191 research outputs found

    Teaching Economics As a Science: The 1930 Yale Lectures of Ragnar Frisch

    Get PDF
    This paper is prepared for the forthcoming publication of Frisch's 1930 Yale lecture notes, A Dynamic Approach to Economic Theory: The Yale Lectures of Ragnar Frisch (details at: http://www.routledgeeconomics.com/books/A-Dynamic-Approach-to-Economic-Theory-isbn9780415564090). As the lecture series was given just as the Econometric Society was founded in 1930. We provide as background, a blow-by-blow story of how the Econometric Society got founded with emphasis on Frisch's role. We then outline how the Yale lecture notes came into being, closely connected to Frisch's econometric work at the time. We comment upon the lectures, relating them to Frisch's later works and, more important, to subsequent developments in economics and econometrics.History of econometrics

    "Big Bang" eller "Steady State"

    Get PDF
    The Limits to Growth: A Report for The Club of Romés Project on the Predicament of Mankind,» By Donella H. Meadows, Dennis L. Meadows, Jørgen Randers and William W. Behrens III. __ I vitenskapen om universets opprinnelse, beståen og endelikt eksisterer det for øvrig stikk i strid med Thomas Kuhns dictum i hans "The Structure of Scientific Revolutions" flere innbyrdes motstridende teorier, blant hvilke de to mest kjente er George Gamows Big Bang-teori og Steady State-teorien til Fred Hoyle et al

    Langtidsprogrammet 1982-1985

    Get PDF
    Langtidsprogrammet har sin opprinnelse i Gerhardsenepokens stabile politiske og økonomiske regime fra 1945 til 1965. Det falt tidlig inn i et mønster der det ble offentliggjort få måneder fOr et Stortingsvalg og med fireårig planhorisont. På denne måten kunne den økonomiske planleggingen kombineres med politisk valgoffensiv på en optimal måte

    What effect does rehabilitation of wastewater pipelines have on the share of infiltration and inflow water (I/I-water)?

    Get PDF
    Infiltration and inflow water (I/I-water) is a big challenge in sewage systems in many countries. I/I-water above an acceptable level indicates that the sewage system is not functioning properly. I/I-water leads to increased pumping costs and increased sewage overflow, leading to increased pollution of the receiving waters. Many rehabilitation projects are driven by the need to reduce the share of I/I-water and common measures are to replace pipes and manholes. The share of I/I-water is predominantly driven by rainfall. This makes it difficult to document the efficiency of mitigating measures. One way to address this issue is to compare data from rehabilitation areas to areas where no measures have been implemented. Three rehabilitation areas in Asker Municipality, Norway, were successfully assessed by applying this approach. Asker has a 100% separate system. The strategy to reduce I/I-water in Asker Municipality was to rehabilitate sewage mains, either by full replacement or lining the old pipes, and replacement of manholes. The assessment shows that rehabilitation of selected municipal pipes, pipes proven to be in bad condition through closed circuit TV inspection, reduced the share of I/I-water only to a limited extent. Since the rehabilitation done was not a complete replacement of all pipes and manholes, the limited effects are assumed to be caused by the water finding other ways into the system. In separate systems other measures than renovations of pipes should be considered when aiming to reduce I/I-water.publishedVersio

    Intensifying rehabilitation of combined sewer systems using trenchless technology in combination with low impact development and green infrastructure

    Get PDF
    Throughout Europe, there is a considerable need for investment in the upgrade of sewer systems – due to three main factors: ageing infrastructure, climate change and urban population growth. The need for investments is expected to grow significantly in the years ahead. Trenchless rehabilitation (no-dig) of sewer pipelines is a cost-efficient and environmental friendly method for upgrading existing pipelines with sufficient capacity. This study examines the possibility of applying no-dig to combined sewer systems (CS) with insufficient capacity. In this study, a concept assessment methodology that combines the analytical approaches from stormwater and sewer system assessments is presented. The methodology was tested on a case area that was part of an environmental project in Oslo, Norway. Three alternative concepts were examined; A0: no-dig and low impact development (LID), A1: no-dig, LID and green infrastructure (GI), and A2: CS up-sizing using open-cut methods. The study concludes that CS with insufficient capacity can be rehabilitated using no-dig if LID and GI. The combination of no-dig and LID reduces costs considerably but does involve the risk of damages from uncontrolled surface runoff. The main risk-reduction measure is the development of GI as an integrated stormwater management system that requires cross-sector collaboration within municipalities.publishedVersio

    A comparative study of mentoring for new teachers

    Get PDF
    The research conducted in Scotland was funded by the Scottish GovernmentPeer reviewedPostprin

    Evaluating Flood Exposure for Properties in Urban Areas Using a Multivariate Modelling Technique

    Get PDF
    Urban flooding caused by heavy rainfall is expected to increase in the future. The main purpose of this study was to investigate the variables characterizing the placement of a house, which seem to have an impact when it comes to the exposure to floods. From the same region in Norway, data from 347 addresses were derived. All addresses were either associated with insurance claims caused by flooding or were randomly selected. A multivariate statistical model, Partial Least Square Regression (PLS), was used. Among others, the analysis has shown that the upstream, sealed area is the most significant variable for characterizing properties’ exposure to urban flooding. The model confirms that flooding tends to occur near old combined sewer mains and in concave curvature, and houses located in steep slopes seem to be less exposed. Using this method, it is possible to rank and quantify significant exposure variables contributing to urban floods within a region. Results from the PLS-analysis might provide important input to professionals, when planning and prioritizing measures. It can also predict flood-prone areas and make residents aware of the risks, which may induce them to implement preventive measures.publishedVersio

    Is there evidence for accelerated polyethylene wear in uncemented compared to cemented acetabular components? A systematic review of the literature

    Get PDF
    Joint arthroplasty registries show an increased rate of aseptic loosening in uncemented acetabular components as compared to cemented acetabular components. Since loosening is associated with particulate wear debris, we postulated that uncemented acetabular components demonstrate a higher polyethylene wear rate than cemented acetabular components in total hip arthroplasty. We performed a systematic review of the peer-reviewed literature, comparing the wear rate in uncemented and cemented acetabular components in total hip arthroplasty. Studies were identified using MEDLINE (PubMed), EMBASE and the Cochrane Central Register of Controlled Trials. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The search resulted in 425 papers. After excluding duplicates and selection based on title and abstracts, nine studies were found eligible for further analysis: two randomised controlled trials, and seven observational studies. One randomised controlled trial found a higher polyethylene wear rate in uncemented acetabular components, while the other found no differences. Three out of seven observational studies showed a higher polyethylene wear in uncemented acetabular component fixation; the other four studies did not show any differences in wear rates. The available evidence suggests that a higher annual wear rate may be encountered in uncemented acetabular components as compared to cemented components

    Identifying critical supply chains and final products: An input-output approach to exploring the energy-water-food nexus

    No full text
    Recent advances in detailed multiregional input-output databases offers new opportunities to use these environmental accounting tools to explore the interrelationships between energy, water and food–the energy-water-food nexus. This paper takes the UK as a case study and calculates energy, water and food consumption-based accounts for 1997-2013. Policies, designed to reduce the environmental impact of consumption of products, can intervene at many stages in a product’s whole life-time from ‘cradle to gate’. We use input-output analysis techniques to investigate the interaction between the energy, water and food impacts of products at different points along their supply chains, from the extraction of material and burning of energy, to the point of final consumption. We identify the twenty most important final products whose large energy, water and food impacts could be captured by various demand-side strategies such as reducing food waste or dietary changes. We then use structural-path analysis to calculate the twenty most important supply chains whose impact could be captured by resource efficiency policies which act at the point of extraction and during the manufacturing process. Finally, we recognise that strategies that aim to reduce environmental impacts should not harm the socioeconomic well-being of the UK and her trade partners and suggest that pathways should be targeted where the employment and value added dependencies are relatively low
    corecore