Sustainable operations and maintenance of water supplies: a conceptual model for engineers and development workers : a thesis submitted in partial fulfilment of the requirement for the degree of Master of Philosophy in Development Studies and Agricultural Engineering at Massey University

There have been major problems with the sustainability of many water supply projects in the Developing World. One major area that influences this sustainability is the ongoing operation and maintenance of the water supply. A number of different surveys have shown that within 12 months of a water project being constructed and handed over to the community or government water dept. between 30-70% are not functioning at all or are not producing their original design supply. The purpose of the research was to produce a conceptual model that could be used by development agencies and engineers to increase the sustainability of water supplies. A review of the literature revealed that the major factors influencing sustainable operation and maintenance of water supplies were, technology, infrastructure for parts, training of both agency and community in maintenance of the water supply, the source of funding for O & M, design, ownership and responsibility, and management. These factors were incorporated into a conceptual model, each factor fitting into one or more of the different stages of a water supply project, namely: 1. Planning; 2. Design; 3. Construction; 4. Transfer Ceremony; and 5. Operations. There were up to four major groups of people involved in this process, namely, an International Development Agency, a Government Water Dept., a Community Water Committee, and a Community or Users. Surveys were conducted in Ethiopia, looking at both urban and rural water projects. The results were used to substantiate the model and/or to revise the model. It was concluded from the survey that the following were influential upon sustainable operation and maintenance in Ethiopia: Community ownership does not equate to community responsibility for O & M; Training of the individual or group responsible for O & M is essential; A lack of infrastructure leds to O & M problems; And, community involvement in all stages of the water supply project is essential. The revised conceptual model presents the processes and factors needed to instigate sustainable O & M of water supply projects in developing countries

Towards an Efficient Evaluation of General Queries

Database applications often require to evaluate queries containing quantifiers or disjunctions, e.g., for handling general integrity constraints. Existing efficient methods for processing quantifiers depart from the relational model as they rely on non-algebraic procedures. Looking at quantified query evaluation from a new angle, we propose an approach to process quantifiers that makes use of relational algebra operators only. Our approach performs in two phases. The first phase normalizes the queries producing a canonical form. This form permits to improve the translation into relational algebra performed during the second phase. The improved translation relies on a new operator - the complement-join - that generalizes the set difference, on algebraic expressions of universal quantifiers that avoid the expensive division operator in many cases, and on a special processing of disjunctions by means of constrained outer-joins. Our method achieves an efficiency at least comparable with that of previous proposals, better in most cases. Furthermore, it is considerably simpler to implement as it completely relies on relational data structures and operators

Hidden Conformal Invariance of Scalar Effective Field Theories

We argue that conformal invariance is a common thread linking several scalar effective field theories that appear in the double copy and scattering equations. For a derivatively coupled scalar with a quartic ${\cal O}(p^4)$ vertex, classical conformal invariance dictates an infinite tower of additional interactions that coincide exactly with Dirac-Born-Infeld theory analytically continued to spacetime dimension $D=0$. For the case of a quartic ${\cal O}(p^6)$ vertex, classical conformal invariance constrains the theory to be the special Galileon in $D=-2$ dimensions. We also verify the conformal invariance of these theories by showing that their amplitudes are uniquely fixed by the conformal Ward identities. In these theories, conformal invariance is a much more stringent constraint than scale invariance.Comment: 7 page

NATURAL LANGUAGE QUERYING OF HISTORICAL DATABASES -- THE QE-III LANGUAGE DEFINITION AND EXAMPLES

Information Systems Working Papers Serie

TOWARDS AN ALGEBRA OF HISTORICAL RELATIONAL DATABASES

In search of the appropriate semantics for the inclusion of structures and operations that will meet the needs of a wide class of users interested in a database system supporting temporal views of their data, the paper includes a discussion of many problems that must be addressed. Salient features of the authorâs Historical Relational Database Model (HRDBM) are presented, and some subtle nuances that time brings to the development of an historical relational algebra are illustrated. Along the way, a number of observations and guidelines are presented that may help guide the search for an historically relationally complete database model and query languages.Information Systems Working Papers Serie

Detailing the Genetic and Environmental Influences Shared between Conventional and Electronic Cigarette Use Across Measures of Initiation and Past 12-Month Use

Introduction. Tobacco use is a public health crisis with nearly 500,000 Americans suffering premature mortality attributable to tobacco use in 2014. New development efforts have created new nicotine delivery systems whose health consequences are not yet fully understood such as electronic cigarettes (ECIG). It is possible there are shared genetic and environmental factors that influence an individual’s liability to initiate cigarette (CIG) or ECIG use, as both systems are designed to deliver nicotine. Methods. Four study designs were used to resolve the genetic and environmental influences that underlie CIG and ECIG initiation. A twin study, scoping review, genome-wide association study (GWAS), and moderation model examined these potential sources of variation. Results. The twin study suggested there were shared genetic factors between CIG and ECIG initiation. Univariate GWAS analysis of ECIG found no genome-wide significant hits among self-identified white participants. Genome-wide polygenic scores also showed no association between CIG and ECIG initiation. Statistical evidence of a weak interaction between ECIG coupon receipt, income level, and CIG use was reported. A review of tobacco use measures in genetically informative samples found that how individual studies measured different aspects of tobacco use lead to different genome-wide significant results. Conclusions. These analyses suggest there are shared genetic and environmental influences between CIG and ECIG. Low sample sizes may have contributed to non-significant findings of measured molecular genetic effects, though genome-wide suggestive findings indicate further research is needed. Further, aggregating genome-wide association study results by biological function may increase the consistency of findings

Comparison of Wechsler Memory Scale–Fourth Edition (WMS–IV) and Third Edition (WMS–III) dimensional structures: Improved ability to evaluate auditory and visual constructs

Dimensional structures underlying the Wechsler Memory Scale–Fourth Edition (WMS–IV) and Wechsler Memory Scale–Third Edition (WMS–III) were compared to determine whether the revised measure has a more coherent and clinically relevant factor structure. Principal component analyses were conducted in normative samples reported in the respective technical manuals. Empirically supported procedures guided retention of dimensions. An invariant two-dimensional WMS–IV structure reflecting constructs of auditory learning/memory and visual attention/memory (C1 = .97; C2 = .96) is more theoretically coherent than the replicable, heterogeneous WMS–III dimension (C1 = .97). This research suggests that the WMS–IV may have greater utility in identifying lateralized memory dysfunction