1,721,029 research outputs found
The Power and Water Sectors
Full text linkThis book evaluates -using for the first time a single consistent methodology and the state-of-the-arte climate scenarios-, the impacts of climate change on hydro-power and irrigation expansion plans in Africa’s main rivers basins (Niger, Senegal, Volta, Congo, Nile, Zambezi, Orange); and outlines an approach to reduce climate risks through suitable adjustments to the planning and design process. The book finds that failure to integrate climate change in the planning and design of power and water infrastructure could entail, in scenarios of drying climate conditions, losses of hydropower revenues between 5% and 60% (depending on the basin); and increases in consumer expenditure for energy up to 3 times the corresponding baseline values. In in wet climate scenarios, business-as-usual infrastructure development could lead to foregone revenues in the range of 15% to 130% of the baseline, to the extent that the larger volume of precipitation is not used to expand the production of hydropower.
Despite the large uncertainty on whether drier or wetter conditions will prevail in the future in Africa, the book finds that by modifying existing investment plans to explicitly handle the risk of large climate swings, can cut in half or more the cost that would accrue by building infrastructure on the basis of the climate of the past
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Efficiency and equity considerations in modeling inter-sectoral water demand in South Africa
Full text linkThesis (PhD (Environmental Economics))--University of Pretoria, 2008.Empirical studies have shown that while global per capita freshwater availability is declining, competition among production sectors for the withdrawal of this resource is rapidly increasing. This situation is exacerbated by the rapid population growth especially in developing countries, urbanization, industrialization, externality problems, environmental sustainability and the need to increase food production. At country specific levels, policies have been designed to institute water use efficiency, equity and sustainability. The need to promote sectoral water use efficiency from the demand-side management requires a study to investigate the responsiveness of different production sectors and sub-sectors to variations in water prices. In most instances however, efficient water allocation compromises social equity, especially in a country where there is widespread poverty and where the gap between the rich and the poor is so wide that policies aimed at promoting economic growth should be carefully investigated to find whether efficient water allocation can also address the issue of equity among the different population groups. Review of empirical literature on the econometric approaches to sectoral water demand analysis shows that the agriculture sector has the least marginal value of water compared with the manufacturing, mining and services sectors. Based on this evidence it can be hypothesized that water reallocation from the agriculture to the non-agriculture sectors in South Africa can lead to growth in sectoral output. However, in a country where there is a wide gap between the rich and the poor, equity issues are high on the development agenda. Therefore, the benefits derived from efficient water reallocation should be equitably distributed to improve the standard of living of the critical population. Hence, the second hypothesis is that water reallocation from the agriculture to the non-agriculture sector can lead to an increase in the income of the critical population. To investigate these hypotheses the study: estimated the sectoral water demand functions and marginal values, used both social accounting matrix multiplier and computable general equilibrium analysis to investigate the impact of water reallocation from the agriculture to the non-agriculture sectors on output, factor payments on households’ welfare and analyzed the households’ welfare of the impact of global change on water resources in South Africa. The study used the Global Trade Analysis Project (GTAP) and United Nations Industrial Development Organization (UNIDO) data, and adopted the marginal productivity approach, and the two-stage model to estimate the global sectoral water demand functions and marginal values for thirteen sectors. This model is extended to the sectoral water demand analysis in South Africa. Thus, to validate the results of the global model, the study estimated sectoral water demand functions in South Africa by extracting data from STATSSA’s census of manufacturing and agricultural and services activities, published for each of the nine provinces in South Africa and the 2002 water supply and use accounts published by the same institution. The study tests the policy relevance of the computed marginal values for South Africa by using these values to investigate the impact of reallocating water from the agriculture to the non-agriculture sectors on output growth, value added, employment and households’ income generation.. To accomplish this objective, the study updates the 1999 social accounting matrix (SAM) for South Africa to reflect 2003 entries, computes the required multipliers and uses these to find how water reallocation on the basis of efficiency impacts sectoral output, households income generation and distribution. However, SAM multiplier analyses assume linearity, factor immobility and constant prices. The study therefore uses the computable general equilibrium analysis to investigate the households’ welfare implications of sectoral water reallocation and reduction due to global change. The SAM multiplier analysis shows that reallocation of water from the agriculture to the non-agriculture sectors leads to decrease in the output of the agriculture and the highly inter-dependent sectors. Specifically, output declines in the agriculture, food, beverages and tobacco and the services sectors, while it increases in the other sectors. However, if more than ten percent of the agriculture sector’s water is reallocated to the non-agriculture sector, net output declines, implying that the decline in output in the agriculture, food, beverages and tobacco and services sectors is more than the increase in output in the other sectors. This has consequences for factor remuneration, employment and households’ income. The above decline in the agriculture sector’s output leads to net job losses. Specifically the jobs lost in the agriculture sector are not countered by jobs created in the other sectors that benefit from the water reallocation. This is due to the fact that there are differences in skills requirements by the sectors. While the agriculture sector employs most of the unskilled workers, the other sectors require more medium and highly skilled individuals. This is reflected by changes in the wages paid to labourers. While the wages of unskilled labourers decline, there is an increase in the wages of medium and highly skilled labourers. The simulation results of the computable general equilibrium analysis show that sectoral water reallocation and reduction adversely impact the least and low-income households’ welfare, while improving the welfare of the high-income households. The interpretation is that with water reallocation or reduction, capital is substituted for water in the non-agriculture sectors and this increases the interest paid on capital, which goes to high-income households who are the owners of the capital. The adverse consequence can be reduced if food consumption by the poor households is maintained. To do this, some welfare measures are necessary. One such measure is the distribution of food stamps to the poor households.Agricultural Economics, Extension and Rural Developmentunrestricte
Enhancing the climate resilience of Africa's infrastructure: the power and water sectors
No full textAfrica has experienced economic growth of more than 5 percent per annum during the past decade, but to sustain this growth, investment in infrastructure is fundamental. Much of these investments will support the construction of long-lived infrastructure (for example, dams, power stations, and irrigation canals), which will be vulnerable to the potentially harsher climate of the future. This book is the first to use a consistent approach across river basins and power systems in Africa, including a comprehensive, broad set of state-of-the-art climate projections to evaluate the risks posed by climate change to planned investments in Africa’s water, and power sectors. It further analyzes how investment plans can be modified to mitigate those risks, and it quantifies the corresponding benefits and costs, within the limits of a largely desk-based assessment. The scope of the study includes seven major river basins (Congo, Niger, Nile, Senegal, Upper Orange, Volta, and Zambezi) and four power pools (Central, Eastern, Southern, and West African). The study addresses the entire program for infrastructure development in Africa (PIDA) hydropower capacity enhancements in the subject basins, as part of the region’s overall power generation plans, as well as additional investments in irrigation that are included in regional and national master plans
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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