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Reduction Scheme (reduction + scheme)
Kinds of Reduction Scheme Selected AbstractsTHE WESTERN AUSTRALIAN POWER DILEMMA,AUSTRALIAN ECONOMIC PAPERS, Issue 4 2009PAUL SIMSHAUSER From 1984 gas-fired power generation had been gradually increasing its share of the electricity market in Western Australia (WA) starting at 1 per cent and rising to about 50 per cent by 2008. Had it continued on this trajectory, the WA power system would have made great advances in terms of cost and environmental efficiencies given the looming commencement of the Carbon Pollution Reduction Scheme in Australia from 2011. However, more recently the cost of natural gas has increased from $3/GJ to $7/GJ following the sudden collapse of the East Spar gas field in the North West Shelf. In this article, we analyse the impact of the gas price increase and demonstrate that despite being the most environmentally efficient conventional technology, natural gas combined cycle plant has been squeezed out of the market which in turn will increase forward electricity price risks to WA consumers through greater exposure to CO2 pricing in the long run. [source] New policies create a new politics: issues of institutional design in climate change policyAUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2010Henry Ergas Institutional design focuses on the task of providing accountability and effective monitoring of decision-making by bodies vested with the coercive powers of the state in a context where information is inherently limited, costly to acquire and asymmetrically distributed. This paper focuses on issues of institutional design in the context of climate change policy. It examines proposals advanced in the June 2008 Draft and Final Reports of the Garnaut Climate Change Review (,Garnaut Reports'), and in the Government's July 2008 Green Paper and December 2008 White Paper on the Carbon Pollution Reduction Scheme (,Green and White Papers') with respect to how revenues raised by the sale of emissions permits would be used; and second, the proposed governance arrangements for the emissions trading scheme. [source] The logic of collective action and Australia's climate policy,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2010John C.V. Pezzey We analyse the long-term efficiency of the emissions target and of the provisions to reduce carbon leakage in the Australian Government's Carbon Pollution Reduction Scheme, as proposed in March 2009, and the nature and likely cause of changes to these features in the previous year. The target range of 5,15 per cent cuts in national emission entitlements during 2000,2020 was weak, in that on balance it is too low to minimise Australia's long-term mitigation costs. The free allocation of output-linked, tradable emissions permits to emissions-intensive, trade-exposed (EITE) sectors was much higher than proposed earlier, or shown to be needed to deal with carbon leakage. It plausibly means that EITE emissions can rise by 13 per cent during 2010,2020, while non-EITE sectors must cut emissions by 34,51 per cent (or make equivalent permit imports) to meet the national targets proposed, far from a cost-effective outcome. The weak targets and excessive EITE assistance illustrate the efficiency-damaging power of collective action by the ,carbon lobby'. Resisting this requires new national or international institutions to assess lobby claims impartially, and more government publicity about the true economic importance of carbon-intensive sectors. [source] Understanding the effect of an emissions trading scheme on electricity generator investment and retirement behaviour: the proposed Carbon Pollution Reduction SchemeAUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2010Neil Ross Lambie The objective of a greenhouse gas (GHG) emissions trading scheme (ETS) is to reduce emissions by transitioning the economy away from the production and consumption of goods and services that are GHG intensive. A GHG ETS has been a public policy issue in Australia for over a decade. The latest policy initiative on an ETS is the proposed Carbon Pollution Reduction Scheme (CPRS). A substantial share of Australia's total GHG reduction under the CPRS is expected to come from the electricity generation sector. This paper surveys the literature on investment behaviour under an ETS. It specifically focuses on the relationship between the design of an ETS and a generator's decisions to invest in low emissions plant and retire high emissions plant. The proposed CPRS provides the context for presenting key findings along with the implications for the electricity generation sector's transition to lower emissions plant. The literature shows that design features such as the method of allocating permits, the stringency of the emissions cap along with permit price uncertainty, provisions for banking, borrowing and internationally trading permits, and the credibility of emissions caps and policy uncertainty may all significantly impact on the investment and retirement behaviour of generators. [source] Auctioning greenhouse gas emissions permits in Australia,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2010Regina Betz The allocation of permits is an important design aspect of an emissions trading scheme. Traditionally, governments have favoured the free allocation of greenhouse gas permits based on individual historical emissions (,grandfathering') or industry benchmark data. Particularly in the European Union (EU), the free allocation of permits has proven complex and inefficient and the distributional implications are politically difficult to justify; auctioning emissions permits has therefore become more popular. The EU is now moving to auction more than 50 per cent of all permits in 2013, and in the US the Regional Greenhouse Gas Initiative (RGGI) has begun auctioning more than 90 per cent of total allowances. Another case in point is the Australian proposal for a Carbon Pollution Reduction Scheme (CPRS), which provides for auctioning a significant share of total permits. This paper discusses the proposed Australian CPRS's auction design. A major difference to other emissions trading schemes is that the CPRS plans to auction multiple vintages of emissions permits simultaneously. [source] A reduced-order modeling technique for tall buildings with active tuned mass damperEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 3 2001Zu-Qing Qu Abstract It is impractical to install sensors on every floor of a tall building to measure the full state vector because of the large number of degrees of freedom. This makes it necessary to introduce reduced-order control. A kind of system reduction scheme (dynamic condensation method) is proposed in this paper. This method is iterative and Guyan condensation is looked upon as an initial approximation of the iteration. Since the reduced-order system is updated repeatedly until a desired one is obtained, the accuracy of the reduced-order system resulting from the proposed method is much higher than that obtained from the Guyan condensation method. Another advantage of the method is that the reduced-order system is defined in the subspace of the original physical space, which makes the state vectors have physical meaning. An eigenvalue shifting technique is applied to accelerate the convergence of iteration and to make the reduced system retain all the dynamic characteristics of the full system within a given frequency range. Two schemes to establish the reduced-order system by using the proposed method are also presented and discussed in this paper. The results for a tall building with active tuned mass damper show that the proposed method is efficient for the reduced-order modelling and the accuracy is very close to exact only after two iterations. Copyright © 2001 John Wiley & Sons, Ltd. [source] A 3D mortar method for solid mechanics,INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2004Michael A. Puso Abstract A version of the mortar method is developed for tying arbitrary dissimilar 3D meshes with a focus on issues related to large deformation solid mechanics. Issues regarding momentum conservation, large deformations, computational efficiency and bending are considered. In particular, a mortar method formulation that is invariant to rigid body rotations is introduced. A scheme is presented for the numerical integration of the mortar surface projection integrals applicable to arbitrary 3D curved dissimilar interfaces. Here, integration need only be performed at problem initialization such that coefficients can be stored and used throughout a quasi-static time stepping process even for large deformation problems. A degree of freedom reduction scheme exploiting the dual space interpolation method such that direct linear solution techniques can be applied without Lagrange multipliers is proposed. This provided a significant reduction in factorization times. Example problems which touch on the aforementioned solid mechanics related issues are presented. Published in 2003 by John Wiley & Sons, Ltd. [source] Krylov model order reduction of finite element approximations of electromagnetic devices with frequency-dependent material propertiesINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2007Hong Wu Abstract A methodology is presented for the Krylov subspace-based model order reduction of finite element models of electromagnetic structures with material properties and impedance boundary conditions exhibiting arbitrary frequency dependence. The proposed methodology is a generalization of an equation-preserving Krylov model order reduction scheme for methodology for second-order, linear dynamical systems. The emphasis of this paper is on the application of this method to the broadband model order reduction of planar circuits including lossy strips of arbitrary thickness and lossy reference planes. In particular, it is shown that the proposed model order reduction methodology provides for the accurately modelling of the impact of the frequency dependence of the internal impedance per unit length of the thick lossy strip on the electromagnetic response of the stripline structure over a very broad, multi-GHz frequency band, extending all the way down to frequencies in the DC neighbourhood. In addition, the application of the proposed methodology to the broadband modelling of electromagnetic coupling between strips on either side of a lossy ground plane is demonstrated. Copyright © 2007 John Wiley & Sons, Ltd. [source] Integration of on-the-fly kinetic reduction with multidimensional CFDAICHE JOURNAL, Issue 5 2010Kaiyuan He Abstract A reduction approach for coupling complex kinetics with engine computational fluid dynamics (CFD) code has been developed. An on-the-fly reduction scheme was used to reduce the reaction mechanism dynamically during the reactive flow calculation in order to couple comprehensive chemistry with flow simulations in each computational cell. KIVA-3V code is used as the CFD framework and CHEMKIN is employed to formulate chemistry, hydrodynamics and transport. Mechanism reduction was achieved by applying element flux analysis on-the-fly in the context of the multidimensional CFD calculation. The results show that incorporating the on-the-fly reduction approach in CFD code enables the simulation of ignition and combustion process accurately compared with detailed simulations. Both species and time-dependant information can be provided by the current model with significantly reduced CPU time. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] DECISION SUPPORT FOR ALLOCATION OF WATERSHED POLLUTION LOAD USING GREY FUZZY MULTIOBJECTIVE PROGRAMMING,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006Ho-Wen Chen ABSTRACT: This paper uses the grey fuzzy multiobjective programming to aid in decision making for the allocation of waste load in a river system under versatile uncertainties and risks. It differs from previous studies by considering a multicriteria objective function with combined grey and fuzzy messages under a cost benefit analysis framework. Such analysis technically integrates the prior information of water quality models, water quality standards, wastewater treatment costs, and potential benefits gained via in-stream water quality improvement. While fuzzy sets are characterized based on semantic and cognitive vagueness in decision making, grey numbers can delineate measurement errors in data collection. By employing three distinct set theoretic fuzzy operators, the synergy of grey and fuzzy implications may smoothly characterize the prescribed management complexity. With the aid of genetic algorithm in the solution procedure, the modeling outputs contribute to the development of an effective waste load allocation and reduction scheme for tributaries in this subwatershed located in the lower Tseng-Wen River Basin, South Taiwan. Research findings indicate that the inclusion of three fuzzy set theoretic operators in decision analysis may delineate different tradeoffs in decision making due to varying changes, transformations, and movements of waste load in association with land use pattern within the watershed. [source] An alternative analytical reduction scheme in the time-domain layered finite element reduction recovery method for high-frequency IC designMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2008Houle Gan Abstract An alternative analytical reduction scheme was proposed in the time-domain layered finite element reduction recovery (LAFE-RR) method for the analysis of high-frequency integrated circuits. This alternative reduction scheme permits the use of general absorbing boundary conditions in the framework of a time-domain LAFE-RR method. In addition, it allows for an application of the LAFE-RR method to circuit problems in which the system matrices in multiple regions need to be reduced separately. Numerical and experimental results are given to demonstrate its validity. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2337,2341, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23630 [source] An adaptive dimension reduction scheme for monitoring feedback-controlled processesQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 3 2009Kaibo Wang Abstract Detecting dynamic mean shifts is particularly important in monitoring feedback-controlled processes in which time-varying shifts are usually observed. When multivariate control charts are being utilized, one way to improve performance is to reduce dimensions. However, it is difficult to identify and remove non-informative variables statically in a process with dynamic shifts, as the contribution of each variable changes continuously over time. In this paper, we propose an adaptive dimension reduction scheme that aims to reduce dimensions of multivariate control charts through online variable evaluation and selection. The resulting chart is expected to keep only informative variables and hence maximize the sensitivity of control charts. Specifically, two sets of projection matrices are presented and dimension reduction is achieved via projecting process vectors into a low-dimensional space. Although developed based on feedback-controlled processes, the proposed scheme can be easily extended to monitor general multivariate applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Computationally Efficient Algorithm For Frequency-Weighted Optimal H, Model ReductionASIAN JOURNAL OF CONTROL, Issue 3 2003Fen Wu ABSTRACT In this paper, a frequency-weighted optimal H, model reduction problem for linear time-invariant (LTI) systems is considered. The objective of this class of model reduction problems is to minimize H, norm of the frequency-weighted truncation error between a given LTI system and its lower order approximation. A necessary and sufficient solvability condition is derived in terms of LMIs with one extra coupling rank constraint, which generally leads to a non-convex feasibility problem. Moreover, it has been shown that the reduced-order model is stable when both stable input and output weights are included, and its state-space data are given explicitly by the solution of the feasibility problem. An efficient model reduction scheme based on cone complementarity algorithm (CCA) is proposed to solve the non-convex conditions involving rank constraint. [source] A closed-loop proposal for hydrogen generation using steel waste and a prototype solar concentratorINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2009Abdul-Majeed Azad Abstract An economically viable and environmental-friendly method of generating PEM grade hydrogen has been proposed and is by the reaction of certain metals with steam, appropriately called ,metal,steam reforming',MSR. The drawbacks of conventional processes (hydrogen and carbothermic reduction schemes) are overcome by resorting to solution-based reduction schemes and are made economically feasible using iron oxides from steel industry's mill-scale waste. A novel aqueous-based room temperature technique using sodium borohydride (NaBH4) as the reducing agent has been developed that produces highly active nanoscale iron particles (,40,nm). By using hydrazine as an inexpensive and, compared with NaBH4, more stable reductant, body centered cubic iron particles with ,5,nm edges were obtained via solvothermal process under mild conditions from acid digested mill-scale waste. The nanoscale zerovalent iron (nZVI) powder showed improved kinetics and greater propensity for hydrogen generation than the coarser microscale iron. The rate constants for the MSR were obtained for all the reduction schemes employed in this work and are given by khydrogen=0.0158,min,1kcarbon=0.0248,min,1ksodiumborohydride=0.0521,min,1 and khydrazine=0.1454,min,1, assuming first order kinetics. Another innovative effort converted the magnetite waste directly into nZVI under solvothermal conditions, thus obviating the sluggish and time-consuming acid dissolution step. This particular aspect has significant ramification in terms of time and cost of making the iron precursor. To initiate and sustain the somewhat endothermic MSR process, a solar concentrator consisting of a convex polyacrylic bowl with reflective aluminum coating was fabricated and evaluated. This unique combination of mill-scale waste as iron source, hydrazine as reductant, mild process conditions and solar energy as the MSR actuator obviates several drawbacks plaguing the grand scheme of producing and delivering pure and humidified H2 to a PEMFC stack. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimal modal reduction of vibrating substructuresINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2003Paul E. Barbone Abstract A structure which consists of a main part and a number of attached substructures is considered. A ,model reduction' scheme is developed and applied to each of the discrete substructures. Linear undamped transient vibrational motion of the structure is assumed, with general external forcing and initial conditions. The goal is to replace each discrete substructure by another substructure with a much smaller number of degrees of freedom, while minimizing the effect this reduction has on the dynamic behaviour of the main structure. The approach taken here involves Ritz reduction and the Dirichlet-to-Neumann map as analysis tools. The resulting scheme is based on a special form of modal reduction, and is shown to be optimal in a certain sense, for long simulation times. The performance of the scheme is demonstrated via numerical examples, and is compared to that of standard modal reduction. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||