TY  - JOUR
A1  - Sun, Hui
A1  - Altherr, Lena
A1  - Pei, Ji
A1  - Pelz, Peter F.
A1  - Yuan, Shouqi
T1  - Optimal booster station design and operation under uncertain load
JF  - Applied Mechanics and Materials
N2  - Given industrial applications, the costs for the operation and maintenance of a pump system typically far exceed its purchase price. For finding an optimal pump configuration which minimizes not only investment, but life-cycle costs, methods like Technical Operations Research which is based on Mixed-Integer Programming can be applied. However, during the planning phase, the designer is often faced with uncertain input data, e.g. future load demands can only be estimated. In this work, we deal with this uncertainty by developing a chance-constrained two-stage (CCTS) stochastic program. The design and operation of a booster station working under uncertain load demand are optimized to minimize total cost including purchase price, operation cost incurred by energy consumption and penalty cost resulting from water shortage. We find optimized system layouts using a sample average approximation (SAA) algorithm, and analyze the results for different risk levels of water shortage. By adjusting the risk level, the costs and performance range of the system can be balanced, and thus the
system’s resilience can be engineered
KW  - Stochastic Programming
KW  - Chance Constraint
KW  - Engineering Application
KW  - Pump System
KW  - Water Distribution
Y1  - 2018
U6  - http://dx.doi.org/10.4028/www.scientific.net/AMM.885.102
SN  - 1662-7482
VL  - 885
SP  - 102
EP  - 115
PB  - Trans Tech Publications
CY  - Bäch
ER  - 
TY  - JOUR
A1  - Altherr, Lena
A1  - Ederer, Thorsten
A1  - Pfetsch, Marc E.
A1  - Pelz, Peter F.
T1  - Maschinelles Design eines optimalen Getriebes
JF  - ATZ - Automobiltechnische Zeitschrift
N2  - Nahezu 100.000 denkbare Strukturen kann ein Getriebe bei gleicher Funktion aufweisen - je nach Ganganzahl und gefordertem Freiheitsgrad. Mit dem traditionellen Ansatz bei der Entwicklung, einzelne vielversprechende Systemkonfigurationen manuell zu identifizieren und zu vergleichen, können leicht innovative und vor allem kostenminimale Lösungen übersehen werden. Im Rahmen eines Forschungsprojekts hat die TU Darmstadt spezielle Optimierungsmethoden angewendet, um auch bei großen Lösungsräumen zielsicher ein für die individuellen Zielstellungen optimales Layout zu finden.
Y1  - 2018
SN  - 2192-8800
U6  - http://dx.doi.org/10.1007/s35148-018-0131-3
VL  - 120
IS  - 10
SP  - 72
EP  - 77
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Rausch, Lea
A1  - Friesen, John
A1  - Altherr, Lena
A1  - Meck, Marvin
A1  - Pelz, Peter F.
T1  - A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data
JF  - Remote Sensing
N2  - Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.
KW  - water supply design
KW  - mathematical optimization
KW  - slum classification
KW  - remote sensing
Y1  - 2018
SN  - 2072-4292
U6  - http://dx.doi.org/10.3390/rs10020216
VL  - 10
IS  - 2
SP  - 1
EP  - 23
PB  - MDPI
CY  - Basel
ER  -