999 resultados para Cycle Decompositions


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As part of an ongoing project, a life cycle inventory (LCI) of aluminium high pressure die casting (HPDC) has been collected. This has been conducted from the view of an individual product and also the entire process. The objective of the study was to analyse the process and suggest changes to reduce environmental impacts. One modem aluminium high pressure die casting plant located in Victoria, Australia was evaluated and modelled. Site specific data on energy and materials was gathered and the process was modelled using a typical automotive component. The paper also presents our experience and methodology used in this inventory data collection process from the real industry for LCA purposes. The inventory data collected itself reveals that the HPDC process is energy intensive and as such the major emissions were from the use of natural gas fired furnaces and from the brown coal derived electricity. It is also found the large environmental benefits of using secondary aluminium over primary aluminium in the HPDC process. A detailed LCA is being cal1ied out based on the inventory obtained.

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In this paper we examine the relative importance of permanent and transitory shocks in explaining variations in income, consumption and investment at business cycle horizons for Australia. We use the common trend–common cycle restrictions to estimate a variance decomposition of shocks, and find that over short horizons the bulk of the variations in income and investment are due to permanent shocks, while transitory shocks explain the bulk of the variations in consumption. The former finding is consistent with real business cycle models which attribute business cycles to aggregate supply shocks, while the findings for consumption are consistent with the Keynesian view, which attributes business cycles to aggregate demand shocks.

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The goal of this paper is to examine the relative importance of permanent and transitory shocks in explaining variations in macroeconomic aggregates for the UK at business cycle horizons. Using the common trend–common cycle restrictions, we estimate a variance decomposition of shocks, and find that over short horizons the bulk of the variations in income and consumption were due to permanent shocks while transitory shocks explain the bulk of the variations in investment. Our findings for income and consumption are consistent with real business cycle models which emphasize the role of aggregate supply shocks, while our findings for investment are consistent with the Keynesian school of thought, which emphasizes the role of aggregate demand shocks in explaining business cycles.

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The scope of this study was to examine the effects of plane strain prestrain, induced via cold-rolling, and subsequent automotive paint bake hardening cycle on both tensile and fatigue properties of a hot rolled TRIP780 multiphase steel. Strain-life data has been generated for as-received (0% prestrain), 10% and 20% prestrained samples, in both baked and unbaked conditions. Cold rolling  increased the number of strain reversals to failure at high cyclic strain amplitudes with no effect at low strain amplitudes. Bake hardening increased the number of reversals to failure at high cyclic strain amplitudes. The prestrained material exhibited partial cyclic softening, with some residual strength increase. The residual strength increase was attributed to the austenite to martensite transformation that occurred during the prestraining process.

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In this paper, we analyse per capita income levels of China's three main regions: the western region, the eastern region and the central region using common cycle and common trend tests. Our main contribution is that we impose the common cycle and common trend restrictions in decomposing shocks into permanent and transitory components. We find that: (i) there is evidence for two cointegrating relationships and one common cycle; and (ii) the variance decomposition analysis of shocks provides evidence that over short horizons, permanent shocks play a large role in explaining variations in regional per capita incomes.

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Introduction: A nonlinear dynamic systems model has previously been proposed to explain pacing strategies employed during exercise.

Purpose: This study was conducted to examine the pacing strategies used under varying conditions during the cycle phase of an Ironman triathlon.

Methods: The bicycles of six well-trained male triathletes were equipped with SRM power meters set to record power output, cadence, speed, and heart rate. The flat, three-lap, out-and-back cycle course, coupled with relatively consistent wind conditions (17-30 km·h-1), enabled comparisons to be made between three consecutive 60-km laps and relative wind direction (headwind vs tailwind).

Results: Participants finished the cycle phase (180 km) with consistently fast performance times (5 h, 11 ± 2 min; top 10% of all finishers). Average power output (239 ± 25 to 203 ± 20 W), cadence (89 ± 6 to 82 ± 8 rpm), and speed (36.5 ± 0.8 to 33.1 ± 0.8 km·h-1) all significantly decreased with increasing number of laps (P < 0.05). These variables, however, were not significantly different between headwind and tailwind sections. The deviation (SD) in power output and cadence did not change with increasing number of laps; however, the deviations in torque (6.8 ± 1.6 and 5.8 ± 1.3 N·m) and speed (2.1 ± 0.5 and 1.6 ± 0.3 km·h-1) were significantly greater under headwind compared with tailwind conditions, respectively. The median power frequency tended to be lower in headwind (0.0480 ± 0.0083) compared with tailwind (0.0531 ± 0.0101) sections.

Conclusion:
These data show evidence that a nonlinear dynamic pacing strategy is used by well-trained triathletes throughout various segments and conditions of the Ironman cycle phase. Moreover, an increased variation in torque and speed was found in the headwind versus the tailwind condition.

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Introduction : It is commonly acknowledged that, for many offenders, alcohol use is strongly associated with criminal behaviour. The belief held by many professionals that the two phenomena are associated, probably in a causal way, has led to the inclusion of alcohol use as a ‘criminogenic need’ in many settings where rehabilitation programmes are used to reduce recidivism. However, the mechanisms and pathways involved in the alcohol–crime link remain poorly understood.

Argument and conclusion : This paper reviews the literature relating to alcohol–offending links and draws some inferences about the role of alcohol use as a criminogenic need in offender rehabilitation. It is proposed that the bi-directional relationship between alcohol use and negative affective states is important in understanding the offence cycle, and that deficits in self-regulation not only characterize both alcohol misuse and negative affect but are also implicated in the offending behaviour itself.

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Environmental decision making during the building design process has typically focused on improvements to operational efficiencies. Improvements to thermal performance and efficiency of appliances and systems within buildings both aim to reduce resource consumption and environmental impacts associated with the operation of buildings. Significant reductions in building energy and water consumption are possible; however often the impacts occurring across the other stages of a building‘s life are not considered or are seen as insignificant in comparison.

Previous research shows that embodied impacts (raw material extraction, processing, manufacture, transportation and construction) can be as significant as those related to building operation. There is, however, limited consistent and comprehensive information available for building designers to make informed decisions in this area. Often the information that is available is from disparate sources, which makes comparison of alternative solutions unreliable and risky. lt is also important that decisions are made from a life cycle perspective, ensuring that strategies to reduce environmental impacts from one life cycle stage do not come at the expense of an increase in overall life cycle impacts

A consistent and comprehensive framework for assessing and specifying building assemblies for enhanced environmental outcomes does not currently exist. This paper presents the initial findings of a project that aims to establish a database of the life cycle energy requirements of a broad range of construction assemblies, based on a comprehensive assessment framework. Life cycle energy requirements have been calculated for eight standard residential construction assemblies integrating an innovative embodied energy assessment technique with thermal performance simulation modelling and ranked according to their performance.

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The continuous debate between the radical and the conservative approaches on which one is more suitable for a successful economic transition seems to be in favour of the latter. With the recent upswing in the property market in Hainan, the review of the 1990s property cycle in Hainan is linked with economic transition in China. A case study approach is used to establish the importance of the 1990s Hainan property cycle to the formation process of the Chinese property market system. The analytical framework is an integration of the theories of property cycles and economic transition, using the conceptual model of typical commercial property markets modified according to the historical settings in Hainan. It is found that the 1990s Hainan property cycle is unique in that the economic transition has been the key driving force. The structural imbalance caused by the equally imbalanced reform process in different sectors in Hainan has been proved an unsuccessful practice. By and large, the 1990s cycle in Hainan lasted for about 10 years and was state-driven. It was considered an experiment conducted by the state in testing the radical approach of economic transition in the property and urban land sectors. It is suggested that current knowledge of emerging commercial property markets, especially their cyclical behaviour, is limited at both theoretical and empirical levels. Evidence from the past 15 years seems to suggest that the structural and investment imbalance in the economic transition was the main cause of the high volatility in the Hainan property market in the 1990s. The emergence of a commercial property market seems to require choosing the right places to start reform with great caution on investment structure and the fundame ntals of the real economy. Eventually, it is essential to adopt a systematic view to assess and to make decision in the process of emergence of property cycles, based on the basic demand and supply patterns in a city’s transitional economy.

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In this paper we test for asymmetric behaviour of business cycles for the G7 countries, using the entropy-based test for asymmetry suggested by Racine and Maasoumi [Racine, J.S., & Maasoumi, E. (in press-a). A versatile and robust metric entropy test of time-reversibility, and other hypotheses, Journal of Econometrics; Racine, J.S., & Maasoumi, E. (in press-b). A robust entropy based test for asymmetry. Econometric Reviews.]. We find overwhelming evidence of symmetry. In only 14% of the cases, we find some evidence of asymmetric behaviour of GDP and per capita GDP. More importantly, the period marked by the flexible exchange rate regime, over which much of the empirical work for the G7 countries has been conducted, evidence suggests that the two GDP series are symmetric.