},
  doi = {10.1016/j.proeng.2015.08.994}
}
Abraham E and Kerrigan EC (2013), "Optimal Active Control and Optimization of a Wave Energy Converter", IEEE Transactions on Sustainable Energy., April, 2013. Vol. 4(2), pp. 324-332.
Abstract: This paper investigates optimal active control schemes applied to a point absorber wave energy converter within a receding horizon fashion. A variational formulation of the power maximization problem is adapted to solve the optimal control problem. The optimal control method is shown to be of a bang-bang type for a power takeoff mechanism that incorporates both linear dampers and active control elements. We also consider a direct transcription of the optimal control problem as a general nonlinear program. A variation of the projected gradient optimization scheme is formulated and shown to be feasible and computationally inexpensive compared to a standard NLP solver. Since the system model is bilinear and the cost function is not convex quadratic, the resulting optimization problem is not a quadratic program. Results will be compared with an optimal command latching method to demonstrate the improvement in absorbed power. All time domain simulations are generated under irregular sea conditions.
BibTeX:
@article{6353624,
  author = {E. Abraham and E. C. Kerrigan},
  title = {Optimal Active Control and Optimization of a Wave Energy Converter},
  journal = {IEEE Transactions on Sustainable Energy},
  year = {2013},
  volume = {4},
  number = {2},
  pages = {324-332},
  doi = {10.1109/TSTE.2012.2224392}
}
Abraham E and Kerrigan EC (2013), "Estimator design for input-constrained bilinear systems with application to wave energy conversion", In 52nd IEEE Conference on Decision and Control., Dec, 2013. , pp. 5686-5691.
Abstract: This paper investigates low-order observer design for bilinear systems with input constraints. A bilinear Luenberger-type observer with an H-infinity performance measure is formulated and the resulting synthesis problem is posed as a matrix inequality optimization for a linear parameter varying system. The resulting (nonconvex) bilinear matrix inequality problem is then solved with an LMI-based algorithm to find low-order nominal and robust quadratically stable observers. The performance of these observers are compared with that of a Kalman filter. In addition to alleviating the need to know the noise spectrum and its lower real-time computational burden, the H-infinity filter is shown to be robust to model uncertainties. The online radiation force estimation problem for a wave energy converter with bilinear dynamics is considered as an example.
BibTeX:
@inproceedings{6760785,
  author = {E. Abraham and E. C. Kerrigan},
  title = {Estimator design for input-constrained bilinear systems with application to wave energy conversion},
  booktitle = {52nd IEEE Conference on Decision and Control},
  year = {2013},
  pages = {5686-5691},
  doi = {10.1109/CDC.2013.6760785}
}
Abraham E and Kerrigan EC (2012), "Optimal active control of a wave energy converter", In 2012 IEEE 51st IEEE Conference on Decision and Control (CDC). , pp. 2415-2420.
BibTeX:
@inproceedings{Abraham2012,
  author = {Abraham, Edo and Kerrigan, Eric C},
  title = {Optimal active control of a wave energy converter},
  booktitle = {2012 IEEE 51st IEEE Conference on Decision and Control (CDC)},
  year = {2012},
  pages = {2415--2420},
  url = {https://ieeexplore.ieee.org/abstract/document/6426993},
  doi = {10.1109/CDC.2012.6426993}
}