9 resultados para Lower and Upper Solutions
em Dalarna University College Electronic Archive
Resumo:
This paper explores the relationship between the growth rate of the average income and income inequality using data at the municipal level in Sweden for the period 1992-2007. We estimate a fixed effects panel data growth model where the within-municipality income inequality is one of the explanatory variables. Different inequality measures (Gini coefficient, top income shares, and measures of inequality in the lower and upper ends of the income distribution) are also examined. We find a positive and significant relationship between income growth and income inequality, measured as the Gini coefficient and top income shares, respectively. In addition, while inequality at the upper end of the income distribution is positively associated with the income growth rate, inequality at the lower end of the income distribution seems to be negatively related to the growth rate. Our findings also suggest that increased income inequality enhances growth more in municipalities with a high level of average income than in those with a low level of average income.
Resumo:
This thesis consists of a summary and four self-contained papers. Paper [I] Following the 1987 report by The World Commission on Environment and Development, the genuine saving has come to play a key role in the context of sustainable development, and the World Bank regularly publishes numbers for genuine saving on a national basis. However, these numbers are typically calculated as if the tax system is non-distortionary. This paper presents an analogue to genuine saving in a second best economy, where the government raises revenue by means of distortionary taxation. We show how the social cost of public debt, which depends on the marginal excess burden, ought to be reflected in the genuine saving. We also illustrate by presenting calculations for Greece, Japan, Portugal, U.K., U.S. and OECD average, showing that the numbers published by the World Bank are likely to be biased and may even give incorrect information as to whether the economy is locally sustainable. Paper [II] This paper examines the relationships among per capita CO2 emissions, per capita GDP and international trade based on panel data spanning the period 1960-2008 for 150 countries. A distinction is also made between OECD and Non-OECD countries to capture the differences of this relationship between developed and developing economies. We apply panel unit root and cointegration tests, and estimate a panel error correction model. The results from the error correction model suggest that there are long-term relationships between the variables for the whole sample and for Non-OECD countries. Finally, Granger causality tests show that there is bi-directional short-term causality between per capita GDP and international trade for the whole sample and between per capita GDP and CO2 emissions for OECD countries. Paper [III] Fundamental questions in economics are why some regions are richer than others, why their growth rates differ, whether their growth rates tend to converge, and what key factors contribute to explain economic growth. This paper deals with the average income growth, net migration, and changes in unemployment rates at the municipal level in Sweden. The aim is to explore in depth the effects of possible underlying determinants with a particular focus on local policy variables. The analysis is based on a three-equation model. Our results show, among other things, that increases in the local public expenditure and income taxe rate have negative effects on subsequent income income growth. In addition, the results show conditional convergence, i.e. that the average income among the municipal residents tends to grow more rapidly in relatively poor local jurisdictions than in initially “richer” jurisdictions, conditional on the other explanatory variables. Paper [IV] This paper explores the relationship between income growth and income inequality using data at the municipal level in Sweden for the period 1992-2007. We estimate a fixed effects panel data growth model, where the within-municipality income inequality is one of the explanatory variables. Different inequality measures (Gini coefficient, top income shares, and measures of inequality in the lower and upper part of the income distribution) are examined. We find a positive and significant relationship between income growth and income inequality measured as the Gini coefficient and top income shares, respectively. In addition, while inequality in the upper part of the income distribution is positively associated with the income growth rate, inequality in the lower part of the income distribution seems to be negatively related to the income growth. Our findings also suggest that increased income inequality enhances growth more in municipalities with a high level of average income than in municipalities with a low level of average income.
Resumo:
The aim of this master thesis is an investigation of the thermal performance of a thermal compound parabolic concentrating (CPC) collector from Solarus. The collector consists of two troughs with absorbers which are coated with different types of paint with unknown properties. The lower and upper trough of the collector have been tested individually. In order to accomplish the performance of the two collectors, a thorough literature study in the fields of CPC technology, various test methods, test standards for solar thermal collectors as well as the latest articles relating on the subject were carried out. In addition, the set‐up of the thermal test rig was part of the thesis as well. The thermal performance was tested according to the steady state test method as described in the European standard 12975‐2. Furthermore, the thermal performance of a conventional flat plate collector was carried out for verification of the test method. The CPC‐Thermal collector from Solarus was tested in 2013 and the results showed four times higher values of the heat loss coefficient UL (8.4 W/m²K) than what has been reported for a commercial collector from Solarus. This value was assumed to be too large and it was assumed that the large value was a result of the test method used that time. Therefore, another aim was the comparison of the results achieved in this work with the results from the tests performed in 2013. The results of the thermal performance showed that the optical efficiency of the lower trough of the CPC‐T collector is 77±5% and the corresponding heat loss coefficient UL 4.84±0.20 W/m²K. The upper trough achieved an optical efficiency of 75±6 % and a heat loss coefficient UL of 6.45±0.27 W/m²K. The results of the heat loss coefficients are valid for temperature intervals between 20°C and 80°C. The different absorber paintings have a significant impact on the results, the lower trough performs overall better. The results achieved in this thesis show lower heat loss coefficients UL and higher optical efficiencies compared to the results from 2013.
Resumo:
Den här studien syftar till att ta reda på vad elever i årskurs 9 och årskurs 1 på gymnasiet anser om bildämnet. Intresset för de olika åldrarna kommer av att eleverna i årskurs 9 läser bild som ett obligatoriskt ämne medan eleverna i årskurs 1 har gjort ett aktivt val för att läsa bild, och studien önskar att belysa eventuella skillnader i elevernas uppfattningar om bildämnet på grund av detta. Studiens utgångspunkt tar avstamp i det sociokulturella perspektivets syn på lärande, estetiska ämnens betydelse för identitetsskapande, skolans uppdrag genom läroplanernas övergripande syften och mål och elevers egna åsikter om ämnet. Genom dessa perspektiv presenteras bildämnets bakgrund i samhället och tidigare forskning inom området, vilket sedan ställs mot elevernas egna utsagor om bildämnets betydelse. Studien bygger på kvalitativa intervjuer där eleverna har intervjuats i mindre grupper och har diskuterat och reflekterat över bildämnets betydelse. Resultatet visar att eleverna menar att bildämnet har störst betydelse som en kreativ paus bland annan undervisning, men att bildämnet också har en viss betydelse för annat lärande, personligt uttryck och som grundläggande kunskaper i framtiden.
Resumo:
The multiprocessor task graph scheduling problem has been extensively studied asacademic optimization problem which occurs in optimizing the execution time of parallelalgorithm with parallel computer. The problem is already being known as one of the NPhardproblems. There are many good approaches made with many optimizing algorithmto find out the optimum solution for this problem with less computational time. One ofthem is branch and bound algorithm.In this paper, we propose a branch and bound algorithm for the multiprocessor schedulingproblem. We investigate the algorithm by comparing two different lower bounds withtheir computational costs and the size of the pruned tree.Several experiments are made with small set of problems and results are compared indifferent sections.
Resumo:
Hur en texts typografiska utformning påverkar hur enkel den blir att läsa är en fråga som har sysselsatt forskare under lång tid. Förhoppningen har varit att få en bättre förståelse för hur läsning går till och hur man bäst bör sätta text för att underlätta för läsaren. Ett problem har dock varit att skapa medvetenhet om forskningens resultat bland dem som arbetar med att sätta text. Tanken med detta examensarbete var att skapa en överblick av forskningen, med inriktning på hur mikrotypografin, det vill säga den typografi som berör detaljer i textens utformning, påverkar läsbarheten i brödtext. Efter litteratursökningar valdes tio vetenskapligt publicerade empiriska studier på detta område ut. Artiklarna beskrevs och diskuterades med hänsyn till deras metodik och deras resultat. Följande mikrotypografiska faktorer behandlades i studierna: skillnader i läsbarhet mellan typsnitt, x-höjdens och teckenavståndets inverkan på läsbarheten, skillnader i läsbarhet mellan gemener, versaler och kursiv text samt skillnader i läsbarhet mellan olika bokstavsformer. Slutsatsen var att forskningen kring läsbarhet ger intressanta inblickar i hur typografin inverkar på läsprocessen. Det begränsade antalet studier på varje område samt brist på studier utförda på svenska gör det dock svårt att skapa konkreta riktlinjer för hur text bör sättas. Vidare konstaterades att studier utförda i samarbete mellan forskare och typografiskt kunniga vore en möjlig metod att sprida kunskap till de typografiska yrkena och öka sannolikheten för praktisk tillämpning av forskningsresultaten.
Resumo:
The p-median model is used to locate P facilities to serve a geographically distributed population. Conventionally, it is assumed that the population patronize the nearest facility and that the distance between the resident and the facility may be measured by the Euclidean distance. Carling, Han, and Håkansson (2012) compared two network distances with the Euclidean in a rural region witha sparse, heterogeneous network and a non-symmetric distribution of thepopulation. For a coarse network and P small, they found, in contrast to the literature, the Euclidean distance to be problematic. In this paper we extend their work by use of a refined network and study systematically the case when P is of varying size (2-100 facilities). We find that the network distance give as gooda solution as the travel-time network. The Euclidean distance gives solutions some 2-7 per cent worse than the network distances, and the solutions deteriorate with increasing P. Our conclusions extend to intra-urban location problems.
Resumo:
BACKGROUND: Despite extensive use of self-rated health questions in youth studies, little is known about what such questions capture among adolescents. Hence, the aim of this study was to explore how adolescents interpret and reason when answering a question about self-rated health. METHODS: A qualitative study using think-aloud interviews explored the question, "How do you feel most of the time?", using five response options ("Very good", "Rather good", "Neither good, nor bad", "Rather bad", and "Very bad"). The study involved 58 adolescents (29 boys and 29 girls) in lower secondary school (7th grade) and upper secondary school (12th grade) in Sweden. RESULTS: Respondents' interpretations of the question about how they felt included social, mental, and physical aspects. Gender differences were found primarily in that girls emphasized stressors, while age differences were reflected mainly in the older respondents' inclusion of a wider variety of influences on their assessments. The five response options all demonstrated differences in self-rated health, and the respondents' understanding of the middle option, "Neither good, nor bad", varied widely. In the answering of potential sensitive survey questions, rationales for providing honest or biased answers were described. CONCLUSIONS: The use of a self-rated health question including the word 'feel' captured a holistic view of health among adolescents. Differences amongst response options should be acknowledged when analyzing self-rated health questions. If anonymity is not feasible when answering questions on self-rated health, a high level of privacy is recommended to increase the likelihood of reliability.
Resumo:
This paper elaborates the routing of cable cycle through available routes in a building in order to link a set of devices, in a most reasonable way. Despite of the similarities to other NP-hard routing problems, the only goal is not only to minimize the cost (length of the cycle) but also to increase the reliability of the path (in case of a cable cut) which is assessed by a risk factor. Since there is often a trade-off between the risk and length factors, a criterion for ranking candidates and deciding the most reasonable solution is defined. A set of techniques is proposed to perform an efficient and exact search among candidates. A novel graph is introduced to reduce the search-space, and navigate the search toward feasible and desirable solutions. Moreover, admissible heuristic length estimation helps to early detection of partial cycles which lead to unreasonable solutions. The results show that the method provides solutions which are both technically and financially reasonable. Furthermore, it is proved that the proposed techniques are very efficient in reducing the computational time of the search to a reasonable amount.