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Cost Estimation (cost + estimation)
Selected AbstractsTransaction Cost Estimation and International Regimes: Of Crystal Balls and Sheriff's PossesINTERNATIONAL STUDIES REVIEW, Issue 1 2004Michael Lipson In the aftermath of the 2003 war in Iraq, there is growing concern over the durability of international institutions and their capacity to withstand international change. Transaction costs are a central factor in theoretical explanations of the conditions under which international institutions will persist or be replaced. Rational institutionalists expect regimes to persist after conditions underlying their creation have changed because of the transaction costs of negotiating a replacement regime. Andrew Moravcsik has recently challenged this view, arguing that such costs are generally low and, in any case, arise from domestic and transnational sources rather than interstate bargaining. Others have argued that transaction costs shape the structure of security institutions. All these approaches assume that states can accurately forecast the transaction costs of maintaining or replacing an international regime. However, as an examination of the replacement of the Coordinating Committee on Multilateral Export Controls (CoCom) by the Wassenaar Arrangement demonstrates, this assumption is not necessarily warranted. This essay reviews transaction-cost-based theories of international cooperation and proposes that incorporation of a variable concerned with states' capacity to estimate transaction costs would improve our theoretical understanding of institutional persistence and change. Moreover, it considers problems of defining and measuring transaction costs, assesses factors limiting states' accurate estimation of transaction costs, and presents some propositions regarding transaction cost estimation and regime persistence. The essay also examines the implications of inaccurate transaction cost estimation for recent US foreign policy and international order. [source] An overview of the mathematical modelling of liquid membrane separation processes in hollow fibre contactorsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2009E Bringas Abstract Liquid membranes have traditionally been employed for liquid/liquid mass transfer and have found applications in industrial, biomedical and analytical fields as well as in hydrometallurgical processes, wastewater treatment and remediation of polluted groundwater. However, in spite of the known advantages of liquid membranes, there are few examples of industrial application. The development of reliable mathematical models and design parameters (mass transport coefficients and equilibrium or kinetic parameters associated with the interfacial reactions) is a necessary step for design, cost estimation, process optimisation and scale-up. This work reports an overview of the different approaches that have been proposed in the literature to the mathematical modelling of liquid membrane separation processes in hollow fibre contactors providing, at the same time, a useful guideline to characterise the mass transport phenomena and a tool for the optimal design and intensification of separation processes. Copyright © 2009 Society of Chemical Industry [source] On Estimating Medical Cost and Incremental Cost-Effectiveness Ratios with Censored DataBIOMETRICS, Issue 4 2001Hongwei Zhao Summary. Medical cost estimation is very important to health care organizations and health policy makers. We consider cost-effectiveness analysis for competing treatments in a staggered-entry, survival-analysis-based clinical trial. We propose a method for estimating mean medical cost over patients in such settings. The proposed estimator is shown to be consistent and asymptotically normal, and its asymptotic variance can be obtained. In addition, we propose a method for estimating the incremental cost-effectiveness ratio and for obtaining a confidence interval for it. Simulation experiments are conducted to evaluate our proposed methods. Finally, we apply our methods to a clinical trial comparing the cost effectiveness of implanted cardiac defibrillators with conventional therapy for individuals at high risk for ventricular arrhythmias. [source] Assessment of the impact of salinity and irradiance on the combined carbon dioxide sequestration and carotenoids production by Dunaliella salina: A mathematical modelBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009O.Q.F. Araújo Abstract Current anthropogenic activities have been causing a significant increase in the atmospheric concentration of CO2 over the past 60 years. To mitigate the consequent global warming problem, efficient technological solutions, based on economical and technical grounds, are required. In this work, microalgae are studied as important biological systems of CO2 fixation into organic compounds through photosynthesis. These microorganisms are potential sources of a wide variety of interesting chemical compounds, which can be used for commercial purposes, reducing the cost of CO2 capture and sequestration. Specifically, Dunaliella salina culture was studied aiming at the impact evaluation of operational conditions over cellular growth and carotenoid production associated with the CO2 sequestration on focus. The main experimental parameters investigated were salinity and irradiance conditions. The experimental results supported the development of a descriptive mathematical model of the process. Based on the proposed model, a sensitivity analysis was carried out to investigate the operational conditions that maximize CO2 consumption and carotenoid production, in order to guide further development of technological routes for CO2 capture through microalgae. A preliminary cost estimation of CO2 sequestration combined to carotenoids production for a 200 MW power plant is presented, based on the growth rates achieved in this study. Biotechnol. Bioeng. 2009;102: 425,435. © 2008 Wiley Periodicals, Inc. [source] Techno-Economic Analysis of Hydrazine Hydrate TechnologiesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2010P. Nikhitha Abstract The increasing demand of current world production for hydrazine hydrate emphasizes the need to focus on the techno-economic analysis of the existing technologies. Three processes, namely the Raschig process, urea process, and peroxide-ketazine process, are chosen for technical analysis followed by cost estimation and economic assessment. The technical part involves the development of flow sheets, process design, carrying out of calculations as well as estimation of raw materials, labor, utilities, and process equipment by sizing and other sub-components. The economic part comprises the estimation of working capital, fixed capital investment, total capital investment, and total production costs. Economic parameters like net profits, rate of return, payback period, and break-even point are also estimated to perform economic analysis. The results obtained from technical analysis and economical feasibility studies show that the peroxide-ketazine-based hydrazine hydrate technology has clear advantages in terms of raw material consumption and economic competitiveness. [source] LCC,The economic pillar of sustainability: Methodology and application to wastewater treatmentENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2003Gerald Rebitzer Industrial applications of supply chain cost management, along with life cycle costing of goods and services, are increasing. Several industrial sectors, in particular the automotive, electronics, and primary materials, have engaged in programs to coordinate upstream and downstream activities to reduce environmental burdens. At the same time, there is an increasing need to pass on information on product, material, and energy flows along the supply chain, as well as to provide data on the use and end-of-life phases of goods and services. Therefore, methods to analyze, assess, and manage these flows, from an economic as well as an environmental perspective, are of essential importance, particularly in established large-scale industries where suppliers are increasingly challenged to provide comprehensive cost and environmental information. In this context, a life cycle costing analysis (LCC), conducted as part of life cycle management activities, can provide important opportunities. Therefore, this paper focuses on a life cycle assessment (LCA)-based LCC method, which utilizes an LCA model as a basis for cost estimations in product development and planning. A case study on life cycle costing of wastewater treatment illustrates the practical use and benefits of the method. [source] Sensitivity Analysis of Human Leg Metabolical CostsPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2005Marko Ackermann The human walking is characterized by skeletal dynamics and muscle excitation patterns minimizing the metabolical energy. This criterion is applied to assess the performance of lower limb prosthetic devices, and to evaluate therapies for patients presenting gait disorders. It is desirable, therefore, to dispose models of the human normal and pathological gaits capable of estimating the metabolical energy expenditure. For the swing phase of normal and pathological gaits a musculoskeletal model of the lower limb is presented to estimate metabolical energy expenditure. The mechanical model has three degrees of freedom and is actuated by eight Hill-type muscle units, and the model for the metabolical costs is adopted from literature. In this paper a combination of inverse and direct dynamics is used, and a sensitivity analysis of the dynamical behavior and the corresponding metabolical costs estimations with respect to parametrized neural excitations is performed. The leg motions are based on experiments in a gait analysis laboratory. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||