Performance evaluation of the ISMLR package for predicting the next day's influent wastewater flowrate at Kirie WRP

2019 ◽  
Vol 80 (4) ◽  
pp. 695-706 ◽  
Author(s):  
Jun-Jie Zhu ◽  
Paul R. Anderson
Keyword(s):  
Low Frequency ◽  
Soft Sensor ◽  
Wastewater Management ◽  
Laboratory Measurements ◽  
Data Retention ◽  
Intelligent Monitoring ◽  
Know How ◽  
Sensor Applications ◽  
Frequency Monitoring ◽  
Available Information

Abstract Soft-sensor applications for wastewater management can provide valuable information for intelligent monitoring and process control above and beyond what is available from conventional hard sensors and laboratory measurements. To realize these benefits, it is important to know how to manage gaps in the data time series, which could result from the failure of hard sensors, errors in laboratory measurements, or low-frequency monitoring schedules. A robust soft-sensor system needs to include a plan to address missing data and efficiently select variable(s) to make the most use of the available information. In this study, we developed and applied an enhanced iterated stepwise multiple linear regression (ISMLR) method through a MATLAB-based package to predict the next day's influent flowrate at the Kirie water reclamation plant (WRP). The method increased the data retention from 77% to 93% and achieved an adjusted R2 up to 0.83 by integrating with a typical artificial neural network.

scholarly journals Economic Determinants of Industrial Water Demand: A Review of the Applied Research Literature

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1684
Author(s):  
Pilar Gracia-de-Rentería ◽  
Ramón Barberán
Keyword(s):  
Water Demand ◽  
Research Literature ◽  
Industrial Water ◽  
Methodological Issues ◽  
Economic Determinants ◽  
Future Studies ◽  
Know How ◽  
Level Of Activity ◽  
Industrial Water Demand ◽  
Available Information

This paper surveys the empirical, economic literature focused on the determinants of industrial water demand. Both the methodological issues and the outcomes of the previous studies are presented and discussed. Attention is given to key methodological issues, such as the available information, the type of data used, the specification of the variables, the choice of the estimated function, its functional form, and the estimation techniques used, highlighting the issues that require greater attention in future studies. Regarding the results, we focus on the estimated elasticities in order to know how the price of water, the level of activity, and the prices of the other inputs influence the demand for water.

scholarly journals A discipline for the avoidance of unnecessary assumptions

1971 ◽  
Vol 5 (3) ◽  
pp. 374-387 ◽  
Author(s):  
Lewis H. Roberts
Keyword(s):  
Scalar Case ◽  
Mean Square ◽  
William Of Ockham ◽  
Know How ◽  
Mathematical Formulas ◽  
The Subject ◽  
To Come ◽  
The Mind ◽  
Available Information ◽  
Do So

Although unnecessary assumptions are something we all try to avoid, advice on how to do so is much harder to come by than admonition. The most widely quoted dictum on the subject, often referred to by writers on philosophy as “Ockham's razor” and attributed generally to William of Ockham, states “Entia non sunt multiplicanda praeter necessitatem”. (Entities are not to be multiplied without necessity.) As pointed out in reference [I], however, the authenticity of this attribution is questionable.The same reference mentions Newton's essentially similar statement in his Principia Mathematica of 1726. Hume [3] is credited by Tribus [2c] with pointing out in 1740 that the problem of statistical inference is to find an assignment of probabilities that “uses the available information and leaves the mind unbiased with respect to what is not known.” The difficulty is that often our data are incomplete and we do not know how to create an intelligible interpretation without filling in some gaps. Assumptions, like sin, are much more easily condemned than avoided.In the author's opinion, important results have been achieved in recent years toward solving the problem of how best to utilize data that might heretofore have been regarded as inadequate. The approach taken and the relevance of this work to certain actuarial problems will now be discussed.Bias and PrejudiceOne type of unnecessary assumption lies in the supposition that a given estimator is unbiased when in fact it has a bias. We need not discuss this aspect of our subject at length here since what we might consider the scalar case of the general problem is well covered in textbooks and papers on sampling theory. Suffice it to say that an estimator is said to be biased if its expected value differs by an incalculable degree from the quantity being estimated. Such differences can arise either through faulty procedures of data collection or through use of biased mathematical formulas. It should be realized that biased formulas and procedures are not necessarily improper when their variance, when added to the bias, is sufficiently small as to yield a mean square error lower than the variance of an alternative, unbiased estimator.

Low-frequency laboratory measurements of the elastic properties of sandstone flooded with supercritical CO2

2013 ◽  
Vol 53 (2) ◽  
pp. 484
Author(s):  
Vassili Mikhaltsevitch ◽  
Maxim Lebedev ◽  
Boris Gurevich
Keyword(s):  
Supercritical Co2 ◽  
Low Frequency ◽  
Bedding Plane ◽  
Residual Water ◽  
Laboratory Measurements ◽  
Elastic Parameters ◽  
Sandstone Sample ◽  
Confining Pressures ◽  
The Difference ◽  
Set Up

This extended abstract presents the results of the first low-frequency experiments conducted on a sandstone sample (Donnybrook, WA) flooded with supercritical CO2 (scCO2). The experiments investigated the effects of scCO2 injection on the elastic and anelastic properties of the rock. The sandstone sample (porosity—11.4%, permeability—0.28 mD) was cut in the direction orthogonal to a formation-bedding plane and tested in a Hoek's triaxial pressure cell equipped with the means for independent control of pore and confining pressures. The pore and confining pressures were set up at 10 and 31 MPa correspondingly. The low-frequency system and the pump comprising of scCO2 were held at a temperature of 42°C. Supercritical CO2 was injected into the sample preliminary saturated with distilled water. The amount of the residual water in the sample after the scCO2 injection was about 40% of pore volume. The elastic parameters obtained for the sample with scCO2 at frequencies from 0.1–100 Hz are very close to those for the dry sample. Some discrepancy in calculated acoustic velocities are caused by the difference in water and scCO2 densities. The measured extensional attenuation is larger when the sample is saturated with scCO2. The applicability of Gassmann's fluid substitution theory for the interpretation of obtained results was also tested during the experiments.

THE MICROCOMPUTER IN THE SCHOOL LIBRARY: MISLIP IN SCOTTISH SECONDARY SCHOOLS

1986 ◽  
Vol 35 (4) ◽  
pp. 220-230
Author(s):  
DOROTHY A. WILLIAMS
Keyword(s):  
Secondary Schools ◽  
School Library ◽  
Independent Learning ◽  
Present Climate ◽  
Know How ◽  
Available Information

The present climate in education is one of change with increasing emphasis on independent learning and resource‐based learning. The decisions facing today's youngsters will require that they know how and where to “find out” for themselves, whether it is where to collect the relevant form, how to locate a useful contact address or how to make sense of the wealth of information available in any particular field of knowledge. Central to this ability to think and learn for oneself is the ability to make the best use of available information.

Transmitted Power in a Structure Using the Effective Mass Parameters

2010 ◽  
Author(s):  
Costin D. Untaroiu ◽  
Alexandrina Untaroiu ◽  
Matthew Wagner ◽  
Paul E. Allaire
Keyword(s):  
Power Flow ◽  
Complex Structure ◽  
Low Frequency ◽  
Connected Components ◽  
Vibration Modes ◽  
Lumped Mass ◽  
Know How ◽  
Stiffness Matrices ◽  
Lumped Mass Method ◽  
Fixed Interface

To reduce the vibration levels in a complex structure, the designer often needs to know how the vibrations in one part of a structure are transmitted to other parts at each interface of the connected components. A lumped-mass method and component mode synthesis is used to evaluate the power flow for vibrations in low-frequency range. The model mass and stiffness matrices are portioned into substructures separated by the interfaces whose power flow should be evaluated. The vibration modes of the substructure are divided into constrained and fixed interface modes corresponding to the interface and interior degree of freedoms, respectively. The effective interface mass criterion is used to rank the most dynamic important modes at each interface. The most important modes are preserved in a reduced model for computing the power flow. A numerical example of a linear system is used to illustrate the application of the new technique.

scholarly journals Leptin Deficiency, Caused by Malnutrition, Makes You Susceptible to SARS-CoV-2 Infection but Could Offer Protection from Severe COVID-19

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Dewald Schoeman ◽  
Burtram C. Fielding
Keyword(s):  
T Cell Activation ◽  
Cell Activation ◽  
Protective Factor ◽  
Severe Disease ◽  
Severe Malnutrition ◽  
Know How ◽  
Leptin Deficiency ◽  
Cellular Immune System ◽  
Cellular Immune ◽  
Available Information

ABSTRACT In much of the developing world, severe malnutrition is the most prevalent cause of immunodeficiency and affects up to 50% of the population in some impoverished communities. As yet, we do not know how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will behave in populations with immunodeficiency caused by malnourishment. Interestingly, researchers are now speculating that, in some instances, a defective cellular immune system could paradoxically be a protective factor against severe disease in certain patients contracting SARS-CoV and SARS-CoV-2. This could be linked to the absence of T-cell activation. Based on available information presented here, it is plausible that the hyperimmune response, and subsequent cytokine storm often associated with severe coronavirus disease 2019 (COVID-19), could be “counteracted” by the defective immune response seen in individuals with malnutrition-induced leptin deficiency. In this paper, we proposed a theory that although those with malnutrition-linked leptin deficiency are at risk of SARS-CoV-2 infection, they are at lower risk of developing severe COVID-19.

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