| publications-4551 |
article |
2003 |
Gregory, Gary and Gregory, Gary D. and Leo, Michael Di and Leo, Michael Di |
Repeated Behavior and Environmental Psychology: The Role of Personal Involvement and Habit Formation in Explaining Water Consumption1 |
Journal of Applied Social Psychology |
10.1111/j.1559-1816.2003.tb01949.x |
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Extending existing theory in social and environmental psychology, we develop a model to study important predictors of water consumption behavior. Overall results provide support for the predictive ability of stimuli (e.g., environmental awareness), reasoned processes (e.g., personal involvement), unreasoned processes (e.g., habits), and situational factors (e.g., income) on water consumption behavior. Findings indicate that households with lower water usage display greater awareness of water conservation issues, are more highly involved in the decision to use water, and tend to form habits associated with lower usage levels. Furthermore, the results are consistent with past research that attitudes toward water usage appear to be poor predictors of water consumption behavior. After controlling for situational factors (e.g., household size), the findings substantiate the role of personal involvement and habit formation in explaining water consumption, lending further support to the adaptation and development of repeated behavior models in environmental psychology. |
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| publications-4552 |
article |
2005 |
Babayan, Artem V. and Babayan, Artem V. and Kapelan, Zoran and Kapelan, Zoran and Savić, Dragan and Savic, Dragan and Walters, Godfrey A. and Walters, Godfrey A. |
Least-Cost Design of Water Distribution Networks under Demand Uncertainty |
Journal of Water Resources Planning and Management |
10.1061/(asce)0733-9496(2005)131:5(375) |
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Due to inherent variability in instantaneous water consumption levels, values of demands at nodes in a water distribution system remain one of the major sources of uncertainty in the network design process. Uncertainty in demand leads to uncertainty in head at the nodes, which, in turn, affects the system performance and has to be taken into account when designing new water distribution systems or extending/rehabilitating existing ones. One approach to dealing with this difficulty is to formulate and solve the stochastic optimization problem providing a robust, cost-effective solution. However, stochastic formulation usually requires Monte Carlo simulation, which involves calculation of a large number of state estimates, even for relatively simple networks. This renders the approach intractable when combined with heuristic adaptive search techniques, such as genetic algorithms (GAs) or simulated annealing. These methodologies require the fitness function to be evaluated for thousands of possible network configurations in the course of the search process. In this paper a new approach to quantifying the influence of demand uncertainty on nodal heads is proposed. The original stochastic model is reformulated as a deterministic one, which uses standard deviation as a natural measure of variability. Such an approach allows the use of effective numerical methods to quantify the influence of uncertainty on the robustness of water distribution system solutions. The deterministic equivalent is then coupled with an efficient GA solver to find robust and economic solutions. The proposed methodology was tested on the New York tunnels and Anytown problems. A number of low cost network solutions were found for different levels of reliability and different forms of probability distribution function for demands. The robustness of the solutions found was compared to known solutions for deterministic formulations, whose results were postprocessed using full Monte Carlo simulation. |
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| publications-4553 |
article |
2008 |
Makropoulos, Christos and Makropoulos, Christos and Natsis, K. and Natsis, K. and Liu, Shuming and Liu, Shuming and Mittas, K. and Mittas, K. and Butler, David and Butler, David |
Decision support for sustainable option selection in integrated urban water management |
Environmental Modelling and Software |
10.1016/j.envsoft.2008.04.010 |
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| publications-4554 |
article |
2009 |
Froehlich, Jon E. and Froehlich, Jon E. and Larson, Eric B. and Larson, Eric C. and Larson, Eric C. and Campbell, Tim and Campbell, Tim and Haggerty, Conor and Haggerty, Conor and Fogarty, James and Fogarty, James and Patel, Shwetak and Patel, Shwetak N. |
HydroSense: infrastructure-mediated single-point sensing of whole-home water activity |
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10.1145/1620545.1620581 |
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Recent work has examined infrastructure-mediated sensing as a practical, low-cost, and unobtrusive approach to sensing human activity in the physical world. This approach is based on the idea that human activities (e.g., running a dishwasher, turning on a reading light, or walking through a doorway) can be sensed by their manifestations in an environment's existing infrastructures (e.g., a home's water, electrical, and HVAC infrastructures). This paper presents HydroSense, a low-cost and easily-installed single-point sensor of pressure within a home's water infrastructure. HydroSense supports both identification of activity at individual water fixtures within a home (e.g., a particular toilet, a kitchen sink, a particular shower) as well as estimation of the amount of water being used at each fixture. We evaluate our approach using data collected in ten homes. Our algorithms successfully identify fixture events with 97.9\% aggregate accuracy and can estimate water usage with error rates that are comparable to empirical studies of traditional utility-supplied water meters. Our results both validate our approach and provide a basis for future improvements. |
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| publications-4555 |
article |
2010 |
van Oel, Pieter and van Oel, Pieter R. and Krol, Maarten S. and Krol, Maarten S. and Krol, Maarten S. and Hoekstra, Arjen Ysbert and Hoekstra, Arjen Ysbert and Taddei, Renzo and Taddei, Renzo |
Feedback mechanisms between water availability and water use in a semi-arid river basin: A spatially explicit multi-agent simulation approach |
Environmental Modelling and Software |
10.1016/j.envsoft.2009.10.018 |
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| publications-4556 |
article |
2017 |
Brenner, Beate and Brenner, Beate and Hummel, Vera and Hummel, Vera |
Digital Twin as Enabler for an Innovative Digital Shopfloor Management System in the ESB Logistics Learning Factory at Reutlingen - University |
Procedia Manufacturing |
10.1016/j.promfg.2017.04.039 |
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Abstract Technologies for mapping the β€_x009c_digital twinβ€_x009d_ have been under development for approximately 20 years. Nowadays increasingly intelligent, individualized products encourages companies to respond innovatively to customer requirements and to handle the rising product variations quickly. An integrated engineering network, spanning across the entire value chain, is operated to intelligently connect various company divisions, and to generate a business ecosystem for products, services and communities. The conditions for the digital twin are thereby determined in which the digital world can be fed into the real, and the real world back into the digital to deal such intelligent products with rising variations. The term digital twin can be described as a digital copy of a real factory, machine, worker etc., that is created and can be independently expanded, automatically updated as well as being globally available in real time. Every real product and production site is permanently accompanied by a digital twin. First prototypes of such digital twins already exist in the ESB Logistics Learning Factory on a cloud- and app-based software that builds on a dynamic, multidimensional data and information model. A standardized language of the robot control systems via software agents and positioning systems has to be integrated. The aspect of the continuity of the real factory in the digital factory as an economical means of ensuring continuous actuality of digital models looks as the basis of changeability. For the indoor localization sensor combinations that in addition to the hardware already contain the software required for the sensor data fusion should be used. Processing systems, scenario-live-simulations and digital shop floor management results in a mandatory procedural combination. Essential to the digital twin is the ability to consistently provide all subsystems with the latest state of all required information, methods and algorithms. |
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| publications-4557 |
article |
2017 |
Li, Chenzhao and Li, Chenzhao and Mahadevan, Sankaran and Mahadevan, Sankaran and You, Liangzhi and Ling, You and Choze, Sergio and Choze, Sergio and Wang, Liping and Wang, Liping and Wang, Liping |
Dynamic Bayesian Network for Aircraft Wing Health Monitoring Digital Twin |
AIAA Journal |
10.2514/1.j055201 |
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Current airframe health monitoring generally relies on deterministic physics models and ground inspections. This paper uses the concept of a dynamic Bayesian network to build a versatile probabilis... |
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| publications-4558 |
article |
2018 |
Schluse, Michael and Schluse, Michael and Priggemeyer, Marc and Priggemeyer, Marc and Atorf, Linus and Atorf, Linus and RoΓ_x009f_mann, JΓΌrgen and Rossmann, Juergen |
Experimentable Digital Twinsβ€”Streamlining Simulation-Based Systems Engineering for Industry 4.0 |
IEEE Transactions on Industrial Informatics |
10.1109/tii.2018.2804917 |
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Digital twins represent real objects or subjects with their data, functions, and communication capabilities in the digital world. As nodes within the internet of things, they enable networking and thus the automation of complex value-added chains. The application of simulation techniques brings digital twins to life and makes them experimentable; digital twins become experimentable digital twins (EDTs). Initially, these EDTs communicate with each other purely in the virtual world. The resulting networks of interacting EDTs model different application scenarios and are simulated in virtual testbeds, providing new foundations for comprehensive simulation-based systems engineering. Its focus is on EDTs, which become more detailed with every single application. Thus, complete digital representations of the respective real assets and their behaviors are created successively. The networking of EDTs with real assets leads to hybrid application scenarios in which EDTs are used in combination with real hardware, thus realizing complex control algorithms, innovative user interfaces, or mental models for intelligent systems. |
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| publications-4559 |
article |
2002 |
MartΓnezβ€EspiΓ±eira, Roberto and MartΓnez-EspiΓ±eira, Roberto |
Residential Water Demand in the Northwest of Spain |
Environmental and Resource Economics |
10.1023/a:1014547616408 |
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A panel of monthly aggregate data from the Northwest of Spain is used to estimate domestic water demand functions under linear and non-linear tariffs. Price, billing, climatic, and sociodemographic variables are used as explanatory variables. The use of intraannual data constitutes a relevant contribution in the European context. Overall marginal price elasticity estimates lie between β’0.12 and β’0.17. Summer-only elasticities and elasticities associated with uses beyond the effectively free allowances seem significantly higher. Climatic variables significantly affect monthly use, although probably less than in other wealthier and drier areas. Domestic water use appears to be a normal good. Copyright Kluwer Academic Publishers 2002 |
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| publications-4560 |
article |
1977 |
Freeman, Linton C. and Freeman, Linton C. |
A Set of Measures of Centrality Based on Betweenness |
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10.2307/3033543 |
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A family of new measures of point and graph centrality based on early intuitions of Bavelas (1948) is introduced. These measures define centrality in terms of the degree to which a point falls on the shortest path between others and there fore has a potential for control of communication. They may be used to index centrality in any large or small network of symmetrical relations, whether connected or unconnected. |
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