1,318 research outputs found

    The development and testing of a purchasing power parity method for comparing construction costs internationally

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    University of Technology, Sydney. Faculty of Design, Architecture and Building.Over the past fifty to sixty years there have been numerous attempts to compare the performance of the construction industries of different countries. In almost all cases the cost of construction has been an important, sometimes the single parameter Cost performance has sometimes been equated to productivity, and productivity measurement and comparison is attempted by governments and their agencies on a regular basis. Fundamental to these exercises has been the necessity to bring construction costs in different national currencies to a common base. This is imperative as amounts in different currencies cannot be directly compared. Money market exchange rates do not provide suitable comparisons as they are too volatile and do not represent true comparisons of the volume or value of construction. Additionally there are real differences in price levels between economies that hamper valid comparisons. Purchasing power parity, however, provides a theoretical basis for cost comparisons without the distortions caused by moving exchange rates and differences in price levels between countries. Using the option of purchasing power parity and its supporting theory, the Law of One Price, a mechanism for bringing construction costs to a common base currency has been devised. It is based on a basket of construction materials and labour referred to as a BLOC (i.e. Basket of Locally Obtained Commodities) and is applied to a hotel project.. The materials and their respective quantities were derived by the analysis of a completed hotel. Labour hours associated with those materials and quantities were derived using published materials/labour ratios for the various items. In this way the basket or BLOC represented a mix of the most cost significant materials in a typical hotel project. Input costs for the BLOC were obtained from six cities, three in Australia plus Auckland, Singapore and Phoenix. BLOC costs were then used to derive a set of purchasing power parity factors specific to the construction industry in each location. These factors were then used to assess the relative cost of construction in each location. The BLOC also provides a straightforward method for comparing productivity between locations. Lower building costs, when expressed in BLOC equivalents, signify higher productivity. While not an absolute measure of productivity this provides a clear indication of relative productivity between locations. The study described provides some interesting results. For example, while construction costs in Sydney are clearly shown to be higher than those in Phoenix the industry in Sydney is shown to be considerably more productive. Higher costs in Sydney are related largely to higher pay for tradespersons and other resources, however, the higher pay is offset by the improved productivity. The method devised satisfies many of the requirements for regional and international cost comparisons. It is theoretically correct and relatively inexpensive to administer and thus provides the opportunity for the gathering data from more respondents in each location and at more frequent intervals. The thesis concludes with suggestions for a number of research projects that would extend this work considerably and greatly expand the body of work devoted to this fundamental construction economics problem

    The Parallax of VHS J1256-1257 from CFHT and Pan-STARRS 1

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    This is the author accepted manuscript. The final version is available from the American Astronomical Society via the DOI in this recordWe present new parallax measurements from the CFHT Infrared Parallax Program and the Pan-STARRS 3π Steradian Survey for the young (≈150−300 Myr) triple system VHS J125601.92−125723.9. This system is composed of a nearly equal-flux binary ("AB") and a wide, possibly planetary-mass companion ("b"). The system's published parallactic distance (12.7±1.0 pc) implies absolute magnitudes unusually faint compared to known young objects and is in tension with the spectrophotometric distance for the central binary (17.2±2.6 pc). Our CFHT and Pan-STARRS parallaxes are consistent, and the more precise CFHT result places VHS J1256-1257 at 22.2+1.1−1.2 pc. Our new distance results in higher values for the companion's mass (19±5 MJup) and temperature (1240±50 K), and also brings the absolute magnitudes of all three components into better agreement with known young objects

    Effectiveness of waste minimisation projects in reducing water demand by UK industry

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    There is growing interest in managing water demand in the UK. A series of waste minimization clubs have been set up within the country and this paper identifies the effectiveness of these clubs in reducing the demand for water within industry. Membership of these clubs is voluntary and the only incentive for industry to reduce water consumption, and consequently the production of effluent, is the almost immediate financial saving made by the company, often achieved by accounting for the water consumption and loss within site from the point of input from the water supplier to output in the form of effluent. On average, companies are able to reduce water consumption by up to 30 percent. If the entire industrial sector within the UK were to achieve this degree of savings, it is possible that approximately 1300Ml/d could be saved

    Zinc intake, status and indices of cognitive function in adults and children: a systematic review and meta-analysis

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    In developing countries, deficiencies of micronutrients are thought to have a major impact on child development; however, a consensus on the specific relationship between dietary zinc intake and cognitive function remains elusive. The aim of this systematic review was to examine the relationship between zinc intake, status and indices of cognitive function in children and adults. A systematic literature search was conducted using EMBASE, MEDLINE and Cochrane Library databases from inception to March 2014. Included studies were those that supplied zinc as supplements or measured dietary zinc intake. A meta-analysis of the extracted data was performed where sufficient data were available. Of all of the potentially relevant papers, 18 studies met the inclusion criteria, 12 of which were randomised controlled trials (RCTs; 11 in children and 1 in adults) and 6 were observational studies (2 in children and 4 in adults). Nine of the 18 studies reported a positive association between zinc intake or status with one or more measure of cognitive function. Meta-analysis of data from the adult’s studies was not possible because of limited number of studies. A meta-analysis of data from the six RCTs conducted in children revealed that there was no significant overall effect of zinc intake on any indices of cognitive function: intelligence, standard mean difference of <0.001 (95% confidence interval (CI) –0.12, 0.13) P=0.95; executive function, standard mean difference of 0.08 (95% CI, –0.06, 022) P=0.26; and motor skills standard mean difference of 0.11 (95% CI –0.17, 0.39) P=0.43. Heterogeneity in the study designs was a major limitation, hence only a small number (n=6) of studies could be included in the meta-analyses. Meta-analysis failed to show a significant effect of zinc supplementation on cognitive functioning in children though, taken as a whole, there were some small indicators of improvement on aspects of executive function and motor development following supplementation but high-quality RCTs are necessary to investigate this further

    Automata for true concurrency properties

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    We present an automata-theoretic framework for the model checking of true concurrency properties. These are specified in a fixpoint logic, corresponding to history-preserving bisimilarity, capable of describing events in computations and their dependencies. The models of the logic are event structures or any formalism which can be given a causal semantics, like Petri nets. Given a formula and an event structure satisfying suitable regularity conditions we show how to construct a parity tree automaton whose language is non-empty if and only if the event structure satisfies the formula. The automaton, due to the nature of event structure models, is usually infinite. We discuss how it can be quotiented to an equivalent finite automaton, where emptiness can be checked effectively. In order to show the applicability of the approach, we discuss how it instantiates to finite safe Petri nets. As a proof of concept we provide a model checking tool implementing the technique

    IFNAR1-Signalling Obstructs ICOS-mediated Humoral Immunity during Non-lethal Blood-Stage Plasmodium Infection

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    Funding: This work was funded by a Career Development Fellowship (1028634) and a project grant (GRNT1028641) awarded to AHa by the Australian National Health & Medical Research Council (NHMRC). IS was supported by The University of Queensland Centennial and IPRS Scholarships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Climate Effects and Feedback Structure Determining Weed Population Dynamics in a Long-Term Experiment

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    Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role of exogenous variables such as climate have been ignored in the study of weed populations and their management. Here, we use long-term data (22 years) on two annual weed species from a locality in Central Spain to determine the importance of endogenous and exogenous processes (local and large-scale climate factors). Our modeling study determined two different feedback structures and climate effects in the two weed species analyzed. While Descurainia sophia exhibited a second-order feedback and low climate influence, Veronica hederifolia was characterized by a first-order feedback structure and important effects from temperature and rainfall. Our results strongly suggest the importance of theoretical population dynamics in understanding plant population systems. Moreover, the use of this approach, discerning between the effect of exogenous and endogenous factors, can be fundamental to applying weed management practices in agricultural systems and to controlling invasive weedy species. This is a radical change from most approaches currently used to guide weed and invasive weedy species managements

    Spatial and Seasonal Distribution of American Whaling and Whales in the Age of Sail

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    American whalemen sailed out of ports on the east coast of the United States and in California from the 18th to early 20th centuries, searching for whales throughout the world’s oceans. From an initial focus on sperm whales (Physeter macrocephalus) and right whales (Eubalaena spp.), the array of targeted whales expanded to include bowhead whales (Balaena mysticetus), humpback whales (Megaptera novaeangliae), and gray whales (Eschrichtius robustus). Extensive records of American whaling in the form of daily entries in whaling voyage logbooks contain a great deal of information about where and when the whalemen found whales. We plotted daily locations where the several species of whales were observed, both those caught and those sighted but not caught, on world maps to illustrate the spatial and temporal distribution of both American whaling activity and the whales. The patterns shown on the maps provide the basis for various inferences concerning the historical distribution of the target whales prior to and during this episode of global whaling
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