Two broad surveys of community- level water consumption and pricing behavior are used to answer questions about water demand in a more flexible and dynamic context than is provided in the literature. Central themes of price representation, aggregation, and dynamic adjustment tie together three econometric demand analyses. The centerpiece of each analysis is an exogenous weighted price representation. A model in first-differences is estimated by ordinary least squares using data from a personally-conducted survey of Texas urban water suppliers. Annual price elasticity is found to vary with weather and income, with a value of -0.127 at the data mean. The dynamic model becomes a periodic error correction model when the residuals of 12 static monthly models are inserted into the difference model. Distinct residential, commercial, and industrial variables and historical climatic conditions are added to the integrated model, using new national data. Quantity demanded is found to be periodically integrated with a common stochastic root. Because of this, the structural monthly models must be cointegrated to be consistent, which they appear to be. The error correction coefficient is estimated at -0.187. Demand is found to be seasonal and slow to adjust to shocks, with little or no adjustment in a single year and 90% adjustment taking a decade or more. Residential and commercial demand parameters are found to be indistinguishable. The sources of price endogeneity and historical fixes are reviewed. Ideal properties of a weighted price index are identified. For schedules containing exactly two rates, weighting is equivalent to a distribution function in consumption. This property is exploited to derive empirical weights from the national data, using values from a nonparametric generalization of the structural demand model and a nonparametric cumulative density function. The result is a generalization of the price difference metric to a weighted level-price index. The validity of a uniform weighting is not rejected. The weighted price index is data intensive, but the payoff is increased depth and precision for the economist and accessibility for the practitioner.

The research reported on in this thesis forms part of the foundation of a bigger research project in which an attempt is made to provide better, faster and more efficient feedback on student writing. The introduction presents the localised and international context of the study, and discusses some of the problems experienced with feedback practice in general. The introduction also gives a preview of the intended practical implementation of the research reported on in this thesis. From there on, the thesis is presented in article form with each article investigating and answering a part of two main guiding questions. These questions are: 1. Does feedback on student writing work? 2. How can feedback on student writing be implemented as effectively as possible? The abstracts for the five individual articles are as follows: Article 1 Article 1 presents a rubric for the evaluation of Computer-Assisted Language Learning (CALL) software based on international recommendations for effective CALL. The rubric is presented after a brief overview of the pedagogical and implementation fundamentals of CALL, and a discussion of what needs to be included in a needs analysis for CALL evaluation. It is then illustrated how the evaluation criteria in the rubric can be used in the design of a new CALL system. Article 2 Providing feedback on student writing is a much-debated topic. One group of researchers argues that it is ineffective and another group remains convinced that it is effective, while at ground level teachers and lecturers simply carry on “marking” texts. The author of this article contends that both arguments have valid contributions to make and uses the arguments both for and against feedback to create a checklist for effective feedback practice. Adhering to this checklist should counter most of the arguments against feedback while supporting and improving the positive arguments in favour of feedback. Article 3 This article reports on an experiment which tested how effectively standardised feedback could be used when marking L2 student writing. The experiment was conducted using a custom-programmed software tool and a set of standardised feedback comments. The results of the experiment prove that standardised feedback can be used consistently and effectively to a degree, even though some refinements are still needed. Using standardised feedback in a standard marking environment can assist markers in raising their awareness of errors and in more accurately identifying where students lack knowledge. With some refinements, it may also be possible to speed up the marking process. Article 4 This article describes an experiment in which Boolean feedback (a kind of checklist) was used to provide feedback on the paragraph structures of first-year students in an academic literacy course. The major problems with feedback on L2 writing are introduced and it is established why a focus on paragraph structures in particular is of importance. The experiment conducted was a two-draft assignment in which three different kinds of feedback (technique A: handwritten comments; technique B: consciousness raising through generalised Boolean feedback; and technique C: specific Boolean feedback) were presented to three different groups of students. The results indicate that specific Boolean feedback is more effective than the other two techniques, partly because a higher proportion of the instances of negative feedback on the first draft were corrected in the second draft (improvements), but more importantly because in the revision a much lower number of changes to the text resulted in negative feedback on the second draft (regressions). For non-specific feedback, almost as many regressions occurred as improvements. In combination with automatic analytical techniques made possible with software, the results from this study make a case for using such checklists to give feedback on student writing. Article 5 This article describes an experiment in which a series of statements, answerable simply with yes or no (labelled Boolean feedback), were used to provide feedback on the introductions, conclusions and paragraph structures of student texts. A write-rewrite assignment (the same structure as in article 4) was used and the quality of the student revisions was evaluated. The results indicate that the students who received Boolean feedback showed greater improvement and fewer regressions than students who received feedback using the traditional method. The conclusion provides a brief summary as well as a preview of the immense future research possibilities made possible by this project. / Thesis (Ph.D. (English))--North-West University, Potchefstroom Campus, 2011.

The research reported on in this thesis forms part of the foundation of a bigger research project in which an attempt is made to provide better, faster and more efficient feedback on student writing. The introduction presents the localised and international context of the study, and discusses some of the problems experienced with feedback practice in general. The introduction also gives a preview of the intended practical implementation of the research reported on in this thesis. From there on, the thesis is presented in article form with each article investigating and answering a part of two main guiding questions. These questions are: 1. Does feedback on student writing work? 2. How can feedback on student writing be implemented as effectively as possible? The abstracts for the five individual articles are as follows: Article 1 Article 1 presents a rubric for the evaluation of Computer-Assisted Language Learning (CALL) software based on international recommendations for effective CALL. The rubric is presented after a brief overview of the pedagogical and implementation fundamentals of CALL, and a discussion of what needs to be included in a needs analysis for CALL evaluation. It is then illustrated how the evaluation criteria in the rubric can be used in the design of a new CALL system. Article 2 Providing feedback on student writing is a much-debated topic. One group of researchers argues that it is ineffective and another group remains convinced that it is effective, while at ground level teachers and lecturers simply carry on “marking” texts. The author of this article contends that both arguments have valid contributions to make and uses the arguments both for and against feedback to create a checklist for effective feedback practice. Adhering to this checklist should counter most of the arguments against feedback while supporting and improving the positive arguments in favour of feedback. Article 3 This article reports on an experiment which tested how effectively standardised feedback could be used when marking L2 student writing. The experiment was conducted using a custom-programmed software tool and a set of standardised feedback comments. The results of the experiment prove that standardised feedback can be used consistently and effectively to a degree, even though some refinements are still needed. Using standardised feedback in a standard marking environment can assist markers in raising their awareness of errors and in more accurately identifying where students lack knowledge. With some refinements, it may also be possible to speed up the marking process. Article 4 This article describes an experiment in which Boolean feedback (a kind of checklist) was used to provide feedback on the paragraph structures of first-year students in an academic literacy course. The major problems with feedback on L2 writing are introduced and it is established why a focus on paragraph structures in particular is of importance. The experiment conducted was a two-draft assignment in which three different kinds of feedback (technique A: handwritten comments; technique B: consciousness raising through generalised Boolean feedback; and technique C: specific Boolean feedback) were presented to three different groups of students. The results indicate that specific Boolean feedback is more effective than the other two techniques, partly because a higher proportion of the instances of negative feedback on the first draft were corrected in the second draft (improvements), but more importantly because in the revision a much lower number of changes to the text resulted in negative feedback on the second draft (regressions). For non-specific feedback, almost as many regressions occurred as improvements. In combination with automatic analytical techniques made possible with software, the results from this study make a case for using such checklists to give feedback on student writing. Article 5 This article describes an experiment in which a series of statements, answerable simply with yes or no (labelled Boolean feedback), were used to provide feedback on the introductions, conclusions and paragraph structures of student texts. A write-rewrite assignment (the same structure as in article 4) was used and the quality of the student revisions was evaluated. The results indicate that the students who received Boolean feedback showed greater improvement and fewer regressions than students who received feedback using the traditional method. The conclusion provides a brief summary as well as a preview of the immense future research possibilities made possible by this project. / Thesis (Ph.D. (English))--North-West University, Potchefstroom Campus, 2011.

The purpose of the paper is to explore the relationship between inflation and unemployment in Germany during the period from 1970 to 2012. Through the methods of cointegration, dynamic OLS and an error correction model, this paper highlights that there is no short run negative relationship between inflation and unemployment, and consequently the short run Phillips curve is an unsuitable instrument for making political decisions. Furthermore, there is a long run relationship between inflation and unemployment, which can be explained with asymmetric nominal wage rigidities and resulting frictional growth. Resulting policy implications reflect the advantage of a permanent higher inflation target for Germany. Since the beginning of the European Monetary Union, Germany has been on average 0.5% under the permanent inflation target of the central bank. Therefore, by using fiscal policy, Germany can reduce permanent unemployment without missing the inflation target of the central bank. Finally, despite of variety of intensive changes in the macroeconomic situation and particularly through the establishment of the European Monetary Union, the CUSUM and CUSUMsq test reveal that the estimate holds validity over the entire observation period and has not changed since the beginning of the European Monetary Union.

The development of a quantum computer presents one of the greatest challenges in science and engineering to date. The promise of more efficient computing based on entangled quantum states and the superposition principle has led to a worldwide explosion of interest in the fields of quantum information and computation. Among the number of hurdles which must first be cleared before we witness a physical realization are problems associated with environment-induced decoherence and noise more generally. However, the discovery of quantum error correction and the establishment of the accuracy threshold theorem provide us with the hope of someday harnessing the potential power a functioning fault-tolerant quantum information processor has to offer. This dissertation contributes to this effort by investigating a particular class of quantum error correcting codes, namely noiseless subsystem encodings. The passive approach to error correction taken by these encodings provides an efficient means of protection from symmetrically coupled system-environment interactions. Here I will present methods for determining the subsystem-preserving evolutions for noiseless subsystem encodings supported by arbitrary-dimensional physical quantum systems. Implications for universal, collective decoherence-free quantum computation using the derived operations are discussed. Moreover, I will present a proposal for an optical device which is capable of preparing a variety of these noiseless subsystem encodings through a postselection strategy.

Within the field of Quantum Information Processing, we study two subjects: For quantum state tomography, one common assumption is that the experimentalist possesses a stationary source of identical states. We challenge this assumption and propose a method to detect and characterize the drift of nonstationary quantum sources. We distinguish diffusive and systematic drifts and examine how quickly one can determine that a source is drifting. Finally, we give an implementation of this proposed measurement for single photons. For quantum computing, fault-tolerant protocols assume that errors are of certain types. But how do we detect errors of the wrong type? The problem is that for large quantum states, a full state description is impossible to analyze, and so one cannot detect all types of errors. We show through a quantum state estimation example (on up to 25 qubits) how to attack this problem using model selection. We use, in particular, the Akaike Information Criterion. Our example indicates that the number of measurements that one has to perform before noticing errors of the wrong type scales polynomially both with the number of qubits and with the error size. This dissertation includes previously published co-authored material.

The purpose of this essay is to answer the following questions: Has the increased e-commerce had a negative impact on the inflation, and is the effect decreasing? and: Is there a long term and/or short term effect by the increased e-commerce on the inflation? To answer the first question a fixed effects regression model is applied, based on panel data for 28 European countries for the time period 2006-2017. The regression obtains results that support the hypothesis that the increased e-commerce has had a negative effect on inflation. Furthermore, the result indicates that the effect is decreasing. The second question is answered with the help of an Error Correction Model and time series data for Sweden during the period 2006-2017. The result shows that there is an error correction towards a long run equilibrium and the short term estimates indicate that there is a negative short term effect of the increased e-commerce on inflation. These results are in line with the hypothesis of this essay as well as previous studies that have examined similar questions.

>Magister Scientiae - MSc / Purpose:This research investigates the existence of long-term equilibrium relationships among the stock market indices of Brazil, Russia, India, China and South Africa (BRICS). It further investigates cointegrated stock pairs for possible implementation of statistical arbitrage trading techniques.Design:We utilize standard multivariate time series analysis procedures to inspect unit roots to assess stationarity of the series. Thereafter, cointegration is tested by the Johansen and Juselius (1990) procedure and the variables are interpreted by a Vector Error Correction Model (VECM). Statistical arbitrage is investigated through the pairs trading technique.Findings:The five stock indices are found to be cointegrated. Analysis shows that the cointegration rank among the variables is significantly influenced by structural breaks. Two pairs of stock variables are also found to be cointegrated. This guaranteed the mean reversion property necessary for the successful execution of the pairs trading technique. Determining the optimal spread threshold also proved to be highly significant with respect to the success of this trading technique.Value:This research seeks to expand on the literature covering long-run co-movements of the volatile emerging market indices. Based on the cointegration relation shared by the BRICS, the research also seeks to encourage risk taking when investing. We achieve this by showing the potential rewards that can be realized through employing appropriate statistical arbitrage trading techniques in these markets.

Thesis discuss about effort to ensure from error, which may occur during transmission over noisy channel. There's used Reed Solomon code. It's block, cyclic and systematic code, which is symbol orientated. Computational process of decoding is mathematically time-consuming. In thesis is closely described Berlekamp-Masey algorithm, used in decoding to evaluate error polynomial. Process is illustrated in application in Matlab. Practical realization uses Reed Solomon code in communication over RS232. Communication is established between computer and microcomputer.

PhD (Advanced Nursing Science) / Department of Advanced Nursing Science / Cervical cancer may be preventable when screening services which detect cancerous cells at an early stage are utilized. Utilization of cervical cancer screening services, taking of Pap smear in particular, is effective if done systematically, that is, yearly or every ten years depending on whether the individual is at risk or not. Failure to utilize cervical cancer screening services predisposes women to cervical cancer because if one is affected, the disease will progress without one being aware. Studies have been carried out in this area, but not much has been done on strategies to promote the utilization of cervical cancer screening services. Purpose The purpose of this study was to develop an intervention strategy to promote utilization of cervical cancer screening services in Vhembe District, Limpopo Province, South Africa. Objective The specific objectives were to explore and describe the provision of cervical cancer screening services by Primary Health Care Nurses (PHCNs); assess the awareness of women on the utilization of cervical cancer screening services; develop an intervention strategy to promote utilization of cervical cancer screening services and to validate an intervention strategy to promote utilization of cervical cancer screening services at Vhembe District in Limpopo Province, South Africa. Methodology The research was conducted in three phases. In Phase I, qualitative and quantitative approaches were used. The qualitative approach was used to explore experiences of nurses concerning the provision of cervical cancer screening services and the quantitative approach applied for assessment of the awareness of women on the utilization of cervical screening services. The population in the qualitative approach were PHCNs providing cervical cancer services and, in the quantitative approach, were women aged 20-59. Nonprobability purposive sampling was used to sample 15 PHCNs and 500 women. Ethical considerations, that is, the rights of all the stakeholders were honoured. Data was collected from PHCNs through semi-structured interviews using an interview guide and from women through questionnaires. Reliability and validity of the research was ensured. Qualitative data was analyzed through open-coding and quantitative data through descriptive statistics (frequencies and percentages). ABSTRACT vi Results In Phase II, an intervention strategy to promote utilization of cervical cancer screening services in Vhembe District, Limpopo Province, South Africa was developed. The Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis was used to analyze the validity. Political, economic, socio-cultural, technological, environmental factors and laws within the opportunities and threats landscape of cervical cancer screening services in Vhembe District were analyzed. The Build, Overcome, Explore and Minimize (BOEM) paradigm was used to developed the intervention strategy. In Phase III, the qualitative and quantitative approach was used to validate the developed intervention strategies. A purposive sampling was used to sample fifteen PHCNs and 4 four managers. Conclusions Intervention strategies with action plans were developed. Recommendations Recommendations related to implementation of strategies to promote utilization of cervical cancer screening services were compiled.