| publications-4641 |
article |
2008 |
Fischer, Corinna and Fischer, Corinna |
Feedback on household electricity consumption: a tool for saving energy? |
Energy Efficiency |
10.1007/s12053-008-9009-7 |
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Improved feedback on electricity consumption may provide a tool for customers to better control their consumption and ultimately save energy. This paper asks which kind of feedback is most successful. For this purpose, a psychological model is presented that illustrates how and why feedback works. Relevant features of feedback are identified that may determine its effectiveness: frequency, duration, content, breakdown, medium and way of presentation, comparisons, and combination with other instruments. The paper continues with an analysis of international experience in order to find empirical evidence for which kinds of feedback work best. In spite of considerable data restraints and research gaps, there is some indication that the most successful feedback combines the following features: it is given frequently and over a long time, provides an appliance-specific breakdown, is presented in a clear and appealing way, and uses computerized and interactive tools. |
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| publications-4642 |
article |
1970 |
Nash, J.E. and Nash, J.E. and Sutcliffe, J. V. and Sutcliffe, J.V. |
River flow forecasting through conceptual models part I — A discussion of principles↠|
Journal of Hydrology |
10.1016/0022-1694(70)90255-6 |
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| publications-4643 |
article |
1973 |
Morgan, W. Douglas and Morgan, W. Douglas |
Residential Water Demand: The Case from Micro Data |
Water Resources Research |
10.1029/wr009i004p01065 |
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A cross section demand function for water is estimated using individual residential dwelling units as the sample. Both assessed value of property and number of persons per dwelling are significant determinates of the quantity of water demanded consistent with the theoretical development. Moreover, it is concluded that there are economies of scale of water use with respect to household size. |
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| publications-4644 |
article |
1974 |
Shamir, Uri and Shamir, Uri |
Optimal Design and Operation of Water Distribution Systems |
Water Resources Research |
10.1029/wr010i001p00027 |
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A methodology is developed for optimal design and/or operation of a water distribution system that is to operate under one or several loading conditions. Decision variables may be design variables, such as pipe diameters, or control variables, such as heads and flows. The objective function may include the initial cost of the design, the cost of operation, the physical measures of performance, and the penalties for violating constraints. Constraints may be imposed on the decision variables and on the performance of the system under each loading. Flow solutions are obtained by a modified Newton-Raphson method employing sparse matrix techniques. Optimization is obtained by a combination of the generalized reduced gradient and penalty methods. Implementation in a computer program and its use on a test problem in both batch and time-sharing modes are described, and it is concluded that the method is computationally feasible. The many different ways in which it can be used to analyze, design, and operate water distribution systems are outlined. |
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| publications-4645 |
article |
1980 |
Anderson, Raymond L. and Anderson, Raymond L. and Miller, Thomas A. and Miller, Thomas A. and Washburn, Monty C. and Washburn, Monty C. |
WATER SAVINGS FROM LAWN WATERING RESTRICTIONS DURING A DROUGHT YEAR, FORT COLLINS, COLORADO |
Journal of The American Water Resources Association |
10.1111/j.1752-1688.1980.tb02443.x |
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: During the drought year of 1977, unusually low river flows during the summer caused the City of Fort Collins, Colorado, to institute lawn watering restrictions for six weeks as a conservation measure. Water use during the restriction period decreased 41 percent below the previous year. The effectiveness of the restrictions, however, has been unclear because abnormally wet weather also appeared to reduce evapotranspiration rates during the period the restrictions were in effect. The statistical analysis indicates that the reduction in water use due to lawn watering restrictions was 603 acre-feet and that abnormal weather reduced use by an additional 659 acre-feet during the same period. During a period of normal evapotranspiration rates, such restrictions would be expected to reduce Fort Collins municipal water usage by 19.7 percent. |
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| publications-4646 |
article |
1981 |
Hansen, Roger D. and Hansen, Roger D. and Narayanan, Rangesan and Narayanan, Rangesan and Narayanan, Rangesan |
A MONTHLY TIME SERIES MODEL OF MUNICIPAL WATER DEMAND |
Journal of The American Water Resources Association |
10.1111/j.1752-1688.1981.tb01263.x |
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A multivariate time series model is formulated to study monthly variations in municipal water demand. The left hand side variable in the multivariate regression model is municipal water demand (gallons per connection per day) and the right hand side contains (explanatory) variables which include price (constant dollars), average temperature, total precipitation, and percentage of daylight hours. The application of the regression model to Salt Lake City Water Department data produced a high multiple correlation coefficient and F-statistic. The regression coefficients for the right hand side variables all have the appropriate sign. In an ex post forecast, the model accurately predicts monthly variations in municipal water demand. The proposed monthly multivariate model is not only found useful for forecasting water demand, but also useful for predicting and studying the impact of nonstructural management decisions such as the effect of price changes, peak load pricing methods, and other water conservation programs. |
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| publications-4647 |
article |
1982 |
Walski, Thomas M. and Walski, Thomas M. and Walski, Thomas M. and Walski, Thomas M. and Pelliccia, Anthony and Pelliccia, Anthony |
Economic analysis of water main breaks |
Journal American Water Works Association |
10.1002/j.1551-8833.1982.tb04874.x |
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Water distribution systems have a finite life. As pipes age, they lose their carrying capacity and become prone to breakage. There comes a time when it is more economical to replace a pipe than to repair it. Many cities, especially older ones in the Northeast, are having to deal with the high breakage rates typical of decaying systems. Unfortunately, little quantitative information is available to help water utilities determine precisely when a pipe should be replaced. The distribution system for the city of Binghamton, N.Y., is more than 100 years old and experiences pipe failures each year. In an effort to upgrade the system at the lowest possible cost, the state of New York asked the Baltimore district of the US Army Corps of Engineers to conduct an urban water supply system study for Binghamton. Baltimore district personnel inventoried the mains in the system, giving special attention to the number of pipe failures. With the use of a computer data base they prepared tables on the characteristics of the system and a report that summarized the occurrence of breaks for each pipe within the system. The report also offered some insight into the probable cause of the varying rates at which breaks occur (e.g., breaks resulting from severe cold weather between the months of |
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| publications-4648 |
article |
1983 |
Kirkpatrick, Scott and Kirkpatrick, Scott and Gelatt, C. D. and Gelatt, C. D. and Vecchi, M.P. and Vecchi, M.P. |
Optimization by Simulated Annealing |
Science |
10.1126/science.220.4598.671 |
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There is a deep and useful connection between statistical mechanics (the behavior of systems with many degrees of freedom in thermal equilibrium at a finite temperature) and multivariate or combinatorial optimization (finding the minimum of a given function depending on many parameters). A detailed analogy with annealing in solids provides a framework for optimization of the properties of very large and complex systems. This connection to statistical mechanics exposes new information and provides an unfamiliar perspective on traditional optimization problems and methods. |
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| publications-4649 |
article |
1986 |
Yeh, William W.β€G. and Yeh, William W.-G. |
Review of Parameter Identification Procedures in Groundwater Hydrology: The Inverse Problem |
Water Resources Research |
10.1029/wr022i002p00095 |
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The purpose of this survey is to review parameter identification procedures in groundwater hydrology and to examine computational techniques which have been developed to solve the inverse problem. Parameter identification methods are classified under the error criterion used in the formulation of the inverse problem. The problem of ill-posedness in connection with the inverse problem is addressed. Typical inverse solution techniques are highlighted. The review also includes the evaluation of methods used for computing the sensitivity matrix. Statistics which can be used to estimate the parameter uncertainty are outlined. Attempts have been made to compare and contrast representative inverse procedures, and direction for future research is suggested. |
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| publications-4650 |
article |
1989 |
Reddy, L. Srinivasa and Reddy, L. Srinivasa and Elango, K. and Elango, K. |
Analysis of water distribution networks with head-dependent outlets |
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10.1080/02630258908970550 |
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Abstract Conventional methods of analysis of a water distribution system impose specified quantities of demand at the nodes and compute the corresponding residual heads. In this study an almost fixed relationship between the residual head and the corresponding outflow is assumed in the analysis. Ignoring this relationship where it is essential may not display the true picture of network performance. Studies in this direction are of recent origin but are seen to impose an upper limit on the outflow beyond a certain level of residual head. In this study a methodology is proposed which takes into account the residual head versus outflow relationship having no clamping of the outflow. An efficient solution technique is employed for solving the governing equations. The appropriateness of the methodology is demonstrated with examples. |
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