Scientific Results

This catalogue is obtained by conducting a systematic literature review of scientific studies and reviews related to monitoring, forecasting, and simulating the inland water cycle. The analysis maps scientific expertise across research groups and classifies findings by the type of inland water studied, application focus, and geographical scope. A gap analysis will identify missing research areas and assess their relevance to policymaking.

ID ▲ Type Year Authors Title Venue/Journal DOI Research type Water System Technical Focus Abstract Link with Projects Link with Tools Related policies ID
publications-4561 article 1978 Gibbs, Kenneth C. and Gibbs, Kenneth C. Price variable in residential water demand models Water Resources Research 10.1029/wr014i001p00015 There have been inconsistencies in past residential water demand studies concerning the specification of the relevant price variable. Both average and marginal price have been used. Households faced with the decision to expand (or contract) their water consumption are responsive to the additional cost (or savings) involved with this decision. The appropriate measure of this price is marginal price, not average price. Data were gathered from a large metropolitan area, Miami, Florida, to illustrate the divergence in estimation from two demand models, identically specified, except for the price variable. One utilized marginal price, the other average price. Predictions of consumption varied from 22 to 107\% between the two models. The average price model significantly overestimated the response of consumption to price and income changes, a result worthy of consideration.
publications-4562 article 1976 Nordin, J. A. and Nordin, John A. A Proposed Modification of Taylor's Demand Analysis: Comment The Bell Journal of Economics 10.2307/3003285 In estimating demand functions for electricity, it is inappropriate to use as a variable (in addition to marginal price) either average price for blocks other than the final one or total payment for blocks other than the final one. It is appropriate to use (in addition to marginal price) a variable equivalent to a lump-sum payment the customer must make before buying as many units as he wants, at the marginal price.
publications-4563 article 1994 Aitken, Campbell and Aitken, Campbell and McMahon, Thomas A. and McMahon, Thomas A. and Wearing, Alexander J. and Wearing, Alexander J. and Finlayson, Brian and Finlayson, Brian Residential Water Use: Predicting and Reducing Consumption1 Journal of Applied Social Psychology 10.1111/j.1559-1816.1994.tb00562.x This project had two goals: to explain variation in residential water consumption and to evaluate methods of encouraging residents to reduce their consumption. Survey data for both studies were collected by mail questionnaire in early 1991, and water consumption figures were recorded between June and August of that year. In Study 1 (n = 264) a three-variable regression model (number of residents, clothes washing machine loads, and property value) accounted for 60\% of the variance. Attitudes, habits and values were very poor predictors of water consumption. In Study 2 (n =226) households were divided into three treatment groups: feedback only, feedback and dissonance, and a control group. Repeated-measures ANOVA revealed that high consumers receiving dissonance and feedback or feedback alone had significantly reduced their water consumption in the treatment period. The implications of these findings are discussed.
publications-4564 article 2005 Kowalski, Mildred Ortu and Kowalski, M. and Marshallsay, D. and Marshallsay, D. Using measured microcomponent data to model the impact of water conservation strategies on the diurnal consumption profile Water Science & Technology: Water Supply 10.2166/ws.2005.0094 A recent collaborative research project by the Water Research Centre (WRc), involving 13 water companies and the UK Environment Agency, has yielded further information on the microcomponents of water use in domestic properties in the UK. Investigating the uncertainty and diurnal variations of the data has allowed the investigation of demand reduction strategies at household and supply area levels. The paper expands on these issues and discusses how this approach can be used to help plan and manage water supply in the future.
publications-4565 article 1984 Maidment, David R. and Maidment, David R. and Parzen, Emanuel and Parzen, Emanuel Cascade Model of Monthly Municipal Water Use Water Resources Research 10.1029/wr020i001p00015 A time series model of monthly municipal water use is formulated as a set of equations representing the effects of four factors on water use: trend, seasonality, autocorrelation, and climatic correlation. The parameters of these equations are found by passing the water use time series through a cascade of four transformations; in each transformation the parameters of an equation associated with one factor are statistically determined and the series transformed to remove the effects of this factor. After the last transformation, only a random error series remains. Monthly municipal water use at Canyon, Texas, from 1961–1978 is modeled as an example. The model explains 86\% of the variance of this series, divided among the four factors as trend (29\%), seasonality (44\%), autocorrelation (2\%), and climatic correlation (11\%). The random error is shown to be normally distributed by a nonparametric procedure characterizing probability families by their density quantile functions.
publications-4566 article 2017 Zhang, Hao and Zhang, Hao and Liu, Qiang and Liu, Qiang and Liu, Qiang and Liu, Qiang and Chen, Xin and Chen, Xin and Chen, Xin and Chen, Xin and Zhang, Ding and Zhang, Ding and Jiang, Pingyu and Leng, Jiewu and Leng, Jiewu and Leng, Jiewu A Digital Twin-Based Approach for Designing and Multi-Objective Optimization of Hollow Glass Production Line IEEE Access 10.1109/access.2017.2766453 Various new national advanced manufacturing strategies, such as Industry 4.0, Industrial Internet, and Made in China 2025, are issued to achieve smart manufacturing, resulting in the increasing number of newly designed production lines in both developed and developing countries. Under the individualized designing demands, more realistic virtual models mirroring the real worlds of production lines are essential to bridge the gap between design and operation. This paper presents a digital twin-based approach for rapid individualized designing of the hollow glass production line. The digital twin merges physics-based system modeling and distributed real-time process data to generate an authoritative digital design of the system at pre-production phase. A digital twin-based analytical decoupling framework is also developed to provide engineering analysis capabilities and support the decision-making over the system designing and solution evaluation. Three key enabling techniques as well as a case study in hollow glass production line are addressed to validate the proposed approach.
publications-4567 article 2017 Tao, Fei and Tao, Fei and Zhang, Meng and Zhang, Meng and Zhang, Meng Digital Twin Shop-Floor: A New Shop-Floor Paradigm Towards Smart Manufacturing IEEE Access 10.1109/access.2017.2756069 With the developments and applications of the new information technologies, such as cloud computing, Internet of Things, big data, and artificial intelligence, a smart manufacturing era is coming. At the same time, various national manufacturing development strategies have been put forward, such as Industry 4.0 , Industrial Internet , manufacturing based on Cyber-Physical System , and Made in China 2025 . However, one of specific challenges to achieve smart manufacturing with these strategies is how to converge the manufacturing physical world and the virtual world, so as to realize a series of smart operations in the manufacturing process, including smart interconnection, smart interaction, smart control and management, etc. In this context, as a basic unit of manufacturing, shop-floor is required to reach the interaction and convergence between physical and virtual spaces, which is not only the imperative demand of smart manufacturing, but also the evolving trend of itself. Accordingly, a novel concept of digital twin shop-floor (DTS) based on digital twin is explored and its four key components are discussed, including physical shop-floor, virtual shop-floor, shop-floor service system, and shop-floor digital twin data. What is more, the operation mechanisms and implementing methods for DTS are studied and key technologies as well as challenges ahead are investigated, respectively.
publications-4568 article 1990 Jowitt, Paul and Jowitt, Paul and Xu, Chengchao and Xu, Chengchao and Xu, Chengchao Optimal Valve Control in Water‐Distribution Networks Journal of Water Resources Planning and Management 10.1061/(asce)0733-9496(1990)116:4(455) The paper concerns the problems of minimization of leakage in water-distribution networks. It has been reported that leakage from some networks may account for a significant amount of the water put into supply. For some aging urban networks, rates of up to 50\% have been quoted, with average rates of 25\% being quite typical. These high rates of leakage represent a significant economic loss. An algorithm for the determination of flow control valve settings to minimize leakage is presented. The nonlinear network equations describing nodal heads and pipeflows are augmented by terms that explicitly account for pressure-dependent leakage and by terms that model the effect of valve actions. Successive linearization of these equations using the linear-theory method allows a linear program that minimizes leakage to be formulated and solved. The performance of the method is demonstrated by application to an example network.
publications-4569 article 1992 Zhang, G.R. and Zhang, G.R. and Kiéné, L. and Kiene, L. and Wable, O. and Wable, O. and Chan, U.S. and Chan, U.S. and Duguet, J.P. and Duguet, J.P. Modelling of chlorine residual in the water distribution network of Macao Environmental Technology 10.1080/09593339209385229 Abstract A study of chlorine modelling in sand filtered water (before postchlorination) of the Macao treatment plant indicates that the chlorine consumption in sand filtered water can be divided into two phases: an initial chlorine consumption during the first hour which corresponds to the contact time in the reservoir of the treatment plant and a long‐term chlorine consumption after one hour in the network which is interpreted in terms of an apparent first‐order equation. According to the experiments performed on the steel and asbestos cement pipes (diameter > 250 mm), the chlorine consumption by pipes is negligible. More experiments need to be performed to verify the eventual influence of water velocity and diameter of pipe on the chlorine consumption by pipe itself. The chlorine disappearance in the network of Macao can be modelled as first order equation with an average apparent kinetic constant 1.3 ± 0.3 × 10−3 min−1 using the Piccolo‐Quality software.
publications-4570 article 1996 Axtell, Robert L. and Axtell, Robert L. and Axelrod, Robert and Axelrod, Robert and Epstein, Joshua M. and Epstein, Joshua M. and Cohen, Michael D. and Cohen, Michael X Aligning Simulation Models: A Case Study and Results Computational and Mathematical Organization Theory 10.1007/bf01299065 This paper develops the concepts and methods of a process we will call "alignment of computational models" of "docking" for short. Alignment is needed to determine whether two models can produce the same results, which in turn is the basis for critical experiments and for tests of whether one model can subsume another. We illustrate our concepts andmethods using as a target a model of cultural transmission built by Axelrod. For comparison we use the Sugarscape model developed by Epstein and Axtell. The two models differ in many ways and, to date, have been employed with quite different aims. The Axelrod model has been used principally for intensive experimentation with parameter variation, and includes only one mechanism. In contrast, the Sugarscape model has been used primarily to generate rich "artificial histories," scenarios that display stylized facts of interest, such as cultural differentiation driven by many different mechanisms including resource availability, migration, trade, and combat. The Sugarscape model was modified so as to reproduce the results of the Axelrod cultural model. Among the questions we address are: what does it mean for two models to be equivalent, how can different standards of equivalence be statistically evaluated, and how do subtle differences in model design affect the results? After attaining a "docking" of the two models, the richer set of mechanisms of the Sugarscape model is used to provide two experiments in sensitivity analysis for the cultural rule of Axelrod's model. Our generally positive experience in this enterprise has suggested that it could be beneficial if alignment and equivalence testing were more widely practiced among computational modellers.