@article{MuellerLeiseLorenzetal.2020, author = {M{\"u}ller, Tim M. and Leise, Philipp and Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.}, title = {Optimization and validation of pumping system design and operation for water supply in high-rise buildings}, series = {Optimization and Engineering}, volume = {2021}, journal = {Optimization and Engineering}, number = {22}, publisher = {Springer}, issn = {1573-2924}, doi = {10.1007/s11081-020-09553-4}, pages = {643 -- 686}, year = {2020}, abstract = {The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps' characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer's point of view, keeping in mind the economically important trade-off between investment and operation costs.}, language = {en} } @inproceedings{MuellerAltherrLeiseetal.2020, author = {M{\"u}ller, Tim M. and Altherr, Lena and Leise, Philipp and Pelz, Peter F.}, title = {Optimization of pumping systems for buildings: Experimental validation of different degrees of model detail on a modular test rig}, series = {Operations Research Proceedings 2019}, booktitle = {Operations Research Proceedings 2019}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-48438-5}, doi = {10.1007/978-3-030-48439-2_58}, pages = {481 -- 488}, year = {2020}, abstract = {Successful optimization requires an appropriate model of the system under consideration. When selecting a suitable level of detail, one has to consider solution quality as well as the computational and implementation effort. In this paper, we present a MINLP for a pumping system for the drinking water supply of high-rise buildings. We investigate the influence of the granularity of the underlying physical models on the solution quality. Therefore, we model the system with a varying level of detail regarding the friction losses, and conduct an experimental validation of our model on a modular test rig. Furthermore, we investigate the computational effort and show that it can be reduced by the integration of domain-specific knowledge.}, language = {en} } @article{AltherrLeisePfetschetal.2018, author = {Altherr, Lena and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas}, title = {Algorithmic design and resilience assessment of energy efficient high-rise water supply systems}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, issn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.211}, pages = {211 -- 223}, year = {2018}, abstract = {High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building.}, language = {en} } @incollection{PfetschAbeleAltherretal.2021, author = {Pfetsch, Marc E. and Abele, Eberhard and Altherr, Lena and B{\"o}lling, Christian and Br{\"o}tz, Nicolas and Dietrich, Ingo and Gally, Tristan and Geßner, Felix and Groche, Peter and Hoppe, Florian and Kirchner, Eckhard and Kloberdanz, Hermann and Knoll, Maximilian and Kolvenbach, Philip and Kuttich-Meinlschmidt, Anja and Leise, Philipp and Lorenz, Ulf and Matei, Alexander and Molitor, Dirk A. and Niessen, Pia and Pelz, Peter F. and Rexer, Manuel and Schmitt, Andreas and Schmitt, Johann M. and Schulte, Fiona and Ulbrich, Stefan and Weigold, Matthias}, title = {Strategies for mastering uncertainty}, series = {Mastering uncertainty in mechanical engineering}, booktitle = {Mastering uncertainty in mechanical engineering}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-78353-2}, doi = {10.1007/978-3-030-78354-9_6}, pages = {365 -- 456}, year = {2021}, abstract = {This chapter describes three general strategies to master uncertainty in technical systems: robustness, flexibility and resilience. It builds on the previous chapters about methods to analyse and identify uncertainty and may rely on the availability of technologies for particular systems, such as active components. Robustness aims for the design of technical systems that are insensitive to anticipated uncertainties. Flexibility increases the ability of a system to work under different situations. Resilience extends this characteristic by requiring a given minimal functional performance, even after disturbances or failure of system components, and it may incorporate recovery. The three strategies are described and discussed in turn. Moreover, they are demonstrated on specific technical systems.}, language = {en} } @article{BraunChengDoweyetal.2021, author = {Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Performance evaluation of skill-based order-assignment in production environments with multi-agent systems}, series = {IEEE Journal of Emerging and Selected Topics in Industrial Electronics}, journal = {IEEE Journal of Emerging and Selected Topics in Industrial Electronics}, number = {Early Access}, publisher = {IEEE}, address = {New York}, issn = {2687-9735}, doi = {10.1109/JESTIE.2021.3108524}, year = {2021}, abstract = {The fourth industrial revolution introduces disruptive technologies to production environments. One of these technologies are multi-agent systems (MASs), where agents virtualize machines. However, the agent's actual performances in production environments can hardly be estimated as most research has been focusing on isolated projects and specific scenarios. We address this gap by implementing a highly connected and configurable reference model with quantifiable key performance indicators (KPIs) for production scheduling and routing in single-piece workflows. Furthermore, we propose an algorithm to optimize the search of extrema in highly connected distributed systems. The benefits, limits, and drawbacks of MASs and their performances are evaluated extensively by event-based simulations against the introduced model, which acts as a benchmark. Even though the performance of the proposed MAS is, on average, slightly lower than the reference system, the increased flexibility allows it to find new solutions and deliver improved factory-planning outcomes. Our MAS shows an emerging behavior by using flexible production techniques to correct errors and compensate for bottlenecks. This increased flexibility offers substantial improvement potential. The general model in this paper allows the transfer of the results to estimate real systems or other models.}, language = {en} } @article{JahnkeRousselHombachetal.2016, author = {Jahnke, Siegfried and Roussel, Johanna and Hombach, Thomas and Kochs, Johannes and Fischbach, Andreas and Huber, Gregor and Scharr, Hanno}, title = {phenoSeeder - A robot system for automated handling and phenotyping of individual seeds}, series = {Plant physiology}, volume = {172}, journal = {Plant physiology}, number = {3}, publisher = {Oxford University Press}, address = {Oxford}, issn = {0032-0889}, doi = {10.1104/pp.16.01122}, pages = {1358 -- 1370}, year = {2016}, abstract = {The enormous diversity of seed traits is an intriguing feature and critical for the overwhelming success of higher plants. In particular, seed mass is generally regarded to be key for seedling development but is mostly approximated by using scanning methods delivering only two-dimensional data, often termed seed size. However, three-dimensional traits, such as the volume or mass of single seeds, are very rarely determined in routine measurements. Here, we introduce a device named phenoSeeder, which enables the handling and phenotyping of individual seeds of very different sizes. The system consists of a pick-and-place robot and a modular setup of sensors that can be versatilely extended. Basic biometric traits detected for individual seeds are two-dimensional data from projections, three-dimensional data from volumetric measures, and mass, from which seed density is also calculated. Each seed is tracked by an identifier and, after phenotyping, can be planted, sorted, or individually stored for further evaluation or processing (e.g. in routine seed-to-plant tracking pipelines). By investigating seeds of Arabidopsis (Arabidopsis thaliana), rapeseed (Brassica napus), and barley (Hordeum vulgare), we observed that, even for apparently round-shaped seeds of rapeseed, correlations between the projected area and the mass of seeds were much weaker than between volume and mass. This indicates that simple projections may not deliver good proxies for seed mass. Although throughput is limited, we expect that automated seed phenotyping on a single-seed basis can contribute valuable information for applications in a wide range of wild or crop species, including seed classification, seed sorting, and assessment of seed quality.}, language = {en} } @article{PoghossianWernerBuniatyanetal.2017, author = {Poghossian, Arshak and Werner, Frederik and Buniatyan, V. V. and Wagner, Torsten and Miamoto, K. and Yoshinobu, T. and Sch{\"o}ning, Michael Josef}, title = {Towards addressability of light-addressable potentiometric sensors: Shunting effect of non-illuminated region and cross-talk}, series = {Sensor and Actuators B: Chemical}, journal = {Sensor and Actuators B: Chemical}, number = {244}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2017.01.047}, pages = {1071 -- 1079}, year = {2017}, abstract = {The LAPS (light-addressable potentiometric sensor) platform is one of the most attractive approaches for chemical and biological sensing with many applications ranging from pH and ion/analyte concentration measurements up to cell metabolism detection and chemical imaging. However, although it is generally accepted that LAPS measurements are spatially resolved, the light-addressability feature of LAPS devices has not been discussed in detail so far. In this work, an extended electrical equivalent-circuit model of the LAPS has been presented, which takes into account possible cross-talk effects due to the capacitive coupling of the non-illuminated region. A shunting effect of the non-illuminated area on the measured photocurrent and addressability of LAPS devices has been studied. It has been shown, that the measured photocurrent will be determined not only by the local interfacial potential in the illuminated region but also by possible interfacial potential changes in the non-illuminated region, yielding cross-talk effects. These findings were supported by the experimental investigations of a penicillin-sensitive multi-spot LAPS and a metal-insulator-semiconductor LAPS as model systems.}, language = {en} } @article{Wrede2016, author = {Wrede, Oliver}, title = {Continuity in travel information}, series = {Information Design Journal}, volume = {22}, journal = {Information Design Journal}, number = {2}, publisher = {John Benjamins}, address = {Amsterdam}, issn = {0142-5471}, doi = {10.1075/idj.22.2.09wre}, pages = {172 -- 178}, year = {2016}, abstract = {This article discusses the contrast between the information transportation companies provide to travellers and that of their brand messaging. Companies' brand messaging often portrays the service they provide as pleasant, stress free and perfect. Customers and users of the service, on the other hand, often describe their experience of the service as a negative one. This article suggests that the brand value would be greater if transportation companies paid more attention to the users' experience when designing their information systems, particularly in worst case scenarios.}, language = {en} } @article{NeuJanserKhatibietal.2017, author = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.}, title = {Fully Automated Operational Modal Analysis using multi-stage clustering}, series = {Mechanical Systems and Signal Processing}, volume = {Vol. 84, Part A}, journal = {Mechanical Systems and Signal Processing}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0888-3270}, doi = {10.1016/j.ymssp.2016.07.031}, pages = {308 -- 323}, year = {2017}, language = {en} } @inproceedings{KonstantinidisKowalskiMartinezetal.2015, author = {Konstantinidis, K. and Kowalski, Julia and Martinez, C. F. and Dachwald, Bernd and Ewerhart, D. and F{\"o}rstner, R.}, title = {Some necessary technologies for in-situ astrobiology on enceladus}, series = {Proceedings of the International Astronautical Congress}, booktitle = {Proceedings of the International Astronautical Congress}, isbn = {978-151081893-4}, pages = {1354 -- 1372}, year = {2015}, language = {en} }