| publications-3891 |
article |
2005 |
Covas, DĪĀdia and Covas, DĪĀdia and Ramos, Helena M. and Ramos, Helena M. and de Almeida, AntĪĀ³nio BetĪĪmio and de Almeida, A. BetĪĪmio |
Standing Wave Difference Method for Leak Detection in Pipeline Systems |
Journal of Hydraulic Engineering |
10.1061/(asce)0733-9429(2005)131:12(1106) |
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The current paper focuses on leakage detection in pipe systems by means of the standing wave difference method (SWDM) used for cable fault location in electrical engineering. This method is based on the generation of a steady-oscillatory flow in a pipe system, by the sinusoidal maneuver of a valve, and the analysis of the frequency response of the system for a certain range of oscillatory frequencies. The SWDM is applied to several configurations of pipe systems with different leak locations and sizes. A leak creates a resonance effect in the pressure signal with a secondary superimposed standing wave. The pressure measurement and the spectral analysis of the maximum pressure amplitude at the excitation site enable the identification of the leak frequencies and, consequently, the estimation of the leak approximate location. Practical difficulties of implementation of this technique in real life systems are discussed. |
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| publications-3892 |
article |
2000 |
Haddad, Brent M. and Haddad, Brent M. |
Economic incentives for water conservation on the Monterey Peninsula : The market proposal |
Journal of The American Water Resources Association |
10.1111/j.1752-1688.2000.tb04244.x |
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: Literatures on price-based urban water conservation and on market-based mechanisms to manage natural resources suggest that market-based management of urban/suburban water use may be feasible. A market-based proposal that emerged from a water shortage on California's Monterey Peninsula is presented. In the proposal, conservation incentives arise both from an ability among end-users of water to reduce consumption and sell use-rights to water, and from a penalty price for consumption in excess of one's use rights. The amount of water associated with use rights is capped and varies according to hydrological, meteorological, ecological, and other criteria. Requirements for further study of the proposal are listed, and the role that similar market-based mechanisms could play in urban water management is discussed. |
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| publications-3893 |
article |
2012 |
JavernickĪ²ā¬ĀWill, Amy and Javernick-Will, Amy |
Motivating Knowledge Sharing in Engineering and Construction Organizations: Power of Social Motivations |
Journal of Management in Engineering |
10.1061/(asce)me.1943-5479.0000076 |
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AbstractKnowledge management initiatives have proliferated in recent years because of the desire to have employees share their knowledge throughout the organization. However, in practice, many of these initiatives fail to achieve their initial goals. Because knowledge fundamentally resides with people, knowledge management research and initiatives must move from a focus on macrolevel variables at the organizational level to include an understanding of microlevel variables at the individual level of why employees engage in these knowledge management initiatives. This research aims to understand participation in organizational knowledge sharing by identifying and exploring the reasons why employees share their knowledge. This is done through qualitative case studies with 48 employees in 13 multinational engineering, construction, and real estate development firms. Using an embedded unit of analysis of knowledge sharing motivations of employees, a qualitative analysis revealed four primary factors related to... |
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| publications-3894 |
article |
2009 |
BarabĪĪ
si, AlbertĪ²ā¬ĀLĪĪ
szlĪĀ³ and BarabĪĪ
si, Albert-LĪĪ
szlĪĀ³ |
Scale-Free Networks: A Decade and Beyond |
Science |
10.1126/science.1173299 |
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For decades, we tacitly assumed that the components of such complex systems as the cell, the society, or the Internet are randomly wired together. In the past decade, an avalanche of research has shown that many real networks, independent of their age, function, and scope, converge to similar architectures, a universality that allowed researchers from different disciplines to embrace network theory as a common paradigm. The decade-old discovery of scale-free networks was one of those events that had helped catalyze the emergence of network science, a new research field with its distinct set of challenges and accomplishments. |
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| publications-3895 |
article |
1990 |
McCulloch, Warren S. and McCulloch, Warren S. and Pitts, Walter and Pitts, Walter |
A logical calculus of the ideas immanent in nervous activity |
Bulletin of Mathematical Biology |
10.1016/s0092-8240(05)80006-0 |
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Because of the Ī²ā¬_x009c_all-or-noneĪ²ā¬_x009d_ character of nervous activity, neural events and the relations among them can be treated by means of propositional logic. It is found that the behavior of every net can be described in these terms, with the addition of more complicated logical means for nets containing circles; and that for any logical expression satisfying certain conditions, one can find a net behaving in the fashion it describes. It is shown that many particular choices among possible neurophysiological assumptions are equivalent, in the sense that for every net behaving under one assumption, there exists another net which behaves under the other and gives the same results, although perhaps not in the same time. Various applications of the calculus are discussed. |
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| publications-3896 |
article |
2005 |
BarĪĪ
n, BenjamĪĀn and BarĪĪ
n, BenjamĪĀn and von LĪĪcken, Christian and von LĪĪcken, Christian and Sotelo, Aldo and Sotelo, Aldo |
Multi-objective pump scheduling optimisation using evolutionary strategies |
Advances in Engineering Software |
10.1016/j.advengsoft.2004.03.012 |
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| publications-3897 |
article |
2013 |
Parker, Joanne M. and Parker, Joanne M. and Wilby, Robert L. and Wilby, Robert L. |
Quantifying Household Water Demand: A Review of Theory and Practice in the UK |
Water Resources Management |
10.1007/s11269-012-0190-2 |
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Socio-economic change, severe droughts, and environmental concerns focus attention on sustainability of water supplies and the ability of water utilities to meet levels of service. Traditionally, water management has been supply-side dominated and long-term demand forecasting has received relatively little attention. However, it is increasingly recognised that water demand management could be a Ī²ā¬Ālow regretĪ²ā¬ā¢ adaptation measure (both financially and environmentally) given large uncertainties about future non-climate and climate pressures. This paper begins with a brief history of household water demand management in the UK. We then review approaches to water demand estimation and forecasting over the short- (daily to season) and long-term (years to decade) and note the paucity of studies on weather and climate. We discuss peak household water use behaviours identified from metering trials, micro-component diary-based studies, and statistical techniques for long-term demand forecasting. We refer to the Anglian Water Services (AWS) Ī²ā¬ĀGolden 100Ī²ā¬ā¢ data to illustrate the significant practical and conceptual issues faced when mining household water use data for weather signals, especially when the data are noisy and originally intended for other applications. Further research is needed into the relationships between climate variables and household micro-component water use, especially for peak demands. |
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| publications-3898 |
article |
2013 |
Linkola, Lilli and Linkola, Lilli and Andrews, Clinton J. and Andrews, Clinton J. and Schuetze, Thorsten and Schuetze, Thorsten |
An Agent Based Model of Household Water Use |
Water |
10.3390/w5031082 |
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Households consume a significant fraction of total potable water production. Strategies to improve the efficiency of water use tend to emphasize technological interventions to reduce or shift water demand. Behavioral water use reduction strategies can also play an important role, but a flexible framework for exploring the Ī²ā¬_x009c_what-ifsĪ²ā¬_x009d_ has not been available. This paper introduces such a framework, presenting an agent-based model of household water-consuming behavior. The model simulates hourly water-using activities of household members within a rich technological and behavioral context, calibrated with appropriate data. Illustrative experiments compare the resulting water usage of U.S. and Dutch households and their associated water-using technologies, different household types (singles, families with children, and retired couples), different water metering regimes, and educational campaigns. All else equal, Dutch and metered households use less water. Retired households use more water because they are more often at home. Water-saving educational campaigns are effective for the part of the population that is receptive. Important interactions among these factors, both technological and behavioral, highlight the value of this framework for integrated analysis of the human-technology-water system. |
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| publications-3899 |
article |
1999 |
Watts, Duncan J. and Watts, Duncan J. |
Networks, dynamics, and the small-world phenomenon |
American Journal of Sociology |
10.1086/210318 |
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The smallĪ²ā¬Āworld phenomenon formalized in this article as the coincidence of high local clustering and short global separation, is shown to be a general feature of sparse, decentralized networks that are neither completely ordered nor completely random. Networks of this kind have received little attention, yet they appear to be widespread in the social and natural sciences, as is indicated here by three distinct examples. Furthermore, small admixtures of randomness to an otherwise ordered network can have a dramatic impact on its dynamical, as well as structural, propertiesĪ²ā¬Āa feature illustrated by a simple model of disease transmission. |
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| publications-3900 |
article |
2013 |
Garrick, Dustin and Garrick, Dustin and Whitten, Stuart M. and Whitten, Stuart M. and Coggan, Anthea and Coggan, Anthea and Coggan, Anthea |
Understanding the evolution and performance of water markets and allocation policy: A transaction costs analysis framework |
Ecological Economics |
10.1016/j.ecolecon.2012.12.010 |
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