scholarly journals Chronological review of South African guidelines for residential average annual water demand with property size as independent variable

2008 ◽  
Vol 27 (4) ◽  
pp. 240-265
Author(s):  
Heinz Jacobs
Keyword(s):  
South African ◽  
Computer Technology ◽  
Water Demand ◽  
Scientific Progress ◽  
Water Systems ◽  
Data Sets ◽  
Research Perspective ◽  
Independent Variable ◽  
Annual Water ◽  
Pure Research

Guidelines for residential average annual water demand (AADD) based on property size were introduced to the South African Civil Engineering fraternity in about 1960, with the most recent publication of such guidelines in 2008. The AADD forms the basis of calculations performed during the design and analysis of water systems. Over the years technology has improved, scientific progress was made and demand has changed, resulting in improved and updated guidelines for AADD. Changes in the guidelines over the years could be considered to be a result of improvement– larger and more accurate data sets are nowadays analysed statistically by improved computer technology. Also, the changes are considered to be the result of scientific advances in the fields of metering, modelling and analysis of water demand. Finally, actual changes in demand occur with time. This research provides the first documented review of the chronological development of AADD guidelines in South Africa. It is noted that only two guidelines were used for relatively long periods of time. In both cases the guidelines would not compare favourably to others from a pure research perspective, but their successful application is the result of a co-ordinated educational and marketing effort. The value of a sustained guideline structure (AADD versus stand size in this case) is also underlined.

Delivering Sustainable Water Systems Using Kalman Filter and Statistical Approach

2017 ◽  
Vol 4 (1) ◽  
pp. 41-52
Author(s):  
Dedy Loebis
Keyword(s):  
Kalman Filtering ◽  
Statistical Approach ◽  
Water Systems ◽  
Data Sets ◽  
Pressure Data ◽  
Burst Event ◽  
Sample Data ◽  
Other Information ◽  
Supply Systems ◽  
Frequency Features

This paper presents the results of work undertaken to develop and test contrasting data analysis approaches for the detection of bursts/leaks and other anomalies within wate r supply systems at district meter area (DMA)level. This was conducted for Yorkshire Water (YW) sample data sets from the Harrogate and Dales (H&D), Yorkshire, United Kingdom water supply network as part of Project NEPTUNE EP/E003192/1 ). A data analysissystem based on Kalman filtering and statistical approach has been developed. The system has been applied to the analysis of flow and pressure data. The system was proved for one dataset case and have shown the ability to detect anomalies in flow and pres sure patterns, by correlating with other information. It will be shown that the Kalman/statistical approach is a promising approach at detecting subtle changes and higher frequency features, it has the potential to identify precursor features and smaller l eaks and hence could be useful for monitoring the development of leaks, prior to a large volume burst event.

scholarly journals A proposed procedure for the analysis of large phytosociological data sets in the classification of South African grasslands

Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
G.J. Bredenkamp ◽  
H. Bezuidenhout
Keyword(s):  
South African ◽  
Plant Communities ◽  
Vegetation Type ◽  
Second Step ◽  
Data Sets ◽  
Vegetation Types ◽  
Related Plant ◽  
Single Cluster ◽  
Synoptic Table

A procedure for the effective classification of large phytosociological data sets, and the combination of many data sets from various parts of the South African grasslands is demonstrated. The procedure suggests a region by region or project by project treatment of the data. The analyses are performed step by step to effectively bring together all releves of similar or related plant communities. The first step involves a separate numerical classification of each subset (region), and subsequent refinement by Braun- Blanquet procedures. The resulting plant communities are summarised in a single synoptic table, by calculating a synoptic value for each species in each community. In the second step all communities in the synoptic table are classified by numerical analysis, to bring related communities from different regions or studies together in a single cluster. After refinement of these clusters by Braun-Blanquet procedures, broad vegetation types are identified. As a third step phytosociological tables are compiled for each iden- tified broad vegetation type, and a comprehensive abstract hierarchy constructed.

scholarly journals Comparative Cladistics: Fossils, Morphological Data Partitions and Lost Branches in the Fossil Tree of Life

2017 ◽  
Author(s):  
Ross Mounce
Keyword(s):  
Large Scale ◽  
Phylogenetic Signal ◽  
Scientific Progress ◽  
Molecular Data ◽  
Morphological Data ◽  
Data Sets ◽  
Phylogenetic Groups ◽  
Use Of Data ◽  
Wide Range ◽  
Cladistic Analyses

In this thesis I attempt to gather together a wide range of cladistic analyses of fossil and extant taxa representing a diverse array of phylogenetic groups. I use this data to quantitatively compare the effect of fossil taxa relative to extant taxa in terms of support for relationships, number of most parsimonious trees (MPTs) and leaf stability. In line with previous studies I find that the effects of fossil taxa are seldom different to extant taxa – although I highlight some interesting exceptions. I also use this data to compare the phylogenetic signal within vertebrate morphological data sets, by choosing to compare cranial data to postcranial data. Comparisons between molecular data and morphological data have been previously well explored, as have signals between different molecular loci. But comparative signal within morphological data sets is much less commonly characterized and certainly not across a wide array of clades. With this analysis I show that there are many studies in which the evidence provided by cranial data appears to be be significantly incongruent with the postcranial data – more than one would expect to see just by the effect of chance and noise alone. I devise and implement a modification to a rarely used measure of homoplasy that will hopefully encourage its wider usage. Previously it had some undesirable bias associated with the distribution of missing data in a dataset, but my modification controls for this. I also take an in-depth and extensive review of the ILD test, noting it is often misused or reported poorly, even in recent studies. Finally, in attempting to collect data and metadata on a large scale, I uncovered inefficiencies in the research publication system that obstruct re-use of data and scientific progress. I highlight the importance of replication and reproducibility – even simple reanalysis of high profile papers can turn up some very different results. Data is highly valuable and thus it must be retained and made available for further re-use to maximize the overall return on research investment.

scholarly journals A comparison of the visual status of dyslexic and non-dyslexic schoolchildren in Durban, South Africa

2011 ◽  
Vol 70 (1) ◽  
Author(s):  
S. O. Wajuihian ◽  
K. S. Naidoo
Keyword(s):  
South African ◽  
Educational Achievement ◽  
Economic Status ◽  
African Population ◽  
South African Population ◽  
Research Perspective ◽  
Black South African ◽  
Visual Status ◽  
Lag Of Accommodation ◽  
Vision Defects

Background:   Reading difficulties constitute an impediment to the learning process and in the educational achievement of a child. Consequently, several studies examined the visual status of dyslexic children in the Caucasian populations. Such studies are lacking in the African populations.Aim: To determine the prevalence of vision defects and investigate if there is an association between dyslexia and vision in a South African population of dyslexic school children.  Methods:  This comparative study assessed the visual function of 62 children (31 dyslexic and 31 normally-reading children), mean age 13 ± 1.42 years and 11.90 ± 0.93 years respectively. The participants were matched for gender, race and socio-economic status. The visual functions evaluated and the techniques used were: visual acuity (LogMAR acuity chart), refraction (static retinos-copy), ocular alignment (cover test) near point of convergence (RAF rule), accommodation facility (± 2 D flipper lenses), amplitude of accommodation (push-up method) relative accommodation(trial lenses) accommodation posture (monocular estimation technique) and vergence reserves (prism bars). Results:   In the following, results are  provided for the dyslexic versus control:  Refractive errors: (hyperopia 6.5% vs 3%,) (myopia 6.5% vs 6.5%), (astigmatism 10% vs 13%), (anisometropia 6.5% vs 6.5%) (amblyopia 6.5% vs 0%), (remote NPC 33% vs 48%) (esophoria at near 3%  vs 0%) (exophoria at near 9.5% vs 0%), (accommodative infacility at near  54% vs 33%), lag of accommodation 39.28% vs 41,93%,  (poor positive fusional amplitude at near, 25% vs 16%). Only the binocular accommodative facility at near was significantly associated with dyslexia (p=0.027). Conclusion: The prevalence of vision defects was similar between the dyslexic and non-dyslexic participants, which suggest that an association between dyslexia and vision variables investigated, cannot be inferred.  This study provides a research perspective on the prevalence of vision defects in a Black South African population of dyslexic children and has clinical relevance and implications for the assessment, detection and management of vision anomalies in dyslexic schoolchildren. (S Afr Optom 2011 70(1) 29-43) 

Reconciling opposites to reach compromise during ELT textbook development

2021 ◽  
pp. 136216882110402
Author(s):  
Dawn Atkinson
Keyword(s):  
English Language ◽  
Language Teaching ◽  
Qualitative Content Analysis ◽  
English Language Teaching ◽  
Data Sets ◽  
Authentic Material ◽  
Research Perspective ◽  
Textbook Evaluation ◽  
Think Aloud Protocols ◽  
Concurrent Verbalization

Though reports of pedagogic materials production point to the range of compromises authors make when writing language teaching textbooks, many accounts are retrospective in nature. This study sought to expand the research perspective by interrogating writing episodes via qualitative content analysis to discover how two expert ELT (English language teaching) textbook writers managed compromises during ongoing coursebook development. The authors’ data sets – primarily composed of think-aloud protocols and transcripts of pre- and post-concurrent verbalization interviews – revealed that they applied pragmatic judgement when contemplating the incorporation of textually authentic material and reconciled continuity and variety when developing unit frameworks and content, all with textbook audiences, contexts, and purposes in mind. Further, one of the authors reached compromise with project partners to integrate monologue and dialog texts into his book, while the other squared pedagogic imperatives with publishing realities by skillfully navigating textbook length, design, and deadline parameters during her project. By reconciling ostensible opposites to reach compromise, the authors balanced complexities to see their books through to completion. This research may inspire neophyte textbook writers’ efforts as they examine the architecture of writing sessions and prompt teachers to weigh authorial choices and balances during ELT textbook evaluation.

Optimisation of water demand forecasting by artificial intelligence with short data sets

2019 ◽  
Vol 177 ◽  
pp. 59-66 ◽  
Author(s):  
Rafael González Perea ◽  
Emilio Camacho Poyato ◽  
Pilar Montesinos ◽  
Juan Antonio Rodríguez Díaz
Keyword(s):  
Artificial Intelligence ◽  
Water Demand ◽  
Demand Forecasting ◽  
Data Sets ◽  
Water Demand Forecasting

scholarly journals Period Changes in Magellanic Cloud Cepheids

1984 ◽  
Vol 108 ◽  
pp. 227-228
Author(s):  
H. Deasy ◽  
P. A. Wayman
Keyword(s):  
South African ◽  
Variable Stars ◽  
Period Change ◽  
Magellanic Clouds ◽  
Rate Of Change ◽  
Data Sets ◽  
Fractional Change ◽  
Rates Of Change ◽  
Observatory Data ◽  
Irregular Period

It has been found possible to obtain information on period change in data on 115 cepheid variable stars in the Magellanic Clouds (84 LMC cepheids and 31 SMC cepheids). Harvard Observatory data of the period 1910 to 1950 (collated by Payne-Gaposchkin and Gaposchkin) are combined with Dunsink Observatory observations carried out by C.J. Butler in 1966/67 and with South African Astronomical Observatory observations covering the years 1975–1977 by Martin, Thomas, Carter and Davies to derive mean periods for the intervals between the various data sets. Using these new periods in conjunction with the very accurate Harvard periods, seperate estimates of the time averaged fractional change of period per day, d/dt (ln P), with corresponding estimated errors, could be evaluated for two epochs, one around 1950 and the other around 1971. It was found that 70 stars give rates of change of period that are not significantly different from zero, that 20 stars have two values of rate of change of period that are in agreement at the two epochs (indicative of secular period change), while 22 stars give two disparate values of rate of change of period (indicative of irregular period changes).

Un modèle hyperbolique pour l'ajustement de faisceaux de courbes hauteur–diamètre

1994 ◽  
Vol 24 (9) ◽  
pp. 1782-1790 ◽  
Author(s):  
Jean-François Dhôte ◽  
Éric de Hercé
Keyword(s):  
Large Range ◽  
Stand Density ◽  
Geometric Feature ◽  
Hyperbolic Model ◽  
Data Sets ◽  
Curve Shape ◽  
Qualitative Behaviour ◽  
Data Set ◽  
Fitting Procedure ◽  
Independent Variable

A hyperbolic model is proposed for the construction of sets of height–diameter curves in even-aged stands. On the basis of 86 samples from pure stands of beech (Fagussilvatica L.) and oak (Quercuspetraea (Matt.) Liebl), this model fitted adequately the geometry of data sets. The qualitative behaviour is correct over the whole range of the independent variable. Each parameter characterizes a significant geometric feature of the curve. The three parameters correspond to the asymptote, the slope at the origin, and the curve shape (curvature). The latter two are fairly stable over a large range of age (30–150 years) and stand density. A fitting procedure is proposed, through step-by-step reductions of the model, to overcome the limitations of poorly conditioned samples; only the asymptote, which is very close to top height, is to be estimated from each data set. The time series of estimates exhibit satisfactory evolutions for a large age interval. We interpret the shape of curve sets as the consequence of dominance on height and diameter growth in hierarchized stands.

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