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Sample records for aspen economic model

  1. Full employment and competition in the Aspen economic model: implications for modeling acts of terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Ehlen, Mark Andrew

    2004-11-01

    Acts of terrorism could have a range of broad impacts on an economy, including changes in consumer (or demand) confidence and the ability of productive sectors to respond to changes. As a first step toward a model of terrorism-based impacts, we develop here a model of production and employment that characterizes dynamics in ways useful toward understanding how terrorism-based shocks could propagate through the economy; subsequent models will introduce the role of savings and investment into the economy. We use Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate for validation purposes that a single-firm economy converges to the known monopoly equilibrium price, output, and employment levels, while multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment. However, we find that competition also leads to churn by consumers seeking lower prices, making it difficult for firms to optimize with respect to wages, prices, and employment levels. Thus, competitive firms generate market ''noise'' in the steady state as they search for prices and employment levels that will maximize profits. In the context of this model, not only could terrorism depress overall consumer confidence and economic activity but terrorist acts could also cause normal short-run dynamics to be misinterpreted by consumers as a faltering economy.

  2. ASPEN+ and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis

    Science.gov (United States)

    ASPEN Plus based simulation models have been developed to design a pyrolysis process for the on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all available Equine Reh...

  3. Aspen: A microsimulation model of the economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.; Quint, T.; Arnold, T.

    1996-10-01

    This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

  4. Aspen Plus® and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis.

    Science.gov (United States)

    Hammer, Nicole L; Boateng, Akwasi A; Mullen, Charles A; Wheeler, M Clayton

    2013-10-15

    Aspen Plus(®) based simulation models have been developed to design a pyrolysis process for on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all the available waste from the site's 41 horses requires a 6 oven dry metric ton per day (ODMTPD) pyrolysis system but it will require a 15 ODMTPD system for waste generated by an additional 150 horses at the expanded area including the College and its vicinity. For this a dual fluidized bed combustion reduction integrated pyrolysis system (CRIPS) developed at USDA's Agricultural Research Service (ARS) was identified as the technology of choice for pyrolysis oil production. The Aspen Plus(®) model was further used to consider the combustion of the produced pyrolysis oil (bio-oil) in the existing boilers that generate hot water for space heating at the Equine Center. The model results show the potential for both the equine facility and the College to displace diesel fuel (fossil) with renewable pyrolysis oil and alleviate a costly waste disposal problem. We predict that all the heat required to operate the pyrolyzer could be supplied by non-condensable gas and about 40% of the biochar co-produced with bio-oil. Techno-economic Analysis shows neither design is economical at current market conditions; however the 15 ODMTPD CRIPS design would break even when diesel prices reach $11.40/gal. This can be further improved to $7.50/gal if the design capacity is maintained at 6 ODMTPD but operated at 4950 h per annum. Published by Elsevier Ltd.

  5. High titer L-lactic acid production from corn stover with minimum wastewater generation and techno-economic evaluation based on Aspen plus modeling.

    Science.gov (United States)

    Liu, Gang; Sun, Jiaoe; Zhang, Jian; Tu, Yi; Bao, Jie

    2015-12-01

    Technological potentials of l-lactic acid production from corn stover feedstock were investigated by experimental and techno-economic studies. An optimal performance with 104.5 g/L in l-lactic acid titer and 71.5% in overall yield from cellulose in corn stover to l-lactic acid using an engineered Pediococcus acidilactici strain were obtained by overcoming several technical barriers. A rigorous Aspen plus model for l-lactic acid production starting from dry dilute acid pretreated and biodetoxified corn stover was developed. The techno-economic analysis shows that the minimum l-lactic acid selling price (MLSP) was $0.523 per kg, which was close to that of the commercial l-lactic acid produced from starch feedstock, and 24% less expensive than that of ethanol from corn stover, even though the xylose utilization was not considered. The study provided a prototype of industrial application and an evaluation model for high titer l-lactic acid production from lignocellulose feedstock. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Refuse Derived Fuel (RDF) production and gasification in a pilot plant integrated with an Otto cycle ICE through Aspen plus™ modelling: Thermodynamic and economic viability.

    Science.gov (United States)

    Násner, Albany Milena Lozano; Lora, Electo Eduardo Silva; Palacio, José Carlos Escobar; Rocha, Mateus Henrique; Restrepo, Julian Camilo; Venturini, Osvaldo José; Ratner, Albert

    2017-11-01

    This work deals with the development of a Refuse Derived Fuel (RDF) gasification pilot plant using air as a gasification agent. A downdraft fixed bed reactor is integrated with an Otto cycle Internal Combustion Engine (ICE). Modelling was carried out using the Aspen Plus™ software to predict the ideal operational conditions for maximum efficiency. Thermodynamics package used in the simulation comprised the Non-Random Two-Liquid (NRTL) model and the Hayden-O'Connell (HOC) equation of state. As expected, the results indicated that the Equivalence Ratio (ER) has a direct influence over the gasification temperature and the composition of the Raw Produced Gas (RPG), and effects of ER over the Lower Heating Value (LHV) and Cold Gasification Efficiency (CGE) of the RPG are also discussed. A maximum CGE efficiency of 57-60% was reached for ER values between 0.25 and 0.3, also an average reactor temperature values in the range of 680-700°C, with a peak LHV of 5.8MJ/Nm 3 . RPG was burned in an ICE, reaching an electrical power of 50kW el . The economic assessment of the pilot plant implementation was also performed, showing the project is feasible, with power above 120kW el with an initial investment of approximately US$ 300,000. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    Science.gov (United States)

    Joshi, D. M.; Patel, H. K.

    2015-10-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

  8. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    International Nuclear Information System (INIS)

    Joshi, D.M.; Patel, H.K.

    2015-01-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant

  9. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  10. Physical property parameter set for modeling ICPP aqueous wastes with ASPEN electrolyte NRTL model

    International Nuclear Information System (INIS)

    Schindler, R.E.

    1996-09-01

    The aqueous waste evaporators at the Idaho Chemical Processing Plant (ICPP) are being modeled using ASPEN software. The ASPEN software calculates chemical and vapor-liquid equilibria with activity coefficients calculated using the electrolyte Non-Random Two Liquid (NRTL) model for local excess Gibbs free energies of interactions between ions and molecules in solution. The use of the electrolyte NRTL model requires the determination of empirical parameters for the excess Gibbs free energies of the interactions between species in solution. This report covers the development of a set parameters, from literature data, for the use of the electrolyte NRTL model with the major solutes in the ICPP aqueous wastes

  11. Converting partially-stocked aspen stands to fully-stocked stands in the Lake States: an economic analysis.

    Science.gov (United States)

    Jeffrey T. Olson; Allen L. Lundgren

    1978-01-01

    The 1968 Wisconsin Forest Survey showed large areas of aspen type that are not considered fully stocked. The economic feasibility of converting partially-stocked stands to full stocking is examined, and a rule presented for determining when a partially-stocked stand should be harvested to maximize its present value.

  12. Simulation of a tubular solid oxide fuel cell stack using AspenPlusTM unit operation models

    International Nuclear Information System (INIS)

    Zhang, W.; Croiset, E.; Douglas, P.L.; Fowler, M.W.; Entchev, E.

    2005-01-01

    The design of a fuel cell system involves both optimization of the fuel cell stack and the balance of plant with respect to efficiency and economics. Many commercially available process simulators, such as AspenPlus TM , can facilitate the analysis of a solid oxide fuel cell (SOFC) system. A SOFC system may include fuel pre-processors, heat exchangers, turbines, bottoming cycles, etc., all of which can be very effectively modelled in process simulation software. The current challenge is that AspenPlus TM or any other commercial process simulators do not have a model of a basic SOFC stack. Therefore, to enable performing SOFC system simulation using one of these simulators, one must construct an SOFC stack model that can be implemented in them. The most common approach is to develop a complete SOFC model in a programming language, such as Fortran, Visual Basic or C++, first and then link it to a commercial process simulator as a user defined model or subroutine. This paper introduces a different approach to the development of a SOFC model by utilizing existing AspenPlus TM functions and existing unit operation modules. The developed ''AspenPlus TM SOFC'' model is able to provide detailed thermodynamic and parametric analyses of the SOFC operation and can easily be extended to study the entire power plant consisting of the SOFC and the balance of plant without the requirement for linking with other software. Validation of this model is performed by comparison to a Siemens-Westinghouse 100 kW class tubular SOFC stack. Sensitivity analyses of major operating parameters, such as utilization factor (U f ), current density (I c ) and steam-carbon ratio (S/C), were performed using the developed model, and the results are discussed in this paper

  13. Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method

    International Nuclear Information System (INIS)

    Queiroz, João A.; Rodrigues, Vitor M.S.; Matos, Henrique A.; Martins, F.G.

    2012-01-01

    Highlights: ► Simulation of cooling tower performance under different operating conditions. ► Cooling tower performance is simulated using ASPEN PLUS. ► Levenberg–Marquardt method used to adjust model parameters. ► Air and water outlet temperatures are in good accordance with experimental data. - Abstract: Simulation of cooling tower performance considering operating conditions away from design is typically based on the geometrical parameters provided by the cooling tower vendor, which are often unavailable or outdated. In this paper a different approach for cooling tower modeling based on equilibrium stages and Murphree efficiencies to describe heat and mass transfer is presented. This approach is validated with published data and with data collected from an industrial application. Cooling tower performance is simulated using ASPEN PLUS. Murphree stage efficiency values for the process simulator model were optimized by minimizing the squared difference between the experimental and calculated data using the Levenberg–Marquardt method. The minimization algorithm was implemented in Microsoft Excel with Visual Basic for Applications, integrated with the process simulator (ASPEN PLUS) using Aspen Simulation Workbook. The simulated cooling tower air and water outlet temperatures are in good accordance with experimental data when applying only the outlet water temperature to calibrate the model. The methodology is accurate for simulating cooling towers at different operational conditions.

  14. Simulation Model of Membrane Gas Separator Using Aspen Custom Modeler

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dong-keun [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Shin, Gahui; Yun, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-12-15

    Membranes are used to separate pure gas from gas mixtures. In this study, three different types of mass transport through a membrane were developed in order to investigate the gas separation capabilities of a membrane. The three different models typically used are a lumped model, a multi-cell model, and a discretization model. Despite the multi-cell model producing similar results to a discretization model, the discretization model was selected for this investigation, due to the cell number dependence of a multi-cell model. The mass transport model was then used to investigate the effects of pressure difference, flow rate, total exposed area, and permeability. The results showed that the pressure difference increased with the stage cut, but the selectivity was a trade-off for the increasing pressure difference. Additionally, even though permeability is an important parameter, the selectivity and stage cut of the membrane converged as permeability increased.

  15. Enhanced model for integrated simulation of an entrained bed gasifier implemented as Aspen Hysys extension

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A; Ferrer-Nadal, S; Kopanos, G; Mitta, N; Pinilla, C A; Nougues, J M; Velo, E; Puigjaner, L [Universitat Politecnica de Catalunya, Barcelona (Spain). Dept. of Chemical Engineering-CEPIMA

    2007-07-01

    In this work an enhanced mathematical model of an entrained bed gasifier has been developed for improved synthesis gas production. The gasification model considers five stages: pyrolysis, volatiles combustion, char combustion, gasification and a final gas equilibrium zone. Mathematical simulations are carried out to help finding out feasible operating conditions of the process to achieve improved process performance. Visual Basic (VB) is tested as tool for modelling, by using the Aspen Hysys Extension (AHE) interface standards. This standard provides a suitable environment for this purpose, since it allows the creation of completely custom modules which are easy to plug and use thus facilitating the handling of complex models ready to interact with commercial simulation platforms. In this work, integration of different models is accomplished in Aspen Hysys (AH), which provides the basic connectivity within models components, and the thermodynamic framework needed. The integrated modules simulation environment platform uses data from ELCOGAS for validation purposes with excellent preliminary results. 9 refs., 2 figs.

  16. Aspen Delineation - Aspen Delineation Project [ds362

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can...

  17. Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

    Science.gov (United States)

    Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

    2016-08-01

    Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff. © 2016 American Society for Parenteral and Enteral Nutrition.

  18. Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

    Science.gov (United States)

    Efthimion, Phillip; Gentile, Charles

    2011-10-01

    The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

  19. ASPEN: A fully kinetic, reduced-description particle-in-cell model for simulating parametric instabilities

    International Nuclear Information System (INIS)

    Vu, H.X.; Bezzerides, B.; DuBois, D.F.

    1999-01-01

    A fully kinetic, reduced-description particle-in-cell (RPIC) model is presented in which deviations from quasineutrality, electron and ion kinetic effects, and nonlinear interactions between low-frequency and high-frequency parametric instabilities are modeled correctly. The model is based on a reduced description where the electromagnetic field is represented by three separate temporal envelopes in order to model parametric instabilities with low-frequency and high-frequency daughter waves. Because temporal envelope approximations are invoked, the simulation can be performed on the electron time scale instead of the time scale of the light waves. The electrons and ions are represented by discrete finite-size particles, permitting electron and ion kinetic effects to be modeled properly. The Poisson equation is utilized to ensure that space-charge effects are included. The RPIC model is fully three dimensional and has been implemented in two dimensions on the Accelerated Strategic Computing Initiative (ASCI) parallel computer at Los Alamos National Laboratory, and the resulting simulation code has been named ASPEN. The authors believe this code is the first particle-in-cell code capable of simulating the interaction between low-frequency and high-frequency parametric instabilities in multiple dimensions. Test simulations of stimulated Raman scattering, stimulated Brillouin scattering, and Langmuir decay instability are presented

  20. Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

    Directory of Open Access Journals (Sweden)

    Rolando Barrera

    2014-01-01

    Full Text Available The production of synthetic or substitute natural gas (SNG from coal is a process of interest in Colombia where the reserves-to-production ratio (R/P for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around 90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical equilibrium with the Gibbs free energy approach. The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis is put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is, energy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold gas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent. Simulations results are compared against available technical data with good accuracy. Thus, the proposed model is considered as a versatile and useful computational tool to study and optimize the coal to SNG process.

  1. Dual RBFNNs-Based Model-Free Adaptive Control With Aspen HYSYS Simulation.

    Science.gov (United States)

    Zhu, Yuanming; Hou, Zhongsheng; Qian, Feng; Du, Wenli

    2017-03-01

    In this brief, we propose a new data-driven model-free adaptive control (MFAC) method with dual radial basis function neural networks (RBFNNs) for a class of discrete-time nonlinear systems. The main novelty lies in that it provides a systematic design method for controller structure by the direct usage of I/O data, rather than using the first-principle model or offline identified plant model. The controller structure is determined by equivalent-dynamic-linearization representation of the ideal nonlinear controller, and the controller parameters are tuned by the pseudogradient information extracted from the I/O data of the plant, which can deal with the unknown nonlinear system. The stability of the closed-loop control system and the stability of the training process for RBFNNs are guaranteed by rigorous theoretical analysis. Meanwhile, the effectiveness and the applicability of the proposed method are further demonstrated by the numerical example and Aspen HYSYS simulation of distillation column in crude styrene produce process.

  2. A kinetic reaction model for biomass pyrolysis processes in Aspen Plus

    International Nuclear Information System (INIS)

    Peters, Jens F.; Banks, Scott W.; Bridgwater, Anthony V.; Dufour, Javier

    2017-01-01

    Highlights: • Predictive kinetic reaction model applicable to any lignocellulosic feedstock. • Calculates pyrolysis yields and product composition as function of reactor conditions. • Detailed modelling of product composition (33 model compounds for the bio-oil). • Good agreement with literature regarding yield curves and product composition. • Successful validation with pyrolysis experiments in bench scale fast pyrolysis rig. - Abstract: This paper presents a novel kinetic reaction model for biomass pyrolysis processes. The model is based on the three main building blocks of lignocellulosic biomass, cellulose, hemicellulose and lignin and can be readily implemented in Aspen Plus and easily adapted to other process simulation software packages. It uses a set of 149 individual reactions that represent the volatilization, decomposition and recomposition processes of biomass pyrolysis. A linear regression algorithm accounts for the secondary pyrolysis reactions, thus allowing the calculation of slow and intermediate pyrolysis reactions. The bio-oil is modelled with a high level of detail, using up to 33 model compounds, which allows for a comprehensive estimation of the properties of the bio-oil and the prediction of further upgrading reactions. After showing good agreement with existing literature data, our own pyrolysis experiments are reported for validating the reaction model. A beech wood feedstock is subjected to pyrolysis under well-defined conditions at different temperatures and the product yields and compositions are determined. Reproducing the experimental pyrolysis runs with the simulation model, a high coincidence is found for the obtained fraction yields (bio-oil, char and gas), for the water content and for the elemental composition of the pyrolysis products. The kinetic reaction model is found to be suited for predicting pyrolysis yields and product composition for any lignocellulosic biomass feedstock under typical pyrolysis conditions

  3. ASPEN simulation of cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Ligang Zheng [CANMET Energy Technology Center, Natural Resources Canada, Nepean, ONT (Canada); Furimsky, E. [IMAG Group, Ottawa, ONT (Canada)

    2003-07-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data. (author)

  4. ASPEN simulation of cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ligang E-mail: lzheng@nrcan.gc.ca; Furimsky, Edward

    2003-07-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data.

  5. ASPEN simulation of cogeneration plants

    International Nuclear Information System (INIS)

    Zheng Ligang; Furimsky, Edward

    2003-01-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data

  6. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Science.gov (United States)

    Huang, Jian-Guo; Stadt, Kenneth J; Dawson, Andria; Comeau, Philip G

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2)>0.67) to represent this complex variation in growth as a function of site, size and competition.

  7. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Directory of Open Access Journals (Sweden)

    Jian-Guo Huang

    Full Text Available We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA, the sum of stem diameter at breast height (SDBH, and density (N for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR, were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2>0.67 to represent this complex variation in growth as a function of site, size and competition.

  8. Fire regimes of quaking aspen in the Mountain West

    Science.gov (United States)

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    settings and correlated aspen functional types. We propose the following aspen fire regime types: (1) fire-independent, stable aspen; (2) fire-influenced, stable aspen; (3) fire-dependent, seral, conifer-aspen mix; (4) fire-dependent, seral, montane aspen-conifer; and (5) fire-dependent, seral, subalpine aspen-conifer. Closing research gaps and validating our proposed aspen fire regime classification will likely require additional site-specific research, enhanced dendrochronology techniques, charcoal and pollen record analysis, spatially-explicit modeling, and other techniques. We hope to encourage development of site-appropriate disturbance ecology characterizations, in order to aid efforts to manage and restore aspen communities and to diagnose key factors contributing to changes in aspen.

  9. Modelling and testing the performance of a commercial ammonia/water absorption chiller using Aspen-Plus platform

    International Nuclear Information System (INIS)

    Mansouri, Rami; Boukholda, Ismail; Bourouis, Mahmoud; Bellagi, Ahmed

    2015-01-01

    A steady-state simulation model of a commercial 3-ton ammonia/water absorption chiller is developed and validated using the flow-sheeting software Aspen-Plus. First an appropriate thermodynamic property model for the ammonia/water fluid mixture is selected. To this purpose nine methods from the software library are pre-selected and tested, but none of the methods predicts the VLE (vapour–liquid equilibrium) with sufficient accuracy. The interaction parameters of these models are then determined by fitting the equations of state (EOS) to VLE data. It is finally found that the Boston–Mathias modified Peng–Robinson EOS with fitted parameters predicts most accurately the VLE for the temperature and pressure ranges encountered in commercial chillers. A simulation model of the machine is then developed. The simulation results are found to be in good agreement with data from literature at a cooling air temperature of 35 ºC. The heat transfer characteristics (UA) of the various heat exchangers of the machine are then determined and the model modified to make it accept these (UA) as input parameters. The comparison of the simulation predictions at cooling air temperatures of 26.7 and 38 ºC with the bibliographical data showed good concordance. The proposed model could be very useful for the analysis and performance prediction of the commercial absorption chiller. - Highlights: • A commercial NH 3 /H 2 O absorption chiller is simulated using the software Aspen-Plus. • Peng-Robinson-Boston-Mathias equation of state is used to predict VLE of NH 3 /H 2 O fluid mixture. • A steady-state model describing the chiller operation is developed. • The model predicts the internal operating conditions and COP of the chiller.

  10. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-05-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  11. Assessing aspen using remote sensing

    Science.gov (United States)

    Randy Hamilton; Kevin Megown; Jeff DiBenedetto; Dale Bartos; Anne Mileck

    2009-01-01

    Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers...

  12. Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

    Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

  13. Models of Economic Analysis

    OpenAIRE

    Adrian Ioana; Tiberiu Socaciu

    2013-01-01

    The article presents specific aspects of management and models for economic analysis. Thus, we present the main types of economic analysis: statistical analysis, dynamic analysis, static analysis, mathematical analysis, psychological analysis. Also we present the main object of the analysis: the technological activity analysis of a company, the analysis of the production costs, the economic activity analysis of a company, the analysis of equipment, the analysis of labor productivity, the anal...

  14. Modelling of an industrial NGL-Recovery unit considering environmental and economic impacts

    International Nuclear Information System (INIS)

    Sharratt, P. N.; Hernandez-Enriquez, A.; Flores-Tlacuahuac, A.

    2009-01-01

    In this work, an integrated model is presented that identifies key areas in the operation of a cryogenic NGL-recovery unit. This methodology sets out to provide deep understanding of various interrelationship across multiple plant operating factors including reliability, which could be essential for substantial improvement of process performance. The integrated model has been developed to predict the economic and environmental impacts of a real cryogenic unit (600 MMCUF/D) during normal operation, and has been built in Aspen TM. (Author)

  15. Modeling solubility of CO2/hydrocarbon gas in ionic liquid ([emim][FAP]) using Aspen Plus simulations.

    Science.gov (United States)

    Bagchi, Bishwadeep; Sati, Sushmita; Shilapuram, Vidyasagar

    2017-08-01

    The Peng-Robinson equation of state with quadratic van der Waals (vdW) mixing rule model was chosen to perform the thermodynamic calculations in Flash3 column of Aspen Plus to predict the solubility of CO 2 or any one of the hydrocarbons (HCs) among methane, ethane, propane, and butane in an ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]). Bubble point pressure, solubility, bubble point temperature, fugacity, and partial molar volume at infinite dilution were obtained from the simulations, and enthalpy of absorption, Gibbs free energy of solvation, and entropy change of absorption were estimated by thermodynamic relations. Results show that carbon chain length has a significant effect on the bubble point pressure. Methane has the highest bubble point pressure among all the considered HCs and CO 2 . The bubble point pressure and fugacity variation with temperature is different for CO 2 as compared to HCs for mole fractions above 0.2. Two different profiles are noticed for enthalpy of absorption when plotted as a function of mole fraction of gas soluble in IL. Partial molar volume of CO 2 decreases with increase in temperature in [emim][FAP], while it is increased for HCs. Bubble point temperature decreases with increase in the mole fraction of the solute. Entropy of solvation increases with temperature till a particular value followed by a decrease with further increase in temperature. Gibbs free energy change of solvation showed that the process of solubility was spontaneous.

  16. Molecular tools and aspen management: A primer and prospectus

    Science.gov (United States)

    Karen E. Mock; Bryce A. Richardson; Paul G. Wolf

    2013-01-01

    Aspen (Populus tremuloides) isaniconic species in North American landscapes, highly valued for recreation, fiber, wildlife and livestock forage, carbon sequestration, biodiversity, and as a fuelbreak. However, there are rising concerns about the ability of aspen to persist in portions of its range, based on bioclimatic modeling, physiological thresholds and mortality...

  17. Economic communication model set

    Science.gov (United States)

    Zvereva, Olga M.; Berg, Dmitry B.

    2017-06-01

    This paper details findings from the research work targeted at economic communications investigation with agent-based models usage. The agent-based model set was engineered to simulate economic communications. Money in the form of internal and external currencies was introduced into the models to support exchanges in communications. Every model, being based on the general concept, has its own peculiarities in algorithm and input data set since it was engineered to solve the specific problem. Several and different origin data sets were used in experiments: theoretic sets were estimated on the basis of static Leontief's equilibrium equation and the real set was constructed on the basis of statistical data. While simulation experiments, communication process was observed in dynamics, and system macroparameters were estimated. This research approved that combination of an agent-based and mathematical model can cause a synergetic effect.

  18. Analysis and Modeling of Vapor Recompressive Distillation Using ASPEN-HYSYS

    Directory of Open Access Journals (Sweden)

    Cinthujaa C. Sivanantha

    2011-10-01

    Full Text Available HYSYS process modeling software was used to analyze the effect of reflux ratio and number of trays on the purity of ethylene in a vapor recompression distillation column and also in an ordinary distillation column. Analysis of data showed that with increased pressure a higher reflux ratio is needed to obtain a purity of 99.9{\\%} for both towers. In addition number of trays was varied to see its effect on purity. Analysis proved that purity increases with number of trays.

  19. The impact of vessel size on vulnerability curves: data and models for within-species variability in saplings of aspen, Populus tremuloides Michx.

    Science.gov (United States)

    Cai, Jing; Tyree, Melvin T

    2010-07-01

    The objective of this study was to quantify the relationship between vulnerability to cavitation and vessel diameter within a species. We measured vulnerability curves (VCs: percentage loss hydraulic conductivity versus tension) in aspen stems and measured vessel-size distributions. Measurements were done on seed-grown, 4-month-old aspen (Populus tremuloides Michx) grown in a greenhouse. VCs of stem segments were measured using a centrifuge technique and by a staining technique that allowed a VC to be constructed based on vessel diameter size-classes (D). Vessel-based VCs were also fitted to Weibull cumulative distribution functions (CDF), which provided best-fit values of Weibull CDF constants (c and b) and P(50) = the tension causing 50% loss of hydraulic conductivity. We show that P(50) = 6.166D(-0.3134) (R(2) = 0.995) and that b and 1/c are both linear functions of D with R(2) > 0.95. The results are discussed in terms of models of VCs based on vessel D size-classes and in terms of concepts such as the 'pit area hypothesis' and vessel pathway redundancy.

  20. Modeling recent economic debates

    Science.gov (United States)

    Skiadas, Christos H.

    The previous years' disaster in the stock markets all over the world and the resulting economic crisis lead to serious criticisms of the various models used. It was evident that large fluctuations and sudden losses may occur even in the case of a well organized and supervised context as it looks to be the European Union. In order to explain the economic systems, we explore models of interacting and conflicting populations. The populations are conflicting into the same environment (a Stock Market or a Group of Countries as the EU). Three models where introduced 1) the Lotka-Volterra 2) the Lanchester or the Richardson model and 3) a new model for two conflicting populations. These models assume immediate interaction between the two conflicting populations. This is usually not the case in a stock market or between countries as delays in the information process arise. The main rules present include mutual interaction between adopters, potential adopters, word-of-mouth communication and of course by taking into consideration the innovation diffusion process. In a previous paper (Skiadas, 2010 [9]) we had proposed and analyzed a model including mutual interaction with delays due to the innovation diffusion process. The model characteristics where expressed by third order terms providing four characteristic symmetric stationary points. In this paper we summarize the previous results and we analyze the case of a non-symmetric case where the leading part receives the information immediately while the second part receives the information following a delay mechanism due to the innovation diffusion process (the spread of information) which can be expressed by a third order term. In the later case the non-symmetric process leads to gains of the leading part while the second part oscillates between gains and losses during time.

  1. ASPEN Version 3.0

    Science.gov (United States)

    Rabideau, Gregg; Chien, Steve; Knight, Russell; Schaffer, Steven; Tran, Daniel; Cichy, Benjamin; Sherwood, Robert

    2006-01-01

    The Automated Scheduling and Planning Environment (ASPEN) computer program has been updated to version 3.0. ASPEN is a modular, reconfigurable, application software framework for solving batch problems that involve reasoning about time, activities, states, and resources. Applications of ASPEN can include planning spacecraft missions, scheduling of personnel, and managing supply chains, inventories, and production lines. ASPEN 3.0 can be customized for a wide range of applications and for a variety of computing environments that include various central processing units and random access memories.

  2. Economic Modelling in Institutional Economic Theory

    Directory of Open Access Journals (Sweden)

    Wadim Strielkowski

    2017-06-01

    Full Text Available Our paper is centered around the formation of theory of institutional modelling that includes principles and ideas reflecting the laws of societal development within the framework of institutional economic theory. We scrutinize and discuss the scientific principles of this institutional modelling that are increasingly postulated by the classics of institutional theory and find their way into the basics of the institutional economics. We propose scientific ideas concerning the new innovative approaches to institutional modelling. These ideas have been devised and developed on the basis of the results of our own original design, as well as on the formalisation and measurements of economic institutions, their functioning and evolution. Moreover, we consider the applied aspects of the institutional theory of modelling and employ them in our research for formalizing our results and maximising the practical outcome of our paper. Our results and findings might be useful for the researchers and stakeholders searching for the systematic and comprehensive description of institutional level modelling, the principles involved in this process and the main provisions of the institutional theory of economic modelling.

  3. Aspen Delineation - Inyo National Forest [ds366

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of known aspen stands where aspen assessments were collected in the Inyo National Forest, Inyo County, California. The Inyo...

  4. Aspen Delineation - Klamath National Forest [ds370

    Data.gov (United States)

    California Natural Resource Agency — The database represents polygons of aspen stands in the Klamath National Forest, Siskiyou County, California. The Klamath National Forest Region 5 Vegetation aspen...

  5. Approach and development strategy for an agent-based model of economic confidence.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Pryor, Richard J.; Jorgensen, Craig Reed

    2004-08-01

    We are extending the existing features of Aspen, a powerful economic modeling tool, and introducing new features to simulate the role of confidence in economic activity. The new model is built from a collection of autonomous agents that represent households, firms, and other relevant entities like financial exchanges and governmental authorities. We simultaneously model several interrelated markets, including those for labor, products, stocks, and bonds. We also model economic tradeoffs, such as decisions of households and firms regarding spending, savings, and investment. In this paper, we review some of the basic principles and model components and describe our approach and development strategy for emulating consumer, investor, and business confidence. The model of confidence is explored within the context of economic disruptions, such as those resulting from disasters or terrorist events.

  6. Macro-economic environmental models

    International Nuclear Information System (INIS)

    Wier, M.

    1993-01-01

    In the present report, an introduction to macro-economic environmental models is given. The role of the models as a tool for policy analysis is discussed. Future applications, as well as the limitations given by the data, are brought into focus. The economic-ecological system is described. A set of guidelines for implementation of the system in a traditional economic macro-model is proposed. The characteristics of empirical national and international environmental macro-economic models so far are highlighted. Special attention is paid to main economic causalities and their consequences for the environmental policy recommendations sat by the models. (au) (41 refs.)

  7. Manipulations to regenerate aspen ecosystems

    Science.gov (United States)

    Wayne D. Shepperd

    2001-01-01

    Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection - the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site...

  8. Repeated Prescribed Burning in Aspen

    Science.gov (United States)

    Donald A. Perala

    1974-01-01

    Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

  9. Decay of aspen in Colorado

    Science.gov (United States)

    Ross W. Davidson; Thomas E. Hinds; Frank G. Hawksworth

    1959-01-01

    Quaking aspen (Populus tremuloides Michx.) stands are extensive in the central Rocky Mountains. The species reaches its maximum development in the mountains and high mesas west of the Continental Divide in Colorado (Baker, 1925). On the better sites aspen yields a greater volume of wood in a shorter period than most of the conifers growing at comparable elevations. The...

  10. Model estimates of leaf area and reference canopy stomatal conductance suggest correlation between phenology and physiology in both trembling aspen and red pine

    Science.gov (United States)

    Mackay, D. S.; Ewers, B. E.; Kruger, E. L.

    2006-12-01

    Phenological variations impact water and carbon fluxes, as evidenced by the large interannual variability of net ecosystem exchange of carbon dioxide and evapotranspiration (ET). In northern Wisconsin we observed daily variations of canopy transpiration from hardwoods from 1.0 to 1.7 mm/day during the leaf unfolding period and 1.7 to 2.6 mm/day with leaves fully out. Correlations between such flux rates and phenology have not been extensively tested and mechanistic connections are in their infancy. Some data suggest that stomatal conductance and photosynthesis increases up to full expansion. Moreover, in conifers, the interaction of phenology and physiology is more complicated than in deciduous trees because needles are retained for several years. Using inverse modeling with a coupled photosynthesis-transpiration model we estimated reference canopy stomatal conductance, Gsref, for red pine (Pinus resinosa), and Gsref and leaf area index, L, for trembling aspen (Populus tremuloides), using 30-min continuous sap flux data spanning a period from just prior to the start of leaf expansion to just after leaf senescence. The red pine showed Gsref ramp up from 105 to 179 mmol m-2 leaf s-1, which represented a 37 to 50 percent increase in Gsref after accounting for maximum possible changes in L. After full leaf out, the trembling aspen were almost immediately defoliated, and then reflushed after three weeks. Model estimates of L reflected this pattern and were consistent with measurements. However, Gsref never exceeded 45 mmol m-2 s-1 prior to defoliation, but peaked at 112 mmol m-2 s-1 after reflushing. These results support the need for further work that aims to separate phenology and physiology.

  11. Simulation and statistical analysis for the optimization of nitrogen liquefaction plant with cryogenic Claude cycle using process modeling tool: ASPEN HYSYS

    International Nuclear Information System (INIS)

    Joshi, D.M.

    2017-01-01

    Cryogenic technology is used for liquefaction of many gases and it has several applications in food process engineering. Temperatures below 123 K are considered to be in the field of cryogenics. Extreme low temperatures are a basic need for many industrial processes and have several applications, such as superconductivity of magnets, space, medicine and gas industries. Several methods can be used to obtain the low temperatures required for liquefaction of gases. The process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure, which is below the critical pressure, is the basic liquefaction process. Different cryogenic cycle configurations are designed for getting the liquefied form of gases at different temperatures. Each of the cryogenic cycles like Linde cycle, Claude cycle, Kapitza cycle or modified Claude cycle has its own advantages and disadvantages. The placement of heat exchangers, Joule-Thompson valve and turboexpander decides the configuration of a cryogenic cycle. Each configuration has its own efficiency according to the application. Here, a nitrogen liquefaction plant is used for the analysis purpose. The process modeling tool ASPEN HYSYS can provide a software simulation approach before the actual implementation of the plant in the field. This paper presents the simulation and statistical analysis of the Claude cycle with the process modeling tool ASPEN HYSYS. It covers the technique used to optimize the liquefaction of the plant. The simulation results so obtained can be used as a reference for the design and optimization of the nitrogen liquefaction plant. Efficient liquefaction will give the best performance and productivity to the plant.

  12. Simulation and statistical analysis for the optimization of nitrogen liquefaction plant with cryogenic Claude cycle using process modeling tool: ASPEN HYSYS

    Science.gov (United States)

    Joshi, D. M.

    2017-09-01

    Cryogenic technology is used for liquefaction of many gases and it has several applications in food process engineering. Temperatures below 123 K are considered to be in the field of cryogenics. Extreme low temperatures are a basic need for many industrial processes and have several applications, such as superconductivity of magnets, space, medicine and gas industries. Several methods can be used to obtain the low temperatures required for liquefaction of gases. The process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure, which is below the critical pressure, is the basic liquefaction process. Different cryogenic cycle configurations are designed for getting the liquefied form of gases at different temperatures. Each of the cryogenic cycles like Linde cycle, Claude cycle, Kapitza cycle or modified Claude cycle has its own advantages and disadvantages. The placement of heat exchangers, Joule-Thompson valve and turboexpander decides the configuration of a cryogenic cycle. Each configuration has its own efficiency according to the application. Here, a nitrogen liquefaction plant is used for the analysis purpose. The process modeling tool ASPEN HYSYS can provide a software simulation approach before the actual implementation of the plant in the field. This paper presents the simulation and statistical analysis of the Claude cycle with the process modeling tool ASPEN HYSYS. It covers the technique used to optimize the liquefaction of the plant. The simulation results so obtained can be used as a reference for the design and optimization of the nitrogen liquefaction plant. Efficient liquefaction will give the best performance and productivity to the plant.

  13. Economic Growth Models Transition

    Directory of Open Access Journals (Sweden)

    Coralia Angelescu

    2006-03-01

    Full Text Available The transitional recession in countries of Eastern Europe has been much longer than expected. The legacy and recent policy mistakes have both contributed to the slow progress. As structural reforms and gradual institution building have taken hold, the post-socialist economics have started to recover, with some leading countries building momentum toward faster growth. There is a possibility that in wider context of globalization several of these emerging market economies will be able to catch up with the more advanced industrial economies in a matter of one or two generations. Over the past few years, most candidate countries have made progress in the transition to a competitive market economy, macroeconomic stabilization and structural reform. However their income levels have remained far below those in the Member States. Measured by per capita income in purchasing power standards, there has been a very limited amount of catching up over the past fourteen years. Prior, the distinctions between Solow-Swan model and endogenous growth model. The interdependence between transition and integration are stated in this study. Finally, some measures of macroeconomic policy for sustainable growth are proposed in correlation with real macroeconomic situation of the Romanian economy. Our study would be considered the real convergence for the Romanian economy and the recommendations for the adequate policies to achieve a fast real convergence and sustainable growth.

  14. Economic Growth Models Transition

    Directory of Open Access Journals (Sweden)

    Coralia Angelescu

    2006-01-01

    Full Text Available The transitional recession in countries of Eastern Europe has been much longer than expected. The legacy and recent policy mistakes have both contributed to the slow progress. As structural reforms and gradual institution building have taken hold, the post-socialist economics have started to recover, with some leading countries building momentum toward faster growth. There is a possibility that in wider context of globalization several of these emerging market economies will be able to catch up with the more advanced industrial economies in a matter of one or two generations. Over the past few years, most candidate countries have made progress in the transition to a competitive market economy, macroeconomic stabilization and structural reform. However their income levels have remained far below those in the Member States. Measured by per capita income in purchasing power standards, there has been a very limited amount of catching up over the past fourteen years. Prior, the distinctions between Solow-Swan model and endogenous growth model. The interdependence between transition and integration are stated in this study. Finally, some measures of macroeconomic policy for sustainable growth are proposed in correlation with real macroeconomic situation of the Romanian economy. Our study would be considered the real convergence for the Romanian economy and the recommendations for the adequate policies to achieve a fast real convergence and sustainable growth.

  15. Landscape dynamics of aspen and conifer forests

    Science.gov (United States)

    Dale L. Bartos

    2001-01-01

    Quaking aspen (Populus tremuloides Michx.) is widely dispersed across the landscape of North America. Seventy-five percent of the aspen in the western United States occurs in the states of Colorado (50%) and Utah (25%). Reproduction in aspen is primarily by asexual means, e.g., root sprouts that are generally referred to as suckers. An aspen clone consists of numerous...

  16. Economic analysis model for total energy and economic systems

    International Nuclear Information System (INIS)

    Shoji, Katsuhiko; Yasukawa, Shigeru; Sato, Osamu

    1980-09-01

    This report describes framing an economic analysis model developed as a tool of total energy systems. To prospect and analyze future energy systems, it is important to analyze the relation between energy system and economic structure. We prepared an economic analysis model which was suited for this purpose. Our model marks that we can analyze in more detail energy related matters than other economic ones, and can forecast long-term economic progress rather than short-term economic fluctuation. From view point of economics, our model is longterm multi-sectoral economic analysis model of open Leontief type. Our model gave us appropriate results for fitting test and forecasting estimation. (author)

  17. Simulating economic effects of disruptions in the telecommunications infrastructure.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Roger Gary; Barton, Dianne Catherine; Reinert, Rhonda K.; Eidson, Eric D.; Schoenwald, David Alan

    2004-01-01

    CommAspen is a new agent-based model for simulating the interdependent effects of market decisions and disruptions in the telecommunications infrastructure on other critical infrastructures in the U.S. economy such as banking and finance, and electric power. CommAspen extends and modifies the capabilities of Aspen-EE, an agent-based model previously developed by Sandia National Laboratories to analyze the interdependencies between the electric power system and other critical infrastructures. CommAspen has been tested on a series of scenarios in which the communications network has been disrupted, due to congestion and outages. Analysis of the scenario results indicates that communications networks simulated by the model behave as their counterparts do in the real world. Results also show that the model could be used to analyze the economic impact of communications congestion and outages.

  18. Using Aspen plus in thermodynamics instruction a step-by-step guide

    CERN Document Server

    Sandler, Stanley I

    2015-01-01

    A step-by-step guide for students (and faculty) on the use of Aspen in teaching thermodynamics Used for a wide variety of important engineering tasks, Aspen Plus software is a modeling tool used for conceptual design, optimization, and performance monitoring of chemical processes. After more than twenty years, it remains one of the most popular and powerful chemical engineering simulation programs used both industrially and academically. Using Aspen Plus in Thermodynamics Instruction: A Step by Step Guide introduces the reader to the use of Aspen Plus in courses in thermodynamics. It prov

  19. Economic modeling of HIV treatments.

    Science.gov (United States)

    Simpson, Kit N

    2010-05-01

    To review the general literature on microeconomic modeling and key points that must be considered in the general assessment of economic modeling reports, discuss the evolution of HIV economic models and identify models that illustrate this development over time, as well as examples of current studies. Recommend improvements in HIV economic modeling. Recent economic modeling studies of HIV include examinations of scaling up antiretroviral (ARV) in South Africa, screening prior to use of abacavir, preexposure prophylaxis, early start of ARV in developing countries and cost-effectiveness comparisons of specific ARV drugs using data from clinical trials. These studies all used extensively published second-generation Markov models in their analyses. There have been attempts to simplify approaches to cost-effectiveness estimates by using simple decision trees or cost-effectiveness calculations with short-time horizons. However, these approaches leave out important cumulative economic effects that will not appear early in a treatment. Many economic modeling studies were identified in the 'gray' literature, but limited descriptions precluded an assessment of their adherence to modeling guidelines, and thus to the validity of their findings. There is a need for developing third-generation models to accommodate new knowledge about adherence, adverse effects, and viral resistance.

  20. Testing a hydraulic trait based model of stomatal control: results from a controlled drought experiment on aspen (Populus tremuloides, Michx.) and ponderosa pine (Pinus ponderosa, Douglas)

    Science.gov (United States)

    Love, D. M.; Venturas, M.; Sperry, J.; Wang, Y.; Anderegg, W.

    2017-12-01

    Modeling approaches for tree stomatal control often rely on empirical fitting to provide accurate estimates of whole tree transpiration (E) and assimilation (A), which are limited in their predictive power by the data envelope used to calibrate model parameters. Optimization based models hold promise as a means to predict stomatal behavior under novel climate conditions. We designed an experiment to test a hydraulic trait based optimization model, which predicts stomatal conductance from a gain/risk approach. Optimal stomatal conductance is expected to maximize the potential carbon gain by photosynthesis, and minimize the risk to hydraulic transport imposed by cavitation. The modeled risk to the hydraulic network is assessed from cavitation vulnerability curves, a commonly measured physiological trait in woody plant species. Over a growing season garden grown plots of aspen (Populus tremuloides, Michx.) and ponderosa pine (Pinus ponderosa, Douglas) were subjected to three distinct drought treatments (moderate, severe, severe with rehydration) relative to a control plot to test model predictions. Model outputs of predicted E, A, and xylem pressure can be directly compared to both continuous data (whole tree sapflux, soil moisture) and point measurements (leaf level E, A, xylem pressure). The model also predicts levels of whole tree hydraulic impairment expected to increase mortality risk. This threshold is used to estimate survivorship in the drought treatment plots. The model can be run at two scales, either entirely from climate (meteorological inputs, irrigation) or using the physiological measurements as a starting point. These data will be used to study model performance and utility, and aid in developing the model for larger scale applications.

  1. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  2. Aspen Delineation - Lassen National Forest [ds372

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (LASSEN_NF_EAGLELAKE_PTS) collected in aspen stands in the in the Eagle...

  3. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  4. Numerical modeling of economic uncertainty

    DEFF Research Database (Denmark)

    Schjær-Jacobsen, Hans

    2007-01-01

    Representation and modeling of economic uncertainty is addressed by different modeling methods, namely stochastic variables and probabilities, interval analysis, and fuzzy numbers, in particular triple estimates. Focusing on discounted cash flow analysis numerical results are presented, comparisons...... are made between alternative modeling methods, and characteristics of the methods are discussed....

  5. ECONOMIC MODELING PROCESSES USING MATLAB

    Directory of Open Access Journals (Sweden)

    Anamaria G. MACOVEI

    2008-06-01

    Full Text Available To study economic phenomena and processes using mathem atical modeling, and to determine the approximatesolution to a problem we need to choose a method of calculation and a numerical computer program, namely thepackage of programs MatLab. Any economic process or phenomenon is a mathematical description of h is behavior,and thus draw up an economic and mathematical model that has the following stages: formulation of the problem, theanalysis process modeling, the production model and design verification, validation and implementation of the model.This article is presented an economic model and its modeling is using mathematical equations and software packageMatLab, which helps us approximation effective solution. As data entry is considered the net cost, the cost of direct andtotal cost and the link between them. I presented the basic formula for determining the total cost. Economic modelcalculations were made in MatLab software package and with graphic representation of its interpretation of the resultsachieved in terms of our specific problem.

  6. The integrated economic model

    International Nuclear Information System (INIS)

    Syrota, J.; Cirelli, J.F.; Brimont, S.; Lyle, C.; Nossent, G.; Moraleda, P.

    2005-01-01

    The setting up of the European energy market has triggered a radical change of the context within with the energy players operated. The natural markets of the incumbent operators, which were formerly demarcated by national and even regional borders, have extended to at least the scale of the European Union. In addition to their geographical development strategy, gas undertakings are diversifying their portfolios towards both upstream as well as downstream activities of the gas chain, and/or extending their offers to other energies and services. Energy players' strategies are rather complex and sometimes give the impression that of being based on contradictory decisions. Some operators widen their field of operations, whereas others specialize in a limited number of activities. This Round Table provides an opportunity to compare business models as adopted by the major gas undertakings in response to structural changes observed in various countries over recent years

  7. Model confirmation in climate economics

    Science.gov (United States)

    Millner, Antony; McDermott, Thomas K. J.

    2016-01-01

    Benefit–cost integrated assessment models (BC-IAMs) inform climate policy debates by quantifying the trade-offs between alternative greenhouse gas abatement options. They achieve this by coupling simplified models of the climate system to models of the global economy and the costs and benefits of climate policy. Although these models have provided valuable qualitative insights into the sensitivity of policy trade-offs to different ethical and empirical assumptions, they are increasingly being used to inform the selection of policies in the real world. To the extent that BC-IAMs are used as inputs to policy selection, our confidence in their quantitative outputs must depend on the empirical validity of their modeling assumptions. We have a degree of confidence in climate models both because they have been tested on historical data in hindcasting experiments and because the physical principles they are based on have been empirically confirmed in closely related applications. By contrast, the economic components of BC-IAMs often rely on untestable scenarios, or on structural models that are comparatively untested on relevant time scales. Where possible, an approach to model confirmation similar to that used in climate science could help to build confidence in the economic components of BC-IAMs, or focus attention on which components might need refinement for policy applications. We illustrate the potential benefits of model confirmation exercises by performing a long-run hindcasting experiment with one of the leading BC-IAMs. We show that its model of long-run economic growth—one of its most important economic components—had questionable predictive power over the 20th century. PMID:27432964

  8. Mathematical modelling in economic processes.

    Directory of Open Access Journals (Sweden)

    L.V. Kravtsova

    2008-06-01

    Full Text Available In article are considered a number of methods of mathematical modelling of economic processes and opportunities of use of spreadsheets Excel for reception of the optimum decision of tasks or calculation of financial operations with the help of the built-in functions.

  9. PLANNING AND MODEL CUBAN ECONOMIC

    Directory of Open Access Journals (Sweden)

    Kenilia Mariela Villalón-Madrazo

    2016-01-01

    Full Text Available Since the Revolution´s Triumph the country assumes that the planning is the axis, as instrument for the economic acting and of the constant development of the socialist relationships of production and it traces the rules required for the best operation in the Cuban economy, and it implants with these concepts the centralized economic pattern that responded to the existent outline in the Soviet Union and the European socialist countries, of centralized planning based on the material balances. In the current situation of the Cuban economy it is thought about bringing up to date the economic pattern in which will stay as priority the planning and not the market. Leaving what it is mentioned above, presently in this work is carried out the analysis of the economic models in Cuba and its linking with the planning, with the objective of giving to know how the pattern economic Cuban is implanted from the first years of the revolution and it has always been the planning its fundamental axis, and as the same one it has left modernizing during the 53 years of the Revolution. It has been carried out an analysis framed approximately in 10 year-old periods pointing out the internal and external factors that have impacted in the Cuban pattern, their adjustments and the role of planning. 

  10. Energy-economic policy modeling

    Science.gov (United States)

    Sanstad, Alan H.

    2018-01-01

    Computational models based on economic principles and methods are powerful tools for understanding and analyzing problems in energy and the environment and for designing policies to address them. Among their other features, some current models of this type incorporate information on sustainable energy technologies and can be used to examine their potential role in addressing the problem of global climate change. The underlying principles and the characteristics of the models are summarized, and examples of this class of model and their applications are presented. Modeling epistemology and related issues are discussed, as well as critiques of the models. The paper concludes with remarks on the evolution of the models and possibilities for their continued development.

  11. Efficiency of economic development models

    Directory of Open Access Journals (Sweden)

    Oana Camelia Iacob

    2013-03-01

    Full Text Available The world economy is becoming increasingly integrated. Integrating emerging economies of Asia, such as China and India increase competition on the world stage, putting pressure on the "actors" already existing. These developments have raised questions about the effectiveness of European development model, which focuses on a high level of equity, insurance and social protection. According to analysts, the world today faces three models of economic development with significant weight in the world: the European, American and Asian. This study will focus on analyzing European development model, and a brief comparison with the United States. In addition, this study aims to highlight the relationship between efficiency and social equity that occurs in each submodel in part of the European model, given that social and economic performance in the EU are not homogeneous. To achieve this, it is necessary to analyze different indicators related to social equity and efficiency respectively, to observe the performance of each submodel individually. The article analyzes data to determine submodel performance according to social equity and economic efficiency.

  12. Can aspen persist in conifer dominated forests?

    Science.gov (United States)

    Douglas H. Page; John D. Shaw

    2016-01-01

    In 1998 we measured a large, old aspen in a mixed spruce-fir-aspen forest on the Utah State University T.W. Daniel Experimental Forest in northern Utah. The tree was 297 years old - about the same age as the oldest spruce in the stand. A search of the forestry literature revealed that the oldest published age for an aspen came from a tree in the Sierra Nevada Range in...

  13. Economic and Technical Assessment of Wood Biomass Fuel Gasification for Industrial Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Anastasia M. Gribik; Ronald E. Mizia; Harry Gatley; Benjamin Phillips

    2007-09-01

    This project addresses both the technical and economic feasibility of replacing industrial gas in lime kilns with synthesis gas from the gasification of hog fuel. The technical assessment includes a materials evaluation, processing equipment needs, and suitability of the heat content of the synthesis gas as a replacement for industrial gas. The economic assessment includes estimations for capital, construction, operating, maintenance, and management costs for the reference plant. To perform these assessments, detailed models of the gasification and lime kiln processes were developed using Aspen Plus. The material and energy balance outputs from the Aspen Plus model were used as inputs to both the material and economic evaluations.

  14. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  15. Aspen Characteristics - Plumas National Forest [ds373

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Beckwourth Ranger District...

  16. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  17. Aspen HYSYS process simulation and Aspen ICARUS cost estimation of CO2 removal plant

    OpenAIRE

    Vozniuk, Ievgeniia Oleksandrivna

    2010-01-01

    An Aspen HYSYS model of CO2 removal was developed and modified with a split-stream configuration in order to reduce energy consumption in the reboiler. The model has been calculated with variation of parameters to optimize the process and find an optimum solution. For the selected base cases the heat exchanger minimum temperature difference was specified to 10K and the removal efficiency was 85%. The reboiler duty of 3.8 MJ/kg CO2 removed for the standard process without split-stream was ...

  18. Aspen Delineation - Klamath National Forest, EUI [ds368

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of known aspen stands where aspen assessments were collected in the Klamath National Forest, Siskiyou County, California. The...

  19. Production economic models of fisheries

    DEFF Research Database (Denmark)

    Andersen, Jesper Levring

    The overall purpose of this PhD thesis is to investigate different aspects of fishermen’s behaviour using production economic models at the individual and industry levels. Three parts make up this thesis. The first part provides an overview of the thesis. The second part consists of four papers......, including all relevant factors in specific analyses is impossible, and it is therefore important to be aware of the most essential ones. As demonstrated in the literature review of Paper 1, a large number of factors may significantly influence fishermen’s short run behaviour, i.e. choice of gear type...

  20. Aspen Code Development Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    none,; Cherry, Robert S. [INL; Richard, Boardman D. [INL

    2013-10-03

    Wyoming has a wealth of primary energy resources in the forms of coal, natural gas, wind, uranium, and oil shale. Most of Wyoming?s coal and gas resources are exported from the state in unprocessed form rather than as refined higher value products. Wyoming?s leadership recognizes the opportunity to broaden the state?s economic base energy resources to make value-added products such as synthetic vehicle fuels and commodity chemicals. Producing these higher value products in an environmentally responsible manner can benefit from the use of clean energy technologies including Wyoming?s abundant wind energy and nuclear energy such as new generation small modular reactors including the high temperature gas-cooled reactors.

  1. The Economics of Online Dating: A Course in Economic Modeling

    Science.gov (United States)

    Monaco, Andrew J.

    2018-01-01

    The author discusses the development of a unique course, The Economics of Online Dating. The course is an upper-level undergraduate course that combines intensive discussion, peer review, and economic theory to teach modeling skills to undergraduates. The course uses the framework of "online dating," interpreted broadly, as a point of…

  2. The Fate of Aspen in a World with Diminishing Snowpacks

    Science.gov (United States)

    Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Kemp, K. B.

    2010-12-01

    Aspen (Populus tremuloides) productivity is tightly coupled with soil moisture. In the mountainous regions of the western USA, annual replenishment of soil moisture commonly occurs during snowmelt. Therefore, snow pack depth and duration can play an important role in sustaining aspen productivity. The presence of almost 50 years of detailed climate data across an elevational transect in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho offers a novel opportunity to better understand the role of shifting precipitation patterns on aspen productivity. Over the past 50 years, the proportion of the precipitation falling in the form of snow decreased by almost a factor of 2 at mid to low elevations in the RCEW, coupled with a roughly four week advance of snow ablation, and decline of large snow drifts that release moisture into the early summer. Results from growth ring increment, stable isotope analysis, sapflux and a process model (Biome BGC), will be used to determine the impact of shifting precipitation patterns on tree productivity along this transect over the past 50 years. Aspen trees located on moist microsites continue to transpire water and maintain high stomatal conductance 21 days later in the growing season relative to individuals on drier microsites. Predictions of net primary productivity (NPP) in aspen are very sensitive to precipitation patterns. NPP becomes negative as early as day 183 (90 days post budbreak) for years with little winter and spring precipitation whereas, in years with ample winter and spring precipitation, NPP remains positive until day 260 when leaf fall occurs. These results give unique insight into the conditions that deciduous tree species will encounter in a warming climate where snow water equivalent continues to diminish and soil moisture declines soon after budbreak occurs.

  3. HOMER Economic Models - US Navy

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Jason William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Myers, Kurt Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This LETTER REPORT has been prepared by Idaho National Laboratory for US Navy NAVFAC EXWC to support in testing pre-commercial SIREN (Simulated Integration of Renewable Energy Networks) computer software models. In the logistics mode SIREN software simulates the combination of renewable power sources (solar arrays, wind turbines, and energy storage systems) in supplying an electrical demand. NAVFAC EXWC will create SIREN software logistics models of existing or planned renewable energy projects at five Navy locations (San Nicolas Island, AUTEC, New London, & China Lake), and INL will deliver additional HOMER computer models for comparative analysis. In the transient mode SIREN simulates the short time-scale variation of electrical parameters when a power outage or other destabilizing event occurs. In the HOMER model, a variety of inputs are entered such as location coordinates, Generators, PV arrays, Wind Turbines, Batteries, Converters, Grid costs/usage, Solar resources, Wind resources, Temperatures, Fuels, and Electric Loads. HOMER's optimization and sensitivity analysis algorithms then evaluate the economic and technical feasibility of these technology options and account for variations in technology costs, electric load, and energy resource availability. The Navy can then use HOMER’s optimization and sensitivity results to compare to those of the SIREN model. The U.S. Department of Energy (DOE) Idaho National Laboratory (INL) possesses unique expertise and experience in the software, hardware, and systems design for the integration of renewable energy into the electrical grid. NAVFAC EXWC will draw upon this expertise to complete mission requirements.

  4. Renewable hydrocarbon fuels from hydrothermal liquefaction: A techno-economic analysis

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Hansen, Nick Høy; Pérez, Oscar Miralles

    2018-01-01

    This study demonstrates the economic feasibility of producing renewable transportation drop-in fuels from lignocellulosic biomass through hydrothermal liquefaction and upgrading. An Aspen Plus® process model is developed based on extensive experimental data to document a techno-economic assessmen...

  5. Using Aspen simulation package to determine solubility of mixed salts in TRU waste evaporator bottoms

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, J.L.

    1998-03-01

    Nitric acid from plutonium process waste is a candidate for waste minimization by recycling. Process simulation software packages, such as Aspen, are valuable tools to estimate how effective recovery processes can be, however, constants in equations of state for many ionic components are not in their data libraries. One option is to combine single salt solubility`s in the Aspen model for mixed salt system. Single salt solubilities were regressed in Aspen within 0.82 weight percent of literature values. These were combined into a single Aspen model and used in the mixed salt studies. A simulated nitric acid waste containing mixed aluminum, calcium, iron, magnesium and sodium nitrate was tested to determine points of solubility between 25 and 100 C. Only four of the modeled experimental conditions, at 50 C and 75 C, produced a saturated solution. While experimental results indicate that sodium nitrate is the first salt to crystallize out, the Aspen computer model shows that the most insoluble salt, magnesium nitrate, the first salt to crystallize. Possible double salt formation is actually taking place under experimental conditions, which is not captured by the Aspen model.

  6. Teaching Economics: A Cooperative Learning Model.

    Science.gov (United States)

    Caropreso, Edward J.; Haggerty, Mark

    2000-01-01

    Describes an alternative approach to introductory economics based on a cooperative learning model, "Learning Together." Discussion of issues in economics education and cooperative learning in higher education leads to explanation of how to adapt the Learning Together Model to lesson planning in economics. A flow chart illustrates the process for a…

  7. Implementing ASPEN on the CRAY computer

    International Nuclear Information System (INIS)

    Duerre, K.H.; Bumb, A.C.

    1981-01-01

    This paper describes our experience in converting the ASPEN program for use on our CRAY computers at the Los Alamos National Laboratory. The CRAY computer is two-to-five times faster than a CDC-7600 for scalar operations, is equipped with up to two million words of high-speed storage, and has vector processing capability. Thus, the CRAY is a natural candidate for programs that are the size and complexity of ASPEN. Our approach to converting ASPEN and the conversion problems are discussed, including our plans for optimizing the program. Comparisons of run times for test problems between the CRAY and IBM 370 computer versions are presented

  8. The Need of a New Economic Model

    Directory of Open Access Journals (Sweden)

    Alexandru Cătălin POPA

    2012-02-01

    Full Text Available The current global economic crisis has proven to be unpredictable for most decision-makers worldwide. Moreover, beliefs deeply embedded in the minds of economists about economics, about the virtues of capitalism and free market began to falter. Sooner or later the current crisis will end. The problem that arises and to which the economic science must answer is whether anything should be changed in the current world economic order and especially what exactly. It is quite vital to ask ourselves today in what kind of society we want to live and whether the current economic model, a model mainly based on monetarist ideas, is helping us to achieve those wishes. In addition to analyzing the root causes that led to the current economic crisis, this article aims to analyze whether the current economic model must change and to outline the features of a possible new model.

  9. Simulación y validación de modelos de destilación por lotes usando Aspen Batch Modeler: recuperación de epóxido de limoneno

    OpenAIRE

    Yeison Agudelo; Rolando Barrera Zapata

    2016-01-01

    Se desarrolló el modelado y simulación de una columna de destilación por lotes para la recuperación de epóxido de limoneno de una mezcla multicomponente, usando el software especializado Aspen Batch Modeler. Para la validación de los modelos se desarrolló el proceso experimental en un equipo de roto-evaporación, donde se varió la composición inicial de la mezcla, temperatura y presión de operación. La composición final de fondos y destilado se determinó a través de cromatografía de gases. Los...

  10. Liquefaction of aspen poplar wood

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M

    1982-01-01

    Dried and green aspen poplar wood suspended in water containing alkali catalysts was converted completely to an oil, water-soluble chemical, and gases by heating for 1 hour in the presence of CO in a rocking batch reactor. Within the ranges of parameters studied: temperature of 593-633 K; nominal reaction times of less than or equal to 1 hour; water-to-wood ratio of 0.5:1-5:1; Na/sub 2/CO/sub 3/, K/sub 2/CO/sub 3/, and NaOH catalysts; amount of catalyst 7.0-12.5%; and initial H-CO ratios of 2:1-0:1, the water-to-wood ratio was most important. Oil yields of approximately 50% with a C plus H content of approximately 80% and representing a C recovery of approximately 66% were obtained. The higher heats of combustion were 32.2-36.0 MJ/kg.

  11. Biomass of Sacrificed Spruce/Aspen (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and aspens in...

  12. Aspen Characteristics - Lassen National Forest [ds371

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected in aspen stands in the in the Eagle Lake Ranger District, Lassen National...

  13. Economic models for battery energy storage

    International Nuclear Information System (INIS)

    Reckrodt, R.C.; Anderson, M.D.; Kluczny, R.M.

    1990-01-01

    While the technology required to produce viable Battery Energy Storage System exists, the economic feasibility (cost vs. benefits) of building these systems requires justification. First, a generalized decision diagram was developed to ensure that all of the economic factors were considered and properly related for the customer-side-of-the meter. Next, two economic models that had consistently given differing results were compared. One was the McKinney model developed at UM-Rolla in 1987; the second was the SYSPLAN model developed by Battelle. Differences were resolved on a point by point basis with reference to the current economic environment. The economic model was upgraded to include the best of both models based on the resolution of these differences. The upgrades were implemented as modifications to the original SYSPLAN (1986 version) to preserve user friendliness. In this paper four specific cases are evaluated and compared. The results are as predicted, since comparison was made with two known models

  14. Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min; James S. Han

    2006-01-01

    Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

  15. Network models in economics and finance

    CERN Document Server

    Pardalos, Panos; Rassias, Themistocles

    2014-01-01

    Using network models to investigate the interconnectivity in modern economic systems allows researchers to better understand and explain some economic phenomena. This volume presents contributions by known experts and active researchers in economic and financial network modeling. Readers are provided with an understanding of the latest advances in network analysis as applied to economics, finance, corporate governance, and investments. Moreover, recent advances in market network analysis  that focus on influential techniques for market graph analysis are also examined. Young researchers will find this volume particularly useful in facilitating their introduction to this new and fascinating field. Professionals in economics, financial management, various technologies, and network analysis, will find the network models presented in this book beneficial in analyzing the interconnectivity in modern economic systems.

  16. The BCRA’s Small Economic Model

    OpenAIRE

    Pedro Elosegui; Guillermo Escudé; Lorena Garegnani; Juan Martín Sotes Paladino

    2007-01-01

    The use of macroeconomic forecasting models is a common practice in central banks for monetary policy design, for the analysis of the current economic developments and for medium and long term forecasts. Among those models, the small-scale macroeconomic models stand out. Though relatively simple, they are structured and take into account the transmission mechanisms that relate the main variables of interest: the interest rate, the exchange rate, GDP and inflation. The Small Economic Model (ME...

  17. Understanding the role of the cytoskeleton in wood formation in angiosperm trees: hybrid aspen (Populus tremula x P. tremuloides) as a model species

    Energy Technology Data Exchange (ETDEWEB)

    Chaffey, N.; Barlow, P. [Bristol Univ., Dept. of Agricultural Sciences, Long Ashton, (United Kingdom); Sundberg, B. [Swedish Univ. of Agricultural Sciences, Dept. of Forest Genetics and Plant Physiology, Umea (Sweden)

    2002-03-01

    The involvement of microfilaments (MFs) and microtubules (MTs) in the development of the radial and axial components of secondary wood in hybrid aspen (Populus tremula X P. tremuloides) was studied by indirect immunofluorescent localization techniques in order to elucidate a consensus view of the roles of the cytoskeleton during wood formation in angiosperm trees. Early and late vessel elements, axial parenchyma, normal-wood fibres and contact and isolation cells were included in addition to cambial cells. Microfilaments were found to be rare in cambial cells, but were abundant and axially arranged in their derivatives once cell elongation begun. Microtubules were randomly oriented in ray and fusiform cells of the cambial zone. Ellipses of microfilaments were associated with pit development in fiber cells and isolation ray cells. Rings of localized microtubules and microfilaments were associated with developing inter-vessel bordered pits and vessel-contact ray cell contact pits. Although only microtubules were seen in the periphery of the perforation plate of vessel elements, a prominent meshwork of microfilaments overlaid the perforation plate itself. These observations indicate that there are corresponding subcellular control points whose manipulation could lead to the development of 'designer wood'. However, such development would require a better understanding of the physiological basis for the behaviour of microtubule and microfibre cytoskeletons during wood formation. 44 refs., 6 figs.

  18. HTGR Application Economic Model Users' Manual

    International Nuclear Information System (INIS)

    Gandrik, A.M.

    2012-01-01

    The High Temperature Gas-Cooled Reactor (HTGR) Application Economic Model was developed at the Idaho National Laboratory for the Next Generation Nuclear Plant Project. The HTGR Application Economic Model calculates either the required selling price of power and/or heat for a given internal rate of return (IRR) or the IRR for power and/or heat being sold at the market price. The user can generate these economic results for a range of reactor outlet temperatures; with and without power cycles, including either a Brayton or Rankine cycle; for the demonstration plant, first of a kind, or nth of a kind project phases; for up to 16 reactor modules; and for module ratings of 200, 350, or 600 MWt. This users manual contains the mathematical models and operating instructions for the HTGR Application Economic Model. Instructions, screenshots, and examples are provided to guide the user through the HTGR Application Economic Model. This model was designed for users who are familiar with the HTGR design and Excel and engineering economics. Modification of the HTGR Application Economic Model should only be performed by users familiar with the HTGR and its applications, Excel, and Visual Basic.

  19. Aspen Delineation - Plumas National Forest, FRRD [ds376

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_FEATHERRIVER_PTS) collected in aspen stands in the Plumas...

  20. Simulating the Dependence of Aspen on Redistributed Snow

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Winstral, A. H.

    2013-12-01

    In mountainous regions across the western USA, the distribution of aspen (Populus tremuloides) is often directly related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho provides a unique opportunity to study the relationship between aspen and redistributed snow. Within the RCEW, the total amount of precipitation has not changed in the past 50 years, but there are sharp declines in the percentage of the precipitation falling as snow. As shifts in the distribution of available moisture continue, future trends in aspen net primary productivity (NPP) remain uncertain. In order to assess the importance of snowdrift subsidies, NPP of three aspen stands was simulated at sites spanning elevational and precipitation gradients using the biogeochemical process model BIOME-BGC. At the aspen site experiencing the driest climate and lowest amount of precipitation from snow, approximately 400 mm of total precipitation was measured from November to March of 2008. However, peak measured snow water equivalent (SWE) held in drifts directly upslope of this stand was approximately 2100 mm, 5 times more moisture than the uniform winter precipitation layer initially assumed by BIOME-BGC. BIOME-BGC simulations in dry years forced by adjusted precipitation data resulted in NPP values approximately 30% higher than simulations assuming a uniform precipitation layer. Using BIOME-BGC and climate data from 1985-2011, the relationship between simulated NPP and measured basal area increments (BAI) improved after accounting for redistributed snow, indicating increased simulation representation. In addition to improved simulation capabilities, soil moisture data, diurnal branch water potential, and stomatal conductance observations at each site detail the use of soil moisture in the rooting zone and the onset

  1. Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    2008-01-01

    Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity in the econo......Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity...... are related to expectations formation, market clearing, nominal rigidities, etc. Finally, the general-partial equilibrium distinction is analyzed....

  2. Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    2008-01-01

    Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity in the econo......Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity...... parameters of the CVAR are shown to be interpretable in terms of expectations formation, market clearing, nominal rigidities, etc. The general-partial equilibrium distinction is also discussed....

  3. A new green process for biodiesel production from waste oils via catalytic distillation using a solid acid catalyst – Modeling, economic and environmental analysis

    Directory of Open Access Journals (Sweden)

    Aashish Gaurav

    2016-04-01

    Full Text Available The challenges in the chemical processing industry today are environmental concerns, energy and capital costs. Catalytic distillation (CD is a green reactor technology which combines a catalytic reaction and separation via distillation in the same distillation column. Utilization of CD in chemical process development could result in capital and energy savings, and the reduction of greenhouse gases. The efficacy of CD and the economic merits, in terms of energy and equipment savings, brought by CD for the production of biodiesel from waste oil such as yellow grease is quantified. Process flow sheets for industrial routes for an annual production of 10 million gallon ASTM purity biodiesel in a conventional process (reactor followed by distillation and CD configurations are modeled in Aspen Plus. Material and energy flows, as well as sized unit operation blocks, are used to conduct an economic assessment of each process. Total capital investment, total operating and utility costs are calculated for each process. The waste oil feedstock is yellow grease containing both triglyceride and free fatty acid. Both transesterification and esterification reactions are considered in the process simulations. Results show a significant advantage of CD compared to a conventional biodiesel processes due to the reduction of distillation columns, waste streams and greenhouse gas emissions. The significant savings in capital and energy costs together with the reduction of greenhouse gases demonstrate that process intensification via CD is a feasible and new green process for the biodiesel production from waste oils. Keywords: Yellow grease, Catalytic distillation, Aspen plus economic analyzer, Process intensification

  4. Aspen biology, community classification, and management in the Blue Mountains

    Science.gov (United States)

    David K. Swanson; Craig L. Schmitt; Diane M. Shirley; Vicky Erickson; Kenneth J. Schuetz; Michael L. Tatum; David C. Powell

    2010-01-01

    Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a...

  5. Evaluation of burned aspen communities in Jackson Hole, Wyoming

    Science.gov (United States)

    Charles E. Kay

    2001-01-01

    Aspen has been declining in Jackson Hole for many years, a condition generally attributed to the fact that lightning fires have been aggressively suppressed since the early 1900s. It is also believed that burning will successfully regenerate aspen stands despite high elk numbers. To test this hypothesis, I evaluated 467 burned and 495 adjacent, unburned aspen stands at...

  6. Understanding the role of the cytoskeleton in wood formation in angiosperm trees: hybrid aspen (Populus tremula x P. tremuloides) as the model species.

    Science.gov (United States)

    Chaffey, Nigel; Barlow, Peter; Sundberg, Björn

    2002-03-01

    The involvement of microfilaments and microtubules in the development of the radial and axial components of secondary xylem (wood) in hybrid aspen (Populus tremula L. x P. tremuloides Michx.) was studied by indirect immunofluorescent localization techniques. In addition to cambial cells, the differentiated cell types considered were early- and late-wood vessel elements, axial parenchyma, normal-wood fibers and gelatinous fibers, and contact and isolation ray cells. Microfilaments were rare in ray cambial cells, but were abundant and axially arranged in their derivatives once cell elongation had begun, and persisted in that orientation in mature ray cells. Microfilaments were axially arranged in fusiform cambial cells and persisted in that orientation in all xylem derivatives of those cells. Microtubules were randomly oriented in ray and fusiform cells of the cambial zone. Dense arrays of parallel-aligned microtubules were oriented near axially in the developing gelatinous fibers, but at a wide range of angles in normal-wood fibers. Ellipses of microfilaments were associated with pit development in fiber cells and isolation ray cells. Rings of co-localized microtubules and microfilaments were associated with developing inter-vessel bordered pits and vessel-contact ray cell contact pits, and, in the case of bordered pits, these rings decreased in diameter as the over-arching pit border increased in size. Although only microtubules were seen at the periphery of the perforation plate of vessel elements, a prominent meshwork of microfilaments overlaid the perforation plate itself. A consensus view of the roles of the cytoskeleton during wood formation in angiosperm trees is presented.

  7. Structural modelling of economic growth: Technological changes

    Directory of Open Access Journals (Sweden)

    Sukharev Oleg

    2016-01-01

    Full Text Available Neoclassical and Keynesian theories of economic growth assume the use of Cobb-Douglas modified functions and other aggregate econometric approaches to growth dynamics modelling. In that case explanations of economic growth are based on the logic of the used mathematical ratios often including the ideas about aggregated values change and factors change a priori. The idea of assessment of factor productivity is the fundamental one among modern theories of economic growth. Nevertheless, structural parameters of economic system, institutions and technological changes are practically not considered within known approaches, though the latter is reflected in the changing parameters of production function. At the same time, on the one hand, the ratio of structural elements determines the future value of the total productivity of the factors and, on the other hand, strongly influences the rate of economic growth and its mode of innovative dynamics. To put structural parameters of economic system into growth models with the possibility of assessment of such modes under conditions of interaction of new and old combinations is an essential step in the development of the theory of economic growth/development. It allows forming stimulation policy of economic growth proceeding from the structural ratios and relations recognized for this economic system. It is most convenient in such models to use logistic functions demonstrating the resource change for old and new combination within the economic system. The result of economy development depends on starting conditions, and on institutional parameters of velocity change of resource borrowing in favour of a new combination and creation of its own resource. Model registration of the resource is carried out through the idea of investments into new and old combinations.

  8. JEDI: Jobs and Economic Development Impact Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-13

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL's researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects and is revised with 2017 figures.

  9. The modelling of economic consequences in COSYMA

    International Nuclear Information System (INIS)

    Faude, D.

    1991-01-01

    A new model for assessing the economic consequences of accidents, called COCO-1 (Cost of Consequences Off-site) has been developed jointly by NRPB and KfK under the CEC MARIA programme. This paper describes the way in which this model, together with other options, has been implemented in the ECONOMICS module of COSYMA. For consistency with the other parts of COSYMA, the coding of the ECONOMICS module is flexible: in several areas, alternative calculational methods are available and the user may select the method by which a particular cost is calculated. To some extent, economic models other than the COCO-1 model may be applied. There are two types of input data in the ECONOMICS module. These are (1) data from preceding COSYMA modules which quantify the magnitude and distribution of health effects and the impact of countermeasures, and (2) economic data, in terms of costs per unit quantity, to convert the preceding data into monetary values. The structure of the module has been determined by the form and availability of the input data, and the general structure of COSYMA. Details of the method of calculation, and the necessary input data, are discussed, for calculation of the economic consequences of the countermeasures considered in COSYMA (evacuation, relocation, sheltering, decontamination and food bans) and for early and late health effects

  10. Economic aspects and models for building codes

    DEFF Research Database (Denmark)

    Bonke, Jens; Pedersen, Dan Ove; Johnsen, Kjeld

    It is the purpose of this bulletin to present an economic model for estimating the consequence of new or changed building codes. The object is to allow comparative analysis in order to improve the basis for decisions in this field. The model is applied in a case study.......It is the purpose of this bulletin to present an economic model for estimating the consequence of new or changed building codes. The object is to allow comparative analysis in order to improve the basis for decisions in this field. The model is applied in a case study....

  11. Economic Models as Devices of Policy Change

    DEFF Research Database (Denmark)

    Henriksen, Lasse Folke

    2013-01-01

    Can the emergence of a new policy model be a catalyst for a paradigm shift in the overall interpretative framework of how economic policy is conducted within a society? This paper claims that models are understudied as devices used by actors to induce policy change. This paper explores the role...... of models in Danish economic policy, where, from the 1970s onwards, executive public servants in this area have exclusively been specialists in model design. To understand changes in economic policy, this paper starts with a discussion of whether the notion of paradigm shift is adequate. It then examines...... the extent to which the performativity approach can help identify macroscopic changes in policy from seemingly microscopic changes in policy models. The concept of performativity is explored as a means of thinking about the constitution of agency directed at policy change. The paper brings this concept...

  12. Economic model of pipeline transportation systems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W. F.

    1977-07-29

    The objective of the work reported here was to develop a model which could be used to assess the economic effects of energy-conservative technological innovations upon the pipeline industry. The model is a dynamic simulator which accepts inputs of two classes: the physical description (design parameters, fluid properties, and financial structures) of the system to be studied, and the postulated market (throughput and price) projection. The model consists of time-independent submodels: the fluidics model which simulates the physical behavior of the system, and the financial model which operates upon the output of the fluidics model to calculate the economics outputs. Any of a number of existing fluidics models can be used in addition to that developed as a part of this study. The financial model, known as the Systems, Science and Software (S/sup 3/) Financial Projection Model, contains user options whereby pipeline-peculiar characteristics can be removed and/or modified, so that the model can be applied to virtually any kind of business enterprise. The several dozen outputs are of two classes: the energetics and the economics. The energetics outputs of primary interest are the energy intensity, also called unit energy consumption, and the total energy consumed. The primary economics outputs are the long-run average cost, profit, cash flow, and return on investment.

  13. Data Driven Economic Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Masoud Kheradmandi

    2018-04-01

    Full Text Available This manuscript addresses the problem of data driven model based economic model predictive control (MPC design. To this end, first, a data-driven Lyapunov-based MPC is designed, and shown to be capable of stabilizing a system at an unstable equilibrium point. The data driven Lyapunov-based MPC utilizes a linear time invariant (LTI model cognizant of the fact that the training data, owing to the unstable nature of the equilibrium point, has to be obtained from closed-loop operation or experiments. Simulation results are first presented demonstrating closed-loop stability under the proposed data-driven Lyapunov-based MPC. The underlying data-driven model is then utilized as the basis to design an economic MPC. The economic improvements yielded by the proposed method are illustrated through simulations on a nonlinear chemical process system example.

  14. Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2015-01-01

    Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as competition, or functional traits, such as allometry. To assess the role of disease in mediating mortality risk in quaking aspen (Populus tremuloides), we developed hierarchical Bayesian models for both disease prevalence in live aspen stems and the resulting survival rates of healthy and diseased aspen near the species' southern range limit using 5088 individual trees on 281 United States Forest Service Forest Inventory and Analysis plots in the southwestern United States.

  15. Market disruption, cascading effects, and economic recovery:a life-cycle hypothesis model.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.

    2004-11-01

    This paper builds upon previous work [Sprigg and Ehlen, 2004] by introducing a bond market into a model of production and employment. The previous paper described an economy in which households choose whether to enter the labor and product markets based on wages and prices. Firms experiment with prices and employment levels to maximize their profits. We developed agent-based simulations using Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate that multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment, but also suffer from market noise stemming from consumer churn. In this paper we introduce a bond market as a mechanism for household savings. We simulate an economy of continuous overlapping generations in which each household grows older in the course of the simulation and continually revises its target level of savings according to a life-cycle hypothesis. Households can seek employment, earn income, purchase goods, and contribute to savings until they reach the mandatory retirement age; upon retirement households must draw from savings in order to purchase goods. This paper demonstrates the simultaneous convergence of product, labor, and savings markets to their calculated equilibria, and simulates how a disruption to a productive sector will create cascading effects in all markets. Subsequent work will use similar models to simulate how disruptions, such as terrorist attacks, would interplay with consumer confidence to affect financial markets and the broader economy.

  16. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, "New Data From the Energy Frontier." There were 54 formal talks, and a considerable number of informal discussions held during the week. The week's events included a public lecture ("The Hunt for the Elusive Higgs Boson" given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was "Indirect and Direct Detection of Dark Matter." It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled "What Makes Up Dark Matter." There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics cafe to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  17. Estimating white trunk rot in aspen stands

    Science.gov (United States)

    Alan C. Jones; Michael E. Ostry

    1998-01-01

    Advanced decay caused by Phellinus tremulae was estimated in 295 trembling aspen on 30 plots in 2 Minnesota counties using existing inventory guides, and then measured by felling and sectioning the trees. In standing trees, decay volume was underestimated by 38% compared to measured decay volume in felled trees. The most reliable external indicator...

  18. Economic modelling for life extension decision making

    International Nuclear Information System (INIS)

    Farber, M.A.; Harrison, D.L.; Carlson, D.D.

    1987-01-01

    This paper presents a methodology for the economic and financial analysis of nuclear plant life extension under uncertainty and demonstrates its use in a case analysis. While the economic and financial evaluation of life extension does not require new analytical tools, such studies should be based on the following three premises. First, the methodology should examine effects at the level of the company or utility system, because the most important economic implications of life extension relate to the altered generation system expansion plan. Second, it should focus on the implications of uncertainty in order to understand the factors that most affect life extension benefits and identify risk management efforts. Third, the methodology should address multiple objectives, at a minimum, both economic and financial objectives. An analysis of the role of life extension for Virginia Power's generating system was performed using the MIDAS model, developed by the Electric Power Research Institute. MIDAS is particularly well suited to this type of study because of its decision analysis framework. The model incorporates modules for load analysis, capacity expansion, production costing, financial analysis, and rates. The decision tree structure facilitates the multiple-scenario analysis of uncertainty. The model's output includes many economic and financial measures, including capital expenditures, fuel and purchases power costs, revenue requirements, average rates, external financing requirements, and coverage ratio. Based on findings for Virginia Power's Surry 1 plant, nuclear plant life extension has economic benefits for a utility's customers and financial benefits for the utility's investors. These benefits depend on a number of economic, technical and regulatory factors. The economic analysis presented in this paper identifies many of the key factors and issues relevant to life extension planning

  19. Spatial Economics Model Predicting Transport Volume

    Directory of Open Access Journals (Sweden)

    Lu Bo

    2016-10-01

    Full Text Available It is extremely important to predict the logistics requirements in a scientific and rational way. However, in recent years, the improvement effect on the prediction method is not very significant and the traditional statistical prediction method has the defects of low precision and poor interpretation of the prediction model, which cannot only guarantee the generalization ability of the prediction model theoretically, but also cannot explain the models effectively. Therefore, in combination with the theories of the spatial economics, industrial economics, and neo-classical economics, taking city of Zhuanghe as the research object, the study identifies the leading industry that can produce a large number of cargoes, and further predicts the static logistics generation of the Zhuanghe and hinterlands. By integrating various factors that can affect the regional logistics requirements, this study established a logistics requirements potential model from the aspect of spatial economic principles, and expanded the way of logistics requirements prediction from the single statistical principles to an new area of special and regional economics.

  20. Logistic map with memory from economic model

    International Nuclear Information System (INIS)

    Tarasova, Valentina V.; Tarasov, Vasily E.

    2017-01-01

    A generalization of the economic model of logistic growth, which takes into account the effects of memory and crises, is suggested. Memory effect means that the economic factors and parameters at any given time depend not only on their values at that time, but also on their values at previous times. For the mathematical description of the memory effects, we use the theory of derivatives of non-integer order. Crises are considered as sharp splashes (bursts) of the price, which are mathematically described by the delta-functions. Using the equivalence of fractional differential equations and the Volterra integral equations, we obtain discrete maps with memory that are exact discrete analogs of fractional differential equations of economic processes. We derive logistic map with memory, its generalizations, and “economic” discrete maps with memory from the fractional differential equations, which describe the economic natural growth with competition, power-law memory and crises.

  1. Agent-based modeling in ecological economics.

    Science.gov (United States)

    Heckbert, Scott; Baynes, Tim; Reeson, Andrew

    2010-01-01

    Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.

  2. Value function in economic growth model

    Science.gov (United States)

    Bagno, Alexander; Tarasyev, Alexandr A.; Tarasyev, Alexander M.

    2017-11-01

    Properties of the value function are examined in an infinite horizon optimal control problem with an unlimited integrand index appearing in the quality functional with a discount factor. Optimal control problems of such type describe solutions in models of economic growth. Necessary and sufficient conditions are derived to ensure that the value function satisfies the infinitesimal stability properties. It is proved that value function coincides with the minimax solution of the Hamilton-Jacobi equation. Description of the growth asymptotic behavior for the value function is provided for the logarithmic, power and exponential quality functionals and an example is given to illustrate construction of the value function in economic growth models.

  3. An economic model for seaborne oil trade

    OpenAIRE

    Hong, Kian-Wah

    1996-01-01

    This thesis aims to provide some insights as to how oil prices and oil flows might vary with the carrying capacity of the tanker fleet as affected by political events. It provides an econometric analysis of tanker freight rates in the modern era and proposes a mathematical (quadratic) programming economic model that links the crude oil market to the supply elasticity of the world oil tanker fleet based on a competitive economy. The economic model can be considered as a version of the Walras-C...

  4. Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

    Directory of Open Access Journals (Sweden)

    Teresa A. Newsome

    2012-01-01

    Full Text Available Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximized R2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. Maximum R2 values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

  5. ECONOMIC MODELING STOCKS CONTROL SYSTEM: SIMULATION MODEL

    OpenAIRE

    Климак, М.С.; Войтко, С.В.

    2016-01-01

    Considered theoretical and applied aspects of the development of simulation models to predictthe optimal development and production systems that create tangible products andservices. It isproved that theprocessof inventory control needs of economicandmathematical modeling in viewof thecomplexity of theoretical studies. A simulation model of stocks control that allows make managementdecisions with production logistics

  6. Economical modelling of social and moral norms

    International Nuclear Information System (INIS)

    Nyborg, Karine

    2001-01-01

    Social norms and moral motivations are often ignored in economic models. It is possible, however, to model social and moral norms within the framework of economical theory. This may be useful even if the exposition is necessarily simplified. The article gives some examples. An analysis shows how the ''No Smoking Act'' may have led to a change in social norms in Norway and indirectly changed the behaviour of smokers in places where this act does not apply. Behaviour with moral motivation may also be affected by changes in regulations, economic incentives or other external conditions. For example, a more efficient collection system for source-separated waste may induce people to sharpen the moral claim on their own efforts. Indeed, interviews show that imposing a fee upon people not volunteering in communal work may cause the attendance to drop further

  7. Modeling the economic consequences of LWR accidents

    International Nuclear Information System (INIS)

    Burke, R.P.; Aldrich, D.C.; Rasmussen, N.C.

    1984-01-01

    Models to be used for analyses of economic risks from events which may occur during LWR plant operation are developed in this study. The models include capabilities to estimate both onsite and offsite costs of LWR events ranging from routine plant outages to severe core-melt accidents resulting in large releases of radioactive material to the environment. The models can be used by both the nuclear power industry and regulatory agencies in cost-benefit analyses for decisionmaking purposes. The newly developed economic consequence models are applied in an example to estimate the economic risks from operation of the Surry Unit 2 plant. The analyses indicate that economic risks from US LWR operation, in contrast to public health risks, are dominated by relatively high-frequency forced outage events. Even for severe (e.g., core-melt) accidents, expected offsite costs are less than expected onsite costs for the Surry site. The implications of these conclusions for nuclear power plant operation and regulation are discussed

  8. Arational heuristic model of economic decision making

    OpenAIRE

    Grandori, Anna

    2010-01-01

    The article discuss the limits of both the rational actor and the behavioral paradigms in explaining and guiding innovative decision making and outlines a model of economic decision making that in the course of being 'heuristic' (research and discovery oriented) is also 'rational' (in the broad sense of following correct reasoning and scientific methods, non 'biasing'). The model specifies a set of 'rational heuristics' for innovative decision making, for the various sub-processes of problem ...

  9. Mathematical model in economic environmental problems

    Energy Technology Data Exchange (ETDEWEB)

    Nahorski, Z. [Polish Academy of Sciences, Systems Research Inst. (Poland); Ravn, H.F. [Risoe National Lab. (Denmark)

    1996-12-31

    The report contains a review of basic models and mathematical tools used in economic regulation problems. It starts with presentation of basic models of capital accumulation, resource depletion, pollution accumulation, and population growth, as well as construction of utility functions. Then the one-state variable model is discussed in details. The basic mathematical methods used consist of application of the maximum principle and phase plane analysis of the differential equations obtained as the necessary conditions of optimality. A summary of basic results connected with these methods is given in appendices. (au) 13 ills.; 17 refs.

  10. Aspen Characteristics - Plumas National Forest, FRRD [ds375

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Feather River Ranger...

  11. Coupling Climate Models and Forward-Looking Economic Models

    Science.gov (United States)

    Judd, K.; Brock, W. A.

    2010-12-01

    Authors: Dr. Kenneth L. Judd, Hoover Institution, and Prof. William A. Brock, University of Wisconsin Current climate models range from General Circulation Models (GCM’s) with millions of degrees of freedom to models with few degrees of freedom. Simple Energy Balance Climate Models (EBCM’s) help us understand the dynamics of GCM’s. The same is true in economics with Computable General Equilibrium Models (CGE’s) where some models are infinite-dimensional multidimensional differential equations but some are simple models. Nordhaus (2007, 2010) couples a simple EBCM with a simple economic model. One- and two- dimensional ECBM’s do better at approximating damages across the globe and positive and negative feedbacks from anthroprogenic forcing (North etal. (1981), Wu and North (2007)). A proper coupling of climate and economic systems is crucial for arriving at effective policies. Brock and Xepapadeas (2010) have used Fourier/Legendre based expansions to study the shape of socially optimal carbon taxes over time at the planetary level in the face of damages caused by polar ice cap melt (as discussed by Oppenheimer, 2005) but in only a “one dimensional” EBCM. Economists have used orthogonal polynomial expansions to solve dynamic, forward-looking economic models (Judd, 1992, 1998). This presentation will couple EBCM climate models with basic forward-looking economic models, and examine the effectiveness and scaling properties of alternative solution methods. We will use a two dimensional EBCM model on the sphere (Wu and North, 2007) and a multicountry, multisector regional model of the economic system. Our aim will be to gain insights into intertemporal shape of the optimal carbon tax schedule, and its impact on global food production, as modeled by Golub and Hertel (2009). We will initially have limited computing resources and will need to focus on highly aggregated models. However, this will be more complex than existing models with forward

  12. Modeling the economics of LLW volume reduction

    International Nuclear Information System (INIS)

    Voth, M.H.; Witzig, W.F.

    1986-01-01

    Generators of low-level (radioactive) waste (LLW) are under pressure to implement volume reduction (VR) programs for political and economic reasons. Political reasons include the appearance of generating less waste or meeting quotas. Economic reasons include avoiding high disposal costs and associated surcharges. Volume reduction results in less total volume over which fixed disposal costs are allocated and therefore higher unit costs for disposal. As numerous small compacts are developed, this often overlooked effect becomes more pronounced. The described model presents two unique significant features. First, a feedback loop considers the impact of VR on disposal rates, and second, it appeals to logic without extensive knowledge of VR technology or computer modeling. The latter feature is especially useful in conveying information to students and nontechnical decision makers, demonstrating the impact of each of a complicated set of variables with reproducible results

  13. Hydro-economic modelling in mining catchments

    Science.gov (United States)

    Ossa Moreno, J. S.; McIntyre, N.; Rivera, D.; Smart, J. C. R.

    2017-12-01

    Hydro-economic models are gaining momentum because of their capacity to model both the physical processes related to water supply, and socio-economic factors determining water demand. This is particularly valuable in the midst of the large uncertainty upon future climate conditions and social trends. Agriculture, urban uses and environmental flows have received a lot of attention from researchers, as these tend to be the main consumers of water in most catchments. Mine water demand, although very important in several small and medium-sized catchments worldwide, has received less attention and only few models have attempted to reproduce its dynamics with other users. This paper describes an on-going project that addresses this gap, by developing a hydro-economic model in the upper Aconcagua River in Chile. This is a mountain catchment with large scale mining and hydro-power users at high altitudes, and irrigation areas in a downstream valley. Relevant obstacles to the model included the lack of input climate data, which is a common feature in several mining areas, the complex hydrological processes in the area and the difficulty of quantifying the value of water used by mines. A semi-distributed model developed within the Water Evaluation and Planning System (WEAP), was calibrated to reproduce water supply, and this was complemented with an analysis of the value of water for mining based on two methods; water markets and an analysis of its production processes. Agriculture and other users were included through methods commonly used in similar models. The outputs help understanding the value of water in the catchment, and its sensitivity to changes in climate variables, market prices, environmental regulations and changes in the production of minerals, crops and energy. The results of the project highlight the importance of merging hydrology and socio-economic calculations in mining regions, in order to better understand trade-offs and cost of opportunity of using

  14. Economic Modeling of Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Rui Bo

    2013-04-01

    Full Text Available Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system operating reserves. Both hourly and 5-minute simulations are considered to capture the economic performance of CAES in the day-ahead (DA and real-time (RT markets. The generalized network flow formulation is used to model the characteristics of CAES in detail. The proposed model is applied on a modified IEEE 24-bus reliability test system. The numerical example shows that besides the economic benefits gained through energy arbitrage in the DA market, CAES can also generate significant profits by providing reserves, compensating for wind forecast errors and intra-hour fluctuation, and participating in the RT market.

  15. Nuclear power investment risk economic model

    International Nuclear Information System (INIS)

    Postula, F.D.; Houghton, W.J.

    1986-01-01

    This paper describes the economic model which was developed to evaluate the net costs incurred by an owner due to an accident induced outage at a nuclear power plant. During such an outage, the portion of the plant operating costs associated with power production are saved; however the owner faces a sizable expense as fossil fuels are burned as a substitute for power from the incapacitated nuclear plant. Additional expenses are incurred by the owner for plant repair and, if necessary, decontamination cost. The model makes provision for mitigating these costs by sales of power, property damage insurance payments, tax write-offs and increased rates

  16. Economic model of the US uranium market

    International Nuclear Information System (INIS)

    Owen, A.D.

    1984-01-01

    An economic model of the US uranium market is developed using annual data for the period 1966-81. The model consists of five stochastic equations explaining uranium consumption, forward commitments, mine production, contract prices, and spot prices. A forecasting exercise is also undertaken. By way of essential background information, however, an analysis of current trends in the international uranium market is given, followed by a summary of historical price movements in the US uranium market. A brief discussion on the current state of the US market precedes the statistical analysis. 19 footnotes and references, 3 tables

  17. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  18. Economic tour package model using heuristic

    Science.gov (United States)

    Rahman, Syariza Abdul; Benjamin, Aida Mauziah; Bakar, Engku Muhammad Nazri Engku Abu

    2014-07-01

    A tour-package is a prearranged tour that includes products and services such as food, activities, accommodation, and transportation, which are sold at a single price. Since the competitiveness within tourism industry is very high, many of the tour agents try to provide attractive tour-packages in order to meet tourist satisfaction as much as possible. Some of the criteria that are considered by the tourist are the number of places to be visited and the cost of the tour-packages. Previous studies indicate that tourists tend to choose economical tour-packages and aiming to visit as many places as they can cover. Thus, this study proposed tour-package model using heuristic approach. The aim is to find economical tour-packages and at the same time to propose as many places as possible to be visited by tourist in a given geographical area particularly in Langkawi Island. The proposed model considers only one starting point where the tour starts and ends at an identified hotel. This study covers 31 most attractive places in Langkawi Island from various categories of tourist attractions. Besides, the allocation of period for lunch and dinner are included in the proposed itineraries where it covers 11 popular restaurants around Langkawi Island. In developing the itinerary, the proposed heuristic approach considers time window for each site (hotel/restaurant/place) so that it represents real world implementation. We present three itineraries with different time constraints (1-day, 2-day and 3-day tour-package). The aim of economic model is to minimize the tour-package cost as much as possible by considering entrance fee of each visited place. We compare the proposed model with our uneconomic model from our previous study. The uneconomic model has no limitation to the cost with the aim to maximize the number of places to be visited. Comparison between the uneconomic and economic itinerary has shown that the proposed model have successfully achieved the objective that

  19. Nuclear power investment risk economic model

    International Nuclear Information System (INIS)

    Houghton, W.J.; Postula, F.D.

    1985-12-01

    This paper describes an economic model which was developed to evaluate the net costs incurred by a utility due to an accident induced outage at a nuclear power plant. During such an outage the portion of the plant operating costs associated with power production are saved; however, the owning utility faces a sizable expense as fossil fuels are burned as a substitute for the incapacitated nuclear power. Additional expenses are incurred by the utility for plant repair and if necessary, decontamination costs. The model makes provision for mitigating these costs by sales of power, property damage insurance payments, tax write-offs and increased rates. Over 60 economic variables contribute to the net cost uncertainty. The values of these variables are treated as uncertainty distributions and are used in a Monte carlo computer program to evaluate the cost uncertainty (investment risk) associated with damage which could occur from various categories of initiating accidents. As an example, results of computations for various levels of damage associated with a loss of coolant accident are shown as a range of consequential plant downtime and unrecovered cost. A typical investment risk profile is shown for these types of accidents. Cost/revenue values for each economic factor are presented for a Three Mile Island - II type accident, e.g., uncontrolled core heatup. 4 refs., 6 figs., 3 tabs

  20. Modeling and simulation of economic processes

    Directory of Open Access Journals (Sweden)

    Bogdan Brumar

    2010-12-01

    Full Text Available In general, any activity requires a longer action often characterized by a degree of uncertainty, insecurity, in terms of size of the objective pursued. Because of the complexity of real economic systems, the stochastic dependencies between different variables and parameters considered, not all systems can be adequately represented by a model that can be solved by analytical methods and covering all issues for management decision analysis-economic horizon real. Often in such cases, it is considered that the simulation technique is the only alternative available. Using simulation techniques to study real-world systems often requires a laborious work. Making a simulation experiment is a process that takes place in several stages.

  1. Economic and Power System Modeling and Analysis | Water Power | NREL

    Science.gov (United States)

    Economic and Power System Modeling and Analysis Economic and Power System Modeling and Analysis technologies, their possible deployment scenarios, and the economic impacts of this deployment. As a research approaches used to estimate direct and indirect economic impacts of offshore renewable energy projects

  2. Orbital Express Mission Operations Planning and Resource Management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Danny

    2008-01-01

    The Orbital Express satellite servicing demonstrator program is a DARPA program aimed at developing "a safe and cost-effective approach to autonomously service satellites in orbit". The system consists of: a) the Autonomous Space Transport Robotic Operations (ASTRO) vehicle, under development by Boeing Integrated Defense Systems, and b) a prototype modular next-generation serviceable satellite, NEXTSat, being developed by Ball Aerospace. Flexibility of ASPEN: a) Accommodate changes to procedures; b) Accommodate changes to daily losses and gains; c) Responsive re-planning; and d) Critical to success of mission planning Auto-Generation of activity models: a) Created plans quickly; b) Repetition/Re-use of models each day; and c) Guarantees the AML syntax. One SRP per day vs. Tactical team

  3. Mycorrhizal fungi of aspen forests: Natural occurrence and potential applications

    Science.gov (United States)

    Cathy L. Cripps

    2001-01-01

    Native mycorrhizal fungi associated with aspen were surveyed on three soil types in the north-central Rocky Mountains. Selected isolates were tested for the ability to enhance aspen seedling growth in vitro. Over 50 species of ectomycorrhizal fungi occur with Populus tremuloides in this region, primarily basidiomycete fungi in the Agaricales. Almost one-third (30%)...

  4. Stand development of trembling aspen in Canaan Valley, West Virginia

    Science.gov (United States)

    James S. Rentch; James T. Anderson

    2008-01-01

    In wetlands of Canaan Valley, West Virginia, trembling aspen occurs as a disjunct population well south of its primary natural range. Based on sample data from 15 stands, we found that aspen occurs as nearly monospecific stands or clones. Eight stands had median ages between 30 and 40 yrs, and we suggest that stand initiation was related to changes in land use after...

  5. DSEM, Radioactive Waste Disposal Site Economic Model

    International Nuclear Information System (INIS)

    Smith, P.R.

    2005-01-01

    1 - Description of program or function: The Disposal Site Economic Model calculates the average generator price, or average price per cubic foot charged by a disposal facility to a waste generator, one measure of comparing the economic attractiveness of different waste disposal site and disposal technology combinations. The generator price is calculated to recover all costs necessary to develop, construct, operate, close, and care for a site through the end of the institutional care period and to provide the necessary financial returns to the site developer and lender (when used). Six alternative disposal technologies, based on either private or public financing, can be considered - shallow land disposal, intermediate depth disposal, above or below ground vaults, modular concrete canister disposal, and earth mounded concrete bunkers - based on either private or public development. 2 - Method of solution: The economic models incorporate default cost data from the Conceptual Design Report (DOE/LLW-60T, June 1987), a study by Rodgers Associates Engineering Corporation. Because all costs are in constant 1986 dollars, the figures must be modified to account for inflation. Interest during construction is either capitalized for the private developer or rolled into the loan for the public developer. All capital costs during construction are depreciated over the operation life of the site using straight-line depreciation for the private sector. 3 - Restrictions on the complexity of the problem: Maxima of - 100 years post-operating period, 30 years operating period, 15 years pre-operating period. The model should be used with caution outside the range of 1.8 to 10.5 million cubic feet of total volume. Depreciation is not recognized with public development

  6. Economics, modeling, planning and management of energy

    International Nuclear Information System (INIS)

    Rogner, H.H.; Khan, A.M.; Furlan, G.

    1989-01-01

    The Workshop attended by 89 participants from 40 countries aimed to provide participants with an overview of global and regional issues and to familiarize them with analytical tools and modeling techniques appropriate for the analysis and planning of national energy systems. Emphasis was placed on energy-economy-interaction, modelling for balancing energy demand and supply, technical-economic evaluation of energy supply alternatives and energy demand management. This volume presents some of the lectures delivered at the Workshop. The material has been organized in five parts under the headings General Review of Current Energy Trends, Energy and Technology Menu, Basic Analytical Approaches, Energy Modeling and Planning, and Energy Management and Policy. A separate abstract was prepared for each of the lectures presented. Refs, figs and tabs

  7. Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport.

    Science.gov (United States)

    Mauriat, Mélanie; Petterle, Anna; Bellini, Catherine; Moritz, Thomas

    2014-05-01

    Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen (Populus tremula × tremuloïdes) plants overexpressing a key gibberellin (GA) biosynthesis gene (AtGA20ox1) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots (ARs) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GAs have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of ARs produced by wild-type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing AtGA20ox1, PttGID1.1 or PttGID1.3 genes (with a 35S promoter) produce few ARs, although ARs develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GAs appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  8. Iterative Repair Planning for Spacecraft Operations Using the Aspen System

    Science.gov (United States)

    Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

    2000-01-01

    This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

  9. Forecasting models for national economic planning

    CERN Document Server

    Heesterman, A R G

    1972-01-01

    This book is about the specification of linear econometric models, and for this reason some important related fields have been deliberately omitted. I did not want to discuss the problems of parameter-estimation, at least not in any detail, as there are other books on these problems written by specialized statisticians. This book is about the models them­ selves and macro-economic models in particular. A second related sub­ ject is the policy decision that can be made with the help of a model. While I did write a chapter on policy decisions, I limited myself to some extent because of my views on planning as such. The logical approach to this problem is in terms of mathematical programming, but our models and our ideas about the policies we want are too crude for its effective utilisation. A realistic formulation of the problem should involve non­ linearities in an essential way, the models I consider (and most existing models) are linear. At the present state of econometrics, I do not really believe in suc...

  10. Economic Modeling Considerations for Rare Diseases.

    Science.gov (United States)

    Pearson, Isobel; Rothwell, Ben; Olaye, Andrew; Knight, Christopher

    2018-05-01

    To identify challenges that affect the feasibility and rigor of economic models in rare diseases and strategies that manufacturers have employed in health technology assessment submissions to demonstrate the value of new orphan products that have limited study data. Targeted reviews of PubMed, the National Institute for Health and Care Excellence's (NICE's) Highly Specialised Technologies (HST), and the Scottish Medicines Consortium's (SMC's) ultra-orphan submissions were performed. A total of 19 PubMed studies, 3 published NICE HSTs, and 11 ultra-orphan SMC submissions were eligible for inclusion. In rare diseases, a number of different factors may affect the model's ability to comply with good practice recommendations. Many products for the treatment of rare diseases have an incomplete efficacy and safety profile at product launch. In addition, there is often limited available natural history and epidemiology data. Information on the direct and indirect cost burden of an orphan disease also may be limited, making it difficult to estimate the potential economic benefit of treatment. These challenges can prevent accurate estimation of a new product's benefits in relation to costs. Approaches that can address such challenges include using patient and/or clinician feedback to inform model assumptions; data from disease analogues; epidemiological techniques, such as matching-adjusted indirect comparison; and long-term data collection. Modeling in rare diseases is often challenging; however, a number of approaches are available to support the development of model structures and the collation of input parameters and to manage uncertainty. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  11. AspenTech shows specific tools for refiners; AspenTech deploie des outils specifiques pour les raffineurs

    Energy Technology Data Exchange (ETDEWEB)

    Legros, E

    2003-10-01

    The supplier of integrated softwares AspenTech has organized last May, the 7 in Gelsenkirchen, on the site of the Veba Oel refinery, a seminar 'refining' intended to show the specificities of its products: Hysys, Aspen Utilities, Icarus...About fifty German engineers and responsible persons coming from refining and engineering firms have participated to this studies day. (O.M.)

  12. Modeling and techno-economic analysis of shale-to-liquid and coal-to-liquid fuels processes

    International Nuclear Information System (INIS)

    Zhou, Huairong; Yang, Siyu; Xiao, Honghua; Yang, Qingchun; Qian, Yu; Gao, Li

    2016-01-01

    To alleviate the conflict between oil supply and demand, Chinese government has accelerated exploration and exploitation of alternative oil productions. STL (Shale-to-liquid) processes and CTL (coal-to-liquid) processes are promising choices to supply oil. However, few analyses have been made on their energy efficiency and economic performance. This paper conducts a detailed analysis of a STL process and a CTL process based on mathematical modeling and simulation. Analysis shows that low efficiency of the STL process is due to low oil yield of the Fushun-type retorting technology. For the CTL process, the utility system provides near to 34% energy consumption of the total. This is because that CTL technologies are in early development and no heat integration between units is implemented. Economic analysis reveals that the total capital investment of the CTL process is higher than that of the STL process. The production cost of the CTL process is right on the same level as that of the STL process. For better techno-economic performance, it is suggested to develop a new retorting technology of high oil yield for the STL process. The remaining retorting gas should be converted to hydrogen and then used for shale oil hydrogenation. For the CTL process, developing an appropriate heat network is an efficient way to apply heat integration. In addition, the CTL process is intended to be integrated with hydrogen rich gas to adjust H_2/CO for better resource utilization. - Highlights: • Aspen Plus software is used for modeling and simulation of a shale-to-liquid (STL) and a coal-to-liquid (CTL) processes. • Techno-economic analysis of STL and CTL processes is conducted. • Suggestions are given for improving energy efficiency and economic performance of STL and CTL processes.

  13. Economic modelling with low-cognition agents

    Science.gov (United States)

    Ormerod, Paul

    2006-10-01

    The standard socio-economic model (SSSM) postulates very considerable cognitive powers on the part of its agents. They are able to gather all relevant information in any given situation, and to take the optimal decision on the basis of it, given their tastes and preferences. This behavioural rule is postulated to be universal. The concept of bounded rationality relaxes this somewhat, by permitting agents to have access to only limited amounts of information. But agents still optimise subject to their information set and tastes. Empirical work in economics over the past 20 years or so has shown that in general these behavioural postulates lack empirical validity. Instead, agents appear to have limited ability to gather information, and use simple rules of thumb to process the information which they have in order to take decisions. Building theoretical models on these realistic foundations which give better accounts of empirical phenomena than does the SSSM is an important challenge to both economists and econophysicists. Considerable progress has already been made in a short space of time, and examples are given in this paper.

  14. USING GEM - GLOBAL ECONOMIC MODEL IN ACHIEVING A GLOBAL ECONOMIC FORECAST

    Directory of Open Access Journals (Sweden)

    Camelia Madalina Orac

    2013-12-01

    Full Text Available The global economic development model has proved to be insufficiently reliable under the new economic crisis. As a result, the entire theoretical construction about the global economy needs rethinking and reorientation. In this context, it is quite clear that only through effective use of specific techniques and tools of economic-mathematical modeling, statistics, regional analysis and economic forecasting it is possible to obtain an overview of the future economy.

  15. Experimental Investigation and Aspen Plus Simulation of the MSW Pyrolysis Process

    Science.gov (United States)

    Ansah, Emmanuel

    Municipal solid waste (MSW) is a potential feedstock for producing transportation fuels because it is readily available using an existing collection/transportation infrastructure and fees are provided by the suppliers or government agencies to treat MSW. North Carolina with a population of 9.4 millions generates 3.629 million metric tons of MSW each year, which contains about 113,396,356 TJs of energy. The average moisture content of MSW samples is 44.3% on a wet basis. About 77% of the dry MSW mass is combustible components including paper, organics, textile and plastics. The average heating values of MSW were 9.7, 17.5, and 22.7 MJ/kg on a wet basis, dry basis and dry combustible basis, respectively. The MSW generated in North Carolina can produce 7.619 million barrels of crude bio-oil or around 4% of total petroleum consumption in North Carolina. MSW can be thermally pyrolyzed into bio-oil in the absence of oxygen or air at a temperature of 500°C or above. As bio-oil can be easily stored and transported, compared to bulky MSW, landfill gas and electricity, pyrolysis offers significant logistical and economic advantages over landfilling and other thermal conversion processes such as combustion and gasification. Crude bio-oils produced from the pyrolysis of MSW can be further refined to transportation fuels in existing petroleum refinery facilities. The objective of this research is to analyze the technical and economic feasibility of pyrolyzing MSW into liquid transportation fuels. A combined thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) instrument, which can serve as a micro-scale pyrolysis reactor, was used to simultaneously determine the degradation characteristics of MSW during pyrolysis. An ASPEN Plus-based mathematical model was further developed to analyze the technical and economic feasibility of pyrolysing of MSW into liquid transportation fuels in fixed bed reactors at varying operating conditions

  16. Limitations of JEDI Models | Jobs and Economic Development Impact Models |

    Science.gov (United States)

    Group's IMPLAN accounting software. For JEDI, these are updated every two years for the best available -output modeling remains a widely used methodology for measuring economic development activity. Definition definition of the geographic area under consideration. Datasets of multipliers from IMPLAN are available at

  17. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  18. Simulation of electric power conservation strategies: model of economic evaluation

    International Nuclear Information System (INIS)

    Pinhel, A.C.C.

    1992-01-01

    A methodology for the economic evaluation model for energy conservation programs to be executed by the National Program of Electric Power Conservation is presented. From data as: forecasting of conserved energy, tariffs, energy costs and budget, the model calculates the economic indexes for the programs, allowing the evaluation of economic impacts in the electric sector. (C.G.C.)

  19. An Alternative Macro-economic Model for the Classroom

    Science.gov (United States)

    Holmes, Bryan

    1976-01-01

    Presents Michal Kalecki's macro-economic model and two-sector version of the model by Robinson and Eatwell as circular flow diagrams. Advantages of using this approach in first-year undergraduate economics programs are discussed. Available from: General Secretary, Economics Association, Room 340, Hamilton House, Mabledon Place, London WC1H 9BH,…

  20. International Jobs and Economic Development Impacts (I-JEDI) Model

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    International Jobs and Economic Development Impacts (I-JEDI) is a freely available economic model that estimates gross economic impacts from wind, solar, biomass, and geothermal energy projects. Building on a similar model for the United States, I-JEDI was developed by the National Renewable Energy Laboratory under the U.S. government's Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) program to support partner countries in assessing economic impacts of LEDS actions in the energy sector.

  1. Optimization of composition and technology for tablets containing aspen bark extract

    Directory of Open Access Journals (Sweden)

    O. I. Onуshkiv

    2015-04-01

    Full Text Available Summary. Influence of quantitativefactorsof basic quality parameters has been investigated for tabletscontainingextractofaspenbark, receivedbydirect pressingmethodand mathematicalplanningof experiment.To set the optimal composition of tablets containingaspen bark extract the proportion ofProsolv 90, Ludiflash and Polyplasdone XL 10 has been studied. The relationship between the studied factors and parameters of tablets’ regression models has been described. As a result tablets containing aspen bark extractwith mentioned above formula match necessary pharmaco-technological parameters of State Pharmacopoeia of Ukraine. Introduction.Peptic and duodenal ulcer are serious problems in modern medicine. According to statistics this disease is found in 12,83 % of the adult population in Ukraine [1]. Among the remedies for treatment and prevention of peptic ulcers we can find herbal medicines that may be used in the treatment of pre-peptic conditions and during an acute period as a means of adjuvant therapy in combination with strong remedies [2]. An antacid, cytoprotective, anti-inflammatory and reparative actions of aspen bark extract were proved by the researches of domestic and foreign scientists [3, 4]. Previously, we researched the mutual influence of excipients on the main indicators of quality of aspen bark extract tablets obtained by direct compression method. Due to these researches the best excipientshave been selected. It is necessary to establish the optimal quantitative proportion of excipients in order to obtain the tablets with suitable parameters that satisfy the requirements of the State Pharmacopoeia of Ukraine (SPU [5, 6]. Rational selection of excipients requires wide range of studies to obtain the optimal composition of the tablets containing aspen bark extract. Using mathematical planning of the experiment gives the possibility to reduce the number of experiments and to obtain the most detailed results of researches about effects

  2. The impact of the British model on economic growth

    Directory of Open Access Journals (Sweden)

    Simon György Jr.

    2007-01-01

    Full Text Available The paper is searching for an answer to the question how the British model affected economic development in its mother country, the United Kingdom. The statistical analysis, models of mathematical economics and econometric investigation make it probable to conclude that there was a substantial difference in success between the Thatcherite and the Blairite economic policies; the latter proved more effective. It is particularly remarkable that the Blairite model, connecting privatization with a successful employment policy, reduced unemployment and social sensitivity, has not only speeded up economic growth but also improved economic equilibrium, curtailing, among others, the budget deficit.

  3. Advanced Small Modular Reactor Economics Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Thomas J [ORNL

    2014-10-01

    The US Department of Energy Office of Nuclear Energy’s Advanced Small Modular Reactor (SMR) research and development activities focus on four key areas: Developing assessment methods for evaluating advanced SMR technologies and characteristics; and Developing and testing of materials, fuels and fabrication techniques; and Resolving key regulatory issues identified by US Nuclear Regulatory Commission and industry; and Developing advanced instrumentation and controls and human-machine interfaces. This report focuses on development of assessment methods to evaluate advanced SMR technologies and characteristics. Specifically, this report describes the expansion and application of the economic modeling effort at Oak Ridge National Laboratory. Analysis of the current modeling methods shows that one of the primary concerns for the modeling effort is the handling of uncertainty in cost estimates. Monte Carlo–based methods are commonly used to handle uncertainty, especially when implemented by a stand-alone script within a program such as Python or MATLAB. However, a script-based model requires each potential user to have access to a compiler and an executable capable of handling the script. Making the model accessible to multiple independent analysts is best accomplished by implementing the model in a common computing tool such as Microsoft Excel. Excel is readily available and accessible to most system analysts, but it is not designed for straightforward implementation of a Monte Carlo–based method. Using a Monte Carlo algorithm requires in-spreadsheet scripting and statistical analyses or the use of add-ons such as Crystal Ball. An alternative method uses propagation of error calculations in the existing Excel-based system to estimate system cost uncertainty. This method has the advantage of using Microsoft Excel as is, but it requires the use of simplifying assumptions. These assumptions do not necessarily bring into question the analytical results. In fact, the

  4. A statistical mechanical model of economics

    Science.gov (United States)

    Lubbers, Nicholas Edward Williams

    Statistical mechanics pursues low-dimensional descriptions of systems with a very large number of degrees of freedom. I explore this theme in two contexts. The main body of this dissertation explores and extends the Yard Sale Model (YSM) of economic transactions using a combination of simulations and theory. The YSM is a simple interacting model for wealth distributions which has the potential to explain the empirical observation of Pareto distributions of wealth. I develop the link between wealth condensation and the breakdown of ergodicity due to nonlinear diffusion effects which are analogous to the geometric random walk. Using this, I develop a deterministic effective theory of wealth transfer in the YSM that is useful for explaining many quantitative results. I introduce various forms of growth to the model, paying attention to the effect of growth on wealth condensation, inequality, and ergodicity. Arithmetic growth is found to partially break condensation, and geometric growth is found to completely break condensation. Further generalizations of geometric growth with growth in- equality show that the system is divided into two phases by a tipping point in the inequality parameter. The tipping point marks the line between systems which are ergodic and systems which exhibit wealth condensation. I explore generalizations of the YSM transaction scheme to arbitrary betting functions to develop notions of universality in YSM-like models. I find that wealth vi condensation is universal to a large class of models which can be divided into two phases. The first exhibits slow, power-law condensation dynamics, and the second exhibits fast, finite-time condensation dynamics. I find that the YSM, which exhibits exponential dynamics, is the critical, self-similar model which marks the dividing line between the two phases. The final chapter develops a low-dimensional approach to materials microstructure quantification. Modern materials design harnesses complex

  5. Aspen Grupp võitis RKASi / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2008-01-01

    Ehitusfirma Aspen Grupp OÜ võitis Tallinna ringkonnakohtus Riigi Kinnisvara AS-i, kes diskvalifitseeris ehitusfirma riigihankelt seaduses olnud maksevõlgnevuse keelu tõttu. Vt. samas: Lahendust ootavad veel kaks kohtuasja

  6. Aspen Forest Cover by Stratum/Plot (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Average percent coverage and standard deviation of each canopy stratum from subplots at each aspen site during the SNF study in the Superior National Forest, Minnesota

  7. Techno-Economic Analysis of Magnesium Extraction from Seawater via a Catalyzed Organo-Metathetical Process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian; Bearden, Mark D.; Fernandez, Carlos A.; Fifield, Leonard S.; Nune, Satish K.; Motkuri, Radha K.; Koech, Philip K.; McGrail, B. Pete

    2018-01-16

    Magnesium (Mg) has many useful applications especially in various Mg alloys which can decrease weight while increasing strength. To increase the affordability and minimize environment consequence, a novel catalyzed organo-metathetical (COMET) process was proposed to extract Mg from seawater aiming to achieve significant reduction in total energy and production cost comparing with the melting salt electrolysis method currently adopted by US Mg LLC. A process flowsheet for a reference COMET process was set-up using Aspen Plus which included five key steps, anhydrous MgCl2 production, transmetallation, dibutyl Mg decomposition, n-BuLi regeneration, and LiCL electrolysis. The energy and production cost and CO2 emission were estimated based on the Aspen modeling using Aspen economic analyzer. Our results showed that it is possible to produce Mg from seawater with a production cost of $2.0/kg-Mg while consuming about 35.3 kWh/kg-Mg and releasing 7.0 kg CO2/kg-Mg. A simplified US Mg manufacturing process was also generated using Aspen and the cost and emission results were estimated for comparison purpose. Under our simulation conditions, the reference COMET process maintain a comparable CO2 emission rate and can save about 40% in production cost and save about 15% energy compared to the simplified US Mg process.

  8. Do Pine Trees in Aspen Stands Increase Bird Diversity

    OpenAIRE

    Rumble, Mark A; Mills, Todd R; Dystra, Brian L; Flake, Lester D

    2001-01-01

    In the Black Hills of South Dakota, quaking aspen (Populus tremuloides) is being replaced by conifers through fire suppression and successional processes. Al- though the Black Hills National forest is removing conifers (primarily ponderosa pine [Pinus ponderosa])toincreasetheaspencommunitiesinsomemixedstands,ForestPlan guidelines allow four conifers per hectare to remain to increase diversity in the remaining aspen stand. We compared bird species richness in pure ponderosa pine, mixed stands ...

  9. REFERENCE MODELS OF ENDOGENOUS ECONOMIC GROWTH

    OpenAIRE

    GEAMĂNU MARINELA

    2012-01-01

    The new endogenous growth theories are a very important research area for shaping the most effective policies and long term sustainable development strategies. Endogenous growth theory has emerged as a reaction to the imperfections of neoclassical theory, by the fact that the economic growth is the endogenous product of an economical system.

  10. Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen

    Science.gov (United States)

    M. E. Kubiske; V. S. Quinn; P. E. Marquardt; D. F. Karnosky

    2007-01-01

    Three model communities of trembling aspen (monoculture, and mixed with either paper birch or sugar maple) were grown for seven years in elevated atmospheric CO2 and O3 using Free Air CO2 Enrichment (FACE) technology. We utilized trends in species' importance, calculated as an index of volume...

  11. Simulation of SOFCs based power generation system using Aspen

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-12-01

    Full Text Available This study presents a thermodynamic Aspen simulation model for Solid Oxide Fuel Cells, SOFCs, based power generation system. In the first step, a steady-state SOFCs system model was developed. The model includes the electrochemistry and the diffusion phenomena. The electrochemical model gives good agreement with experimental data in a wide operating range. Then, a parametric study has been conducted to estimate effects of the oxygen to carbon ratio, O/C, on reformer temperature, fuel cell temperature, fuel utilization, overall fuel cell performance, and the results are discussed in this paper. In the second step, a dynamic analysis of SOFCs characteristic has been developed. The aim of dynamic modelling was to find the response of the system against the fuel utilization and the O/C ratio variations. From the simulations, it was concluded that both developed models in the steady and dynamic state were reasonably accurate and can be used for system level optimization studies of the SOFC based power generation system.

  12. Environmental flows in hydro-economic models

    Science.gov (United States)

    Pereau, Jean-Christophe; Pryet, Alexandre

    2018-03-01

    The protection of environmental flows, as a management objective for a regulating agency, needs to be consistent with the aquifer water balance and the degree of resource renewability. A stylized hydro-economic model is used where natural recharge, which sustains environmental flows, is considered both in the aquifer water budget and in the welfare function as ecosystem damage. Groundwater recharge and the associated natural drainage may be neglected for aquifers containing fossil water, where the groundwater is mined. However, when dealing with an aquifer that constitutes a renewable resource, for which recharge is not negligible, natural drainage should explicitly appear in the water budget. In doing so, the optimum path of net extraction rate does not necessarily converge to the recharge rate, but depends on the costs associated with ecosystem damages. The optimal paths and equilibrium values for the water volume and water extraction are analytically derived, and numerical simulations based on the Western La Mancha aquifer (southwest Spain) illustrate the theoretical results of the study.

  13. Economic contract theory tests models of mutualism.

    Science.gov (United States)

    Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

    2010-09-07

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

  14. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Science.gov (United States)

    Oldén, Anna; Ovaskainen, Otso; Kotiaho, Janne S; Laaka-Lindberg, Sanna; Halme, Panu

    2014-01-01

    Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered) and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old-growth forests.

  15. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Directory of Open Access Journals (Sweden)

    Anna Oldén

    Full Text Available Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L. retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old

  16. New exposure-based metric approach for evaluating O3 risk to North American aspen forests

    International Nuclear Information System (INIS)

    Percy, K.E.; Nosal, M.; Heilman, W.; Dann, T.; Sober, J.; Legge, A.H.; Karnosky, D.F.

    2007-01-01

    The United States and Canada currently use exposure-based metrics to protect vegetation from O 3 . Using 5 years (1999-2003) of co-measured O 3 , meteorology and growth response, we have developed exposure-based regression models that predict Populus tremuloides growth change within the North American ambient air quality context. The models comprised growing season fourth-highest daily maximum 8-h average O 3 concentration, growing degree days, and wind speed. They had high statistical significance, high goodness of fit, include 95% confidence intervals for tree growth change, and are simple to use. Averaged across a wide range of clonal sensitivity, historical 2001-2003 growth change over most of the 26 M ha P. tremuloides distribution was estimated to have ranged from no impact (0%) to strong negative impacts (-31%). With four aspen clones responding negatively (one responded positively) to O 3 , the growing season fourth-highest daily maximum 8-h average O 3 concentration performed much better than growing season SUM06, AOT40 or maximum 1 h average O 3 concentration metrics as a single indicator of aspen stem cross-sectional area growth. - A new exposure-based metric approach to predict O 3 risk to North American aspen forests has been developed

  17. An Alternative Theoretical Model for Economic Reforms in Africa ...

    African Journals Online (AJOL)

    This paper offers an alternative model for economic reforms in Africa. It proposes that Africa can still get on the pathway of sustained economic growth if economic reforms can focus on a key variable, namely, the price of non-tradables. Prices of non-tradables are generally less in Africa than in advanced economies, and the ...

  18. Long-term monitoring of western aspen--lessons learned.

    Science.gov (United States)

    Strand, E K; Bunting, S C; Starcevich, L A; Nahorniak, M T; Dicus, G; Garrett, L K

    2015-08-01

    Aspen woodland is an important ecosystem in the western United States. Aspen is currently declining in western mountains; stressors include conifer expansion due to fire suppression, drought, disease, heavy wildlife and livestock use, and human development. Forecasting of tree species distributions under future climate scenarios predicts severe losses of western aspen within the next 50 years. As a result, aspen has been selected as one of 14 vital signs for long-term monitoring by the National Park Service Upper Columbia Basin Network. This article describes the development of a monitoring protocol for aspen including inventory mapping, selection of sampling locations, statistical considerations, a method for accounting for spatial dependence, field sampling strategies, and data management. We emphasize the importance of collecting pilot data for use in statistical power analysis and semi-variogram analysis prior to protocol implementation. Given the spatial and temporal variability within aspen stem size classes, we recommend implementing permanent plots that are distributed spatially within and among stands. Because of our careful statistical design, we were able to detect change between sampling periods with desired confidence and power. Engaging a protocol development and implementation team with necessary and complementary knowledge and skills is critical for success. Besides the project leader, we engaged field sampling personnel, GIS specialists, statisticians, and a data management specialist. We underline the importance of frequent communication with park personnel and network coordinators.

  19. Proof of Economic Viability of Blended Learning Business Models

    Science.gov (United States)

    Druhmann, Carsten; Hohenberg, Gregor

    2014-01-01

    The discussion on economically sustainable business models with respect to information technology is lacking in many aspects of proven approaches. In the following contribution the economic viability is valued based on a procedural model for design and evaluation of e-learning business models in the form of a case study. As a case study object a…

  20. Modeling Renewable Penertration Using a Network Economic Model

    Science.gov (United States)

    Lamont, A.

    2001-03-01

    This paper evaluates the accuracy of a network economic modeling approach in designing energy systems having renewable and conventional generators. The network approach models the system as a network of processes such as demands, generators, markets, and resources. The model reaches a solution by exchanging prices and quantity information between the nodes of the system. This formulation is very flexible and takes very little time to build and modify models. This paper reports an experiment designing a system with photovoltaic and base and peak fossil generators. The level of PV penetration as a function of its price and the capacities of the fossil generators were determined using the network approach and using an exact, analytic approach. It is found that the two methods agree very closely in terms of the optimal capacities and are nearly identical in terms of annual system costs.

  1. Economic modeling for life extension decision making

    International Nuclear Information System (INIS)

    Farber, M.A.; Harrison, D.L.; Carlson, D.D.

    1986-01-01

    This paper presents a methodology for the economic and financial analysis of nuclear plant life extension under uncertainty and demonstrates its use in a case analysis. While the economic and financial evaluation of life extension does not require new analytical tools, such studies should be based on the following three premises. First, the methodology should examine effects at the level of the company or utility system, because the most important economic implications of life extension relate to the altered generation system expansion plan. Second, it should focus on the implications of uncertainty in order to understand the factors that most affect life extension benefits and identify risk management efforts. Third, the methodology should address multiple objectives, at a minimum, both economic and financial objectives

  2. Modelling and sequential simulation of multi-tubular metallic membrane and techno-economics of a hydrogen production process employing thin-layer membrane reactor

    KAUST Repository

    Shafiee, Alireza

    2016-09-24

    A theoretical model for multi-tubular palladium-based membrane is proposed in this paper and validated against experimental data for two different sized membrane modules that operate at high temperatures. The model is used in a sequential simulation format to describe and analyse pure hydrogen and hydrogen binary mixture separations, and then extended to simulate an industrial scale membrane unit. This model is used as a sub-routine within an ASPEN Plus model to simulate a membrane reactor in a steam reforming hydrogen production plant. A techno-economic analysis is then conducted using the validated model for a plant producing 300 TPD of hydrogen. The plant utilises a thin (2.5 μm) defect-free and selective layer (Pd75Ag25 alloy) membrane reactor. The economic sensitivity analysis results show usefulness in finding the optimum operating condition that achieves minimum hydrogen production cost at break-even point. A hydrogen production cost of 1.98 $/kg is estimated while the cost of the thin-layer selective membrane is found to constitute 29% of total process capital cost. These results indicate the competiveness of this thin-layer membrane process against conventional methods of hydrogen production. © 2016 Hydrogen Energy Publications LLC

  3. Conceptual model of management steadfast economic development production-economic systems

    OpenAIRE

    Prokhorova, V.

    2010-01-01

    The article is devoted developments of conceptual model of management proof economic development of the industrialeconomy systems. Features are certain, the algorithm of impulse is offered and intercommunication of contours of management proof economic development of the industrialeconomy systems is investigational

  4. Is our economic model compatible with sustainable development?

    DEFF Research Database (Denmark)

    Røpke, Inge

    2003-01-01

    The paper concerns the contradictions between sustainability and the present economic growth model. The discussion relates to the work of Jan Otto Andersson.......The paper concerns the contradictions between sustainability and the present economic growth model. The discussion relates to the work of Jan Otto Andersson....

  5. Economic assessment model architecture for AGC/AVLIS selection

    International Nuclear Information System (INIS)

    Hoglund, R.L.

    1984-01-01

    The economic assessment model architecture described provides the flexibility and completeness in economic analysis that the selection between AGC and AVLIS demands. Process models which are technology-specific will provide the first-order responses of process performance and cost to variations in process parameters. The economics models can be used to test the impacts of alternative deployment scenarios for a technology. Enterprise models provide global figures of merit for evaluating the DOE perspective on the uranium enrichment enterprise, and business analysis models compute the financial parameters from the private investor's viewpoint

  6. Static and dynamic models in economics

    Science.gov (United States)

    Safiullin, N. Z.; Safiullin, B. L.

    2018-05-01

    In this article, the authors consider the impact of information and advertising on consumer behavior and the process of producing differentiation formation. Advertising, television, radio, magazines and direct mail as major constraints of mass media may act as sources of information. Economic modernization is aimed at development of acceleration of the knowledge intensive industries, which contribute to Russia’s position in terms of the world economy; the recovering process of the Russian economic manufacturing base; development of import substitution industries and limited participation in international labor specialization.

  7. Modeling the Economic Behavior of Households within the Context of Development of Economic Thought

    Directory of Open Access Journals (Sweden)

    Ivanov Roman V.

    2017-04-01

    Full Text Available The main purpose of the publication is to study formation of the household economic behavior modeling in the context of development of economic thought and methods of the economic-mathematical modeling. The study was carried out under the assumption that, when studying the development of theoretical and methodological foundations of the economic behavior of households one must take into account not only the history of development of economic theory, but also the transformation of attitudes in other areas of human knowledge, in particular the paradigm shift in scientific thinking. It has been specified that the massive use of mathematical methods in economics is associated with formation of the marginal theory and at the same time – with the proliferation of the marginal analysis. At the present stage, the economic behavior of households is being analyzed in the terms of concepts such as neoclassicism, institutionalism and behaviorism. But by dividing the concepts of «individual» and «household», it can be argued that precisely the institutionalism in conjunction with synergistic approach provide the basis for elaboration of strategies for the economic behavior of households, ensuring their economic security.

  8. Modelling management process of key drivers for economic sustainability in the modern conditions of economic development

    Directory of Open Access Journals (Sweden)

    Pishchulina E.S.

    2017-01-01

    Full Text Available The text is about issues concerning the management of driver for manufacturing enterprise economic sustainability and manufacturing enterprise sustainability assessment as the key aspect of the management of enterprise economic sustainability. The given issues become topical as new requirements for the methods of manufacturing enterprise management in the modern conditions of market economy occur. An economic sustainability model that is considered in the article is an integration of enterprise economic growth, economic balance of external and internal environment and economic sustainability. The method of assessment of economic sustainability of a manufacturing enterprise proposed in the study allows to reveal some weaknesses in the enterprise performance, and untapped reserves, which can be further used to improve the economic sustainability and efficiency of the enterprise. The management of manufacturing enterprise economic sustainability is one of the most important factors of business functioning and development in modern market economy. The relevance of this trend is increasing in accordance with the objective requirements of the growing volumes of production and sale, the increasing complexity of economic relations, changing external environment of an enterprise.

  9. The Structured Intuitive Model for Product Line Economics (SIMPLE)

    National Research Council Canada - National Science Library

    Clements, Paul C; McGregor, John D; Cohen, Sholom G

    2005-01-01

    .... This report presents the Structured Intuitive Model of Product Line Economics (SIMPLE), a general-purpose business model that supports the estimation of the costs and benefits in a product line development organization...

  10. Economic modeling and energy policy planning. [technology transfer, market research

    Science.gov (United States)

    Thompson, R. G.; Schwartz, A., Jr.; Lievano, R. J.; Stone, J. C.

    1974-01-01

    A structural economic model is presented for estimating the demand functions for natural gas and crude oil in industry and in steam electric power generation. Extensions of the model to other commodities are indicated.

  11. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  12. Aspen Global Change Institute Summer Science Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Katzenberger, John; Kaye, Jack A

    2006-10-01

    The Aspen Global Change Institute (AGCI) successfully organized and convened six interdisciplinary meetings over the course of award NNG04GA21G. The topics of the meetings were consistent with a range of issues, goals and objectives as described within the NASA Earth Science Enterprise Strategic Plan and more broadly by the US Global Change Research Program/Our Changing Planet, the more recent Climate Change Program Strategic Plan and the NSF Pathways report. The meetings were chaired by two or more leaders from within the disciplinary focus of each session. 222 scholars for a total of 1097 participants-days were convened under the auspices of this award. The overall goal of each AGCI session is to further the understanding of Earth system science and global environmental change through interdisciplinary dialog. The format and structure of the meetings allows for presentation by each participant, in-depth discussion by the whole group, and smaller working group and synthesis activities. The size of the group is important in terms of the group dynamics and interaction, and the ability for each participant's work to be adequately presented and discussed within the duration of the meeting, while still allowing time for synthesis

  13. Economic management model of nuclear power plant research institute

    International Nuclear Information System (INIS)

    Schultz, O.

    1993-01-01

    Brief information about the development of economic management and processing of economic information in the Nuclear Power Plants Research Institute Trnava is given in the paper. The existing economic management model of the Institute impacts positively the fulfillment of economic indicators. When applying this model, activities of individual divisions are emphasized and presentation of the Institute as a global professional capacity is suppressed. With regards to this influence, it will be necessary to look for such system elements that will impact the integrity of the Institute in the future period positively

  14. Models of the Economic Growth and their Relevance

    Directory of Open Access Journals (Sweden)

    Nicolae MOROIANU

    2012-06-01

    Full Text Available Until few years ago, the economic growth was something perfect normal, part of an era marked by the transformation speed. Normality itself has been transformed and we currently are influenced by other rules, unknown yet, which should answer the question: “How do we return to the economic growth?” The economic growth and the models aiming to solve this problem concern the economic history even since its beginnings. In this paper we would like to find out what is the relevance that the well-known macroeconomic models still have and which might be their applicability level in a framework created by a black swan event type.

  15. [Decision modeling for economic evaluation of health technologies].

    Science.gov (United States)

    de Soárez, Patrícia Coelho; Soares, Marta Oliveira; Novaes, Hillegonda Maria Dutilh

    2014-10-01

    Most economic evaluations that participate in decision-making processes for incorporation and financing of technologies of health systems use decision models to assess the costs and benefits of the compared strategies. Despite the large number of economic evaluations conducted in Brazil, there is a pressing need to conduct an in-depth methodological study of the types of decision models and their applicability in our setting. The objective of this literature review is to contribute to the knowledge and use of decision models in the national context of economic evaluations of health technologies. This article presents general definitions about models and concerns with their use; it describes the main models: decision trees, Markov chains, micro-simulation, simulation of discrete and dynamic events; it discusses the elements involved in the choice of model; and exemplifies the models addressed in national economic evaluation studies of diagnostic and therapeutic preventive technologies and health programs.

  16. Chemical studies on oils derived from aspen poplar wood, cellulose, and an isolated aspen poplar lignin

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Pepper, J M; Roy, J C; Mathews, J F

    1983-01-01

    An initial study has been made of the chemical nature of the oil phase resulting from the conversion of aspen poplar wood, cellulose, and an isolated lignin from the aspen poplar as a result of their interactions with water and carbon monoxide in the presence of sodium carbonate at 360 degrees C. Gas chromatographic analysis of the sodium hydroxide soluble fractions from each substrate revealed similar spectra of alkyl-substituted phenols. The relative abundance of identified low molecular weight phenolic compounds decreased from lignin to wood to cellulose. This was in agreement with the known phenolic nature of lignin. As well, it confirmed the synthesis during reaction of such compounds from a carbohydrate substrate. Gas chromatographic analysis of the whole oils also revealed the presence in each case of several alkyl-substituted cyclopentanones whose relative abundance decreased from cellulose to wood to lignin. Silica gel column separation of the oils, after a charcoal treatment, followed by capillary gas chromatographic - mass spectrometric analyses of the resulting fraction indicated the presence of other higher molecular weight phenols, napthols, cycloalkanols, and polycyclic and long chain alkanes and alkenes.

  17. Mathematical model comparing of the multi-level economics systems

    Science.gov (United States)

    Brykalov, S. M.; Kryanev, A. V.

    2017-12-01

    The mathematical model (scheme) of a multi-level comparison of the economic system, characterized by the system of indices, is worked out. In the mathematical model of the multi-level comparison of the economic systems, the indicators of peer review and forecasting of the economic system under consideration can be used. The model can take into account the uncertainty in the estimated values of the parameters or expert estimations. The model uses the multi-criteria approach based on the Pareto solutions.

  18. Agent-based models in economics a toolkit

    CERN Document Server

    Fagiolo, Giorgio; Gallegati, Mauro; Richiardi, Matteo; Russo, Alberto

    2018-01-01

    In contrast to mainstream economics, complexity theory conceives the economy as a complex system of heterogeneous interacting agents characterised by limited information and bounded rationality. Agent Based Models (ABMs) are the analytical and computational tools developed by the proponents of this emerging methodology. Aimed at students and scholars of contemporary economics, this book includes a comprehensive toolkit for agent-based computational economics, now quickly becoming the new way to study evolving economic systems. Leading scholars in the field explain how ABMs can be applied fruitfully to many real-world economic examples and represent a great advancement over mainstream approaches. The essays discuss the methodological bases of agent-based approaches and demonstrate step-by-step how to build, simulate and analyse ABMs and how to validate their outputs empirically using the data. They also present a wide set of applications of these models to key economic topics, including the business cycle, lab...

  19. Fuel modelling and its economical competitiveness

    International Nuclear Information System (INIS)

    Marino, A.C.; Savino, E.J.

    1996-01-01

    Due to reasons of economical competitiveness, there is at present a strong need in the nuclear industry to improve fuel performance under more demanding operating conditions, such as those resulting from an extended burnup. This requires a good understanding of the properties of fuel rod materials and their in-service performance. As it can be easily foreseen, thermal, mechanical and microstructural irradiation effects are strongly interrelated while the fuel is at reactor operating conditions. (author). 7 refs., 16 figs

  20. Environmental problems and economic development in an endogenous fertility model

    OpenAIRE

    Frank Joest; Martin Quaas; Johannes Schiller

    2006-01-01

    Population growth is often viewed as a most oppressive global problem with respect to environmental deterioration, but the relationships between population development, economic dynamics and environmental pollution are complex due to various feedback mechanisms. We analyze society’s economic decisions on birth rates, investment into human and physical capital, and polluting emissions within an optimal control model of the coupled demographic-economic-environmental system. We show that a long-...

  1. HTGR Application Economic Model Users' Manual

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Gandrik

    2012-01-01

    The High Temperature Gas-Cooled Reactor (HTGR) Application Economic Model was developed at the Idaho National Laboratory for the Next Generation Nuclear Plant Project. The HTGR Application Economic Model calculates either the required selling price of power and/or heat for a given internal rate of return (IRR) or the IRR for power and/or heat being sold at the market price. The user can generate these economic results for a range of reactor outlet temperatures; with and without power cycles, including either a Brayton or Rankine cycle; for the demonstration plant, first of a kind, or nth of a kind project phases; for up to 16 reactor modules; and for module ratings of 200, 350, or 600 MWt. This users manual contains the mathematical models and operating instructions for the HTGR Application Economic Model. Instructions, screenshots, and examples are provided to guide the user through the HTGR Application Economic Model. This model was designed for users who are familiar with the HTGR design and Excel and engineering economics. Modification of the HTGR Application Economic Model should only be performed by users familiar with the HTGR and its applications, Excel, and Visual Basic.

  2. Models of economic geography: dynamics, estimation and policy evaluation

    OpenAIRE

    Knaap, Thijs

    2004-01-01

    In this thesis we look at economic geography models from a number of angles. We started by placing the theory in a context of preceding theories, both earlier work on spatial economics and other children of the monopolistic competition ‘revolution.’ Next, we looked at the theoretical properties of these models, especially when we allow firms to have different demand functions for intermediate goods. We estimated the model using a dataset on US states, and computed a number of counterfactuals....

  3. Moving forward socio-economically focused models of deforestation

    OpenAIRE

    DEZÉCACHE CAMILLE; SALLES JEAN-MICHEL; VIEILLEDENT GHISLAIN; HÉRAULT BRUNO

    2017-01-01

    While high resolution spatial variables contribute to a good fit of spatially-explicit deforestation models, socio-economic processes are often beyond the scope of these models. Such a low level of interest in the socio-economic dimension of deforestation limits the relevancy of these models for decision making and may be the cause of their failure to accurately predict observed deforestation trends in the medium term. This study aims to propose a flexible methodology for taking into account ...

  4. Aspen in the Sierra Nevada: Regional conservation of a continental species

    Science.gov (United States)

    Paul C. Rogers; Wayne D. Shepperd; Dale L. Bartos

    2007-01-01

    Quaking aspen (Populus tremuloides Michx.) a common species in North America, is a minor species in the Sierra Nevada of California. However, the limited coverage of aspen in this area appears to carry a disproportionate biodiversity load: numerous species are dependent on the unique components of aspen forests habitat. Land managers in the region...

  5. Trembling aspen response to a mixed-severity wildfire in the Black Hills, South Dakota, USA

    Science.gov (United States)

    Tara L. Keyser; Frederick W. Smith; Wayne D. Shepperd

    2005-01-01

    Trembling aspen (Populus tremuloides Michx.) regeneration dynamics including sprout production, growth, and clone size were measured to determine the effects of fire on small aspen clone persistence following a mixedseverity wildfire in the Black Hills, South Dakota. Four years postfire, 10 small, isolated aspen clones per low and high fire severity...

  6. Characteristics of aspen infected with heartrot: Implications for cavity-nesting birds

    Science.gov (United States)

    Chris Witt

    2010-01-01

    Phellinus tremulae is an important fungal decay agent common to aspen and a critical component to the cavity-nesting bird complex found in western aspen stands. Little information exists on the conditions that facilitate infection and spread of P. tremulae in aspen forests. I used Forest Inventory and Analysis (FIA) data to explore the relationships of several tree and...

  7. Simulation of quaking aspen potential fire behavior in Northern Utah, USA

    Science.gov (United States)

    R. Justin DeRose; A. Joshua Leffler

    2014-01-01

    Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

  8. Lichen community change in response to succession in aspen forests of the southern Rocky Mountains

    Science.gov (United States)

    Paul C. Rogers; Ronald J. Ryel

    2008-01-01

    In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about...

  9. Modelling Dynamics of Main Economic Indicators of an Enterprise

    Directory of Open Access Journals (Sweden)

    Sherstennykov Yurii V.

    2014-03-01

    Full Text Available The article develops an economic and mathematical model of dynamics of main economic indicators of an enterprise, reflected in six book-keeping accounts with consideration of logistics and interrelation with current market characteristics and needs of products consumers. It applies this model for a quantitative study of influence of an advertising campaign and seasonality upon quantitative indicators of economic activity of the enterprise. The enterprise operation programme includes internal financial and economic procedures, which ensure the production process, and also connection with suppliers and buyers (customers. When setting different initial conditions, it is possible to trace transitional processes and enterprise entering (under favourable conditions the stationary mode of operation or its laying-off (in case of insufficiency of circulating funds. The developed model contains many parameters, which allow not only study of dependence of enterprise operation on alteration of one of them but also optimisation of economic conditions of functioning.

  10. Models of economic geography : dynamics, estimation and policy evaluation

    NARCIS (Netherlands)

    Knaap, Thijs

    2004-01-01

    In this thesis we look at economic geography models from a number of angles. We started by placing the theory in a context of preceding theories, both earlier work on spatial economics and other children of the monopolistic competition ‘revolution.’ Next, we looked at the theoretical properties of

  11. Modeling ecological and economic systems with STELLA : Part III

    NARCIS (Netherlands)

    Costanza, Robert; Voinov, Alexey

    2001-01-01

    This special issue contains a group of eight modeling studies covering a range of ecological and economic systems and problems. The models were all developed using Stella®, an icon-based software package specifically designed for dynamic systems modeling. Models included in the special issue were

  12. FISHRENT; Bio-economic simulation and optimisation model

    NARCIS (Netherlands)

    Salz, P.; Buisman, F.C.; Soma, K.; Frost, H.; Accadia, P.; Prellezo, R.

    2011-01-01

    Key findings: The FISHRENT model is a major step forward in bio-economic model-ling, combining features that have not been fully integrated in earlier models: 1- Incorporation of any number of species (or stock) and/or fleets 2- Integration of simulation and optimisation over a period of 25 years 3-

  13. Computer models for economic and silvicultural decisions

    Science.gov (United States)

    Rosalie J. Ingram

    1989-01-01

    Computer systems can help simplify decisionmaking to manage forest ecosystems. We now have computer models to help make forest management decisions by predicting changes associated with a particular management action. Models also help you evaluate alternatives. To be effective, the computer models must be reliable and appropriate for your situation.

  14. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation...... with respect to a variety of SOFC inputs. SOFC stack operation on syn-gas is compared to operation on different coal properties and as expected there is a drop in performance, which is attributed to increased input fuel and air flow due to the lower quality of the fuel gas....

  15. Moving forward socio-economically focused models of deforestation.

    Science.gov (United States)

    Dezécache, Camille; Salles, Jean-Michel; Vieilledent, Ghislain; Hérault, Bruno

    2017-09-01

    Whilst high-resolution spatial variables contribute to a good fit of spatially explicit deforestation models, socio-economic processes are often beyond the scope of these models. Such a low level of interest in the socio-economic dimension of deforestation limits the relevancy of these models for decision-making and may be the cause of their failure to accurately predict observed deforestation trends in the medium term. This study aims to propose a flexible methodology for taking into account multiple drivers of deforestation in tropical forested areas, where the intensity of deforestation is explicitly predicted based on socio-economic variables. By coupling a model of deforestation location based on spatial environmental variables with several sub-models of deforestation intensity based on socio-economic variables, we were able to create a map of predicted deforestation over the period 2001-2014 in French Guiana. This map was compared to a reference map for accuracy assessment, not only at the pixel scale but also over cells ranging from 1 to approximately 600 sq. km. Highly significant relationships were explicitly established between deforestation intensity and several socio-economic variables: population growth, the amount of agricultural subsidies, gold and wood production. Such a precise characterization of socio-economic processes allows to avoid overestimation biases in high deforestation areas, suggesting a better integration of socio-economic processes in the models. Whilst considering deforestation as a purely geographical process contributes to the creation of conservative models unable to effectively assess changes in the socio-economic and political contexts influencing deforestation trends, this explicit characterization of the socio-economic dimension of deforestation is critical for the creation of deforestation scenarios in REDD+ projects. © 2017 John Wiley & Sons Ltd.

  16. Evaluation to the aspen for the air pollution monitoring

    International Nuclear Information System (INIS)

    De La Rosa, D.; Lima, L.; Santana, J.L.; Olivares, S.; Martin, R.; Garcia, M.

    2003-01-01

    Aspen is not often used in bio monitoring programs, but when it is, several interacting and confounding variables have to be considered. Biomass of leaves, and height changes are not easy linked with air pollution, whereas dry weight and leaf abscission are. Visible injury diagnosis and crown thinning are useful records for bio monitoring programs to consider, but skill and understanding of air pollution effects versus seasonal effects are very important. Understanding of actual air pollution symptoms and elemental ratios are especially important. Clonal response and heritability is discuses below, and has to be considered in any bio monitoring program. Above all, integration of aspen response with other key variables is key

  17. PERACETIC ACID PRETREATMENT OF ALFALFA STEM AND ASPEN BIOMASS

    OpenAIRE

    Lei Xu,; Ulrike W. Tschirner

    2011-01-01

    Alfalfa stems and ground aspen were exposed to peracetic acid (0.5 to 9% on biomass) at temperatures ranging from 40 to 100° C and reaction times from 1 to 5 hours. Glucose release as a percentage of total cellulose content was determined using subsequent standard enzymatic hydrolysis. Statistical analysis confirmed that aspen showed a strong response to peracetic acid addition rate. 9% peracetic acid removed 14% of the original lignin and increased the rate of glucose release from 23% to 44%...

  18. Large scale hydro-economic modelling for policy support

    Science.gov (United States)

    de Roo, Ad; Burek, Peter; Bouraoui, Faycal; Reynaud, Arnaud; Udias, Angel; Pistocchi, Alberto; Lanzanova, Denis; Trichakis, Ioannis; Beck, Hylke; Bernhard, Jeroen

    2014-05-01

    To support European Union water policy making and policy monitoring, a hydro-economic modelling environment has been developed to assess optimum combinations of water retention measures, water savings measures, and nutrient reduction measures for continental Europe. This modelling environment consists of linking the agricultural CAPRI model, the LUMP land use model, the LISFLOOD water quantity model, the EPIC water quality model, the LISQUAL combined water quantity, quality and hydro-economic model, and a multi-criteria optimisation routine. With this modelling environment, river basin scale simulations are carried out to assess the effects of water-retention measures, water-saving measures, and nutrient-reduction measures on several hydro-chemical indicators, such as the Water Exploitation Index (WEI), Nitrate and Phosphate concentrations in rivers, the 50-year return period river discharge as an indicator for flooding, and economic losses due to water scarcity for the agricultural sector, the manufacturing-industry sector, the energy-production sector and the domestic sector, as well as the economic loss due to flood damage. Recently, this model environment is being extended with a groundwater model to evaluate the effects of measures on the average groundwater table and available resources. Also, water allocation rules are addressed, while having environmental flow included as a minimum requirement for the environment. Economic functions are currently being updated as well. Recent development and examples will be shown and discussed, as well as open challenges.

  19. Partial differential equation models in the socio-economic sciences

    KAUST Repository

    Burger, Martin; Caffarelli, Luis; Markowich, Peter A.

    2014-01-01

    Mathematical models based on partial differential equations (PDEs) have become an integral part of quantitative analysis in most branches of science and engineering, recently expanding also towards biomedicine and socio-economic sciences

  20. Bifurcations of a class of singular biological economic models

    International Nuclear Information System (INIS)

    Zhang Xue; Zhang Qingling; Zhang Yue

    2009-01-01

    This paper studies systematically a prey-predator singular biological economic model with time delay. It shows that this model exhibits two bifurcation phenomena when the economic profit is zero. One is transcritical bifurcation which changes the stability of the system, and the other is singular induced bifurcation which indicates that zero economic profit brings impulse, i.e., rapid expansion of the population in biological explanation. On the other hand, if the economic profit is positive, at a critical value of bifurcation parameter, the system undergoes a Hopf bifurcation, i.e., the increase of delay destabilizes the system and bifurcates into small amplitude periodic solution. Finally, by using Matlab software, numerical simulations illustrate the effectiveness of the results obtained here. In addition, we study numerically that the system undergoes a saddle-node bifurcation when the bifurcation parameter goes through critical value of positive economic profit.

  1. "Economic microscope": The agent-based model set as an instrument in an economic system research

    Science.gov (United States)

    Berg, D. B.; Zvereva, O. M.; Akenov, Serik

    2017-07-01

    To create a valid model of a social or economic system one must consider a lot of parameters, conditions and restrictions. Systems and, consequently, the corresponding models are proved to be very complicated. The problem of such system model engineering can't be solved only with mathematical methods usage. The decision could be found in computer simulation. Simulation does not reject mathematical methods, mathematical expressions could become the foundation for a computer model. In these materials the set of agent-based computer models is under discussion. All the set models simulate productive agents communications, but every model is geared towards the specific goal, and, thus, has its own algorithm and its own peculiarities. It is shown that computer simulation can discover new features of the agents' behavior that can not be obtained by analytical solvation of mathematical equations and thus plays the role of some kind of economic microscope.

  2. A Discrete Monetary Economic Growth Model with the MIU Approach

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2008-01-01

    Full Text Available This paper proposes an alternative approach to economic growth with money. The production side is the same as the Solow model, the Ramsey model, and the Tobin model. But we deal with behavior of consumers differently from the traditional approaches. The model is influenced by the money-in-the-utility (MIU approach in monetary economics. It provides a mechanism of endogenous saving which the Solow model lacks and avoids the assumption of adding up utility over a period of time upon which the Ramsey approach is based.

  3. Growing Season Conditions Mediate the Dependence of Aspen on Redistributed Snow Under Climate Change.

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

    2016-12-01

    Precipitation regimes in many semiarid ecosystems are becoming increasingly dominated by winter rainfall as a result of climate change. Across these regions, snowpack plays a vital role in the distribution and timing of soil moisture availability. Rising temperatures will result in a more uniform distribution of soil moisture, advanced spring phenology, and prolonged growing seasons. Productive and wide ranging tree species like aspen, Populus tremuloides, may experience increased vulnerability to drought and mortality resulting from both reduced snowpack and increased evaporative demand during the growing season. We simulated the net primary production (NPP) of aspen stands spanning the rain:snow transition zone in the Reynolds Creek Critical Zone Observatory (RCCZO) in southwest Idaho, USA. Within the RCCZO, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. The biogeochemical process model Biome-BGC was used to simulate aspen NPP at three stands located directly below snowdrifts that provide melt water late into the spring. After adjusting precipitation inputs to account for the redistribution of snow, we assessed climate change impacts on future aspen productivity. Mid-century (2046-2065) aspen NPP was simulated using temperature projections from a multi-model average under high emission conditions using the Multivariate Adaptive Constructed Analogs (MACA) data set. While climate change simulations indicated over a 20% decrease in annual NPP for some years, NPP rates for other mid-century years remained relatively unchanged due to variations in growing season conditions. Mid-century years with the largest decreases in NPP typically showed increased spring transpiration rates resulting from earlier leaf flush combined with warmer spring conditions. During these years, the onset of drought stress occurred

  4. Models and relations in economics and econometrics

    DEFF Research Database (Denmark)

    Juselius, Katarina

    1999-01-01

    Based on a money market analysis using the cointegrated VAR model the paper demonstrates some possible pitfalls in macroeconomic inference as a direct consequence of inadequate stochastic model formulation. A number of questions related to concepts such as empirical and theoretical steady...

  5. The methodology of energy policy-making in economical models

    Energy Technology Data Exchange (ETDEWEB)

    Poursina, B.

    1998-08-01

    Scrutiny and careful study in energy is a subject that in human science has been investigated from different point of view. The expansion of this research, because of its importance and effect in different dimensions of human life, has also arrived in the field of political and economic sciences. Economics evaluates the energy phenomenon at the side of elements such as labor, capital and technology in the production functions of firms. The nature of these discussions is mainly from the viewpoint of micro analyses. Nevertheless, the variation and challenges concerning energy and environment during the recent decades and the economists` detailed investigations in its analysis and evaluation have led to the arrival of energy discussions in a special shape in macro planning and large economic models. The paper compares various energy models - EFDM, MEDEE, MIDAS and HERMES. This extent of planning and consequently modelling which lacks a background in the processes of economic researches, deals with analysis of energy and economics reacting effects. Modelling of energy-economy interaction and energy policy in modeling macroeconomics large models are new ideas in energy studies and economics. 7 refs., 6 figs., 1 tab.

  6. Modelling the interaction between flooding events and economic growth

    Directory of Open Access Journals (Sweden)

    J. Grames

    2015-06-01

    Full Text Available Socio-hydrology describes the interaction between the socio-economy and water. Recent models analyze the interplay of community risk-coping culture, flooding damage and economic growth (Di Baldassarre et al., 2013; Viglione et al., 2014. These models descriptively explain the feedbacks between socio-economic development and natural disasters like floods. Contrary to these descriptive models, our approach develops an optimization model, where the intertemporal decision of an economic agent interacts with the hydrological system. In order to build this first economic growth model describing the interaction between the consumption and investment decisions of an economic agent and the occurrence of flooding events, we transform an existing descriptive stochastic model into an optimal deterministic model. The intermediate step is to formulate and simulate a descriptive deterministic model. We develop a periodic water function to approximate the former discrete stochastic time series of rainfall events. Due to the non-autonomous exogenous periodic rainfall function the long-term path of consumption and investment will be periodic.

  7. Econometric modelling of economic security in business operations management

    OpenAIRE

    Chagovets, L. О.; Nevezhin, V. P.; Zakharova, О. V.

    2014-01-01

    The article deals with econometric modeling of economic security. The model of evaluating transaction costs effect on the level of enterprise economic security is provided. The econometric models of evaluating economic security that are used in research are based on panel data. According to the results, the reserves for increasing the general level of economic security due to transaction costs reduction are revealed. Розглянуто питання економетричного моделювання економічної безпеки. Предс...

  8. R.M. Solow Adjusted Model of Economic Growth

    Directory of Open Access Journals (Sweden)

    Ion Gh. Rosca

    2007-05-01

    Full Text Available Besides the models of M. Keynes, R.F. Harrod, E. Domar, D. Romer, Ramsey-Cass-Koopmans etc., the R.M. Solow model is part of the category which characterizes the economic growth. The paper proposes the study of the R.M. Solow adjusted model of economic growth, while the adjustment consisting in the model adaptation to the Romanian economic characteristics. The article is the first one from a three paper series dedicated to the macroeconomic modelling theme, using the R.M. Solow model, such as: “Measurement of the economic growth and extensions of the R.M. Solow adjusted model” and “Evolution scenarios at the Romanian economy level using the R.M. Solow adjusted model”. The analysis part of the model is based on the study of the equilibrium to the continuous case with some interpretations of the discreet one, by using the state diagram. The optimization problem at the economic level is also used; it is built up of a specified number of representative consumers and firms in order to reveal the interaction between these elements.

  9. Widespread triploidy in Western North American aspen (Populus tremuloides.

    Directory of Open Access Journals (Sweden)

    Karen E Mock

    Full Text Available We document high rates of triploidy in aspen (Populus tremuloides across the western USA (up to 69% of genets, and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species, climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.

  10. The 2013 Aspen Prize for Community College Excellence

    Science.gov (United States)

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  11. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Science.gov (United States)

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  12. Historical patterns in lichen communities of montane quaking aspen forests

    Science.gov (United States)

    Paul C. Rogers; Dale L. Bartos; Ronald J. Ryel

    2011-01-01

    Climate shifts and resource exploitation in Rocky Mountain forests have caused profound changes in quaking aspen (Populus tremuloides Michx.) structure and function since Euro-American settlement. It therefore seems likely that commensurate shifts in dependent epiphytes would follow major ecological transitions. In the current study, we merge several lines of inquiry...

  13. Economic MPC based on LPV model for thermostatically controlled loads

    DEFF Research Database (Denmark)

    Zemtsov, Nikita; Hlava, Jaroslav; Frantsuzova, Galina

    2017-01-01

    Rapid increase of the renewable energy share in electricity production requires optimization and flexibility of the power consumption side. Thermostatically controlled loads (TCLs) have a large potential for regulation service provision. Economic model predictive control (MPC) is an advanced...... control method which can be used to syncronize the power consumption with undispatchable renewable electricity production. Thermal behavior of TCLs can be described by linear models based on energy balance of the system. In some cases, parameters of the model may be time-varying. In this work, we present...... a modified economic MPC based on linear parameter-varying model. In particular, we provide an exact transformation from a standard economic MPC formulation to a linear program. We assume that the variables influencing the model parameters are known (predictable) for the prediction horizon of the controller...

  14. Confronting the Economic Model with the Data

    DEFF Research Database (Denmark)

    Johansen, Søren

    2006-01-01

    methods. When this is not the case, but likelihood methods are applied nonetheless, the result is incorrect inference. In his paper we illustrate the problem of possible incorrect inference with a recent application of a DSGE model to US data (Ireland, 2004). Specifically, this paper discusses two broad...

  15. Economic Models and Algorithms for Distributed Systems

    CERN Document Server

    Neumann, Dirk; Altmann, Jorn; Rana, Omer F

    2009-01-01

    Distributed computing models for sharing resources such as Grids, Peer-to-Peer systems, or voluntary computing are becoming increasingly popular. This book intends to discover fresh avenues of research and amendments to existing technologies, aiming at the successful deployment of commercial distributed systems

  16. ECONOMIC AND MATHEMATICAL MODELING INNOVATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    D.V. Makarov

    2014-06-01

    Full Text Available The paper presents one of the mathematical tools for modeling innovation processes. With the help of Kondratieff long waves can define innovation cycles. However, complexity of the innovation system implies a qualitative description. The article describes the problems of this area of research.

  17. Economic Modeling and Analysis of Educational Vouchers

    Science.gov (United States)

    Epple, Dennis; Romano, Richard

    2012-01-01

    The analysis of educational vouchers has evolved from market-based analogies to models that incorporate distinctive features of the educational environment. These distinctive features include peer effects, scope for private school pricing and admissions based on student characteristics, the linkage of household residential and school choices in…

  18. Essays on model averaging and political economics

    NARCIS (Netherlands)

    Wang, W.

    2013-01-01

    This thesis first investigates various issues related with model averaging, and then evaluates two policies, i.e. West Development Drive in China and fiscal decentralization in U.S, using econometric tools. Chapter 2 proposes a hierarchical weighted least squares (HWALS) method to address multiple

  19. Generic modelling framework for economic analysis of battery systems

    DEFF Research Database (Denmark)

    You, Shi; Rasmussen, Claus Nygaard

    2011-01-01

    opportunities, a generic modelling framework is proposed to handle this task. This framework outlines a set of building blocks which are necessary for carrying out the economic analysis of various BS applications. Further, special focus is given on describing how to use the rainflow cycle counting algorithm...... for battery cycle life estimation, since the cycle life plays a central role in the economic analysis of BS. To illustrate the modelling framework, a case study using a Sodium Sulfur Battery (NAS) system with 5-minute regulating service is performed. The economic performances of two dispatch scenarios, a so......Deregulated electricity markets provide opportunities for Battery Systems (BS) to participate in energy arbitrage and ancillary services (regulation, operating reserves, contingency reserves, voltage regulation, power quality etc.). To evaluate the economic viability of BS with different business...

  20. Orbital Express mission operations planning and resource management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel

    2008-04-01

    As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less labor-power rises. Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Like a tow-truck delivering gas to a car on the road, the "servicing" satellite of OE had to find the "client" from several kilometers away, connect directly to the client, and transfer fluid (or a battery) autonomously, while on earth-orbit. The mission met 100% of its success criteria, and proved that autonomous satellite servicing is now a reality for space operations. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. As the constraints for execution could change weekly, daily, and even hourly, the tools used create the mission execution plans needed to be flexible and adaptable to many different kinds of changes. At the same time, the hard constraints of the plans needed to be maintained and satisfied. The Automated Scheduling and Planning Environment (ASPEN) tool, developed at the Jet Propulsion Laboratory, was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, an overview of the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the NASA's Earth Observing One mission's EO1 satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing.

  1. Migration modelling in the New Economic Geography

    OpenAIRE

    Camacho Pérez, Maria del Carmen

    2010-01-01

    The benchmark of this paper is the Fujita and Thisse (2002) core-periphery model, which adds a R&D sector with skilled labor to create new varieties for the modern sector. The number of R&D firms increases not only with the number of existing patents and knowledge spillovers but also with the number of skilled workers who can migrate and choose theregion offering the better lifetime salary.The main objective of the present work is to analyse the long-term consequences of the choice of the mig...

  2. CRISP. Information Security Models and Their Economics

    International Nuclear Information System (INIS)

    Gustavsson, R.; Mellstrand, P.; Tornqvist, B.

    2005-03-01

    The deliverable D1.6 includes background material and specifications of a CRISP Framework on protection of information assets related to power net management and management of business operations related to energy services. During the project it was discovered by the CRISP consortium that the original description of WP 1.6 was not adequate for the project as such. The main insight was that the original emphasis on cost-benefit analysis of security protection measures was to early to address in the project. This issue is of course crucial in itself but requires new models of consequence analysis that still remains to be developed, especially for the new business models we are investigated in the CRISP project. The updated and approved version of the WP1.6 description, together with the also updated WP2.4 focus on Dependable ICT support of Power Grid Operations constitutes an integrated approach towards dependable and secure future utilities and their business processes. This document (D1.6) is a background to deliverable D2.4. Together they provide a dependability and security framework to the three CRISP experiments in WP3

  3. An economic model of amniocentesis choice.

    Science.gov (United States)

    Fajnzylber, Eduardo; Hotz, V Joseph; Sanders, Seth G

    2010-03-01

    Medical practitioners typically utilize the following protocol when advising pregnant women about testing for the possibility of genetic disorders with their fetus: Pregnant women over the age of 35 should be tested for Down syndrome and other genetic disorders, while for younger women, such tests are discouraged (or not discussed) as the test can cause a pregnancy to miscarry. The logic appears compelling. The rate at which amniocentesis causes a pregnancy to miscarry is constant while the rate of genetic disorder rises substantially over a woman's reproductive years. Hence the potential benefit from testing - being able to terminate a fetus that is known to have a genetic disorder - rises with maternal age. This article argues that this logic is incomplete. While the benefits to testing do rise with age, the costs rise as well. Undergoing an amniocentesis always entails the risk of inducing a miscarriage of a healthy fetus. However, these costs are lower at early ages, because there is a higher probability of being able to replace a miscarried fetus with a healthy birth at a later age. We develop and calibrate a dynamic model of amniocentesis choice to explore this tradeoff. For parameters that characterize realistic age patterns of chromosomal abnormalities, fertility rates and miscarriages following amniocentesis, our model implies a falling, rather than rising, rate of amniocentesis as women approach menopause.

  4. Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

    Science.gov (United States)

    Leanne M. Vigue; Richard L. Lindroth

    2010-01-01

    Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

  5. Economic Modeling as a Component of Academic Strategic Planning.

    Science.gov (United States)

    MacKinnon, Joyce; Sothmann, Mark; Johnson, James

    2001-01-01

    Computer-based economic modeling was used to enable a school of allied health to define outcomes, identify associated costs, develop cost and revenue models, and create a financial planning system. As a strategic planning tool, it assisted realistic budgeting and improved efficiency and effectiveness. (Contains 18 references.) (SK)

  6. Modeling and forecasting mortality with economic growth : a multipopulation approach

    NARCIS (Netherlands)

    Boonen, T.J.; Li, H.

    2017-01-01

    Research on mortality modeling of multiple populations focuses mainly on extrapolating past mortality trends and summarizing these trends by one or more common latent factors. This article proposes a multipopulation stochastic mortality model that uses the explanatory power of economic growth. In

  7. Economic modelling of pork production-marketing chains

    NARCIS (Netherlands)

    Ouden, den M.

    1996-01-01

    The research described in this thesis was focused on the development of economic simulation and optimization computer models to support decision making with respect to pork production- marketing chains. The models include three production stages: pig farrowing, pig fattening and pig slaughtering

  8. Activity-Based Costing Model for Assessing Economic Performance.

    Science.gov (United States)

    DeHayes, Daniel W.; Lovrinic, Joseph G.

    1994-01-01

    An economic model for evaluating the cost performance of academic and administrative programs in higher education is described. Examples from its application at Indiana University-Purdue University Indianapolis are used to illustrate how the model has been used to control costs and reengineer processes. (Author/MSE)

  9. Criteria for comparing economic impact models of tourism

    NARCIS (Netherlands)

    Klijs, J.; Heijman, W.J.M.; Korteweg Maris, D.; Bryon, J.

    2012-01-01

    There are substantial differences between models of the economic impacts of tourism. Not only do the nature and precision of results vary, but data demands, complexity and underlying assumptions also differ. Often, it is not clear whether the models chosen are appropriate for the specific situation

  10. Building Better Ecological Machines: Complexity Theory and Alternative Economic Models

    Directory of Open Access Journals (Sweden)

    Jess Bier

    2016-12-01

    Full Text Available Computer models of the economy are regularly used to predict economic phenomena and set financial policy. However, the conventional macroeconomic models are currently being reimagined after they failed to foresee the current economic crisis, the outlines of which began to be understood only in 2007-2008. In this article we analyze the most prominent of this reimagining: Agent-Based models (ABMs. ABMs are an influential alternative to standard economic models, and they are one focus of complexity theory, a discipline that is a more open successor to the conventional chaos and fractal modeling of the 1990s. The modelers who create ABMs claim that their models depict markets as ecologies, and that they are more responsive than conventional models that depict markets as machines. We challenge this presentation, arguing instead that recent modeling efforts amount to the creation of models as ecological machines. Our paper aims to contribute to an understanding of the organizing metaphors of macroeconomic models, which we argue is relevant conceptually and politically, e.g., when models are used for regulatory purposes.

  11. Detection of Aspens Using High Resolution Aerial Laser Scanning Data and Digital Aerial Images

    Directory of Open Access Journals (Sweden)

    Kalle Eerikäinen

    2008-08-01

    Full Text Available The aim was to use high resolution Aerial Laser Scanning (ALS data and aerial images to detect European aspen (Populus tremula L. from among other deciduous trees. The field data consisted of 14 sample plots of 30 m × 30 m size located in the Koli National Park in the North Karelia, Eastern Finland. A Canopy Height Model (CHM was interpolated from the ALS data with a pulse density of 3.86/m2, low-pass filtered using Height-Based Filtering (HBF and binarized to create the mask needed to separate the ground pixels from the canopy pixels within individual areas. Watershed segmentation was applied to the low-pass filtered CHM in order to create preliminary canopy segments, from which the non-canopy elements were extracted to obtain the final canopy segmentation, i.e. the ground mask was analysed against the canopy mask. A manual classification of aerial images was employed to separate the canopy segments of deciduous trees from those of coniferous trees. Finally, linear discriminant analysis was applied to the correctly classified canopy segments of deciduous trees to classify them into segments belonging to aspen and those belonging to other deciduous trees. The independent variables used in the classification were obtained from the first pulse ALS point data. The accuracy of discrimination between aspen and other deciduous trees was 78.6%. The independent variables in the classification function were the proportion of vegetation hits, the standard deviation of in pulse heights, accumulated intensity at the 90th percentile and the proportion of laser points reflected at the 60th height percentile. The accuracy of classification corresponded to the validation results of earlier ALS-based studies on the classification of individual deciduous trees to tree species.

  12. A Model for Assessing the Gender Aspect in Economic Policy

    Directory of Open Access Journals (Sweden)

    Ona Rakauskienė

    2015-06-01

    Full Text Available The purpose of research is to develop a conceptual model for assessing the impact of the gender aspect on economic policy at macro– and microeconomic levels. The research methodology is based on analysing scientific approaches to the gender aspect in economics and gender–responsive budgeting as well as determining the impact of the gender aspect on GDP, foreign trade, the state budget and the labour market. First, the major findings encompass the main idea of a conceptual model proposing that a socio–economic picture of society can be accepted as completed only when, alongside public and private sectors, includes the care/reproductive sector that is dominated by women and creating added value in the form of educated human resources; second, macroeconomics is not neutral in terms of gender equality. Gender asymmetry is manifested not only at the level of microeconomics (labour market and business but also at the level of macroeconomics (GDP, the state budget and foreign trade, which has a negative impact on economic growth and state budget revenues. In this regard, economic decisions, according to the principles of gender equality and in order to achieve gender equality in economics, must be made, as the gender aspect has to be also implemented at the macroeconomic level.

  13. Physical-Socio-Economic Modeling of Climate Change

    Science.gov (United States)

    Chamberlain, R. G.; Vatan, F.

    2008-12-01

    Because of the global nature of climate change, any assessment of the effects of plans, policies, and response to climate change demands a model that encompasses the entire Earth System, including socio- economic factors. Physics-based climate models of the factors that drive global temperatures, rainfall patterns, and sea level are necessary but not sufficient to guide decision making. Actions taken by farmers, industrialists, environmentalists, politicians, and other policy makers may result in large changes to economic factors, international relations, food production, disease vectors, and beyond. These consequences will not be felt uniformly around the globe or even across a given region. Policy models must comprehend all of these considerations. Combining physics-based models of the Earth's climate and biosphere with societal models of population dynamics, economics, and politics is a grand challenge with high stakes. We propose to leverage our recent advances in modeling and simulation of military stability and reconstruction operations to models that address all these areas of concern. Following over twenty years' experience of successful combat simulation, JPL has started developing Minerva, which will add demographic, economic, political, and media/information models to capabilities that already exist. With these new models, for which we have design concepts, it will be possible to address a very wide range of potential national and international problems that were previously inaccessible. Our climate change model builds on Minerva and expands the geographical horizon from playboxes containing regions and neighborhoods to the entire globe. This system consists of a collection of interacting simulation models that specialize in different aspects of the global situation. They will each contribute to and draw from a pool of shared data. The basic models are: the physical model; the demographic model; the political model; the economic model; and the media

  14. Energy technologies and energy efficiency in economic modelling

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik

    1998-01-01

    This paper discusses different approaches to incorporating energy technologies and technological development in energy-economic models. Technological development is a very important issue in long-term energy demand projections and in environmental analyses. Different assumptions on technological ...... of renewable energy and especially wind power will increase the rate of efficiency improvement. A technologically based model in this case indirectly makes the energy efficiency endogenous in the aggregate energy-economy model....... technological development. This paper examines the effect on aggregate energy efficiency of using technological models to describe a number of specific technologies and of incorporating these models in an economic model. Different effects from the technology representation are illustrated. Vintage effects...... illustrates the dependence of average efficiencies and productivity on capacity utilisation rates. In the long run regulation induced by environmental policies are also very important for the improvement of aggregate energy efficiency in the energy supply sector. A Danish policy to increase the share...

  15. Mechanistic simulation of batch acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping using Aspen Plus™.

    Science.gov (United States)

    Darkwah, Kwabena; Nokes, Sue E; Seay, Jeffrey R; Knutson, Barbara L

    2018-05-22

    Process simulations of batch fermentations with in situ product separation traditionally decouple these interdependent steps by simulating a separate "steady state" continuous fermentation and separation units. In this study, an integrated batch fermentation and separation process was simulated for a model system of acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping, such that the fermentation kinetics are linked in real-time to the gas stripping process. A time-dependent cell growth, substrate utilization, and product production is translated to an Aspen Plus batch reactor. This approach capitalizes on the phase equilibria calculations of Aspen Plus to predict the effect of stripping on the ABE fermentation kinetics. The product profiles of the integrated fermentation and separation are shown to be sensitive to gas flow rate, unlike separate steady state fermentation and separation simulations. This study demonstrates the importance of coupled fermentation and separation simulation approaches for the systematic analyses of unsteady state processes.

  16. How does economic theory explain the Hubbert peak oil model?

    International Nuclear Information System (INIS)

    Reynes, F.; Okullo, S.; Hofkes, M.

    2010-01-01

    The aim of this paper is to provide an economic foundation for bell shaped oil extraction trajectories, consistent with Hubbert's peak oil model. There are several reasons why it is important to get insight into the economic foundations of peak oil. As production decisions are expected to depend on economic factors, a better comprehension of the economic foundations of oil extraction behaviour is fundamental to predict production and price over the coming years. The investigation made in this paper helps us to get a better understanding of the different mechanisms that may be at work in the case of OPEC and non-OPEC producers. We show that profitability is the main driver behind production plans. Changes in profitability due to divergent trajectories between costs and oil price may give rise to a Hubbert production curve. For this result we do not need to introduce a demand or an exploration effect as is generally assumed in the literature.

  17. Evolutionary modelling of the macro-economic impacts of catastrophic flood events

    NARCIS (Netherlands)

    Safarzynska, K.E.; Brouwer, R.; Hofkes, M.

    2013-01-01

    This paper examines the possible contribution of evolutionary economics to macro-economic modelling of flood impacts to provide guidance for future economic risk modelling. Most macro-economic models start from a neoclassical economic perspective and focus on equilibrium outcomes, either in a static

  18. ONTOLOGICAL MODEL OF STRATEGIC ECONOMIC SECURITY OF ENTERPRISE

    Directory of Open Access Journals (Sweden)

    L. A. Zaporozhtseva

    2014-01-01

    Full Text Available Article explains the necessity the application of the ontological approach to modeling the strategic economic security in the formalization of the basic categories of domain company recognized its benefits. Among the advantages of the model distinguishes its versatility and ability to describe various aspects of strategic security - the system strategies and goals of the organization and business processes; possibility of its use at different levels of detail - from the top-level description of the basic categories of management, to design-level analytic applications; as well as the adaptability of the model, with depth on particular aspects determined by practical necessity and not regulated methodology. The model integrates various aspects of the concept of enterprise architecture and organizes conceptual apparatus. Ontological model easy to understand and adjust as business architects and specialists in designing systems of economic security and offers many categories of verbal representation of the domain of the enterprise. Proved the feasibility of using process-functional approach in providing strategic economic security, according to which the components of such a security company proposed as business processes, finance, staff and contractors. The article presents the author's ontological model of strategic economic security, including endangered sites, the presence of factors that threaten the security of the object and the subject of providing security. Further, it is proved that in the subjects of security impact on the object using the tools, measures and activities within the strategy formed the mechanism is implemented managerial decisions to strengthen the strategic economic security. The process of diagnosis, detection, identification of threats of economic security, and the development of enterprise development strategies, taking into account its level of economic security must be under the constant supervision of the process of

  19. Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment

    Science.gov (United States)

    Smith, David Solance; Fettig, Stephen M.; Bowker, Matthew A.

    2016-01-01

    Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute to aspen’s decline, increased browsing by elk (Cervus elaphus), which have experienced dramatic population increases in the last ∼80 years, may severely inhibit aspen growth and regeneration. Fires are known to favor aspen recovery, but in the last several decades the spatial scale and intensity of wildfires has greatly increased, with poorly understood ramifications for aspen growth. Here, focusing on the 2000 Cerro Grande fire in central New Mexico – one of the earliest fires described as a “mega-fire” - we use three methods to examine the impact of elk browsing on aspen regeneration after a mega-fire. First, we use an exclosure experiment to show that aspen growing in the absence of elk were 3× taller than trees growing in the presence of elk. Further, aspen that were both protected from elk and experienced burning were 8.5× taller than unburned trees growing in the presence of elk, suggesting that the combination of release from herbivores and stimulation from fire creates the largest aspen growth rates. Second, using surveys at the landscape level, we found a correlation between elk browsing intensity and aspen height, such that where elk browsing was highest, aspen were shortest. This relationship between elk browsing intensity and aspen height was stronger in burned (r = −0.53) compared to unburned (r = −0.24) areas. Third, in conjunction with the landscape-level surveys, we identified possible natural refugia, microsites containing downed logs, shrubs etc. that may inhibit elk browsing by physically blocking aspen from elk or by impeding elk’s ability to move through the forest patch. We did not find any

  20. Modeling and Forecasting Mortality With Economic Growth: A Multipopulation Approach.

    Science.gov (United States)

    Boonen, Tim J; Li, Hong

    2017-10-01

    Research on mortality modeling of multiple populations focuses mainly on extrapolating past mortality trends and summarizing these trends by one or more common latent factors. This article proposes a multipopulation stochastic mortality model that uses the explanatory power of economic growth. In particular, we extend the Li and Lee model (Li and Lee 2005) by including economic growth, represented by the real gross domestic product (GDP) per capita, to capture the common mortality trend for a group of populations with similar socioeconomic conditions. We find that our proposed model provides a better in-sample fit and an out-of-sample forecast performance. Moreover, it generates lower (higher) forecasted period life expectancy for countries with high (low) GDP per capita than the Li and Lee model.

  1. An object-oriented approach to energy-economic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wise, M.A.; Fox, J.A.; Sands, R.D.

    1993-12-01

    In this paper, the authors discuss the experiences in creating an object-oriented economic model of the U.S. energy and agriculture markets. After a discussion of some central concepts, they provide an overview of the model, focusing on the methodology of designing an object-oriented class hierarchy specification based on standard microeconomic production functions. The evolution of the model from the class definition stage to programming it in C++, a standard object-oriented programming language, will be detailed. The authors then discuss the main differences between writing the object-oriented program versus a procedure-oriented program of the same model. Finally, they conclude with a discussion of the advantages and limitations of the object-oriented approach based on the experience in building energy-economic models with procedure-oriented approaches and languages.

  2. Sustainable economic production quantity models for inventory systems with shortage

    DEFF Research Database (Denmark)

    Taleizadeh, Ata Allah; Soleymanfar, Vahid Reza; Govindan, Kannan

    2018-01-01

    optimal values of inventory system variables, we solve four independent profit maximization problems for four different situations. These proposed models include a basic model in which shortages are not allowed, and when shortages are allowed, the lost sale, full backordering and partial backordering...... (EPQ). The theoretical sustainable EOQ and EPQ models are basic models that ignore many real-life conditions such as the possibility of stock-out in inventory systems. In this paper, we develop four new sustainable economic production quantity models that consider different shortage situations. To find...

  3. Economic analysis of Marine Protected Areas: Bioeconomic Modeling and Economic Valuation Approaches

    OpenAIRE

    Bui, Bich Xuan

    2017-01-01

    The papers 2 and 3 of this thesis are not available in Munin. Paper 2: Xuan, B. B., Sandorf, E. D., Aanesen, M.: “Informing Management Strategies for a Reserve: Results from a Discrete Choice Experiment Survey”. (Manuscript). Paper 3: Xuan, B. B.: “Extractive and Non-extractive Values of a Marine Protected Area: A Bio-economic Model Application". (Manuscript). Marine protected areas (MPAs) are often established for conservation objectives. Benefits provided by MPAs exceed pure biod...

  4. Modelling the interaction between flooding events and economic growth

    Science.gov (United States)

    Grames, Johanna; Fürnkranz-Prskawetz, Alexia; Grass, Dieter; Viglione, Alberto; Blöschl, Günter

    2016-04-01

    Recently socio-hydrology models have been proposed to analyze the interplay of community risk-coping culture, flooding damage and economic growth. These models descriptively explain the feedbacks between socio-economic development and natural disasters such as floods. Complementary to these descriptive models, we develop a dynamic optimization model, where the inter-temporal decision of an economic agent interacts with the hydrological system. This interdisciplinary approach matches with the goals of Panta Rhei i.e. to understand feedbacks between hydrology and society. It enables new perspectives but also shows limitations of each discipline. Young scientists need mentors from various scientific backgrounds to learn their different research approaches and how to best combine them such that interdisciplinary scientific work is also accepted by different science communities. In our socio-hydrology model we apply a macro-economic decision framework to a long-term flood-scenario. We assume a standard macro-economic growth model where agents derive utility from consumption and output depends on physical capital that can be accumulated through investment. To this framework we add the occurrence of flooding events which will destroy part of the capital. We identify two specific periodic long term solutions and denote them rich and poor economies. Whereas rich economies can afford to invest in flood defense and therefore avoid flood damage and develop high living standards, poor economies prefer consumption instead of investing in flood defense capital and end up facing flood damages every time the water level rises. Nevertheless, they manage to sustain at least a low level of physical capital. We identify optimal investment strategies and compare simulations with more frequent and more intense high water level events.

  5. Economic decision making and the application of nonparametric prediction models

    Science.gov (United States)

    Attanasi, E.D.; Coburn, T.C.; Freeman, P.A.

    2008-01-01

    Sustained increases in energy prices have focused attention on gas resources in low-permeability shale or in coals that were previously considered economically marginal. Daily well deliverability is often relatively small, although the estimates of the total volumes of recoverable resources in these settings are often large. Planning and development decisions for extraction of such resources must be areawide because profitable extraction requires optimization of scale economies to minimize costs and reduce risk. For an individual firm, the decision to enter such plays depends on reconnaissance-level estimates of regional recoverable resources and on cost estimates to develop untested areas. This paper shows how simple nonparametric local regression models, used to predict technically recoverable resources at untested sites, can be combined with economic models to compute regional-scale cost functions. The context of the worked example is the Devonian Antrim-shale gas play in the Michigan basin. One finding relates to selection of the resource prediction model to be used with economic models. Models chosen because they can best predict aggregate volume over larger areas (many hundreds of sites) smooth out granularity in the distribution of predicted volumes at individual sites. This loss of detail affects the representation of economic cost functions and may affect economic decisions. Second, because some analysts consider unconventional resources to be ubiquitous, the selection and order of specific drilling sites may, in practice, be determined arbitrarily by extraneous factors. The analysis shows a 15-20% gain in gas volume when these simple models are applied to order drilling prospects strategically rather than to choose drilling locations randomly. Copyright ?? 2008 Society of Petroleum Engineers.

  6. Models of Russia's Participation in Regional Economic Integration

    Directory of Open Access Journals (Sweden)

    Darya I. Ushkalova

    2014-01-01

    Full Text Available The article analyses models and mechanisms of Russia's participation in integration processes in Post-Soviet space in recent years. The article examines the model of integration of Customs Union Common Economic Space Eurasian Economic Union and particular mechanisms of its realization. It also examines key challenges to further development of integration in the frameworks of Eurasian Economic Union including exhausting of short-term and medium-term integration effects against a background of low level of economic cooperation and the lack of effective mechanism of interest coordination and decisionmaking similar to qualified majority. It concludes that deterioration of mutual trade dynamics in Customs Union is determined by fundamental factors, first of all, exhausting of medium-term integration effects which lead to extension of mutual trade immediately after Customs Union creation but do not change its qualitative characteristics in long-term outlook. The author shows an absence of significant long-term integration effects which were based on increase of domestic market capacity due to a modification of economic structure. It is founded that appearance of such long-term integration effects is possible only in the context of coalescence of national economies at the microlevel based on development of system of communications between enterprises including intrasectoral industrial cooperation. The article also analyses results of realization of Russia's strategy of interaction with states beyond Eurasian Economic Union based on open regionalism concept. The paper presents recommendation on perfection of tools of integration in and outside Eurasian Economic Union. In particular, creation of system of decentralized organizations is proposed, for the implementation of specific cooperation projects in selected areas, taking into account the multiplier effect of such a "point-aimed" action/

  7. Real-Time Optimization for Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Edlund, Kristian; Frison, Gianluca

    2012-01-01

    In this paper, we develop an efficient homogeneous and self-dual interior-point method for the linear programs arising in economic model predictive control. To exploit structure in the optimization problems, the algorithm employs a highly specialized Riccati iteration procedure. Simulations show...

  8. Neural networks in economic modelling : An empirical study

    NARCIS (Netherlands)

    Verkooijen, W.J.H.

    1996-01-01

    This dissertation addresses the statistical aspects of neural networks and their usability for solving problems in economics and finance. Neural networks are discussed in a framework of modelling which is generally accepted in econometrics. Within this framework a neural network is regarded as a

  9. Aligning the economic modeling of software reuse with reuse practices

    NARCIS (Netherlands)

    Postmus, D.; Meijler, 27696

    In contrast to current practices where software reuse is applied recursively and reusable assets are tailored trough parameterization or specialization, existing reuse economic models assume that (i) the cost of reusing a software asset depends on its size and (ii) reusable assets are developed from

  10. The use of modeling in the economic evaluation of vaccines

    NARCIS (Netherlands)

    Bos, Jasper M; Alphen, Loek van; Postma, Maarten J

    2002-01-01

    As a consequence of the increased role of pharmacoeconomics in policy-making, economic evaluations are performed at more and more early stages in the development of a therapeutic. This implies the development of models to assess the future impact of an intervention and to account for the level of

  11. A mean-field game economic growth model

    KAUST Repository

    Gomes, Diogo A.; Lafleche, Laurent; Nurbekyan, Levon

    2016-01-01

    Here, we examine a mean-field game (MFG) that models the economic growth of a population of non-cooperative, rational agents. In this MFG, agents are described by two state variables - the capital and consumer goods they own. Each agent seeks

  12. Bio-economic household modelling for agricultural intensification

    NARCIS (Netherlands)

    Kruseman, G.

    2000-01-01

    This study contributes to the quest for sustainable agricultural intensification through the development of a quantitative bio-economic modelling framework that allows assessment of new technology and policy measures in terms of household welfare and sustainability indicators. The main aim

  13. Models of Economic Growth and Development in the Context of ...

    African Journals Online (AJOL)

    The better-known models of economic growth such as the Lewis, Rostow,. Harrod-Domar ... produce highly educated populaces usually reap the benefits of such in terms of high per capita ..... The Russian revolution of 1917 led by Lenin proposed in theory a .... This was about government intervention into the economy to ...

  14. Student Migration to Online Education: An Economic Model

    Science.gov (United States)

    Eisenhauer, Joseph G.

    2013-01-01

    The popularity of distance education has increasingly led universities to consider expanding their online offerings. Remarkably few financial models have been presented for online courses, however, and fewer still have investigated the economic consequences of the migration, or cross-over, of students from traditional classes within the…

  15. INFORMATION SYSTEM FOR MODELING ECONOMIC AND FINANCIAL PERFORMANCES

    Directory of Open Access Journals (Sweden)

    Boldeanu Dana Maria

    2009-05-01

    Full Text Available The analysis of the most important financial and economic indicators at the level of some organizations from the same sector of activity, the selection of performance ratios and generating a particular analysis model help companies to move from the desire

  16. A survey on the geometry of production models in economics

    Directory of Open Access Journals (Sweden)

    Alina-Daniela Vîlcu

    2017-01-01

    Full Text Available In this article we survey selected recent results on the geometry of production models, focussing on the main production functions that are usually analyzed in economics, namely homogeneous, homothetic, quasi-sum and quasi-product production functions.

  17. Using STELLA Simulation Models to Teach Natural Resource Economics

    Science.gov (United States)

    Dissanayake, Sahan T. M.

    2016-01-01

    In this article, the author discusses how graphical simulation models created using STELLA software can be used to present natural resource systems in an intuitive way in undergraduate natural resource economics classes based on his experiences at a leading research university, a state university, and a leading liberal arts college in the United…

  18. An Economic Model of Workplace Mobbing in Academe

    Science.gov (United States)

    Faria, Joao Ricardo; Mixon, Franklin G., Jr.; Salter, Sean P.

    2012-01-01

    Workplace bullying or mobbing can be defined as the infliction of various forms of abuse (e.g., verbal, emotional, psychological) against a colleague or subordinate by one or more other members of a workplace. Even in the presence of academic tenure, workplace mobbing remains a prevalent issue in academe. This study develops an economic model that…

  19. R.M. Solow Adjusted Model of Economic Growth

    Directory of Open Access Journals (Sweden)

    Ion Gh. Rosca

    2007-05-01

    The analysis part of the model is based on the study of the equilibrium to the continuous case with some interpretations of the discreet one, by using the state diagram. The optimization problem at the economic level is also used; it is built up of a specified number of representative consumers and firms in order to reveal the interaction between these elements.

  20. Experimental Study of Impregnation Birch and Aspen Samples

    Directory of Open Access Journals (Sweden)

    Igor Vladislavovich Grigorev

    2014-10-01

    Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

  1. Using Economic Impact Models as an Educational Tool in Community Economic Development Programming: Lessons from Pennsylvania and Wisconsin.

    Science.gov (United States)

    Shields, Martin; Deller, Steven C.

    2003-01-01

    Outlines an educational process designed to help provide communities with economic, social, and political information using community economic impact modeling. Describes the process of community meetings using economic impact, community demographics, and fiscal impact modules and the local preconditions that help make the process successful. (SK)

  2. Accounting for household heterogeneity in general equilibrium economic growth models

    International Nuclear Information System (INIS)

    Melnikov, N.B.; O'Neill, B.C.; Dalton, M.G.

    2012-01-01

    We describe and evaluate a new method of aggregating heterogeneous households that allows for the representation of changing demographic composition in a multi-sector economic growth model. The method is based on a utility and labor supply calibration that takes into account time variations in demographic characteristics of the population. We test the method using the Population-Environment-Technology (PET) model by comparing energy and emissions projections employing the aggregate representation of households to projections representing different household types explicitly. Results show that the difference between the two approaches in terms of total demand for energy and consumption goods is negligible for a wide range of model parameters. Our approach allows the effects of population aging, urbanization, and other forms of compositional change on energy demand and CO 2 emissions to be estimated and compared in a computationally manageable manner using a representative household under assumptions and functional forms that are standard in economic growth models.

  3. Maximum likelihood estimation of finite mixture model for economic data

    Science.gov (United States)

    Phoong, Seuk-Yen; Ismail, Mohd Tahir

    2014-06-01

    Finite mixture model is a mixture model with finite-dimension. This models are provides a natural representation of heterogeneity in a finite number of latent classes. In addition, finite mixture models also known as latent class models or unsupervised learning models. Recently, maximum likelihood estimation fitted finite mixture models has greatly drawn statistician's attention. The main reason is because maximum likelihood estimation is a powerful statistical method which provides consistent findings as the sample sizes increases to infinity. Thus, the application of maximum likelihood estimation is used to fit finite mixture model in the present paper in order to explore the relationship between nonlinear economic data. In this paper, a two-component normal mixture model is fitted by maximum likelihood estimation in order to investigate the relationship among stock market price and rubber price for sampled countries. Results described that there is a negative effect among rubber price and stock market price for Malaysia, Thailand, Philippines and Indonesia.

  4. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

    Science.gov (United States)

    Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

    2017-06-01

    High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Control of chaotic dynamics in an OLG economic model

    International Nuclear Information System (INIS)

    Mendes, Diana A; Mendes, Vivaldo

    2005-01-01

    This paper deals with the control of chaotic economic motion. We show that very complicated dynamics arising, e.g., from an overlapping generations model (OLG) with production and an endogenous intertemporal decision between labour and leisure, which produces chaos, can in fact be controlled with relative simplicity. The aperiodic and very complicated motion that stems from this model can be subject to control by small perturbations in its parameters and turned into a stable steady state or into a regular cycle. Therefore, the system can be controlled without changing of its original properties. To perform the control of the totally unstable equilibrium (both eigenvalues with modulus greater than unity) in this economic model we apply the pole-placement technique, developed by Romeiras, Grebogi, Ott and Dayawansa (1992). The application of control methods to chaotic economic dynamics may raise serious reservations, at least on mathematical and logical grounds, to some recent views on economics which have argued that economic policy becomes useless in the presence of chaotic motion (and thus, that the performance of the economic system cannot be improved by public intervention, i.e., that the amplitude of cycles can not be controlled or reduced). In fact, the fine tuning of the system (that is, the control) can be performed without having to rely only on infinitesimal accuracy in the perturbation to the system, because the control can be performed with larger or smaller perturbations, but neither too large (because these would lead to a different fixed point of the system, therefore modifying its original nature), nor too small because the control becomes too inefficient

  6. A Reformulation of Normative Economics for Models with Endogenous Preferences

    OpenAIRE

    Vipul Bhatt; Masao Ogaki; Yuichi Yaguchi

    2014-01-01

    This paper proposes a framework to balance considerations of welfarism and virtue ethics in the normative analysis of economic models with endogenous preferences. We introduce the moral evaluation function (MEF), which ranks alternatives based purely on virtue ethics, and define the social objective function (SOF), which combines the Social Welfare Function (SWF) and the MEF. In a model of intergenerational altruism with endogenous time preference, using numerical simulations we show that max...

  7. A Reformulation of Normative Economics for Models with Endogenous

    OpenAIRE

    Bhatt, Vipul; Ogaki, Masao; Yaguchi, Yuichi

    2015-01-01

    This paper proposes a framework to balance considerations of welfarism and virtue ethics in the normative analysis of economic models with endogenous preferences. We introduce the moral evaluation function (MEF), which ranks alternatives based purely on virtue ethics, and define the social objective function (SOF), which combines the Social Welfare Function (SWF) and the MEF. In a model of intergenerational altruism with endogenous time preference, using numerical simulations we show that max...

  8. Evaluating Behavioral Economic Models of Heavy Drinking Among College Students.

    Science.gov (United States)

    Acuff, Samuel F; Soltis, Kathryn E; Dennhardt, Ashley A; Berlin, Kristoffer S; Murphy, James G

    2018-05-14

    Heavy drinking among college students is a significant public health concern that can lead to profound social and health consequences, including alcohol use disorder. Behavioral economics posits that low future orientation and high valuation of alcohol (alcohol demand) combined with deficits in alternative reinforcement increase the likelihood of alcohol misuse (Bickel et al., 2011). Despite this, no study has examined the incremental utility of all three variables simultaneously in a comprehensive model METHOD: The current study uses structural equation modeling to test the associations between behavioral economic variables - alcohol demand (latent), future orientation (measured with a delay discounting task and the Consideration of Future Consequences (CFC) scale), and proportionate substance-related reinforcement - and alcohol consumption and problems among 393 heavy drinking college students. Two models are tested: 1) an iteration of the reinforcer pathology model that includes an interaction between future orientation and alcohol demand; and 2) an alternative model evaluating the interconnectedness of behavioral economic variables in predicting problematic alcohol use RESULTS: The interaction effects in model 1 were nonsignificant. Model 2 suggests that greater alcohol demand and proportionate substance-related reinforcement is associated with greater alcohol consumption and problems. Further, CFC was associated with alcohol-related problems and lower proportionate substance-related reinforcement but was not significantly associated with alcohol consumption or alcohol demand. Finally, greater proportionate substance-related reinforcement was associated with greater alcohol demand CONCLUSIONS: Our results support the validity of the behavioral economic reinforcer pathology model as applied to young adult heavy drinking. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. A Pedagogical Note on Modeling the Economic Benefit of Emissions Abatement vs. the Economic Harm from Emissions

    OpenAIRE

    Christopher S. Decker

    2012-01-01

    The number of undergraduate-level textbooks on environmental economics has increased in recent years, but the textbook treatment of optimal emissions (abatement) varies markedly from textbook to textbook. In particular, there is no consensus as to whether to model the economic “bad” (i.e. emissions) or the economic “good” (abatement). This inconsistency can lead to some needless confusion for students introduced to environmental economics for the first time, particularly those students outsid...

  10. Economics.

    Science.gov (United States)

    Palley, Paul D; Parcero, Miriam E

    2016-10-01

    A review of literature in the calendar year 2015 dedicated to environmental policies and sustainable development, and economic policies. This review is divided into these sections: sustainable development, irrigation, ecosystems and water management, climate change and disaster risk management, economic growth, water supply policies, water consumption, water price regulation, and water price valuation.

  11. A review of mathematical models in economic environmental problems

    DEFF Research Database (Denmark)

    Nahorski, Z.; Ravn, H.F.

    2000-01-01

    The paper presents a review of mathematical models used,in economic analysis of environmental problems. This area of research combines macroeconomic models of growth, as dependent on capital, labour, resources, etc., with environmental models describing such phenomena like natural resources...... exhaustion or pollution accumulation and degradation. In simpler cases the models can be treated analytically and the utility function can be optimized using, e.g., such tools as the maximum principle. In more complicated cases calculation of the optimal environmental policies requires a computer solution....

  12. Adverse Influence of Radio Frequency Background on Trembling Aspen Seedlings: Preliminary Observations

    Directory of Open Access Journals (Sweden)

    Katie Haggerty

    2010-01-01

    Full Text Available Numerous incidents of aspen decline have been recorded in North America over the past half century, and incidents of very rapid mortality of aspen clones have been observed in Colorado since 2004. The radio frequency (RF environment of the earth has undergone major changes in the past two centuries due to the development and use of electricity in power and communications applications, and the anthropogenic RF background continues to increase in intensity and complexity. This study suggests that the RF background may have strong adverse effects on growth rate and fall anthocyanin production in aspen, and may be an underlying factor in aspen decline.

  13. Modelling the interaction between flooding events and economic growth

    Science.gov (United States)

    Grames, Johanna; Grass, Dieter; Prskawetz, Alexia; Blöschl, Günther

    2015-04-01

    Socio-hydrology describes the interaction between the socio-economy, water and population dynamics. Recent models analyze the interplay of community risk-coping culture, flooding damage and economic growth (Di Baldassarre, 2013, Viglione, 2014). These models descriptively explain the feedbacks between socio-economic development and natural disasters like floods. Contrary to these descriptive models, our approach develops an optimization model, where the intertemporal decision of an economic agent interacts with the hydrological system. This is the first economic growth model describing the interaction between the consumption and investment decisions of an economic agent and the occurrence of flooding events: Investments in defense capital can avoid floods even when the water level is high, but on the other hand such investment competes with investment in productive capital and hence may reduce the level of consumption. When floods occur, the flood damage therefore depends on the existing defense capital. The aim is to find an optimal tradeoff between investments in productive versus defense capital such as to optimize the stream of consumption in the long-term. We assume a non-autonomous exogenous periodic rainfall function (Yevjevich et.al. 1990, Zakaria 2001) which implies that the long-term equilibrium will be periodic . With our model we aim to derive mechanisms that allow consumption smoothing in the long term, and at the same time allow for optimal investment in flood defense to maximize economic output. We choose an aggregate welfare function that depends on the consumption level of the society as the objective function. I.e. we assume a social planer with perfect foresight that maximizes the aggregate welfare function. Within our model framework we can also study whether the path and level of defense capital (that protects people from floods) is related to the time preference rate of the social planner. Our model also allows to investigate how the frequency

  14. Modeling human behavior in economics and social science.

    Science.gov (United States)

    Dolfin, M; Leonida, L; Outada, N

    2017-12-01

    The complex interactions between human behaviors and social economic sciences is critically analyzed in this paper in view of possible applications of mathematical modeling as an attainable interdisciplinary approach to understand and simulate the aforementioned dynamics. The quest is developed along three steps: Firstly an overall analysis of social and economic sciences indicates the main requirements that a contribution of mathematical modeling should bring to these sciences; subsequently the focus moves to an overview of mathematical tools and to the selection of those which appear, according to the authors bias, appropriate to the modeling; finally, a survey of applications is presented looking ahead to research perspectives. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. ECONOMIC FORECASTS BASED ON ECONOMETRIC MODELS USING EViews 5

    Directory of Open Access Journals (Sweden)

    Cornelia TomescuDumitrescu,

    2009-05-01

    Full Text Available The forecast of evolution of economic phenomena represent on the most the final objective of econometrics. It withal represent a real attempt of validity elaborate model. Unlike the forecasts based on the study of temporal series which have an recognizable inertial character the forecasts generated by econometric model with simultaneous equations are after to contour the future of ones of important economic variables toward the direct and indirect influences bring the bear on their about exogenous variables. For the relief of the calculus who the realization of the forecasts based on the econometric models its suppose is indicate the use of the specialized informatics programs. One of this is the EViews which is applied because it reduces significant the time who is destined of the econometric analysis and it assure a high accuracy of calculus and of the interpretation of results.

  16. The Economic Basis of the Model of Traditional Montenegrin Masculinity

    Directory of Open Access Journals (Sweden)

    Branko Banović

    2016-02-01

    Full Text Available The model of traditional Montenegrin masculinity is inseparable from the social formations that have contributed to its creation, hence the need for its more thorough economic, social and historical contextualization. It is particularly important to distinguish the two components of the model of traditional Montenegrin masculinity, which tend to be intertwined and are therefore difficult to separate. The first concerns the gender roles assigned to men and women in an economy based on livestock raising, warfare, and raiding, while the other concerns the concept of gender roles shaped by fictional, ethnological and historical narratives. The paper attempts to problematize the economic basis of the model of traditional Montenegrin masculinity in the context of a semi-nomadic livestock raising economy and a clan’s collective property.

  17. 2012 Aspen Winter Conferences on High Energy and Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Olivier, Dore [California Inst. of Technology (CalTech), Pasadena, CA (United States); Fox, Patrick [Aspen Center for Physics, CO (United States); Furic, Ivan [Univ. of Florida, Gainesville, FL (United States); Halkiadakis, Eva [Rutgers Univ., Piscataway, NJ (United States); Schmidt, Fabian [California Inst. of Technology (CalTech), Pasadena, CA (United States); Senatore, Leonardo [Stanford Univ., CA (United States); Smith, Kendrick M. [Princeton Univ., NJ (United States); Whiteson, Daniel [Univ. of California, Irvine, CA (United States)

    2012-05-01

    Aspen Center for Physics Project Summary DE-SC0007313 Budget Period: 1/1/2012 to 12/31/2012 The Hunt for New Particles, from the Alps to the Plains to the Rockies The 2012 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 11 to February 17, 2012. Sixty-seven participants from nine countries, and several universities and national labs attended the workshop titled, The Hunt for New Particles, from the Alps to the Plains to the Rockies. There were 53 formal talks, and a considerable number of informal discussions held during the week. The weeks events included a public lecture-Hunting the Dark Universe given by Neal Weiner from New York University) and attended by 237 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists conducted by Spencer Chang (University of Oregon), Matthew Reece (Harvard University) and Julia Shelton (Yale University) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by John Campbell (Fermilab), Patrick Fox (Fermilab), Ivan Furic (University of Florida), Eva Halkiadakis (Rutgers University) and Daniel Whiteson (University of California Irvine). Additional information is available at http://indico.cern.ch/conferenceDisplay.py?confId=143360. Inflationary Theory and its Confrontation with Data in the Planck Era The 2012 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was Inflationary Theory and its Confrontation with Data in the Planck Era. It was held from January 30 to February 4, 2012. The 62 participants came from 7 countries and attended 43 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists

  18. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    Science.gov (United States)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  19. Basin Economic Allocation Model (BEAM): An economic model of water use developed for the Aral Sea Basin

    Science.gov (United States)

    Riegels, Niels; Kromann, Mikkel; Karup Pedersen, Jesper; Lindgaard-Jørgensen, Palle; Sokolov, Vadim; Sorokin, Anatoly

    2013-04-01

    The water resources of the Aral Sea basin are under increasing pressure, particularly from the conflict over whether hydropower or irrigation water use should take priority. The purpose of the BEAM model is to explore the impact of changes to water allocation and investments in water management infrastructure on the overall welfare of the Aral Sea basin. The BEAM model estimates welfare changes associated with changes to how water is allocated between the five countries in the basin (Kazakhstan, Kyrgyz Republic, Tajikistan, Turkmenistan and Uzbekistan; water use in Afghanistan is assumed to be fixed). Water is allocated according to economic optimization criteria; in other words, the BEAM model allocates water across time and space so that the economic welfare associated with water use is maximized. The model is programmed in GAMS. The model addresses the Aral Sea Basin as a whole - that is, the rivers Syr Darya, Amu Darya, Kashkadarya, and Zarafshan, as well as the Aral Sea. The model representation includes water resources, including 14 river sections, 6 terminal lakes, 28 reservoirs and 19 catchment runoff nodes, as well as land resources (i.e., irrigated croplands). The model covers 5 sectors: agriculture (crops: wheat, cotton, alfalfa, rice, fruit, vegetables and others), hydropower, nature, households and industry. The focus of the model is on welfare impacts associated with changes to water use in the agriculture and hydropower sectors. The model aims at addressing the following issues of relevance for economic management of water resources: • Physical efficiency (estimating how investments in irrigation efficiency affect economic welfare). • Economic efficiency (estimating how changes in how water is allocated affect welfare). • Equity (who will gain from changes in allocation of water from one sector to another and who will lose?). Stakeholders in the region have been involved in the development of the model, and about 10 national experts, including

  20. Economism

    Directory of Open Access Journals (Sweden)

    P. Simons

    2010-07-01

    Full Text Available Modern society is characterised not only by a fascination with scientific technology as a means of solving all problems, especially those that stand in the way of material progress (technicism, but also by an obsessive interest in everything that has to do with money (economism or mammonism. The article discusses the relationship between technicism and economism, on the basis of their relationship to utilitarian thinking: the quest for the greatest happiness for the greatest number of people. Recent major studies of neo-liberalism (seen as an intensification of utilitarianism by Laval and Dardot are used as reference to the development of utilitarianism. It is suggested that the western view of the world, as expressed in economism and technicism, with a utilitarian ethics, features three absolutisations: those of theoretical thinking, technology and economics. In a second part, the article draws on the framework of reformational philosophy to suggest an approach that, in principle, is not marred by such absolutisations.

  1. Economic value added model upon conditions of banking company

    Directory of Open Access Journals (Sweden)

    Vlasta Kašparovská

    2008-01-01

    Full Text Available The content of this article is the application of the economic value added model (EVA upon the conditions of a banking company. Due to the character of banking business, which is in a different structure of financial sheet, it is not possible to use the standard model EVA for this banking company. The base of this article is the outlined of basic principles of the EVA mode in a non-banking company. Basic specified banking activity dissimilarities are analysed and a directed methodology adjustment of a model such as this, so that it is possible to use it for a banking company.

  2. Modeling the clinical and economic implications of obesity using microsimulation.

    Science.gov (United States)

    Su, W; Huang, J; Chen, F; Iacobucci, W; Mocarski, M; Dall, T M; Perreault, L

    2015-01-01

    The obesity epidemic has raised considerable public health concerns, but there are few validated longitudinal simulation models examining the human and economic cost of obesity. This paper describes a microsimulation model as a comprehensive tool to understand the relationship between body weight, health, and economic outcomes. Patient health and economic outcomes were simulated annually over 10 years using a Markov-based microsimulation model. The obese population examined is nationally representative of obese adults in the US from the 2005-2012 National Health and Nutrition Examination Surveys, while a matched normal weight population was constructed to have similar demographics as the obese population during the same period. Prediction equations for onset of obesity-related comorbidities, medical expenditures, economic outcomes, mortality, and quality-of-life came from published trials and studies supplemented with original research. Model validation followed International Society for Pharmacoeconomics and Outcomes Research practice guidelines. Among surviving adults, relative to a matched normal weight population, obese adults averaged $3900 higher medical expenditures in the initial year, growing to $4600 higher expenditures in year 10. Obese adults had higher initial prevalence and higher simulated onset of comorbidities as they aged. Over 10 years, excess medical expenditures attributed to obesity averaged $4280 annually-ranging from $2820 for obese category I to $5100 for obese category II, and $8710 for obese category III. Each excess kilogram of weight contributed to $140 higher annual costs, on average, ranging from $136 (obese I) to $152 (obese III). Poor health associated with obesity increased work absenteeism and mortality, and lowered employment probability, personal income, and quality-of-life. This validated model helps illustrate why obese adults have higher medical and indirect costs relative to normal weight adults, and shows that medical costs

  3. Automated economic analysis model for hazardous waste minimization

    International Nuclear Information System (INIS)

    Dharmavaram, S.; Mount, J.B.; Donahue, B.A.

    1990-01-01

    The US Army has established a policy of achieving a 50 percent reduction in hazardous waste generation by the end of 1992. To assist the Army in reaching this goal, the Environmental Division of the US Army Construction Engineering Research Laboratory (USACERL) designed the Economic Analysis Model for Hazardous Waste Minimization (EAHWM). The EAHWM was designed to allow the user to evaluate the life cycle costs for various techniques used in hazardous waste minimization and to compare them to the life cycle costs of current operating practices. The program was developed in C language on an IBM compatible PC and is consistent with other pertinent models for performing economic analyses. The potential hierarchical minimization categories used in EAHWM include source reduction, recovery and/or reuse, and treatment. Although treatment is no longer an acceptable minimization option, its use is widespread and has therefore been addressed in the model. The model allows for economic analysis for minimization of the Army's six most important hazardous waste streams. These include, solvents, paint stripping wastes, metal plating wastes, industrial waste-sludges, used oils, and batteries and battery electrolytes. The EAHWM also includes a general application which can be used to calculate and compare the life cycle costs for minimization alternatives of any waste stream, hazardous or non-hazardous. The EAHWM has been fully tested and implemented in more than 60 Army installations in the United States

  4. Schumpeterian economic dynamics as a quantifiable model of evolution

    Science.gov (United States)

    Thurner, Stefan; Klimek, Peter; Hanel, Rudolf

    2010-07-01

    We propose a simple quantitative model of Schumpeterian economic dynamics. New goods and services are endogenously produced through combinations of existing goods. As soon as new goods enter the market, they may compete against already existing goods. In other words, new products can have destructive effects on existing goods. As a result of this competition mechanism, existing goods may be driven out from the market—often causing cascades of secondary defects (Schumpeterian gales of destruction). The model leads to generic dynamics characterized by phases of relative economic stability followed by phases of massive restructuring of markets—which could be interpreted as Schumpeterian business 'cycles'. Model time series of product diversity and productivity reproduce several stylized facts of economics time series on long timescales, such as GDP or business failures, including non-Gaussian fat tailed distributions and volatility clustering. The model is phrased in an open, non-equilibrium setup which can be understood as a self-organized critical system. Its diversity dynamics can be understood by the time-varying topology of the active production networks.

  5. Simulation and validation of chemical-looping combustion using ASPEN plus

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ling [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States); Zhang, Zheming; Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

    2013-07-01

    Laboratory-scale experimental studies have demonstrated that Chemical-Looping Combustion (CLC) is an advanced technology which holds great potential for high-efficiency low-cost carbon capture. The generated syngas in CLC is subsequently oxidized to CO2 and H2O by reaction with an oxygen carrier. In this paper, process-level models of CLC are established in ASPEN Plus code for detailed simulations. The entire CLC process, from the beginning of coal gasification to reduction and oxidation of the oxygen carrier is modeled. The heat content of each major component such as fuel and air reactors and air/flue gas heat exchangers is carefully examined. Large amount of energy is produced in the fuel reactor, but energy needs to be supplied to the air reactor. The overall performance and efficiency of the modeled CLC systems are also evaluated.

  6. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    increases. But, tree growth response should be studied before any conclusions can be drawn regarding biomass production in the experiments. The similarities in plant response to Ashes+N and NPK suggests that Ashes+N can be used as a P and K resource in the fertilization of young stands of birch and hybrid aspen. If the Ashes+N treatment results in increased N availability due to the pH increase, possibly the N dose could be lowered in order to decrease the risks for N leaching without negative effects on tree N uptake. Tools for the prediction of N mineralization need to be developed. The energy harvest for fertilized birch and hybrid aspen appear to be at least as high as for fertilized Norway spruce. Intensive cultivation including fertilization of young stands appears to be energy efficient: the energy input is a small fraction of the increase in energy harvest. Residue based fertilization appears to be more energy efficient than fertilization with NPK. If production systems other than the ones currently applied are more efficient in terms of sustainable energy production it is important to review the funding of research and development within the field. Which species or species mixtures are most efficient under which soil and climatic condition? Management programs and harvesting techniques need to be developed. More studies on fertilization response and energy harvest in deciduous species with and without the use of residue based fertilizers are needed in order to develop guidelines for the sustainable production of forest bio energy. Empirical studies should be combined with modeling studies in order to improve the understanding of the systems and predictability of management measures. Residue based fertilization appears to be attractive both environmentally and economically, but it is important that such systems are evaluated closely in terms of growth response, nutrient leaching, carbon and metal balances, etc. in comparison with conventional fertilization

  7. Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

    Science.gov (United States)

    Mulligan, Kevin B.; Brown, Casey; Yang, Yi-Chen E.; Ahlfeld, David P.

    2014-03-01

    This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi-Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self-interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single-cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.

  8. A non-linear model of economic production processes

    Science.gov (United States)

    Ponzi, A.; Yasutomi, A.; Kaneko, K.

    2003-06-01

    We present a new two phase model of economic production processes which is a non-linear dynamical version of von Neumann's neoclassical model of production, including a market price-setting phase as well as a production phase. The rate of an economic production process is observed, for the first time, to depend on the minimum of its input supplies. This creates highly non-linear supply and demand dynamics. By numerical simulation, production networks are shown to become unstable when the ratio of different products to total processes increases. This provides some insight into observed stability of competitive capitalist economies in comparison to monopolistic economies. Capitalist economies are also shown to have low unemployment.

  9. Nonlinear Economic Model Predictive Control Strategy for Active Smart Buildings

    DEFF Research Database (Denmark)

    Santos, Rui Mirra; Zong, Yi; Sousa, Joao M. C.

    2016-01-01

    Nowadays, the development of advanced and innovative intelligent control techniques for energy management in buildings is a key issue within the smart grid topic. A nonlinear economic model predictive control (EMPC) scheme, based on the branch-and-bound tree search used as optimization algorithm ...... controller is shown very reliable keeping the comfort levels in the two considered seasons and shifting the load away from peak hours in order to achieve the desired flexible electricity consumption.......Nowadays, the development of advanced and innovative intelligent control techniques for energy management in buildings is a key issue within the smart grid topic. A nonlinear economic model predictive control (EMPC) scheme, based on the branch-and-bound tree search used as optimization algorithm...

  10. Economic model predictive control theory, formulations and chemical process applications

    CERN Document Server

    Ellis, Matthew; Christofides, Panagiotis D

    2017-01-01

    This book presents general methods for the design of economic model predictive control (EMPC) systems for broad classes of nonlinear systems that address key theoretical and practical considerations including recursive feasibility, closed-loop stability, closed-loop performance, and computational efficiency. Specifically, the book proposes: Lyapunov-based EMPC methods for nonlinear systems; two-tier EMPC architectures that are highly computationally efficient; and EMPC schemes handling explicitly uncertainty, time-varying cost functions, time-delays and multiple-time-scale dynamics. The proposed methods employ a variety of tools ranging from nonlinear systems analysis, through Lyapunov-based control techniques to nonlinear dynamic optimization. The applicability and performance of the proposed methods are demonstrated through a number of chemical process examples. The book presents state-of-the-art methods for the design of economic model predictive control systems for chemical processes. In addition to being...

  11. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    International Nuclear Information System (INIS)

    Bassyouni, M.; Waheed ul Hasan, Syed; Abdel-Aziz, M.H.; Abdel-hamid, S.M.-S.; Naveed, Shahid; Hussain, Ahmed; Ani, Farid Nasir

    2014-01-01

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO 2 and CH 4 in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H 2 = 56.27%, CO = 21.71%, CO 2 = 18.24%, CH 4 = 3.78%). Increasing steam to biomass ratio increases CO 2 and H 2 at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas

  12. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    Energy Technology Data Exchange (ETDEWEB)

    Bassyouni, M. [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Waheed ul Hasan, Syed [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Abdel-Aziz, M.H., E-mail: helmy2002@gmail.com [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt); Abdel-hamid, S. M.-S. [Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Naveed, Shahid [Punjab Institute of Contemporary Sciences, 5.5 KM Raiwind Road, Lahore (Pakistan); Hussain, Ahmed [Department of Nuclear Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ani, Farid Nasir [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, UTM 81310 Johor Bahru (Malaysia)

    2014-12-15

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO{sub 2} and CH{sub 4} in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H{sub 2} = 56.27%, CO = 21.71%, CO{sub 2} = 18.24%, CH{sub 4} = 3.78%). Increasing steam to biomass ratio increases CO{sub 2} and H{sub 2} at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas.

  13. Modeling hard clinical end-point data in economic analyses.

    Science.gov (United States)

    Kansal, Anuraag R; Zheng, Ying; Palencia, Roberto; Ruffolo, Antonio; Hass, Bastian; Sorensen, Sonja V

    2013-11-01

    The availability of hard clinical end-point data, such as that on cardiovascular (CV) events among patients with type 2 diabetes mellitus, is increasing, and as a result there is growing interest in using hard end-point data of this type in economic analyses. This study investigated published approaches for modeling hard end-points from clinical trials and evaluated their applicability in health economic models with different disease features. A review of cost-effectiveness models of interventions in clinically significant therapeutic areas (CV diseases, cancer, and chronic lower respiratory diseases) was conducted in PubMed and Embase using a defined search strategy. Only studies integrating hard end-point data from randomized clinical trials were considered. For each study included, clinical input characteristics and modeling approach were summarized and evaluated. A total of 33 articles (23 CV, eight cancer, two respiratory) were accepted for detailed analysis. Decision trees, Markov models, discrete event simulations, and hybrids were used. Event rates were incorporated either as constant rates, time-dependent risks, or risk equations based on patient characteristics. Risks dependent on time and/or patient characteristics were used where major event rates were >1%/year in models with fewer health states (Models of infrequent events or with numerous health states generally preferred constant event rates. The detailed modeling information and terminology varied, sometimes requiring interpretation. Key considerations for cost-effectiveness models incorporating hard end-point data include the frequency and characteristics of the relevant clinical events and how the trial data is reported. When event risk is low, simplification of both the model structure and event rate modeling is recommended. When event risk is common, such as in high risk populations, more detailed modeling approaches, including individual simulations or explicitly time-dependent event rates, are

  14. Estimation of Continuous Time Models in Economics: an Overview

    OpenAIRE

    Clifford R. Wymer

    2009-01-01

    The dynamics of economic behaviour is often developed in theory as a continuous time system. Rigorous estimation and testing of such systems, and the analysis of some aspects of their properties, is of particular importance in distinguishing between competing hypotheses and the resulting models. The consequences for the international economy during the past eighteen months of failures in the financial sector, and particularly the banking sector, make it essential that the dynamics of financia...

  15. Dynamic ecological-economic modeling approach for management of shellfish aquaculture

    CSIR Research Space (South Africa)

    Nobre, AM

    2008-02-01

    Full Text Available The objective of this report is to conceptualize ecological and economic interactions in mariculture; to implement a dynamic ecological-economic model in order to: simulate the socio-economics of aquaculture production, simulate its effects...

  16. An Economic Model of U.S. Airline Operating Expenses

    Science.gov (United States)

    Harris, Franklin D.

    2005-01-01

    This report presents a new economic model of operating expenses for 67 airlines. The model is based on data that the airlines reported to the United States Department of Transportation in 1999. The model incorporates expense-estimating equations that capture direct and indirect expenses of both passenger and cargo airlines. The variables and business factors included in the equations are detailed enough to calculate expenses at the flight equipment reporting level. Total operating expenses for a given airline are then obtained by summation over all aircraft operated by the airline. The model's accuracy is demonstrated by correlation with the DOT Form 41 data from which it was derived. Passenger airlines are more accurately modeled than cargo airlines. An appendix presents a concise summary of the expense estimating equations with explanatory notes. The equations include many operational and aircraft variables, which accommodate any changes that airline and aircraft manufacturers might make to lower expenses in the future. In 1999, total operating expenses of the 67 airlines included in this study amounted to slightly over $100.5 billion. The economic model reported herein estimates $109.3 billion.

  17. Investigation of international energy economics. [Use of econometric model EXPLOR

    Energy Technology Data Exchange (ETDEWEB)

    Deonigi, D.E.; Clement, M.; Foley, T.J.; Rao, S.A.

    1977-03-01

    The Division of International Affairs of the Energy Research and Development Administration is assessing the long-range economic effects of energy research and development programs in the U.S. and other countries, particularly members of the International Energy Agency (IEA). In support of this effort, a program was designed to coordinate the capabilities of five research groups--Rand, Virginia Polytechnic Institute, Brookhaven National Laboratory, Lawrence Livermore Laboratory, and Pacific Northwest Laboratory. The program could evaluate the international economics of proposed or anticipated sources of energy. This program is designed to be general, flexible, and capable of evaluating a diverse collection of potential energy (nuclear and nonnuclear) related problems. For example, the newly developed methodology could evaluate the international and domestic economic impact of nuclear-related energy sources, but also existing nonnuclear and potential energy sources such as solar, geothermal, wind, etc. Major items to be included would be the cost of exploration, cost of production, prices, profit, market penetration, investment requirements and investment goods, economic growth, change in balance of payments, etc. In addition, the changes in cost of producing all goods and services would be identified for each new energy source. PNL developed (1) a means of estimating the demands for major forms of energy by country, and (2) a means of identifying results or impacts on each country. The results for each country were then to be compared to assess relative advantages. PNL relied on its existing general econometric model, EXPLOR, to forecast the demand for energy by country. (MCW)

  18. Tax Compliance Models: From Economic to Behavioral Approaches

    Directory of Open Access Journals (Sweden)

    Larissa Margareta BĂTRÂNCEA

    2012-06-01

    Full Text Available The paper reviews the models of tax compliance with an emphasis on economic and behavioral perspectives. Although the standard tax evasion model of Allingham and Sandmo and other similar economic models capture some important aspects of tax compliance (i.e., taxpayers’ response to increases in tax rate, audit probability, penalty rate they do not suffice the need for an accurate prediction of taxpayers’ behavior. The reason is that they do not offer a comprehensive perspective on the sociological and psychological factors which shape compliance (i.e., attitudes, beliefs, norms, perceptions, motivations. Therefore, the researchers have considered examining taxpayers’ inner motivations, beliefs, perceptions, attitudes in order to accurately predict taxpayers’ behavior. As a response to their quest, behavioral models of tax compliance have emerged. Among the sociological and psychological factors which shape tax compliance, the ‘slippery slope’ framework singles out trust in authorities and the perception of the power of authorities. The aim of the paper is to contribute to the understanding of the reasons for which there is a need for a tax compliance model which incorporates both economic and behavioral features and why governments and tax authorities should consider these models when designing fiscal policies.

  19. Hybrid Aspen Response to Shearing in Minnesota: Implications for Biomass Production

    Science.gov (United States)

    Grant M. Domke; Andrew J. David; Anthony W. D' Amato; Alan R. Ek; Gary W. Wycoff

    2011-01-01

    There is great potential for the production of woody biomass feedstocks from hybrid aspen stands; however, little is known about the response of these systems to silvicultural treatments, such as shearing. We sought to address this need by integrating results from more than 20 years of individual tree and yield measurements in hybrid aspen (Populus tremuloides Mich. ×...

  20. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, Joseph N.T., E-mail: darbah@ohio.ed [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Department of Environmental and Plant Biology, Ohio University, 315 Porter Hall, Athens, OH 45701 (United States); Sharkey, Thomas D. [Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 (United States); Calfapietra, Carlo [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR), Via Salaria km 29300, 00016 Monterotondo Scalo, Roma (Italy); Karnosky, David F. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States)

    2010-04-15

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO{sub 2} and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO{sub 2} protected photosynthesis of both species against moderate heat stress. Elevated CO{sub 2} increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO{sub 2} treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO{sub 2} were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO{sub 2}. Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO{sub 2} confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  1. Nest-site selection and nest survival of Lewis's woodpecker in aspen riparian woodlands

    Science.gov (United States)

    Karen R. Newlon; Victoria A. Saab

    2011-01-01

    Riparian woodlands of aspen (Populus tremuloides) provide valuable breeding habitat for several cavity-nesting birds. Although anecdotal information for this habitat is available for Lewis's Woodpecker (Melanerpes lewis), no study has previously examined the importance of aspen woodlands to this species' breeding biology. From 2002 to 2004, we monitored 76...

  2. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca

    2015-01-01

    quality were all invariant to the reaction temperature. By increasing the crude glycerol to aspen wood mass ratio from 0:1 to 3:1, char yield was decreased from 18.3% (only aspen wood) to 3.4%. Furthermore, the biocrude quality in terms of the effective hydrogen-to-carbon ratio (H/Ceff) was significantly...

  3. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Sharkey, Thomas D.; Calfapietra, Carlo; Karnosky, David F.

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO 2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO 2 protected photosynthesis of both species against moderate heat stress. Elevated CO 2 increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO 2 treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO 2 were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO 2 . Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO 2 confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  4. The aspen mortality summit; December 18 and 19, 2006; Salt Lake City, UT

    Science.gov (United States)

    Dale L. Bartos; Wayne D. Shepperd

    2010-01-01

    The USDA Forest Service Rocky Mountain Research Station sponsored an aspen summit meeting in Salt Lake City, Utah, on December 18 and19, 2006, to discuss the rapidly increasing mortality of aspen (Populus tremuloides) throughout the western United States. Selected scientists, university faculty, and managers from Federal, State, and non-profit agencies with experience...

  5. Differential response of Aspen and Birch trees to heat stress under elevated carbon dioxide

    Science.gov (United States)

    Joseph N.T. Darbah; Thomas D. Sharkey; Carlo Calfapietra; David F. Karnosky

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO2 protected photosynthesis of both species against moderate heat stress. Elevated CO...

  6. Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

    Science.gov (United States)

    Buck, Joshua R; St Clair, Samuel B

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

  7. Factors influencing epiphytic lichen communities in aspen-associated forests of the Bear River Range, Idaho and Utah

    Science.gov (United States)

    Paul C. Rogers

    2007-01-01

    In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing...

  8. 76 FR 69279 - Notice of Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy...

    Science.gov (United States)

    2011-11-08

    ... Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy Project, Wyoming... Statement (EIS) for the Quaking Aspen Wind Energy Project (Quaking Aspen). By this notice, BLM is: (1..._Wind_Energy[email protected] ; or Mail: 280 Highway 191 N., Rock Springs, WY 82901. Documents pertinent to...

  9. Allozyme and microsatellite data reveal small clone size and high genetic diversity in aspen in the southern Cascade Mountains

    Science.gov (United States)

    Jennifer DeWoody; Thomas H. Rickman; Bobette E. Jones; Valerie D. Hipkins

    2009-01-01

    The most widely distributed tree in North America, quaking aspen (Populus tremuloides, Michx.), reproduces sexually via seed and clonally via suckers. The size of aspen clones varies geographically, generally smaller in the east and large in the arid Intermountain West. In order to describe clone size and genetic structure of aspen in the southern Cascade...

  10. Habitone analysis of quaking aspen in the Utah Book Cliffs: Effects of site water demand and conifer cover

    Science.gov (United States)

    Joseph O. Sexton; R. Douglas Ramsey; Dale L. Bartos

    2006-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America, but its presence is declining across much of the Western United States. Aspen decline is complex, but results largely from two factors widely divergent in temporal scale: (1) Holocene climatic drying of the region has led to water limitation of aspen seedling...

  11. A model to determine the economic viability of water fluoridation.

    Science.gov (United States)

    Kroon, Jeroen; van Wyk, Philippus Johannes

    2012-01-01

    In view of concerns expressed by South African local authorities the aim of this study was to develop a model to determine whether water fluoridation is economically viable to reduce dental caries in South Africa. Microsoft Excel software was used to develop a model to determine economic viability of water fluoridation for 17 water providers from all nine South African provinces. Input variables for this model relate to chemical cost, labor cost, maintenance cost of infrastructure, opportunity cost, and capital depreciation. The following output variables were calculated to evaluate the cost of water fluoridation: per capita cost per year, cost-effectiveness and cost-benefit. In this model it is assumed that the introduction of community water fluoridation can reduce caries prevalence by an additional 15 percent and that the savings in cost of treatment will be equal to the average fee for a two surface restoration. Water providers included in the study serve 53.5 percent of the total population of South Africa. For all providers combined chemical cost contributes 64.5 percent to the total cost, per capita cost per year was $0.36, cost-effectiveness was calculated as $11.41 and cost-benefit of the implementation of water fluoridation was 0.34. This model confirmed that water fluoridation is an economically viable option to prevent dental caries in South African communities, as well as conclusions over the last 10 years that water fluoridation leads to significant cost savings and remains a cost-effective measure for reducing dental caries, even when the caries-preventive effectiveness is modest. © 2012 American Association of Public Health Dentistry.

  12. Mathematical modeling in economics, ecology and the environment

    CERN Document Server

    Hritonenko, Natali

    2013-01-01

    Updated to textbook form by popular demand, this second edition discusses diverse mathematical models used in economics, ecology, and the environmental sciences with emphasis on control and optimization. It is intended for graduate and upper-undergraduate course use, however, applied mathematicians, industry practitioners, and a vast number of interdisciplinary academics will find the presentation highly useful. Core topics of this text are: ·         Economic growth and technological development ·         Population dynamics and human impact on the environment ·         Resource extraction and scarcity ·         Air and water contamination ·         Rational management of the economy and environment ·         Climate change and global dynamics The step-by-step approach taken is problem-based and easy to follow. The authors aptly demonstrate that the same models may be used to describe different economic and environmental processes and that similar invest...

  13. Financial Transaction Tax: Determination of Economic Impact Under DSGE Model

    Directory of Open Access Journals (Sweden)

    Veronika Solilová

    2015-01-01

    Full Text Available The discussion about the possible taxation of the financial sector has started in the European Union as a result of the financial crisis which has spread to the Europe from the United States in 2008 and consequently of the massive financial interventions by governments made in favour of the financial sector. On 14 February 2013, after rejection of the draft of the directive introducing a common system of financial transaction tax in 2011, the European Commission introduced the financial transaction tax through enhanced cooperation. The aim of the paper is to research economic impact of financial transaction tax on EU (EU27 or EU11 with respect to the DSGE model which was used for the determination of impacts. Based on our analysis the DSGE model can be considered as underestimated in case of the impact on economic growth and an overestimated in case of the revenue collection. Particularly, the overall impact of the financial transaction tax considering cascade effects of securities (tax rate 2.2% and derivatives (tax rate 0.2% is ranged between −4.752 and 1.472 percent points of GDP. And further, is assumed that the relocation effects of business/trade can be in average 40% causes a decline of expected tax revenues in the amount of 13bn EUR. Thus, at a time of fragile economic growth across the EU and the increased risk of recession in Europe, the introduction of the FTT should be undesirable.

  14. Electric vehicle charge planning using Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus; Poulsen, Niels K.; Madsen, Henrik

    2012-01-01

    Economic Model Predictive Control (MPC) is very well suited for controlling smart energy systems since electricity price and demand forecasts are easily integrated in the controller. Electric vehicles (EVs) are expected to play a large role in the future Smart Grid. They are expected to provide...... grid services, both for peak reduction and for ancillary services, by absorbing short term variations in the electricity production. In this paper the Economic MPC minimizes the cost of electricity consumption for a single EV. Simulations show savings of 50–60% of the electricity costs compared...... to uncontrolled charging from load shifting based on driving pattern predictions. The future energy system in Denmark will most likely be based on renewable energy sources e.g. wind and solar power. These green energy sources introduce stochastic fluctuations in the electricity production. Therefore, energy...

  15. CLUSTERS AS A MODEL OF ECONOMIC DEVELOPMENT OF SERBIA

    Directory of Open Access Journals (Sweden)

    Marko Laketa

    2013-12-01

    Full Text Available Insufficient competitiveness of small and medium enterprises in Serbia can be significantly improved by a system of business associations through clusters, business incubators and technology parks. This connection contributes to the growth and development of not only the cluster members, but has a regional and national dimension as well because without it there is no significant breakthrough on the international market. The process of association of small and medium enterprises in clusters and other forms of interconnection in Serbia is far from the required and potential level.The awareness on the importance of clusters in a local economic development through contributions to the advancement of small and medium sized enterprises is not yet sufficiently mature. Support to associating into clusters and usage of their benefits after the model of highly developed countries is the basis for leading a successful economic policy and in Serbia there are all necessary prerequisites for it.

  16. Toward linking demographic and economic models for impact assessment

    International Nuclear Information System (INIS)

    Williams, C.A.; Meenan, C.D.

    1991-01-01

    One of the objectives of the Yucca Mountain Project, in Southern Nevada, is to evaluate the effects of the development of a high-level nuclear waste repository. As described in the Section 175 Report to the Congress of the US, the temporal scope of this repository project encompasses approximately 70 years and includes four phases: Site characterization and licensing, construction, operation, and closure and decommissioning. If retrieval of the waste were to be required, the temporal scope of the repository project could be extended to approximately 100 years. The study of the potential socioeconomic effects of this project is the foundation for this paper. This paper focuses on the economic and demographic aspects and a possible method to interface the two. First, the authors briefly discuss general socioeconomic modeling theory from a county level view point, as well as methods for the apportionment of county level data to sub-county areas. Next, the authors describe the unique economic and demographic conditions which exist in Nevada at both the state and county levels. Finally, the authors evaluate a possible procedure for analyzing repository effects at a sub-county level; this involves discussion of an interface linking the economic and demographic aspects, which is based on the reconciliation of supply and demand for labor. The authors conclude that the basis for further model development may rely on the interaction of supply and demand to produce change in wage rates. These changes in expected wages should be a justification for allocating economic migrants (who may respond to Yucca Mountain Project development) into various communities

  17. Unification and mechanistic detail as drivers of model construction: models of networks in economics and sociology.

    Science.gov (United States)

    Kuorikoski, Jaakko; Marchionni, Caterina

    2014-12-01

    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant.

  18. Clinical laboratory as an economic model for business performance analysis.

    Science.gov (United States)

    Buljanović, Vikica; Patajac, Hrvoje; Petrovecki, Mladen

    2011-08-15

    To perform SWOT (strengths, weaknesses, opportunities, and threats) analysis of a clinical laboratory as an economic model that may be used to improve business performance of laboratories by removing weaknesses, minimizing threats, and using external opportunities and internal strengths. Impact of possible threats to and weaknesses of the Clinical Laboratory at Našice General County Hospital business performance and use of strengths and opportunities to improve operating profit were simulated using models created on the basis of SWOT analysis results. The operating profit as a measure of profitability of the clinical laboratory was defined as total revenue minus total expenses and presented using a profit and loss account. Changes in the input parameters in the profit and loss account for 2008 were determined using opportunities and potential threats, and economic sensitivity analysis was made by using changes in the key parameters. The profit and loss account and economic sensitivity analysis were tools for quantifying the impact of changes in the revenues and expenses on the business operations of clinical laboratory. Results of simulation models showed that operational profit of €470 723 in 2008 could be reduced to only €21 542 if all possible threats became a reality and current weaknesses remained the same. Also, operational gain could be increased to €535 804 if laboratory strengths and opportunities were utilized. If both the opportunities and threats became a reality, the operational profit would decrease by €384 465. The operational profit of the clinical laboratory could be significantly reduced if all threats became a reality and the current weaknesses remained the same. The operational profit could be increased by utilizing strengths and opportunities as much as possible. This type of modeling may be used to monitor business operations of any clinical laboratory and improve its financial situation by implementing changes in the next fiscal

  19. Clinical laboratory as an economic model for business performance analysis

    Science.gov (United States)

    Buljanović, Vikica; Patajac, Hrvoje; Petrovečki, Mladen

    2011-01-01

    Aim To perform SWOT (strengths, weaknesses, opportunities, and threats) analysis of a clinical laboratory as an economic model that may be used to improve business performance of laboratories by removing weaknesses, minimizing threats, and using external opportunities and internal strengths. Methods Impact of possible threats to and weaknesses of the Clinical Laboratory at Našice General County Hospital business performance and use of strengths and opportunities to improve operating profit were simulated using models created on the basis of SWOT analysis results. The operating profit as a measure of profitability of the clinical laboratory was defined as total revenue minus total expenses and presented using a profit and loss account. Changes in the input parameters in the profit and loss account for 2008 were determined using opportunities and potential threats, and economic sensitivity analysis was made by using changes in the key parameters. The profit and loss account and economic sensitivity analysis were tools for quantifying the impact of changes in the revenues and expenses on the business operations of clinical laboratory. Results Results of simulation models showed that operational profit of €470 723 in 2008 could be reduced to only €21 542 if all possible threats became a reality and current weaknesses remained the same. Also, operational gain could be increased to €535 804 if laboratory strengths and opportunities were utilized. If both the opportunities and threats became a reality, the operational profit would decrease by €384 465. Conclusion The operational profit of the clinical laboratory could be significantly reduced if all threats became a reality and the current weaknesses remained the same. The operational profit could be increased by utilizing strengths and opportunities as much as possible. This type of modeling may be used to monitor business operations of any clinical laboratory and improve its financial situation by

  20. Recovering aspen follow changing elk dynamics in Yellowstone: evidence of a trophic cascade?

    Science.gov (United States)

    Painter, Luke E; Beschta, Robert L; Larsen, Eric J; Ripple, William J

    2015-01-01

    To investigate the extent and causes of recent quaking aspen (Populus tremuloides) recruitment in northern Yellowstone National Park, we measured browsing intensity and height of young aspen in 87 randomly selected aspen stands in 2012, and compared our results to similar data collected in 1997-1998. We also examined the relationship between aspen recovery and the distribution of Rocky Mountain elk (Cervus elaphus) and bison (Bison bison) on the Yellowstone northern ungulate winter range, using ungulate fecal pile densities and annual elk count data. In 1998, 90% of young aspen were browsed and none were taller-than 200 cm, the height at which aspen begin to escape from elk browsing. In 2012, only 37% in the east and 63% in the west portions of the winter range were browsed, and 65% of stands in the east had young aspen taller than 200 cm. Heights of young aspen were inversely related to browsing intensity, with the least browsing and greatest heights in the eastern portion of the range, corresponding with recent changes in elk density and distribution. In contrast with historical elk distribution (1930s-1990s), the greatest densities of elk recently (2006-2012) have been north of the park boundary (approximately 5 elk/km2), and in the western part of the range (2-4 elk/km2), with relatively few elk in the eastern portion of the range (wolves (Canis lupius) in 1995-1996 played a role in these changing elk population dynamics, interacting with other influences including increased predation by bears (Ursus spp.), competition with an expanding bison population, and shifting patterns of human land use and hunting outside the park. The resulting new aspen recruitment is evidence of a landscape-scale trophic cascade in which a resurgent large carnivore community, combined with other ecological changes, has benefited aspen through effects on ungulate prey.

  1. Modelling the economic consequences of Marine Protected Areas using the BEMCOM model

    DEFF Research Database (Denmark)

    Hoff, A.; Andersen, J.L.; Christensen, Asbjørn

    2013-01-01

    the question ‘what’s best?’, i.e. finds the overall optimal effort allocation, from an economic point of view, between multiple harvesting fleets fishing under a subset of restrictions on catches and effort levels. The BEMCOM model is described and applied to the case of the Danish sandeel fishery in the North......This paper introduces and describes in detail the bioeconomic optimization model BEMCOM (BioEconomic Model to evaluate the COnsequences of Marine protected areas) that has been developed to assess the economic effects of introducing Marine Protected Areas (MPA) for fisheries. BEMCOM answers...... Sea. It has several times been suggested to close parts of the sandeel fishery in the North Sea out of concern for other species feeding on sandeel and/or spawning in the sandeel habitats. The economic effects of such closures have been assessed using BEMCOM. The results indicate that the model yields...

  2. Direct regional energy/economic modeling (DREEM) design

    Energy Technology Data Exchange (ETDEWEB)

    Hall, P.D.; Pleatsikas, C.J.

    1979-10-01

    This report summarizes an investigation into the use of regional and multiregional economic models for estimating the indirect and induced impacts of Federally-mandated energy policies. It includes an examination of alternative types of energy policies that can impact regional economies and the available analytical frameworks for measuring the magnitudes and spatial extents of these impacts. One such analytical system, the National Regional Impact Evaluation System (NRIES), currently operational in the Bureau of Economic Analysis (BEA), is chosen for more detailed investigation. The report summarizes the models capabilities for addressing various energy policy issues and then demonstrates the applicability of the model in specified contexts by developing appropriate input data for three scenarios. These scenarios concern the multi-state impacts of alternative coal-mining-development decisions, multi-regional impacts of macroeconomic change, and the comprehensive effects of an alternative national energy supply trajectory. On the basis of this experience, the capabilities of NRIES for analyzing energy-policy issues are summarized in a concluding chapter.

  3. Empirical Bayes Credibility Models for Economic Catastrophic Losses by Regions

    Directory of Open Access Journals (Sweden)

    Jindrová Pavla

    2017-01-01

    Full Text Available Catastrophic events affect various regions of the world with increasing frequency and intensity. The number of catastrophic events and the amount of economic losses is varying in different world regions. Part of these losses is covered by insurance. Catastrophe events in last years are associated with increases in premiums for some lines of business. The article focus on estimating the amount of net premiums that would be needed to cover the total or insured catastrophic losses in different world regions using Bühlmann and Bühlmann-Straub empirical credibility models based on data from Sigma Swiss Re 2010-2016. The empirical credibility models have been developed to estimate insurance premiums for short term insurance contracts using two ingredients: past data from the risk itself and collateral data from other sources considered to be relevant. In this article we deal with application of these models based on the real data about number of catastrophic events and about the total economic and insured catastrophe losses in seven regions of the world in time period 2009-2015. Estimated credible premiums by world regions provide information how much money in the monitored regions will be need to cover total and insured catastrophic losses in next year.

  4. Partial differential equation models in the socio-economic sciences.

    Science.gov (United States)

    Burger, Martin; Caffarelli, Luis; Markowich, Peter A

    2014-11-13

    Mathematical models based on partial differential equations (PDEs) have become an integral part of quantitative analysis in most branches of science and engineering, recently expanding also towards biomedicine and socio-economic sciences. The application of PDEs in the latter is a promising field, but widely quite open and leading to a variety of novel mathematical challenges. In this introductory article of the Theme Issue, we will provide an overview of the field and its recent boosting topics. Moreover, we will put the contributions to the Theme Issue in an appropriate perspective. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  5. A mean-field game economic growth model

    KAUST Repository

    Gomes, Diogo A.

    2016-08-05

    Here, we examine a mean-field game (MFG) that models the economic growth of a population of non-cooperative, rational agents. In this MFG, agents are described by two state variables - the capital and consumer goods they own. Each agent seeks to maximize his/her utility by taking into account statistical data about the whole population. The individual actions drive the evolution of the players, and a market-clearing condition determines the relative price of capital and consumer goods. We study the existence and uniqueness of optimal strategies of the agents and develop numerical methods to compute these strategies and the equilibrium price.

  6. Germany's socio-economic model and the Euro crisis

    Directory of Open Access Journals (Sweden)

    Michael Dauderstädt

    2013-03-01

    Full Text Available Germany's socio-economic model, the "social market economy", was established in West Germany after World War II and extended to the unified Germany in 1990. During a prolonged recession after the adoption of the Euro in 1998, major reforms (Agenda 2010 were introduced which many consider as the key of Germany's recent success. The reforms had mixed results: employment increased but has consisted to a large extent of precarious low-wage jobs. Growth depended on export surpluses based on an internal real devaluation (low unit labour costs which make Germany vulnerable to global recessions as in 2009. Overall inequality increased substantially.

  7. Partial differential equation models in the socio-economic sciences

    KAUST Repository

    Burger, Martin

    2014-10-06

    Mathematical models based on partial differential equations (PDEs) have become an integral part of quantitative analysis in most branches of science and engineering, recently expanding also towards biomedicine and socio-economic sciences. The application of PDEs in the latter is a promising field, but widely quite open and leading to a variety of novel mathematical challenges. In this introductory article of the Theme Issue, we will provide an overview of the field and its recent boosting topics. Moreover, we will put the contributions to the Theme Issue in an appropriate perspective.

  8. ANALYSIS OF ECONOMIC MODELS OF POTATO PRODUCTION IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Miomir JOVANOVIC

    2014-04-01

    Full Text Available The northern region of Montenegro represents a very important resource for agricultural production. However, the depopulation of the analysed area, pronounced in-kind character of production without significant participation of market producers, lack of market research, stronger vertical and horizontal connection between primary production and processing sectors have significant impacts causing the low level of competitiveness of agricultural production. Potato production in the analysed area has recorded positive trends in last ten years. This paper presents economic models of agriculture households on the analysed area from the potatoes production point of view.

  9. Economic man as model man: Ideal types, idealization and caricatures

    NARCIS (Netherlands)

    Morgan, M.S.

    2006-01-01

    Economics revolves around a central character: "economic man." As historians, we are all familiar with various episodes in the history of this character, and we appreciate his ever-changing aspect even while many of our colleagues in economics think the rational economic agent of neoclassical

  10. Process model economics of xanthan production from confectionery industry wastewaters.

    Science.gov (United States)

    Bajić, Bojana Ž; Vučurović, Damjan G; Dodić, Siniša N; Grahovac, Jovana A; Dodić, Jelena M

    2017-12-01

    In this research a process and cost model for a xanthan production facility was developed using process simulation software (SuperPro Designer ® ). This work represents a novelty in the field for two reasons. One is that xanthan gum has been produced from several wastes but never from wastewaters from confectionery industries. The other more important is that the aforementioned software, which in intended exclusively for bioprocesses, is used for generating a base case, i.e. starting point for transferring the technology to industrial scales. Previously acquired experimental knowledge about using confectionery wastewaters from five different factories as substitutes for commercially used cultivation medium have been incorporated into the process model in order to obtain an economic viability of implementing such substrates. A lower initial sugar content in the medium based on wastewater (28.41 g/L) compared to the synthetic medium (30.00 g/L) gave a lower xanthan content at the end of cultivation (23.98 and 26.27 g/L, respectively). Although this resulted in somewhat poorer economic parameters, they were still in the range of being an investment of interest. Also the possibility of utilizing a cheap resource (waste) and reducing pollution that would result from its disposal has a positive effect on the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. OBJECT ORIENTED MODELLING, A MODELLING METHOD OF AN ECONOMIC ORGANIZATION ACTIVITY

    Directory of Open Access Journals (Sweden)

    TĂNĂSESCU ANA

    2014-05-01

    Full Text Available Now, most economic organizations use different information systems types in order to facilitate their activity. There are different methodologies, methods and techniques that can be used to design information systems. In this paper, I propose to present the advantages of using the object oriented modelling at the information system design of an economic organization. Thus, I have modelled the activity of a photo studio, using Visual Paradigm for UML as a modelling tool. For this purpose, I have identified the use cases for the analyzed system and I have presented the use case diagram. I have, also, realized the system static and dynamic modelling, through the most known UML diagrams.

  12. Economic Model Predictive Control for Spray Drying Plants

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert

    and a complexity reduced control model is used for state estimation and prediction in the controllers. These models facilitate development and comparison of control strategies. We develop two MPC strategies; a linear tracking MPC with a Real-Time Optimization layer (MPC with RTO) and an Economic Nonlinear MPC (E...... horizon, out of which only the first input is applied to the dryer. This procedure is repeated at each sample instant and is solved numerically in real-time. The MPC with RTO tracks a target that optimizes the cost of operation at steady-state. The E-MPC optimizes the cost of operation directly by having...... this objective directly in the controller. The need for the RTO layer is then eliminated. We demonstrate the application of the proposed MPC with RTO to control an industrial GEA MSDTM-1250 spray dryer, which produces approximately 7500 kg/hr of enriched milk powder. Compared to the conventional PI controller...

  13. Risk reserve constrained economic dispatch model with wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, W.; Sun, H.; Peng, Y. [Department of Electrical and Electronics Engineering, Dalian University of Technology, Dalian, 116024 (China)

    2010-12-15

    This paper develops a modified economic dispatch (ED) optimization model with wind power penetration. Due to the uncertain nature of wind speed, both overestimation and underestimation of the available wind power are compensated using the up and down spinning reserves. In order to determine both of these two reserve demands, the risk-based up and down spinning reserve constraints are presented considering not only the uncertainty of available wind power, but also the load forecast error and generator outage rates. The predictor-corrector primal-dual interior point method is utilized to solve the proposed ED model. Simulation results of a system with ten conventional generators and one wind farm demonstrate the effectiveness of the proposed method. (authors)

  14. Economic implications of Japan's aging population: a macro-economic demographic modeling approach.

    Science.gov (United States)

    Ogawa, N

    1982-01-01

    This paper utilizes a macroeconomic demographic model to analyze the probable impact of population aging on various public programs in Japan. Rapid fertility decline aided by mortality decline has caused the proportion of the Japanese population aged 65 and over to increase from 4.9% in 1950 to 9.0% in 1980. A population projection based on the 1975 population census assumes a recovery of fertility from a total fertility rate (TFR) of 1.9 in 1976 to 2.16 in 1980 and a gradual decline to 2.1 by 1987, while an alternative projection assumes a continuing fertility decline to a TFR of 1.65 in 2025. According to these assumptions, in 2025 18.12% to 21.29% of the total population would be aged 65 or over and 38.66% to 43.80% of the working age population would be aged 45-64. A macroeconomic neoclassical growth model with some Keynesian features was formulated to evaluate the future impact of population aging on social security programs. Population changes are transmitted to economic variables in the model through the supply of labor, level of savings, public health care plans, and old-age pension schemes. The simulation experiments included the 2 population projections and 2 alternative production functions, 1 with the quality of labor incorporated and 1 without. The results indicated that, regardless of the population projection and production function used, the growth of the economy is likely to slow to 1 or 0% in the beginning of the next century due to decreased growth of the labor force and a change in its quality due to age-compositional variations. Public health insurance schemes and pension plans will require increasing financial resources as a result of accelerated population aging; depending on the choice of benefit levels, the proportion of national income allocated to them is expected to range from 14%-40% in the year 2010. Per capita gross national product will continue to grow despite decreased economic growth, but savings might be adversely affected if the

  15. Applied economic model development algorithm for electronics company

    Directory of Open Access Journals (Sweden)

    Mikhailov I.

    2017-01-01

    Full Text Available The purpose of this paper is to report about received experience in the field of creating the actual methods and algorithms that help to simplify development of applied decision support systems. It reports about an algorithm, which is a result of two years research and have more than one-year practical verification. In a case of testing electronic components, the time of the contract conclusion is crucial point to make the greatest managerial mistake. At this stage, it is difficult to achieve a realistic assessment of time-limit and of wage-fund for future work. The creation of estimating model is possible way to solve this problem. In the article is represented an algorithm for creation of those models. The algorithm is based on example of the analytical model development that serves for amount of work estimation. The paper lists the algorithm’s stages and explains their meanings with participants’ goals. The implementation of the algorithm have made possible twofold acceleration of these models development and fulfilment of management’s requirements. The resulting models have made a significant economic effect. A new set of tasks was identified to be further theoretical study.

  16. Eliciting expert opinion for economic models: an applied example.

    Science.gov (United States)

    Leal, José; Wordsworth, Sarah; Legood, Rosa; Blair, Edward

    2007-01-01

    Expert opinion is considered as a legitimate source of information for decision-analytic modeling where required data are unavailable. Our objective was to develop a practical computer-based tool for eliciting expert opinion about the shape of the uncertainty distribution around individual model parameters. We first developed a prepilot survey with departmental colleagues to test a number of alternative approaches to eliciting opinions on the shape of the uncertainty distribution around individual parameters. This information was used to develop a survey instrument for an applied clinical example. This involved eliciting opinions from experts to inform a number of parameters involving Bernoulli processes in an economic model evaluating DNA testing for families with a genetic disease, hypertrophic cardiomyopathy. The experts were cardiologists, clinical geneticists, and laboratory scientists working with cardiomyopathy patient populations and DNA testing. Our initial prepilot work suggested that the more complex elicitation techniques advocated in the literature were difficult to use in practice. In contrast, our approach achieved a reasonable response rate (50%), provided logical answers, and was generally rated as easy to use by respondents. The computer software user interface permitted graphical feedback throughout the elicitation process. The distributions obtained were incorporated into the model, enabling the use of probabilistic sensitivity analysis. There is clearly a gap in the literature between theoretical elicitation techniques and tools that can be used in applied decision-analytic models. The results of this methodological study are potentially valuable for other decision analysts deriving expert opinion.

  17. Global economic consequences of selected surgical diseases: a modelling study.

    Science.gov (United States)

    Alkire, Blake C; Shrime, Mark G; Dare, Anna J; Vincent, Jeffrey R; Meara, John G

    2015-04-27

    The surgical burden of disease is substantial, but little is known about the associated economic consequences. We estimate the global macroeconomic impact of the surgical burden of disease due to injury, neoplasm, digestive diseases, and maternal and neonatal disorders from two distinct economic perspectives. We obtained mortality rate estimates for each disease for the years 2000 and 2010 from the Institute of Health Metrics and Evaluation Global Burden of Disease 2010 study, and estimates of the proportion of the burden of the selected diseases that is surgical from a paper by Shrime and colleagues. We first used the value of lost output (VLO) approach, based on the WHO's Projecting the Economic Cost of Ill-Health (EPIC) model, to project annual market economy losses due to these surgical diseases during 2015-30. EPIC attempts to model how disease affects a country's projected labour force and capital stock, which in turn are related to losses in economic output, or gross domestic product (GDP). We then used the value of lost welfare (VLW) approach, which is conceptually based on the value of a statistical life and is inclusive of non-market losses, to estimate the present value of long-run welfare losses resulting from mortality and short-run welfare losses resulting from morbidity incurred during 2010. Sensitivity analyses were performed for both approaches. During 2015-30, the VLO approach projected that surgical conditions would result in losses of 1·25% of potential GDP, or $20·7 trillion (2010 US$, purchasing power parity) in the 128 countries with data available. When expressed as a proportion of potential GDP, annual GDP losses were greatest in low-income and middle-income countries, with up to a 2·5% loss in output by 2030. When total welfare losses are assessed (VLW), the present value of economic losses is estimated to be equivalent to 17% of 2010 GDP, or $14·5 trillion in the 175 countries assessed with this approach. Neoplasm and injury account

  18. Inventory of aspen trees in spruce dominated stands in conservation area

    Directory of Open Access Journals (Sweden)

    Matti Maltamo

    2015-05-01

    Full Text Available Background The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes: volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning (ALS data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots (5–10 to values of 25%–50% with 10 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our

  19. The physical and mathematical model of dynamic economic analysis and assessment for NPP

    International Nuclear Information System (INIS)

    Xu Jiming

    1992-01-01

    A set physical and mathematical model of dynamic economic analysis referring to international general sub-item and account of investment and constant money levelized model and combining current economic analysis method in China for nuclear power plant was established. The model can be used in economic analysis not only for nuclear power plant but also for coal-fired power plant and can satisfy demand of doing economic analysis and assessment for nuclear power plant and conventional power plant

  20. Agricultural climate impacts assessment for economic modeling and decision support

    Science.gov (United States)

    Thomson, A. M.; Izaurralde, R. C.; Beach, R.; Zhang, X.; Zhao, K.; Monier, E.

    2013-12-01

    A range of approaches can be used in the application of climate change projections to agricultural impacts assessment. Climate projections can be used directly to drive crop models, which in turn can be used to provide inputs for agricultural economic or integrated assessment models. These model applications, and the transfer of information between models, must be guided by the state of the science. But the methodology must also account for the specific needs of stakeholders and the intended use of model results beyond pure scientific inquiry, including meeting the requirements of agencies responsible for designing and assessing policies, programs, and regulations. Here we present methodology and results of two climate impacts studies that applied climate model projections from CMIP3 and from the EPA Climate Impacts and Risk Analysis (CIRA) project in a crop model (EPIC - Environmental Policy Indicator Climate) in order to generate estimates of changes in crop productivity for use in an agricultural economic model for the United States (FASOM - Forest and Agricultural Sector Optimization Model). The FASOM model is a forward-looking dynamic model of the US forest and agricultural sector used to assess market responses to changing productivity of alternative land uses. The first study, focused on climate change impacts on the UDSA crop insurance program, was designed to use available daily climate projections from the CMIP3 archive. The decision to focus on daily data for this application limited the climate model and time period selection significantly; however for the intended purpose of assessing impacts on crop insurance payments, consideration of extreme event frequency was critical for assessing periodic crop failures. In a second, coordinated impacts study designed to assess the relative difference in climate impacts under a no-mitigation policy and different future climate mitigation scenarios, the stakeholder specifically requested an assessment of a

  1. Anticipating the uncertain: economic modeling and climate change policy

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Svenn

    2012-11-01

    With this thesis I wish to contribute to the understanding of how uncertainty and the anticipation of future events by economic actors affect climate policies. The thesis consists of four papers. Two papers are analytical models which explicitly consider that emissions are caused by extracting scarce fossil fuels which in the future must be replaced by clean technologies. The other two are so called numerical integrated assessment models. Such models represent the world economy, the climate system and the interactions between those two quantitatively, complementing more abstract theoretical work. Should policy makers discriminate between subsidizing renewable energy sources such as wind or solar power, and technologies such as carbon capture and storage (CCS)? Focusing only on the dynamic supply of fossil fuels and hence Co{sub 2}, we find here that cheaper future renewables cause extraction to speed up, lower costs of CCS may delay it. CCS hence may dampen the dynamic inefficiency caused by the absence of comprehensive climate policies today. Does it matter whether uncertainty about future damage assessment is due to scientific complexities or stems from the political process? In paper two, I find that political and scientific uncertainties have opposing effects on the incentives to investment in renewables and the extraction of fossil fuels: The prospect of scientific learning about the climate system increases investment incentives and, ceteris paribus, slows extraction down; uncertainty about future political constellations does the opposite. The optimal carbon tax under scientific uncertainty equals expected marginal damages, whereas political uncertainty demands a tax below marginal damages that decreases over time. Does uncertainty about economic growth impact optimal climate policy today? Here we are the first to consistently analyze how uncertainty about future economic growth affects optimal emission reductions and the optimal social cost of carbon. We

  2. 2012 Aspen Winter Conference New Paradigms for Low-Dimensional Electronic Materials, February 5-10, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Joel; Rabe, Karin; Nayak, Chetan; Troyer, Matthias

    2012-05-01

    Aspen Center for Physics Project Summary DOE Budget Period: 10/1/2011 to 9/30/2012 Contract # DE-SC0007479 New Paradigms for Low-Dimensional Electronic Materials The 2012 Aspen Winter Conference on Condensed Matter Physics was held at the Aspen Center for Physics from February 5 to 10, 2012. Seventy-four participants from seven countries, and several universities and national labs attended the workshop titled, New Paradigms for Low-Dimensional Electronic Materials. There were 34 formal talks, and a number of informal discussions held during the week. Talks covered a variety of topics related to DOE BES priorities, including, for example, advanced photon techniques (Hasan, Abbamonte, Orenstein, Shen, Ghosh) and predictive theoretical modeling of materials properties (Rappe, Pickett, Balents, Zhang, Vanderbilt); the full conference schedule is provided with this report. The week's events included a public lecture (Quantum Matters given by Chetan Nayak from Microsoft Research) and attended by 234 members of the public, and a physics caf© geared for high schoolers that is a discussion with physicists conducted by Kathryn Moler (Stanford University) and Andrew M. Rappe (University of Pennsylvania) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by Joel Moore (University of California Berkeley), Chetan Nayak (Microsoft Research), Karin Rabe (Rutgers University), and Matthias Troyer (ETH Zurich). Two organizers who did not attend the conference were Gabriel Aeppli (University College London & London Centre for Nanotechnology) and Andrea Cavalleri (Oxford University & Max Planck Hamburg).

  3. Pollution and economic growth in a model of overlapping generations

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Eric O`N. [Department of Economics, The Ohio State University, Columbus, OH (United States); Van Marrewijk, Charles [Department of Economics, Erasmus University, Rotterdam (Netherlands)

    1994-01-22

    We analyze a model of overlapping generations in which clean air, a pure public consumption good, is used as a private input into production. Although production exhibits constant returns to scale, endogenous growth can occur because the economy has tWO sectors. In a laissez-faire equilibrium, there is no market for pollution rights, and firms appropriate clean air in an arbitrary manner. Growth occurs only if the marginal propensity to save is high enough and the asymptotic share of pollution in the investment sector is zero. Firms generate quasi-rents that are the value of pollution rights. These quasi-rents crowd out investment and slow economic growth. A laissez- faire equilibrium may not support Pareto optimal allocations, but a Pigouvian tax with lump-sum distribution of the resulting revenues does. Hence, a pollution lax yields a double dividend because it can increase both the static efficiency of the economy and its growth rate. 1 fig., 20 refs.

  4. Pollution and economic growth in a model of overlapping generations

    International Nuclear Information System (INIS)

    Fisher, Eric O'N.; Van Marrewijk, Charles

    1994-01-01

    We analyze a model of overlapping generations in which clean air, a pure public consumption good, is used as a private input into production. Although production exhibits constant returns to scale, endogenous growth can occur because the economy has tWO sectors. In a laissez-faire equilibrium, there is no market for pollution rights, and firms appropriate clean air in an arbitrary manner. Growth occurs only if the marginal propensity to save is high enough and the asymptotic share of pollution in the investment sector is zero. Firms generate quasi-rents that are the value of pollution rights. These quasi-rents crowd out investment and slow economic growth. A laissez- faire equilibrium may not support Pareto optimal allocations, but a Pigouvian tax with lump-sum distribution of the resulting revenues does. Hence, a pollution lax yields a double dividend because it can increase both the static efficiency of the economy and its growth rate. 1 fig., 20 refs

  5. Modelling Technical and Economic Parameters in Selection of Manufacturing Devices

    Directory of Open Access Journals (Sweden)

    Naqib Daneshjo

    2017-11-01

    Full Text Available Sustainable science and technology development is also conditioned by continuous development of means of production which have a key role in structure of each production system. Mechanical nature of the means of production is complemented by controlling and electronic devices in context of intelligent industry. A selection of production machines for a technological process or technological project has so far been practically resolved, often only intuitively. With regard to increasing intelligence, the number of variable parameters that have to be considered when choosing a production device is also increasing. It is necessary to use computing techniques and decision making methods according to heuristic methods and more precise methodological procedures during the selection. The authors present an innovative model for optimization of technical and economic parameters in the selection of manufacturing devices for industry 4.0.

  6. Economical analysis based on a simplified model of micro distillery

    International Nuclear Information System (INIS)

    Bristoti, A.; Adams, R.

    1987-01-01

    The investment costs of the hydrate alcohol distillery as well as the energy balance of its production made inviable its diffusion on a small scale. The present economical analysis is based on a simplified model of micro distillery where the reduction on investment costs in based on technical data based on the possibility of the utilization of an hydrate alcohol with a higher water constant than the usual, i. e. around 85 0 GL. The engineering project of this plant eliminates all pumps, all the liquids (water, sugar cane, syrup and wine) are fed by gravity. The bagasse is considered a noble by-product and it is utilized in poultry industry as a substitute of wood dust. All the heat needs of the micro distillery are supplied by wood. (author)

  7. Using hydro-economic modelling to investigate trade-offs between ecological and economic water management objectives

    DEFF Research Database (Denmark)

    Riegels, Niels

    is that land and water use levels predicted by the two approaches are essentially the same. The prediction that high-value irrigated crops will not replace low-value crops is not unreasonable given behavior observed in the baseline data set and highlights the limitations of using economic models calibrated......In regions where water scarcity exists, economic analysis can help identify ways to increase benefits of water use. The European Union’s Water Framework Directive (WFD), is an example of a law that requires the use of economic principles, approaches, and instruments in water resources management....... One of these instruments is water pricing. This study develops an approach for implementing the water pricing guidelines of the WFD at the river basin scale and then uses hydro-economic modelling to estimate the impacts of applying these guidelines. The central purpose of the WFD is the protection...

  8. A spatial-dynamic value transfer model of economic losses from a biological invasion

    Science.gov (United States)

    Thomas P. Holmes; Andrew M. Liebhold; Kent F. Kovacs; Betsy. Von Holle

    2010-01-01

    Rigorous assessments of the economic impacts of introduced species at broad spatial scales are required to provide credible information to policy makers. We propose that economic models of aggregate damages induced by biological invasions need to link microeconomic analyses of site-specific economic damages with spatial-dynamic models of value change associated with...

  9. Economic Crisis and Marital Problems in Turkey: Testing the Family Stress Model

    Science.gov (United States)

    Aytac, Isik A.; Rankin, Bruce H.

    2009-01-01

    This paper applied the family stress model to the case of Turkey in the wake of the 2001 economic crisis. Using structural equation modeling and a nationally representative urban sample of 711 married women and 490 married men, we tested whether economic hardship and the associated family economic strain on families resulted in greater marital…

  10. Bio-economic modeling of water quality improvements using a dynamic applied general equilibrium approach

    NARCIS (Netherlands)

    Dellink, R.; Brouwer, R.; Linderhof, V.G.M.; Stone, K.

    2011-01-01

    An integrated bio-economic model is developed to assess the impacts of pollution reduction policies on water quality and the economy. Emission levels of economic activities to water are determined based on existing environmental accounts. These emission levels are built into a dynamic economic model

  11. Modeling the economic outcomes of immuno-oncology drugs: alternative model frameworks to capture clinical outcomes.

    Science.gov (United States)

    Gibson, E J; Begum, N; Koblbauer, I; Dranitsaris, G; Liew, D; McEwan, P; Tahami Monfared, A A; Yuan, Y; Juarez-Garcia, A; Tyas, D; Lees, M

    2018-01-01

    Economic models in oncology are commonly based on the three-state partitioned survival model (PSM) distinguishing between progression-free and progressive states. However, the heterogeneity of responses observed in immuno-oncology (I-O) suggests that new approaches may be appropriate to reflect disease dynamics meaningfully. This study explored the impact of incorporating immune-specific health states into economic models of I-O therapy. Two variants of the PSM and a Markov model were populated with data from one clinical trial in metastatic melanoma patients. Short-term modeled outcomes were benchmarked to the clinical trial data and a lifetime model horizon provided estimates of life years and quality adjusted life years (QALYs). The PSM-based models produced short-term outcomes closely matching the trial outcomes. Adding health states generated increased QALYs while providing a more granular representation of outcomes for decision making. The Markov model gave the greatest level of detail on outcomes but gave short-term results which diverged from those of the trial (overstating year 1 progression-free survival by around 60%). Increased sophistication in the representation of disease dynamics in economic models is desirable when attempting to model treatment response in I-O. However, the assumptions underlying different model structures and the availability of data for health state mapping may be important limiting factors.

  12. A microbial model of economic trading and comparative advantage.

    Science.gov (United States)

    Enyeart, Peter J; Simpson, Zachary B; Ellington, Andrew D

    2015-01-07

    The economic theory of comparative advantage postulates that beneficial trading relationships can be arrived at by two self-interested entities producing the same goods as long as they have opposing relative efficiencies in producing those goods. The theory predicts that upon entering trade, in order to maximize consumption both entities will specialize in producing the good they can produce at higher efficiency, that the weaker entity will specialize more completely than the stronger entity, and that both will be able to consume more goods as a result of trade than either would be able to alone. We extend this theory to the realm of unicellular organisms by developing mathematical models of genetic circuits that allow trading of a common good (specifically, signaling molecules) required for growth in bacteria in order to demonstrate comparative advantage interactions. In Conception 1, the experimenter controls production rates via exogenous inducers, allowing exploration of the parameter space of specialization. In Conception 2, the circuits self-regulate via feedback mechanisms. Our models indicate that these genetic circuits can demonstrate comparative advantage, and that cooperation in such a manner is particularly favored under stringent external conditions and when the cost of production is not overly high. Further work could involve implementing the models in living bacteria and searching for naturally occurring cooperative relationships between bacteria that conform to the principles of comparative advantage. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

    Science.gov (United States)

    Asko Noormets; Olevi Kull; Anu Sober; Mark E. Kubiske; David F. Karnosky

    2010-01-01

    The effect of elevated CO2 and O3 on apparent quantum yield (ø), maximum photosynthesis (Pmax), carboxylation efficiency (Vcmax) and electron transport capacity (Jmax) at different canopy locations was studied in two aspen (Populus...

  14. Effects of elevated CO2 and ozone on phenolic glycosides of trembling aspen

    Science.gov (United States)

    James K. Nitao; Muraleedharan G. Nair; William J. Mattson; Daniel A. Herms; Bruce A. Birr; Mark D. Coleman; Terry M. Trier; J. G. Isebrands

    1996-01-01

    We tested the effects of elevated CO2 and ozone on concentrations of the phenolic glycosides salicortin and tremulacin in immature and mature foliage of the trembling aspen (Populus tremuloides) clones 216, 259, and 271.

  15. 77 FR 60373 - Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and Piute...

    Science.gov (United States)

    2012-10-03

    ....u s. In addition, an Open House will be held at the Sevier County Administrative Building in... continual maintenance, fencing is not a long term sustainable response option for protecting aspen sprouts...

  16. Technological, economic and environmental evaluation of rice husk gasification in a biorefinery context to produce indirect energy as jet fuel

    Directory of Open Access Journals (Sweden)

    Juan Jacobo Jaramillo Obando

    2017-09-01

    Full Text Available Higher alcohol 1-octanol was evaluated as jet fuel potential. The synthesis of the 1-octanol was modeled and the technological, economic and environmental evaluation of the global production process of the rice husk gasification was performed. The best operating conditions to 1-octanol synthesis were obtained in packed bed reactor PBR using Matlab software. Mass and energy balances were calculated using Aspen Plus Software. Economic assessment was developed using Aspen Process Economic Analyzer Software. Environmental impact evaluation was carried out using the waste reduction algorithm WAR. Process yield was 0.83 kg of 1-Octanol by kg of rice husk. Total production cost obtained was USD 0.957 per kg of 1-octanol and the total PEI of product leave the system is 0.08142 PEI/kg with a PEI mitigated of 12.97 PEI/kg. Production process of high alcohols from rice husk shows a high potential technological, economical and environmental as a sustainable industry at take advantage of an agroindustrial residue and transformed in products with added value and energy. 1-octanol as jet fuel has a potential but need to be more studied for direct use in jet motors.

  17. Modelling the economic impacts of addressing climate change

    International Nuclear Information System (INIS)

    2002-01-01

    This Power Point report presents highlights of the latest economic modelling of Canada's Kyoto commitment to address climate change. It presents framework assumptions and a snapshot under 4 scenarios. The objective of this report is to evaluate the national, sectoral, provincial and territorial impacts of the federal reference case policy package in which the emissions reduction target is 170 Mt from a business-as-usual scenario. The reference case policy package also includes 30 Mt of sinks from current packages of which 20 Mt are derived from the forestry sector and the remainder from agricultural sector. The report examined 4 scenarios based on 2 international carbon prices ($10 and $50) per tonne of carbon dioxide in 2010. The scenarios were also based on the fiscal assumptions that climate change initiatives and revenue losses would directly affect the governments' balances, or that the government balances are maintained by increasing personal income tax. A comparison of impacts under each of the 4 scenarios to 2010 was presented. The model presents impacts on GDP, employment, disposable income per household, and energy prices. 4 tabs., 4 figs

  18. Economic perspective of marine reserves in fisheries: a bioeconomic model.

    Science.gov (United States)

    Chakraborty, Kunal; Kar, T K

    2012-12-01

    The present paper describes a prey-predator type fishery model with prey dispersal in a two-patch environment, one of which is a free fishing zone and other is protected zone. The objective of the paper is to maximize the net economic revenue earn from the fishery through implementing the sustainable properties of the fishery to keep the ecological balance. Biological measures are introduced to increase the understanding of the mechanisms in the bioeconomic system. The importance of marine reserve is analyzed through the obtained results of the numerical simulations of proposed model system. The results depict that reserves will be most effective when coupled with harvesting controls in adjacent fisheries. The paper also incorporates the induced cost and premium from establishing a marine protected area in a fishery. It is found that premium of marine protected area (MPA) increases with the increasing size of the reserve. Results are analyzed with the help of graphical illustrations. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Public sector administration of ecological economics systems using mediated modeling.

    Science.gov (United States)

    van den Belt, Marjan; Kenyan, Jennifer R; Krueger, Elizabeth; Maynard, Alison; Roy, Matthew Galen; Raphael, Ian

    2010-01-01

    In today's climate of government outsourcing and multiple stakeholder involvement in public sector management and service delivery, it is more important than ever to rethink and redesign the structure of how policy decisions are made, implemented, monitored, and adapted to new realities. The traditional command-and-control approach is now less effective because an increasing amount of responsibility to deliver public goods and services falls on networks of nongovernment agencies. Even though public administrators are seeking new decision-making models in an increasingly more complex environment, the public sector currently only sparsely utilizes Mediated Modeling (MM). There is growing evidence, however, that by employing MM and similar tools, public interest networks can be better equipped to deal with their long-term viability while maintaining the short-term needs of their clients. However, it may require a shift in organizational culture within and between organizations to achieve the desired results. This paper explores the successes and barriers to implementing MM and similar tools in the public sector and offers insights into utilizing them through a review of case studies and interdisciplinary literature. We aim to raise a broader interest in MM and similar tools among public sector administrators at various administrative levels. We focus primarily, but not exclusively, on those cases operating at the interface of ecology and socio-economic systems.

  20. Sustainability and economics: The Adirondack Park experience, a forest economic-ecological model, and solar energy policy

    Science.gov (United States)

    Erickson, Jon David

    The long-term sustainability of human communities will depend on our relationship with regional environments, our maintenance of renewable resources, and our successful disengagement from nonrenewable energy dependence. This dissertation investigates sustainability at these three levels, following a critical analysis of sustainability and economics. At the regional environment level, the Adirondack Park of New York State is analyzed as a potential model of sustainable development. A set of initial and ongoing conditions are presented that both emerge from and support a model of sustainability in the Adirondacks. From these conditions, a clearer picture emerges of the definition of regional sustainability, consequences of its adoption, and lessons from its application. Next, an economic-ecological model of the northern hardwood forest ecosystem is developed. The model integrates economic theory and intertemporal ecological concepts, linking current harvest decisions with future forest growth, financial value, and ecosystem stability. The results indicate very different economic and ecological outcomes by varying opportunity cost and ecosystem recovery assumptions, and suggest a positive benefit to ecological recovery in the forest rotation decision of the profit maximizing manager. The last section investigates the motives, economics, and international development implications of renewable energy (specifically photovoltaic technology) in rural electrification and technology transfer, drawing on research in the Dominican Republic. The implications of subsidizing a photovoltaic market versus investing in basic research are explored.

  1. Current challenges in health economic modeling of cancer therapies: a research inquiry.

    Science.gov (United States)

    Miller, Jeffrey D; Foley, Kathleen A; Russell, Mason W

    2014-05-01

    The demand for economic models that evaluate cancer treatments is increasing, as healthcare decision makers struggle for ways to manage their budgets while providing the best care possible to patients with cancer. Yet, after nearly 2 decades of cultivating and refining techniques for modeling the cost-effectiveness and budget impact of cancer therapies, serious methodologic and policy challenges have emerged that question the adequacy of economic modeling as a sound decision-making tool in oncology. We sought to explore some of the contentious issues associated with the development and use of oncology economic models as informative tools in current healthcare decision-making. Our objective was to draw attention to these complex pharmacoeconomic concerns and to promote discussion within the oncology and health economics research communities. Using our combined expertise in health economics research and economic modeling, we structured our inquiry around the following 4 questions: (1) Are economic models adequately addressing questions relevant to oncology decision makers; (2) What are the methodologic limitations of oncology economic models; (3) What guidelines are followed for developing oncology economic models; and (4) Is the evolution of oncology economic modeling keeping pace with treatment innovation? Within the context of each of these questions, we discuss issues related to the technical limitations of oncology modeling, the availability of adequate data for developing models, and the problems with how modeling analyses and results are presented and interpreted. There is general acceptance that economic models are good, essential tools for decision-making, but the practice of oncology and its rapidly evolving technologies present unique challenges that make assessing and demonstrating value especially complex. There is wide latitude for improvement in oncology modeling methodologies and how model results are presented and interpreted. Complex technical and

  2. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    Science.gov (United States)

    Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

  3. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

    Directory of Open Access Journals (Sweden)

    Kathryn M Robinson

    Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  4. Predation risk, elk, and aspen: tests of a behaviorally mediated trophic cascade in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Winnie, John A

    2012-12-01

    Aspen in the Greater Yellowstone Ecosystem are hypothesized to be recovering from decades of heavy browsing by elk due to a behaviorally mediated trophic cascade (BMTC). Several authors have suggested that wolves interact with certain terrain features, creating places of high predation risk at fine spatial scales, and that elk avoid these places, which creates refugia for plants. This hypothesized BMTC could release aspen from elk browsing pressure, leading to a patchy recovery in places of high risk. I tested whether four specific, hypothesized fine-scale risk factors are correlated with changes in current elk browsing pressure on aspen, or with aspen recruitment since wolf reintroduction, in the Daly Creek drainage in Yellowstone National Park, and near two aspen enclosures outside of the park boundary. Aspen were not responding to hypothesized fine-scale risk factors in ways consistent with the current BMTC hypothesis.

  5. Modeling the Development of Vocational Competence: A Psychometric Model for Economic Domains

    Science.gov (United States)

    Klotz, Viola Katharina; Winther, Esther; Festner, Dagmar

    2015-01-01

    This article discusses the development of vocational competence through economic vocational educational training (VET) from a theoretical and psychometric perspective. Most assessment and competence models tend to adopt a state perspective toward assessments of competence and carve out different structures of competence for diverse vocational…

  6. Studying Economic Space: Synthesis of Balance and Game-Theoretic Methods of Modelling

    Directory of Open Access Journals (Sweden)

    Natalia Gennadyevna Zakharchenko

    2015-12-01

    Full Text Available The article introduces questions about development of models used to study economic space. The author proposes the model that combines balance and game-theoretic methods for estimating system effects of economic agents’ interactions in multi-level economic space. The model is applied to research interactions between economic agents that are spatially heterogeneous within the Russian Far East. In the model the economic space of region is considered in a territorial dimension (the first level of decomposing space and also in territorial and product dimensions (the second level of decomposing space. The paper shows the mechanism of system effects formation that exists in the economic space of region. The author estimates system effects, analyses the real allocation of these effects between economic agents and identifies three types of local industrial markets: with zero, positive and negative system effects

  7. Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

    Science.gov (United States)

    Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

  8. A Simple Model of Entrepreneurship for Principles of Economics Courses

    Science.gov (United States)

    Gunter, Frank R.

    2012-01-01

    The critical roles of entrepreneurs in creating, operating, and destroying markets, as well as their importance in driving long-term economic growth are still generally either absent from principles of economics texts or relegated to later chapters. The primary difficulties in explaining entrepreneurship at the principles level are the lack of a…

  9. A Survey of Economic Models of Criminal Behavior

    Science.gov (United States)

    1987-10-01

    Economic Research, 1-54. Bentham , Jeremy (1931). Theory of Legislation. New York: Harcourt Brace. Block, Michael K. and J. M. Heineke (1975). A Labor...criminology in the eighteenth and nineteenth centuries, Beccaria and Bentham , explicitly applied an economic framework. Becker sees his work as re

  10. A Panel Threshold Model of Tourism Specialization and Economic Development

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); T. Khamkaew (Tanchanok); M.J. McAleer (Michael)

    2009-01-01

    textabstractThe significant impact of international tourism in stimulating economic growth is especially important from a policy perspective. For this reason, the relationship between international tourism and economic growth would seem to be an interesting empirical issue. In particular, if there

  11. Economic analysis of open space box model utilization in spacecraft

    Science.gov (United States)

    Mohammad, Atif F.; Straub, Jeremy

    2015-05-01

    It is a known fact that the amount of data about space that is stored is getting larger on an everyday basis. However, the utilization of Big Data and related tools to perform ETL (Extract, Transform and Load) applications will soon be pervasive in the space sciences. We have entered in a crucial time where using Big Data can be the difference (for terrestrial applications) between organizations underperforming and outperforming their peers. The same is true for NASA and other space agencies, as well as for individual missions and the highly-competitive process of mission data analysis and publication. In most industries, conventional opponents and new candidates alike will influence data-driven approaches to revolutionize and capture the value of Big Data archives. The Open Space Box Model is poised to take the proverbial "giant leap", as it provides autonomic data processing and communications for spacecraft. We can find economic value generated from such use of data processing in our earthly organizations in every sector, such as healthcare, retail. We also can easily find retailers, performing research on Big Data, by utilizing sensors driven embedded data in products within their stores and warehouses to determine how these products are actually used in the real world.

  12. A BEHAVIORAL ECONOMIC MODEL OF ALCOHOL ADVERTISING AND PRICE

    Science.gov (United States)

    SAFFER, HENRY; DAVE, DHAVAL; GROSSMAN, MICHAEL

    2016-01-01

    SUMMARY This paper presents a new empirical study of the effects of televised alcohol advertising and alcohol price on alcohol consumption. A novel feature of this study is that the empirical work is guided by insights from behavioral economic theory. Unlike the theory used in most prior studies, this theory predicts that restriction on alcohol advertising on TV would be more effective in reducing consumption for individuals with high consumption levels but less effective for individuals with low consumption levels. The estimation work employs data from the National Longitudinal Survey of Youth, and the empirical model is estimated with quantile regressions. The results show that advertising has a small positive effect on consumption and that this effect is relatively larger at high consumption levels. The continuing importance of alcohol taxes is also supported. Education is employed as a proxy for self-regulation, and the results are consistent with this assumption. The key conclusion is that restrictions on alcohol advertising on TV would have a small negative effect on drinking, and this effect would be larger for heavy drinkers. PMID:25919364

  13. Risk-trading in flood management: An economic model.

    Science.gov (United States)

    Chang, Chiung Ting

    2017-09-15

    Although flood management is no longer exclusively a topic of engineering, flood mitigation continues to be associated with hard engineering options. Flood adaptation or the capacity to adapt to flood risk, as well as a demand for internalizing externalities caused by flood risk between regions, complicate flood management activities. Even though integrated river basin management has long been recommended to resolve the above issues, it has proven difficult to apply widely, and sometimes even to bring into existence. This article explores how internalization of externalities as well as the realization of integrated river basin management can be encouraged via the use of a market-based approach, namely a flood risk trading program. In addition to maintaining efficiency of optimal resource allocation, a flood risk trading program may also provide a more equitable distribution of benefits by facilitating decentralization. This article employs a graphical analysis to show how flood risk trading can be implemented to encourage mitigation measures that increase infiltration and storage capacity. A theoretical model is presented to demonstrate the economic conditions necessary for flood risk trading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Modeling the economics and market adoption of distributed power generation

    International Nuclear Information System (INIS)

    Maribu, Karl Magnus

    2006-01-01

    After decades of power generating units increasing in size, there is currently a growing focus on distributed generation, power generation close to energy loads. Investments in large-scale units have been driven by economy of scale, but recent technological improvements on small generating plants have made it possible to exploit the benefits of local power generation to a larger extent than previously. Distributed generation can improve power system efficiency because heat can be recovered from thermal units to supply heat and thermally activated cooling, and because small-scale renewables have a promising end-user market. Further benefits of distributed generation include improved reliability, deferral of often controversial and costly grid investments and reduction of grid losses. The new appeal of small-scale power generation means that there is a need for new tools to analyze distributed generation, both from a system perspective and from the perspective of potential developers. In this thesis, the focus is on the value of power generation for end-users. The thesis identifies how an end-user can find optimal distributed generation systems and investment strategies under a variety of economic and regulatory scenarios. The final part of the thesis extends the analysis with a bottom up model of how the economics of distributed generation for a representative set of building types can transfer to technology diffusion in a market. Four separate research papers make up the thesis. In the first paper, Optimal Investment Strategies in Decentralized Renewable Power Generation under Uncertainty, a method for evaluation of investments in renewable power units under price uncertainty is presented. It is assumed the developer has a building with an electricity load and a renewable power resource. The case study compares a set of wind power systems with different capacity and finds that capacity depends on the electricity price and that there under uncertain prices can be a

  15. Applicability of genetic algorithms to parameter estimation of economic models

    Directory of Open Access Journals (Sweden)

    Marcel Ševela

    2004-01-01

    Full Text Available The paper concentrates on capability of genetic algorithms for parameter estimation of non-linear economic models. In the paper we test the ability of genetic algorithms to estimate of parameters of demand function for durable goods and simultaneously search for parameters of genetic algorithm that lead to maximum effectiveness of the computation algorithm. The genetic algorithms connect deterministic iterative computation methods with stochastic methods. In the genteic aůgorithm approach each possible solution is represented by one individual, those life and lifes of all generations of individuals run under a few parameter of genetic algorithm. Our simulations resulted in optimal mutation rate of 15% of all bits in chromosomes, optimal elitism rate 20%. We can not set the optimal extend of generation, because it proves positive correlation with effectiveness of genetic algorithm in all range under research, but its impact is degreasing. The used genetic algorithm was sensitive to mutation rate at most, than to extend of generation. The sensitivity to elitism rate is not so strong.

  16. A Behavioral Economic Model of Alcohol Advertising and Price.

    Science.gov (United States)

    Saffer, Henry; Dave, Dhaval; Grossman, Michael

    2016-07-01

    This paper presents a new empirical study of the effects of televised alcohol advertising and alcohol price on alcohol consumption. A novel feature of this study is that the empirical work is guided by insights from behavioral economic theory. Unlike the theory used in most prior studies, this theory predicts that restriction on alcohol advertising on TV would be more effective in reducing consumption for individuals with high consumption levels but less effective for individuals with low consumption levels. The estimation work employs data from the National Longitudinal Survey of Youth, and the empirical model is estimated with quantile regressions. The results show that advertising has a small positive effect on consumption and that this effect is relatively larger at high consumption levels. The continuing importance of alcohol taxes is also supported. Education is employed as a proxy for self-regulation, and the results are consistent with this assumption. The key conclusion is that restrictions on alcohol advertising on TV would have a small negative effect on drinking, and this effect would be larger for heavy drinkers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Economic Crises and the Complexity of Animal Spirits Modeling

    Directory of Open Access Journals (Sweden)

    Grigore PIROŞCĂ

    2011-02-01

    Full Text Available The rationale of this research goes into the origins of the economic crises from a different way of economic thinking, hence the professional interest on bringing again into the light the concept of animal spirits, used for the first time from classic liberals like David Hume, developed by doctrine founder John Maynard Keynes, and captured as groundbreaking economic crisis hypothesis in Nobel Prize laureates’ books like George Akerlof. A familiar account of the last financial crisis underlines the collapse of confidence and evaporation of trust which leaded to failure of corporate governance and easy money policy. Nor were these problems of recent origin; they were rooted in deep structural changes in the economy that date back many years. Financial innovations overheated the world economy and gained steam because of irrational exuberance over a risk free better future. Considering the evidence analyzed in this paper work, this approach of economic crisis through animal spirits puts forward new highlights of economic thought.

  18. EUROPEAN SOCIAL MODEL.COMPETITIVE ADVANTAGE OR ECONOMIC HANDICAP

    Directory of Open Access Journals (Sweden)

    Iovitu Mariana

    2010-07-01

    Full Text Available “Corporative social responsibility” (CSR represents equally a very actual debate, but also an appraisal criteria of the dynamic of eco-social integration quality process at European level. Especially that the protection need is demanded by the current economic crisis. This concept is meant to combine the position, attitude and behaviour of the trade-unions with the interests of employer’s organisations in search of possible influential mechanisms of the competitive advantage at European level. Due to the current economic crisis, the implications on the labour force market are causing an explainable anxiety. The attention of the decision takers is oriented towards joining the objectives “social well being with economic well being” in view of an expected economic come back. This approach proves a significant change at the level of economic and social policies within the European Union.

  19. Modeling economic growth fuelled by science and technology

    Directory of Open Access Journals (Sweden)

    Leonardo Costa Ribeiro

    2010-06-01

    Full Text Available This paper suggests a simulation model to investigate how science and technology fuel economic growth. This model is built upon a synthesis of technological capabilities represented by national innovation systems. This paper gathers data of papers and patents for 183 countries between 1999 and 2003, as well as GDP and population for 2003. These data show a strong correlation between science, technology and income. Three simulation exercises are performed. Feeding our algorithm with data for population, patents and scientific papers, we obtain the world income distribution. These results support our conjecture on the role of science and technology as sources of the wealth of nations.Este artigo propõe um modelo de simulação para investigar a contribuição da ciência e da tecnologia para o crescimento econômico. O ponto de partida são os sistemas nacionais de inovação, um conceito que sintetiza a capacitação tecnológica das nações. Desta forma, o modelo pode preservar simplicidade e parcimônia. Os dados coletados (patentes, artigos e PIB e população, para 183 países indicam uma forte correlação entre ciência, tecnologia e renda. Três exercícios com simulações são realizados para diversos momentos do tempo, mostrando a progressiva aderência do modelo a essas variáveis tecnológicas.

  20. An Idealized Cognitive Model Analysis of Metaphors in American Economic News Report

    Science.gov (United States)

    Qin, Yang

    2018-03-01

    On the basis of the theoretical framework of Lakoff’s Conceptual Metaphor, the paper researches into the cognitive model of conceptual metaphors in American Economic News Reports. Moreover, the paper tries to analyze economic discourse by the application of Idealized Cognitive Model of its metaphorical thinking combined with cultural model and reflect the ideology of the media. It aims to help English learners ponder the implied meaning the economic news reports conveyed and take a new look at metaphors between the lines.

  1. Forecast Accuracy and Economic Gains from Bayesian Model Averaging using Time Varying Weights

    NARCIS (Netherlands)

    L.F. Hoogerheide (Lennart); R.H. Kleijn (Richard); H.K. van Dijk (Herman); M.J.C.M. Verbeek (Marno)

    2009-01-01

    textabstractSeveral Bayesian model combination schemes, including some novel approaches that simultaneously allow for parameter uncertainty, model uncertainty and robust time varying model weights, are compared in terms of forecast accuracy and economic gains using financial and macroeconomic time

  2. Developing models that analyze the economic/environmental trade-offs implicit in water resource management

    Science.gov (United States)

    Howitt, R. E.

    2016-12-01

    Hydro-economic models have been used to analyze optimal supply management and groundwater use for the past 25 years. They are characterized by an objective function that usually maximizes economic measures such as consumer and producer surplus subject to hydrologic equations of motion or water distribution systems. The hydrologic and economic components are sometimes fully integrated. Alternatively they may use an iterative interactive process. Environmental considerations have been included in hydro-economic models as inequality constraints. Representing environmental requirements as constraints is a rigid approximation of the range of management alternatives that could be used to implement environmental objectives. The next generation of hydro-economic models, currently being developed, require that the environmental alternatives be represented by continuous or semi-continuous functions which relate water resource use allocated to the environment with the probabilities of achieving environmental objectives. These functions will be generated by process models of environmental and biological systems which are now advanced to the state that they can realistically represent environmental systems and flexibility to interact with economic models. Examples are crop growth models, climate modeling, and biological models of forest, fish, and fauna systems. These process models can represent environmental outcomes in a form that is similar to economic production functions. When combined with economic models the interacting process models can reproduce a range of trade-offs between economic and environmental objectives, and thus optimize social value of many water and environmental resources. Some examples of this next-generation of hydro-enviro- economic models are reviewed. In these models implicit production functions for environmental goods are combined with hydrologic equations of motion and economic response functions. We discuss models that show interaction between

  3. Linking Simple Economic Theory Models and the Cointegrated Vector AutoRegressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    This paper attempts to clarify the connection between simple economic theory models and the approach of the Cointegrated Vector-Auto-Regressive model (CVAR). By considering (stylized) examples of simple static equilibrium models, it is illustrated in detail, how the theoretical model and its stru....... Further fundamental extensions and advances to more sophisticated theory models, such as those related to dynamics and expectations (in the structural relations) are left for future papers......This paper attempts to clarify the connection between simple economic theory models and the approach of the Cointegrated Vector-Auto-Regressive model (CVAR). By considering (stylized) examples of simple static equilibrium models, it is illustrated in detail, how the theoretical model and its......, it is demonstrated how other controversial hypotheses such as Rational Expectations can be formulated directly as restrictions on the CVAR-parameters. A simple example of a "Neoclassical synthetic" AS-AD model is also formulated. Finally, the partial- general equilibrium distinction is related to the CVAR as well...

  4. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  5. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity. Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  6. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  7. A Study on the development of macro environmental economic model(I)

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Young Keun; Han, Min Jung [Korea Environment Institute, Seoul (Korea)

    1998-12-01

    This study is the first year study of the two year research project for developing a macro environmental economic model to analyze environment and economics. By using this model, the economic effects of investment on pollution reduction and on energy conservation are analyzed. Also, a comprehensive modeling of analyzing effects of environmental tax, reduction on greenhouse gas emission, and problems on foreign exchange on environment and economy is a main goal of this study. It is planned to develop a simulation program for the estimation of model and policies using environmental and economic data. 126 refs., 2 figs., 5 tabs.

  8. Multimodel simulations of forest harvesting effects on long‐term productivity and CN cycling in aspen forests.

    Science.gov (United States)

    Wang, Fugui; Mladenoff, David J; Forrester, Jodi A; Blanco, Juan A; Schelle, Robert M; Peckham, Scott D; Keough, Cindy; Lucash, Melissa S; Gower, Stith T

    The effects of forest management on soil carbon (C) and nitrogen (N) dynamics vary by harvest type and species. We simulated long-term effects of bole-only harvesting of aspen (Populus tremuloides) on stand productivity and interaction of CN cycles with a multiple model approach. Five models, Biome-BGC, CENTURY, FORECAST, LANDIS-II with Century-based soil dynamics, and PnET-CN, were run for 350 yr with seven harvesting events on nutrient-poor, sandy soils representing northwestern Wisconsin, United States. Twenty CN state and flux variables were summarized from the models' outputs and statistically analyzed using ordination and variance analysis methods. The multiple models' averages suggest that bole-only harvest would not significantly affect long-term site productivity of aspen, though declines in soil organic matter and soil N were significant. Along with direct N removal by harvesting, extensive leaching after harvesting before canopy closure was another major cause of N depletion. These five models were notably different in output values of the 20 variables examined, although there were some similarities for certain variables. PnET-CN produced unique results for every variable, and CENTURY showed fewer outliers and similar temporal patterns to the mean of all models. In general, we demonstrated that when there are no site-specific data for fine-scale calibration and evaluation of a single model, the multiple model approach may be a more robust approach for long-term simulations. In addition, multimodeling may also improve the calibration and evaluation of an individual model.

  9. Growth structure and environment. 6 contributions to the macro economic model development

    International Nuclear Information System (INIS)

    Wier, Mette

    1998-04-01

    This thesis comprises 6 papers on the application of macro economic models to environmental problems. Interactions between the economic and the ecological models are elucidated and a description is given of a possible systematization of of the environmental-economic cycle within a macro economic model. Economic and technological limitations affecting the potential environmental advantages are discussed. In the second part of the thesis the general interdependence of production and consumption, and the various forms of environmental stress is analyzed. For this purpose an environment-related input-output model is presented, where for each industry there are given emissions and/or consumption of natural resources (so-called environmental coefficients), which are likely to originate from the activities of this industry. As examples of macro economic modelling,the nitrogen cycle in Denmark, environmental effects of consumer choice, use of building materials and emission due to energy generation and consumption etc. are analyzed. (EG) 146 refs

  10. Are wolves saving Yellowstone's aspen? A landscape-level test of a behaviorally mediated trophic cascade.

    Science.gov (United States)

    Kauffman, Matthew J; Brodie, Jedediah F; Jules, Erik S

    2010-09-01

    Behaviorally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. Based primarily on systems involving small-bodied predators, BMTCs have been proposed as both strong and ubiquitous in natural ecosystems. Recently, however, synthetic work has suggested that the existence of BMTCs may be mediated by predator hunting mode, whereby passive (sit-and-wait) predators have much stronger effects than active (coursing) predators. One BMTC that has been proposed for a wide-ranging active predator system involves the reintroduction of wolves (Canis lupus) to Yellowstone National Park, USA, which is thought to be leading to a recovery of trembling aspen (Populus tremuloides) by causing elk (Cervus elaphus) to avoid foraging in risky areas. Although this BMTC has been generally accepted and highly popularized, it has never been adequately tested. We assessed whether wolves influence aspen by obtaining detailed demographic data on aspen Stands using tree rings and by monitoring browsing levels in experimental elk exclosures arrayed across a gradient of predation risk for three years. Our study demonstrates that the historical failure of aspen to regenerate varied widely among stands (last recruitment year ranged from 1892 to 1956), and our data do not indicate an abrupt cessation of recruitment. This pattern of recruitment failure appears more consistent with a gradual increase in elk numbers rather than a rapid behavioral shift in elk foraging following wolf extirpation. In addition, our estimates of relative survivorship of young browsable aspen indicate that aspen are not currently recovering in Yellowstone, even in the presence of a large wolf population. Finally, in an experimental test of the BMTC hypothesis we found that the impacts of elk browsing on aspen demography are not diminished in sites where elk are at higher risk of predation by wolves. These findings suggest the need to further evaluate how trophic

  11. Cultural Tourism – a Model for Economic Development

    Directory of Open Access Journals (Sweden)

    Mihaela-Carmen MUNTEAN

    2012-11-01

    Full Text Available Tourism is a complex activity whose development is manifested in a fast pace, which in the last period determined it to become one of the most spectacular phenomena of recent decades, with important economic effects and particularly, social and human effects. This form of cultural tourism is identified as an engine for development and promotion of local cultural identities, offering neighboring communities an opportunity to preservation of cultural heritage as a resource for socio-economic local development. Thus, cultural tourism is the boundary between culture and tourism industry, its development influencing each other. Cultural tourism is a form of economic development based on cultural resources, contributing to national economic development.

  12. Understanding the Drivers of Economic Growth: Grounding Endogenous Economic Growth Models in Resource-Advantage Theory

    OpenAIRE

    Hunt, Shelby D.

    2012-01-01

    Foss (2012) provides an informed and informative comment on my article “Trust, Personal Moral Codes, and the Resource-Advantage Theory of Competition: Explaining Productivity, Economic Growth, and Wealth Creation” (Hunt, 2012). In general, his comment is highly supportive of both the theory and the arguments developed in my article. He does, however, raise certain issues that need to be addressed. These issues relate to the concept of total factor productivity, the role of institutions in pro...

  13. Special Issue on Using Econometrics for Assessing Economic Models

    DEFF Research Database (Denmark)

    Juselius, Katarina

    2009-01-01

    Two methodological approaches to empirical economics which are labelled ‘theory first' versus ‘reality first' are introduced building the background for the discussion of the individual contributions to this special issue.......Two methodological approaches to empirical economics which are labelled ‘theory first' versus ‘reality first' are introduced building the background for the discussion of the individual contributions to this special issue....

  14. Review of regional economic models with special reference to labor impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, G.; Mason, B.

    1979-06-01

    This paper reviews several regional economic models and examines the capabilities of these models for assessing the total employment impacts of solar energy adoption. Five generic analytic methods are discussed: economic base analysis, shift-share analysis, demographic-economic interaction models, input-output analysis, and industrial location analysis. Ten regional models incorporating some aspect of these methods are reviewed. From the model review, the conclusion is drawn that there is no single model that fits all of the necessary criteria for planned research efforts. Models that appear to hold promise are the Economic Activity Analysis (EAA) Model, the Regional Industrial Multipliers System (RIMS), the Multiregion, Multi-industry (MRMI) Model, and the MULTIREGION model.

  15. Integrated climate modelling at the Kiel Institute for World Economics: The DART Model and its applications

    OpenAIRE

    Deke, Oliver; Peterson, Sonja

    2003-01-01

    The aim of this paper is to give an overview over the DART model and its applications. The main focus is on the implementation of climate impacts into DART in the course of coupling DART to the ocean-atmosphere model and on the associated empirical problems. The basic DART model and some applications are presented in the next section. Section 3 describes in detail how the economic impacts of climate change on the agricultural sector and the impact of sea level rise are implemented in DART. Se...

  16. Aspen Simulation of Diesel-Biodiesel Blends Combustion

    Directory of Open Access Journals (Sweden)

    Pérez-Sánchez Armando

    2015-01-01

    Full Text Available Biodiesel is a fuel produced by transesterification of vegetable oils or animal fats, which currently is gaining attention as a diesel substitute. It represents an opportunity to reduce CO2, SO2, CO, HC, PAH and PM emissions and contributes to the diversification of fuels in Mexico's energetic matrix. The results of the simulation of the combustion process are presented in this paper with reference to an engine specification KUBOTA D600-B, operated with diesel-biodiesel blends. The physicochemical properties of the compounds and the operating conditions of equipment were developed using the simulator Aspen® and supplementary information. The main aspects of the engine working conditions were considered such as diesel-biodiesel ratio, air/fuel mixture, temperature of the combustion gases and heat load. Diesel physicochemical specifications were taken from reports of PEMEX and SENER. Methyl esters corresponding to the transesterification of fatty acids that comprise castor oil were regarded as representative molecules of biodiesel obtained from chromatographic analysis. The results include CO2, water vapor, combustion efficiency, power and lower calorific value of fuels.

  17. Modeling the economic costs of disasters and recovery: analysis using a dynamic computable general equilibrium model

    Science.gov (United States)

    Xie, W.; Li, N.; Wu, J.-D.; Hao, X.-L.

    2014-04-01

    Disaster damages have negative effects on the economy, whereas reconstruction investment has positive effects. The aim of this study is to model economic causes of disasters and recovery involving the positive effects of reconstruction activities. Computable general equilibrium (CGE) model is a promising approach because it can incorporate these two kinds of shocks into a unified framework and furthermore avoid the double-counting problem. In order to factor both shocks into the CGE model, direct loss is set as the amount of capital stock reduced on the supply side of the economy; a portion of investments restores the capital stock in an existing period; an investment-driven dynamic model is formulated according to available reconstruction data, and the rest of a given country's saving is set as an endogenous variable to balance the fixed investment. The 2008 Wenchuan Earthquake is selected as a case study to illustrate the model, and three scenarios are constructed: S0 (no disaster occurs), S1 (disaster occurs with reconstruction investment) and S2 (disaster occurs without reconstruction investment). S0 is taken as business as usual, and the differences between S1 and S0 and that between S2 and S0 can be interpreted as economic losses including reconstruction and excluding reconstruction, respectively. The study showed that output from S1 is found to be closer to real data than that from S2. Economic loss under S2 is roughly 1.5 times that under S1. The gap in the economic aggregate between S1 and S0 is reduced to 3% at the end of government-led reconstruction activity, a level that should take another four years to achieve under S2.

  18. Simulation of the gasification of animal wastes in a dual gasifier using Aspen Plus®

    International Nuclear Information System (INIS)

    Fernandez-Lopez, M.; Pedroche, J.; Valverde, J.L.; Sanchez-Silva, L.

    2017-01-01

    Highlights: • The gasification of manure was evaluated using the software Aspen Plus®. • Composition and LHV of the obtained syngas depends on the operating conditions. • CO 2 net emissions for the steam and CO 2 gasification processes were calculated. • Manure steam gasification can be used as feedstock for Fischer-Tropsch. • Manure CO 2 gasification lead to a syngas suitable for energy production. - Abstract: The gasification of an animal waste biomass (manure) in a dual gasifier was studied using the software Aspen Plus®. For this purpose, a model based on a Gibbs free energy reactor was considered. Effects of the gasification temperature, the gasifying/biomass ratio and the use of steam and CO 2 as the gasifying agents on the composition and the low heating value (LHV) of the produced syngas were evaluated. In this sense, the H 2 /CO ratio and the LHV were the parameters calculated to stablish the best operating conditions for the production of either hydrocarbons via Fischer-Tropsch or energy. Furthermore, the CO 2 net emissions generated by the gasification process were also important in the selection of the best operating conditions from an environmental point of view. The obtained results showed that for both gasifying agents the H 2 and CO production was favoured at high temperatures whereas the production of CH 4 and CO 2 was favoured at low ones. On the other hand, the H 2 production was higher when steam was used as the gasifying agent and the formation of CO was enhanced when CO 2 was considered as gasification agent. An increase of the gasifying agent/biomass ratio had a negatively influence on the production of CH 4 , leading to a decrease of the LHV. Therefore, steam as the gasifying agent and high temperatures favoured the obtaining of a syngas suitable for the Fischer-Tropsch process whereas CO 2 and low gasification temperatures enhanced a syngas with a high LHV which could be used for energy production. Finally, the net CO 2

  19. Modeling the economic outcomes of immuno-oncology drugs: alternative model frameworks to capture clinical outcomes

    Directory of Open Access Journals (Sweden)

    Gibson EJ

    2018-03-01

    Full Text Available EJ Gibson,1 N Begum,1 I Koblbauer,1 G Dranitsaris,2 D Liew,3 P McEwan,4 AA Tahami Monfared,5,6 Y Yuan,7 A Juarez-Garcia,7 D Tyas,8 M Lees9 1Wickenstones Ltd, Didcot, UK; 2Augmentium Pharma Consulting Inc, Toronto, ON, Canada; 3Department of Epidemiology and Preventive Medicine, Alfred Hospital, Monash University, Melbourne, VIC, Australia; 4Health Economics and Outcomes Research Ltd, Cardiff, UK; 5Bristol-Myers Squibb Canada, Saint-Laurent, QC Canada; 6Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada; 7Bristol-Myers Squibb, Princeton, NJ, USA; 8Bristol-Myers Squibb, Uxbridge, UK; 9Bristol-Myers Squibb, Rueil-Malmaison, France Background: Economic models in oncology are commonly based on the three-state partitioned survival model (PSM distinguishing between progression-free and progressive states. However, the heterogeneity of responses observed in immuno-oncology (I-O suggests that new approaches may be appropriate to reflect disease dynamics meaningfully. Materials and methods: This study explored the impact of incorporating immune-specific health states into economic models of I-O therapy. Two variants of the PSM and a Markov model were populated with data from one clinical trial in metastatic melanoma patients. Short-term modeled outcomes were benchmarked to the clinical trial data and a lifetime model horizon provided estimates of life years and quality adjusted life years (QALYs. Results: The PSM-based models produced short-term outcomes closely matching the trial outcomes. Adding health states generated increased QALYs while providing a more granular representation of outcomes for decision making. The Markov model gave the greatest level of detail on outcomes but gave short-term results which diverged from those of the trial (overstating year 1 progression-free survival by around 60%. Conclusion: Increased sophistication in the representation of disease dynamics in economic models

  20. Gender Discrimination, Education and Economic Growth in a Generalized Uzawa-Lucas Two-Sector Model

    OpenAIRE

    Zhang Wei-Bin

    2014-01-01

    This paper is mainly concerned with relationships between economic growth and gender discrimination in labor markets and education. Although discrimination in different fields has well been addresses and modelled in the economic literature, there are only a few growth models with endogenous wealth and human capital accumulation, gender time distribution between work, leisure and education under gender (positive or negative) discrimination. The production and economic structures, human capital...

  1. The role of decision analytic modeling in the health economic assessment of spinal intervention.

    Science.gov (United States)

    Edwards, Natalie C; Skelly, Andrea C; Ziewacz, John E; Cahill, Kevin; McGirt, Matthew J

    2014-10-15

    Narrative review. To review the common tenets, strengths, and weaknesses of decision modeling for health economic assessment and to review the use of decision modeling in the spine literature to date. For the majority of spinal interventions, well-designed prospective, randomized, pragmatic cost-effectiveness studies that address the specific decision-in-need are lacking. Decision analytic modeling allows for the estimation of cost-effectiveness based on data available to date. Given the rising demands for proven value in spine care, the use of decision analytic modeling is rapidly increasing by clinicians and policy makers. This narrative review discusses the general components of decision analytic models, how decision analytic models are populated and the trade-offs entailed, makes recommendations for how users of spine intervention decision models might go about appraising the models, and presents an overview of published spine economic models. A proper, integrated, clinical, and economic critical appraisal is necessary in the evaluation of the strength of evidence provided by a modeling evaluation. As is the case with clinical research, all options for collecting health economic or value data are not without their limitations and flaws. There is substantial heterogeneity across the 20 spine intervention health economic modeling studies summarized with respect to study design, models used, reporting, and general quality. There is sparse evidence for populating spine intervention models. Results mostly showed that interventions were cost-effective based on $100,000/quality-adjusted life-year threshold. Spine care providers, as partners with their health economic colleagues, have unique clinical expertise and perspectives that are critical to interpret the strengths and weaknesses of health economic models. Health economic models must be critically appraised for both clinical validity and economic quality before altering health care policy, payment strategies, or

  2. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  3. The yield of natural trembling aspen (populus tremula L.) stands (northern and eastern anatolia)

    International Nuclear Information System (INIS)

    Misir, M.; Misir, N.

    2013-01-01

    Trembling aspen (Populus tremula L.) is one of the most resistant to cold natural species in Turkey. In spite of its importance, there is no research on the yield. Hence, site productivity was determined and yield Table for undisturbed natural trembling aspen stands in Turkey was developed. Data were obtained from a total of 46 plots ranging in age from 17 to 82 years. Yield Table indicates that trembling aspen is very slow growing in young and middle age and Current Annual Increment (CAI) and Mean Annual Increment (MAI) values do not reach its maximum value, even at age 70. This is a proof that trembling aspen is not a fast growing species as expected. The reason for its slow growth is attributed to very short period of growth at very high altitudes. However, in the event of 50 years rotation age, mean annual volume increments of 8.0, 3.6 and 1.1 m3 are estimated for trembling aspen for site classes I, II and III, respectively. At extended rotations, trees of pole sizes could be obtained on all site classes. (author)

  4. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  5. Costs and benefits of controlling quarantine diseases : a bio-economic modeling approach

    NARCIS (Netherlands)

    Breukers, M.L.H.; Mourits, M.C.M.; Werf, van der W.; Oude Lansink, A.G.J.M.

    2008-01-01

    This article describes a bio-economic model to quantify the costs and benefits of controlling plant quarantine diseases. The model integrates the epidemiology and economic consequences of a quarantine disease. It allows for ex ante evaluation of control scenarios for their cost-effectiveness, taking

  6. Evaluation of the Stress Adjustment and Adaptation Model among Families Reporting Economic Pressure

    Science.gov (United States)

    Vandsburger, Etty; Biggerstaff, Marilyn A.

    2004-01-01

    This research evaluates the Stress Adjustment and Adaptation Model (double ABCX model) examining the effects resiliency resources on family functioning when families experience economic pressure. Families (N = 128) with incomes at or below the poverty line from a rural area of a southern state completed measures of perceived economic pressure,…

  7. Economic efficiency versus social equality? The U.S. liberal model versus the European social model.

    Science.gov (United States)

    Navarro, Vicente; Schmitt, John

    2005-01-01

    This article begins by challenging the widely held view in neoliberal discourse that there is a necessary trade-off between higher efficiency and lower reduction of inequalities: the article empirically shows that the liberal, U.S. model has been less efficient economically (slower economic growth, higher unemployment) than the social model in existence in the European Union and in the majority of its member states. Based on the data presented, the authors criticize the adoption of features of the liberal model (such as deregulation of their labor markets, reduction of public social expenditures) by some European governments. The second section analyzes the causes for the slowdown of economic growth and the increase of unemployment in the European Union--that is, the application of monetarist and neoliberal policies in the institutional frame of the European Union, including the Stability Pact, the objectives and modus operandi of the European Central Bank, and the very limited resources available to the European Commission for stimulating and distributive functions. The third section details the reasons for these developments, including (besides historical considerations) the enormous influence of financial capital in the E.U. institutions and the very limited democracy. Proposals for change are included.

  8. Nonlinear economic dynamics and financial modelling: essays in honour of Carl Chiarella

    NARCIS (Netherlands)

    Dieci, R.; He, X.Z.; Hommes, C.

    2014-01-01

    This book reflects the state of the art on nonlinear economic dynamics, financial market modelling and quantitative finance. It contains eighteen papers with topics ranging from disequilibrium macroeconomics, monetary dynamics, monopoly, financial market and limit order market models with boundedly

  9. Practical Validation of Economic Efficiency Modelling Method for Multi-Boiler Heating System

    Directory of Open Access Journals (Sweden)

    Aleksejs Jurenoks

    2017-12-01

    Full Text Available In up-to-date conditions information technology is frequently associated with the modelling process, using computer technology as well as information networks. Statistical modelling is one of the most widespread methods of research of economic systems. The selection of methods of modelling of the economic systems depends on a great number of conditions of the researched system. Modelling is frequently associated with the factor of uncertainty (or risk, who’s description goes outside the confines of the traditional statistical modelling, which, in its turn, complicates the modelling which, in its turn, complicates the modelling process. This article describes the modelling process of assessing the economic efficiency of a multi-boiler adaptive heating system in real-time systems which allows for dynamic change in the operation scenarios of system service installations while enhancing the economic efficiency of the system in consideration.

  10. Petroleum Refinery Jobs and Economic Development Impact (JEDI) Model User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Marshall [MRG and Associates, Nevada City, CA (United States)

    2013-12-31

    The Jobs and Economic Development Impact (JEDI) models, developed through the National Renewable Energy Laboratory (NREL), are user-friendly tools utilized to estimate the economic impacts at the local level of constructing and operating fuel and power generation projects for a range of conventional and renewable energy technologies. The JEDI Petroleum Refinery Model User Reference Guide was developed to assist users in employing and understanding the model. This guide provides information on the model's underlying methodology, as well as the parameters and references used to develop the cost data utilized in the model. This guide also provides basic instruction on model add-in features, operation of the model, and a discussion of how the results should be interpreted. Based on project-specific inputs from the user, the model estimates job creation, earning and output (total economic activity) for a given petroleum refinery. This includes the direct, indirect and induced economic impacts to the local economy associated with the refinery's construction and operation phases. Project cost and job data used in the model are derived from the most current cost estimations available. Local direct and indirect economic impacts are estimated using economic multipliers derived from IMPLAN software. By determining the regional economic impacts and job creation for a proposed refinery, the JEDI Petroleum Refinery model can be used to field questions about the added value refineries may bring to the local community.

  11. Studies on the products resulting from the conversion of aspen poplar to an oil

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M; Zohdi, H

    1981-01-01

    The reactions involved in the conversion of aspen poplar into a variety of chemical products as a result of its interaction with CO and H/sub 2/O in the presence of Na/sub 2/CO/sub 3/ at elevated temperatures and pressures are considered. The original C content of the wood is distributed between an oil phase, a complex mixture of highly oxygenated H/sub 2/O-soluble products many of which were identified as low-molecular-weight aliphatic alcohols, ketones, and acids, and a gaseous phase consisting of mainly H and CO/sub 2/. Using model substances (cellulose, cellobiose, -D-glucose, D-fructose, D-xylose, sorbitol, glycerol, and an isolated lignin) information was obtained on the origin of the oil and of the H/sub 2/O-soluble products. Studies at 160 degrees - 360 degrees revealed a marked exothermic reaction occurring at 200-240 degrees for wood and cellulose, which was reflected in the nature of the resulting product. With increasing temperature an increase in the yields of the H/sub 2/O-souluble derivatives and also a change in their relative abundance was observed.

  12. Bioenergy harvest impacts to biodiversity and resilience vary across aspen-dominated forest ecosystems in the Lake States region, USA

    Science.gov (United States)

    Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik; Kris Verheyen

    2016-01-01

    Questions: Does the increase in disturbance associated with removing harvest residues negatively impact biodiversity and resilience in aspen-dominated forest ecosystems? How do responses of functional diversity measures relate to community recovery and standing biomass? Location: Aspen (Populus tremuloides, Michx.) mixedwood forests in Minnesota...

  13. Summary and abstracts from Sudden Aspen Decline (SAD) Meeting; Fort Collins, Colorado, February 12-13, 2008

    Science.gov (United States)

    Paul C. Rogers

    2008-01-01

    In recent years the aspen research and management community has witnessed increasing accounts of unexplained aspen die-offs across the Rocky Mountain region. In response, two meetings were held to address the issue; this paper summarizes the most recent gathering, a symposium held in Fort Collins at the USDA Forest Service, Rocky Mountain Research Station, on February...

  14. Moderate-scale mapping methods of aspen stand types: a case study for Cedar Mountain in southern Utah

    Science.gov (United States)

    Chad M. Oukrop; David M. Evans; Dale L. Bartos; R. Douglas Ramsey; Ronald J. Ryel

    2011-01-01

    Quaking aspen (Populus tremuloides Michx.) are the most widely distributed tree species across North America, but its dominance is declining in many areas of the western United States, with certain areas experiencing rapid mortality events over the past decade. The loss of aspen from western landscapes will continue to profoundly impact biological, commercial, and...

  15. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

    Science.gov (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  16. The current Russian model of social development, and economic growth

    Directory of Open Access Journals (Sweden)

    V V Paramonov

    2016-12-01

    Full Text Available Although the Article 7 of the Constitution of Russia adopted in 1993 defines the country as a social state, the contemporary social and economic situation is significantly different from this declaration. The author considers the current situation focusing on the foundations of the welfare state. The indicators of social inequality and stratification that allow to identify the country as a social state prove the widening gap between the rich and poor. In recent years, nothing has been done to achieve the more equitable distribution of income and national wealth, which led to the further growth of social inequality exceeding the global indices. The author believes that the high level of social inequality negatively affects the economic growth. Based on the studies of Russian scientists he concludes that equal distribution of income provides higher rates of economic growth and prosperity of the country. The modified theory of the factors of production explains this interconnection, and adds a few more factors, including such a specific resource as sales market, to three factors introduced by J.B. Say at the beginning of the XIX century. The huge social inequality and, consequently, a significant number of the poor deprive the country of such an important resource. To change the situation, the author proposes to return to the progressive tax scale and introduce the zero rate of income tax for the poorest groups in order to create prerequisites for the growth of consumer demand under the economic crisis.

  17. JEDI for Advanced Users | Jobs and Economic Development Impact Models |

    Science.gov (United States)

    discussion. Users with more experience with power generation projects and/or economic impact analysis can , earnings, and output (per million dollars change in final demand) as well as personal consumption Services Professional Services Retail Trade Transportation, Communication and Public Utilities Wholesale

  18. Folk-Economic Beliefs: An Evolutionary Cognitive Model.

    Science.gov (United States)

    Boyer, Pascal; Petersen, Michael Bang

    2017-10-12

    The domain of "folk-economics" consists in explicit beliefs about the economy held by laypeople, untrained in economics, about such topics as e.g., the causes of the wealth of nations, the benefits or drawbacks of markets and international trade, the effects of regulation, the origins of inequality, the connection between work and wages, the economic consequences of immigration, or the possible causes of unemployment. These beliefs are crucial in forming people's political beliefs, and in shaping their reception of different policies. Yet, they often conflict with elementary principles of economic theory and are often described as the consequences of ignorance, irrationality or specific biases. As we will argue, these past perspectives fail to predict the particular contents of popular folk-economic beliefs and, as a result, there is no systematic study of the cognitive factors involved in their emergence and cultural success. Here we propose that the cultural success of particular beliefs about the economy is predictable if we consider the influence of specialized, largely automatic inference systems that evolved as adaptations to ancestral human small-scale sociality. These systems, for which there is independent evidence, include free-rider detection, fairness-based partner-choice, ownership intuitions, coalitional psychology, and more. Information about modern mass-market conditions activates these specific inference-systems, resulting in particular intuitions, e.g., that impersonal transactions are dangerous or that international trade is a zero-sum game. These intuitions in turn make specific policy proposals more likely than others to become intuitively compelling, and as a consequence exert a crucial influence on political choices.

  19. Integrating global socio-economic influences into a regional land use change model for China

    Science.gov (United States)

    Xu, Xia; Gao, Qiong; Peng, Changhui; Cui, Xuefeng; Liu, Yinghui; Jiang, Li

    2014-03-01

    With rapid economic development and urbanization, land use in China has experienced huge changes in recent years; and this will probably continue in the future. Land use problems in China are urgent and need further study. Rapid land-use change and economic development make China an ideal region for integrated land use change studies, particularly the examination of multiple factors and global-regional interactions in the context of global economic integration. This paper presents an integrated modeling approach to examine the impact of global socio-economic processes on land use changes at a regional scale. We develop an integrated model system by coupling a simple global socio-economic model (GLOBFOOD) and regional spatial allocation model (CLUE). The model system is illustrated with an application to land use in China. For a given climate change, population growth, and various socio-economic situations, a global socio-economic model simulates the impact of global market and economy on land use, and quantifies changes of different land use types. The land use spatial distribution model decides the type of land use most appropriate in each spatial grid by employing a weighted suitability index, derived from expert knowledge about the ecosystem state and site conditions. A series of model simulations will be conducted and analyzed to demonstrate the ability of the integrated model to link global socioeconomic factors with regional land use changes in China. The results allow an exploration of the future dynamics of land use and landscapes in China.

  20. Scenario Analysis With Economic-Energy Systems Models Coupled to Simple Climate Models

    Science.gov (United States)

    Hanson, D. A.; Kotamarthi, V. R.; Foster, I. T.; Franklin, M.; Zhu, E.; Patel, D. M.

    2008-12-01

    Here, we compare two scenarios based on Stanford University's Energy Modeling Forum Study 22 on global cooperative and non-cooperative climate policies. In the former, efficient transition paths are implemented including technology Research and Development effort, energy conservation programs, and price signals for greenhouse gas (GHG) emissions. In the non-cooperative case, some countries try to relax their regulations and be free riders. Total emissions and costs are higher in the non-cooperative scenario. The simulations, including climate impacts, run to the year 2100. We use the Argonne AMIGA-MARS economic-energy systems model, the Texas AM University's Forest and Agricultural Sector Optimization Model (FASOM), and the University of Illinois's Integrated Science Assessment Model (ISAM), with offline coupling between the FASOM and AMIGA-MARS and an online coupling between AMIGA-MARS and ISAM. This set of models captures the interaction of terrestrial systems, land use, crops and forests, climate change, human activity, and energy systems. Our scenario simulations represent dynamic paths over which all the climate, terrestrial, economic, and energy technology equations are solved simultaneously Special attention is paid to biofuels and how they interact with conventional gasoline/diesel fuel markets. Possible low-carbon penetration paths are based on estimated costs for new technologies, including cellulosic biomass, coal-to-liquids, plug-in electric vehicles, solar and nuclear energy. We explicitly explore key uncertainties that affect mitigation and adaptation scenarios.

  1. MULTIREGION: a simulation-forecasting model of BEA economic area population and employment. [Bureau of Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R.J.; Westley, G.W.; Herzog, H.W. Jr.; Kerley, C.R.; Bjornstad, D.J.; Vogt, D.P.; Bray, L.G.; Grady, S.T.; Nakosteen, R.A.

    1977-10-01

    This report documents the development of MULTIREGION, a computer model of regional and interregional socio-economic development. The MULTIREGION model interprets the economy of each BEA economic area as a labor market, measures all activity in terms of people as members of the population (labor supply) or as employees (labor demand), and simultaneously simulates or forecasts the demands and supplies of labor in all BEA economic areas at five-year intervals. In general the outputs of MULTIREGION are intended to resemble those of the Water Resource Council's OBERS projections and to be put to similar planning and analysis purposes. This report has been written at two levels to serve the needs of multiple audiences. The body of the report serves as a fairly nontechnical overview of the entire MULTIREGION project; a series of technical appendixes provide detailed descriptions of the background empirical studies of births, deaths, migration, labor force participation, natural resource employment, manufacturing employment location, and local service employment used to construct the model.

  2. Techno-economic and environmental assessment of biogas production from banana peel (Musa paradisiaca) in a biorefinery concept.

    Science.gov (United States)

    Martínez-Ruano, Jimmy Anderson; Caballero-Galván, Ashley Sthefanía; Restrepo-Serna, Daissy Lorena; Cardona, Carlos Ariel

    2018-04-07

    Two scenarios for the biogas production using Banana Peel as raw material were evaluated. The first scenario involves the stand-alone production of biogas and the second scenario includes the biogas production together with other products under biorefinery concept. In both scenarios, the influence of the production scale on the process economy was assessed and feasibility limits were defined. For this purpose, the mass and energy balances were established using the software Aspen Plus along with kinetic models reported in the literature. The economic and environmental analysis of the process was performed considering Colombian economic conditions. As a result, it was found that different process scales showed great potential for biogas production. Thus, plants with greater capacity have a greater economic benefit than those with lower capacity. However, this benefit leads to high-energy consumption and greater environmental impact.

  3. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  4. Defensive effects of extrafloral nectaries in quaking aspen differ with scale.

    Science.gov (United States)

    Mortensen, Brent; Wagner, Diane; Doak, Patricia

    2011-04-01

    The effects of plant defenses on herbivory can differ among spatial scales. This may be particularly common with indirect defenses, such as extrafloral nectaries (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive effects of EFNs in quaking aspen (Populus tremuloides Michx.) against damage by a specialist herbivore, the aspen leaf miner (Phyllocnistis populiella Cham.), at the scale of individual leaves and entire ramets (i.e., stems). Experiments excluding crawling arthropods revealed that the effects of aspen EFNs differed at the leaf and ramet scales. Crawling predators caused similar reductions in the percent leaf area mined on individual leaves with and without EFNs. However, the extent to which crawling predators increased leaf miner mortality and, consequently, reduced mining damage increased with EFN expression at the ramet scale. Thus, aspen EFNs provided a diffuse defense, reducing damage to leaves across a ramet regardless of leaf-scale EFN expression. We detected lower leaf miner damage and survival unassociated with crawling predators on EFN-bearing leaves, suggesting that direct defenses (e.g., chemical defenses) were stronger on leaves with than without EFNs. Greater direct defenses on EFN-bearing leaves may reduce the probability of losing these leaves and thus weakening ramet-scale EFN defense. Aspen growth was not related to EFN expression or the presence of crawling predators over the course of a single season. Different effects of aspen EFNs at the leaf and ramet scales suggest that future studies may benefit from examining indirect defenses simultaneously at multiple scales.

  5. MODELS OF APPLICATION ECONOMIC VALUE ADDED IN AUTOMOTIVE COMPANY

    Directory of Open Access Journals (Sweden)

    Eva MALICHOVA

    2017-09-01

    Full Text Available Enterprises are currently trying to bring new technologies into production and use new procedures and recommendations in various management activities. However, they should not forget to change their approach to the evaluation of the results achieved and focus on the use of modern methods of performance evaluation and prove to apply them in their enterprises. The aim of this paper is to point out several variants of the calculation of Economic value added (EVA indicator, define the possibilities to apply EVA methods to the conditions of enterprises in the Slovak Republic and the need to adjust data providing financial statements and data for current accounts. Application of economic value added should be able to contribute to changes in the views of the owners and managers of enterprises in the Slovak republic for use not only as financial indicators.

  6. Chaos control in an economic model via minimum entropy strategy

    Energy Technology Data Exchange (ETDEWEB)

    Salarieh, Hassan [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 11365-9567, Tehran (Iran, Islamic Republic of)], E-mail: salarieh@mech.sharif.edu; Alasty, Aria [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 11365-9567, Tehran (Iran, Islamic Republic of); National Research Institute for Science Policy (NRISP), Soheil Street, Shirazi Avenue, Tehran (Iran, Islamic Republic of)], E-mail: aalasti@sharif.edu

    2009-04-30

    In this paper, minimum entropy algorithm for controlling chaos, is applied to a Cournot duopoly with different constant marginal costs, as a discrete-time dynamical system which shows chaotic behavior. The ME control is implemented through delayed feedback. It is assumed that the equations of the dynamical system are not known, so the feedback gain cannot be obtained analytically from the system equations. In the ME method the feedback gain is obtained adaptively in such a way that the entropy of the system converges to zero, hence a fixed point of the system will be stabilized. Application of the proposed method with different economic control strategies is numerically investigated. Simulation results show the effectiveness of the ME method for controlling chaos in economic systems with unknown equations.

  7. Review of whole-farm economic modelling for irrigation farming ...

    African Journals Online (AJOL)

    Optimisation models take the opportunity cost of water into account while ... against the extra time needed to validate models and generate the required information. ... Modelling decision-making by means of a single-attribute utility function is ...

  8. Legal and Economic Aspects of the Macedonian Model of Franchising

    OpenAIRE

    Sotiroski, Ljupco; Filiposki, Oliver

    2016-01-01

    Franchising is done by global regulatory framework and has an impact to the national legal sources. This article aims to emphasize the importance and functionality of the legal and economic aspects of the Macedonian franchising module and practice. In respect of Macedonian case, the franchising mechanism is getting direct consequences of the national trade in the small and still developing Macedonian economy. The envisaged paper explores various options for national regulation in light of exi...

  9. Economics of extreme weather events: Terminology and regional impact models

    OpenAIRE

    Jahn, Malte

    2015-01-01

    Impacts of extreme weather events are relevant for regional (in the sense of subnational) economies and in particular cities in many aspects. Cities are the cores of economic activity and the amount of people and assets endangered by extreme weather events is large, even under the current climate. A changing climate with changing extreme weather patterns and the process of urbanization will make the whole issue even more relevant in the future. In this paper, definitions and terminology in th...

  10. Coupled flare attractors – a discrete prototype for economic modelling

    Directory of Open Access Journals (Sweden)

    Georg C. Hartmann

    1999-01-01

    Full Text Available A chaotic environment can give rise to “flares” if an autocatalytic variable responds in a multiplicative, threshold-type fashion to the environmental forcing. An “economic unit” similarly depends in its growth behavior on the unpredictable (chaotic? buying habits of its customers, say. It turns out that coupled flare attractors are surprisingly robust in the sense that the resulting “economy” is largely independent of the extent of diffusive coupling used. Some simulations are presented.

  11. Aligning economic impact with environmental benefits: a green strategy model

    OpenAIRE

    Gu, Q.; Lago, P.; Potenza, S.

    2012-01-01

    To achieve lower energy consumption many green strategies (e.g. virtualize applications and consolidate them on shared server machines, or optimize the usage of the private cloud by opening up to external consumers) have been discussed. In practice, however, the major incentive for a company to go green is reducing costs. While green strategies often focus on technical and environmental issues, they hardly address the economic impact that they may bring. If green strategies do not lead to an ...

  12. The impact of remittances on economic growth: An econometric model

    Directory of Open Access Journals (Sweden)

    Dietmar Meyer

    2017-05-01

    In other words, the econometric analysis will be based on those six remittance receiving countries. The paper is then to review the empirical literature devoted to the impact of remittances on economic growth, in order, to identify empirically if there are significant relationships between remittances and growth in these countries. The results suggest that remittances have a positive impact on growth and that this impact increases at higher levels of remittances relative to GDP.

  13. An Agent-Based Dynamic Model of Politics, Fertility and Economic Development

    OpenAIRE

    Zining Yang

    2016-01-01

    In the political economy of development, government policy choices at a single point in time can dramatically affect a country's development path by impacting fertility, economic and political decisions across generations. Combining system dynamics and agent-based modeling approaches in a complex adaptive system, a simulation framework of the Politics of Fertility and Economic Development (POFED) is formalized to understand the relationship between politics, economic, and demography change at...

  14. Technical and economic assessment of processes for the production of butanol and acetone

    Science.gov (United States)

    1982-01-01

    This report represents a preliminary technical and economic evaluation of a process which produces mixed solvents (butaol/acetone/ethanol) via fermentation of sugars derived from renewable biomass resources. The objective is to assess the technology of producing butanol/acetone from biomass, and select a viable process capable of serving as a base case model for technical and economic analysis. It is anticipated that the base case process developed herein can then be used as the basis for subsequent studies concerning biomass conversion processes capable of producing a wide range of chemicals. The general criteria utilized in determining the design basis for the process are profit potential and non-renewable energy displacement potential. The feedstock chosen, aspen wood, was selected from a number of potential renewable biomass resources as the most readily available in the United States and for its relatively large potential for producing reducing sugars.

  15. Optimal model of economic diplomacy of Republic of Croatia in the contexst of global intelligence revolution

    Directory of Open Access Journals (Sweden)

    Zdravko Bazdan

    2010-12-01

    Full Text Available The aim of this study is to point to the fact that economic diplomacy is a relatively new practice in international economics, specifically the expansion of the occurrence of Intelligence Revolution. The history in global relations shows that without economic diplomacy there is no optimal economic growth and social development. It is important to note that economic diplomacy should be important for our country and the political elite, as well as for the administration of Croatian economic subjects that want to compete in international market economy. Comparative analysis are particularly highlighted by French experience. Therefore, Croatia should copy the practice of those countries that are successful in economic diplomacy. And in the curricula - especially of our economic faculties - we should introduce the course of Economic Diplomacy. It is important to note, that in order to form our optimal model of economic diplomacy which would be headed by the President of Republic of Croatia formula should be based on: Intelligence Security Agency (SOA, Intelligence Service of the Ministry of Foreign Affairs and European Integration, Intelligence Service of the Croatian Chamber of Commerce and the Intelligence Service of the Ministry of Economy, Labor and Entrepreneurship. Described model would consist of intelligence subsystem with at least twelve components.

  16. Quantitative Analysis of Intra Urban Growth Modeling using socio economic agents by combining cellular automata model with agent based model

    Science.gov (United States)

    Singh, V. K.; Jha, A. K.; Gupta, K.; Srivastav, S. K.

    2017-12-01

    Recent studies indicate that there is a significant improvement in the urban land use dynamics through modeling at finer spatial resolutions. Geo-computational models such as cellular automata and agent based model have given evident proof regarding the quantification of the urban growth pattern with urban boundary. In recent studies, socio- economic factors such as demography, education rate, household density, parcel price of the current year, distance to road, school, hospital, commercial centers and police station are considered to the major factors influencing the Land Use Land Cover (LULC) pattern of the city. These factors have unidirectional approach to land use pattern which makes it difficult to analyze the spatial aspects of model results both quantitatively and qualitatively. In this study, cellular automata model is combined with generic model known as Agent Based Model to evaluate the impact of socio economic factors on land use pattern. For this purpose, Dehradun an Indian city is selected as a case study. Socio economic factors were collected from field survey, Census of India, Directorate of economic census, Uttarakhand, India. A 3X3 simulating window is used to consider the impact on LULC. Cellular automata model results are examined for the identification of hot spot areas within the urban area and agent based model will be using logistic based regression approach where it will identify the correlation between each factor on LULC and classify the available area into low density, medium density, high density residential or commercial area. In the modeling phase, transition rule, neighborhood effect, cell change factors are used to improve the representation of built-up classes. Significant improvement is observed in the built-up classes from 84 % to 89 %. However after incorporating agent based model with cellular automata model the accuracy improved from 89 % to 94 % in 3 classes of urban i.e. low density, medium density and commercial classes

  17. The economic efficiency of conservation measures for amphibians in organic farming--results from bio-economic modelling.

    Science.gov (United States)

    Schuler, Johannes; Sattler, Claudia; Helmecke, Angela; Zander, Peter; Uthes, Sandra; Bachinger, Johann; Stein-Bachinger, Karin

    2013-01-15

    This paper presents a whole farm bio-economic modelling approach for the assessment and optimisation of amphibian conservation conditions applied at the example of a large scale organic farm in North-Eastern Germany. The assessment focuses mainly on the habitat quality as affected by conservation measures such as through specific adapted crop production activities (CPA) and in-field buffer strips for the European tree frog (Hyla arborea), considering also interrelations with other amphibian species (i.e. common spadefoot toad (Pelobates fuscus), fire-bellied toad (Bombina bombina)). The aim of the approach is to understand, analyse and optimize the relationships between the ecological and economic performance of an organic farming system, based on the expectation that amphibians are differently impacted by different CPAs. The modelling system consists of a set of different sub-models that generate a farm model on the basis of environmentally evaluated CPAs. A crop-rotation sub-model provides a set of agronomically sustainable crop rotations that ensures overall sufficient nitrogen supply and controls weed, pest and disease infestations. An economic sub-model calculates the gross margins for each possible CPA including costs of inputs such as labour and machinery. The conservation effects of the CPAs are assessed with an ecological sub-model evaluates the potential negative or positive effect that each work step of a CPA has on amphibians. A mathematical programming sub-model calculates the optimal farm organization taking into account the limited factors of the farm (e.g. labour, land) as well as ecological improvements. In sequential model runs, the habitat quality is to be improved by the model, while the highest possible gross margin is still to be achieved. The results indicate that the model can be used to show the scope of action that a farmer has to improve habitat quality by reducing damage to amphibian population on its land during agricultural activities

  18. On the economic benefit of utility based estimation of a volatility model

    OpenAIRE

    Adam Clements; Annastiina Silvennoinen

    2009-01-01

    Forecasts of asset return volatility are necessary for many financial applications, including portfolio allocation. Traditionally, the parameters of econometric models used to generate volatility forecasts are estimated in a statistical setting and subsequently used in an economic setting such as portfolio allocation. Differences in the criteria under which the model is estimated and applied may inhibit reduce the overall economic benefit of a model in the context of portfolio allocation. Thi...

  19. Simulation of the SSC [Superconducting Super Collider] refrigeration system using the ASPEN/SP process simulator

    International Nuclear Information System (INIS)

    Rasson, J.; Dweck, J.

    1990-08-01

    The SSC Magnet must maintain at a super conducting temperature of 4 K. The proposed refrigeration cooling processes consist of fairly simple closed cycles which take advantage of the Joule-Thompson effect via a series of expansions and compressions of helium gas which has been precooled by liquid nitrogen. The processes currently under consideration consist of three cycles, the 20 K shield cooling, the 45 K helium refrigerator and the helium liquefier. The process units which are to be employed are compressors, turbines, expanders, mixers, flashes, two stream heat exchangers and multiple stream heat exchangers. The cycles are to be operated at or near steady state. Due to the large number of competing cooling sector designs to be considered and the high capital and operating costs of the proposed processes, the SSC Laboratory requires a software tool for the validation and optimization of the individual designs and for the performance of cost-benefit analyses among competing designs. Since these processes are steady state flow processes involving primarily standard unit operations, a decision was made to investigate the application of a commercial process simulator to the task. Several months of internal evaluations by the SSC Laboratory revealed that while the overall structure and calculation approach of number of the commercial simulators were appropriate for this task, all were lacking essential capabilities in the areas of thermodynamic property calculations for cryogenic systems and modeling of complex, multiple stream heat exchangers. An acceptable thermodynamics model was provided and a series of simple, but representative benchmark problems developed. The model and problems were provided to three software vendors. Based on the results of the benchmark test, the ASPEN/SP process simulator was selected for future modeling work

  20. Economic impacts of climate change. Flooding and salinity in scenarios, models and cases

    International Nuclear Information System (INIS)

    Jonkhoff, W.; Koops, O.; Van der Krogt, R.; Oude Essink, G.; Rietveld, E.

    2008-07-01

    In this report, climatic and economic scenarios are combined and future risks are calculated for the consequences of climate change, such as a rising sea level, flooding, extreme draughts and salinity. The calculation of these economic effects of climate change are based on climate scenarios of the KNMI (Royal Dutch Meteorological Institute), TNO's RAEM model (Spatial General Economic Model), the high tide information system of the Dutch Ministry of Waterways and Public Works and the Space scanner of the Environmental Assessment Agency. Next to information on scenarios and models, this report also addresses damage calculations of flooding near Lopik and Ter Heide. The report ends with policy recommendations for adaptation policy. [mk] [nl

  1. Economic modeling using evolutionary algorithms : the effect of binary encoding of strategies

    NARCIS (Netherlands)

    Waltman, L.R.; Eck, van N.J.; Dekker, Rommert; Kaymak, U.

    2011-01-01

    We are concerned with evolutionary algorithms that are employed for economic modeling purposes. We focus in particular on evolutionary algorithms that use a binary encoding of strategies. These algorithms, commonly referred to as genetic algorithms, are popular in agent-based computational economics

  2. Economic Disadvantage in Complex Family Systems: Expansion of Family Stress Models

    Science.gov (United States)

    Barnett, Melissa A.

    2008-01-01

    Economic disadvantage is associated with multiple risks to early socioemotional development. This article reviews research regarding family stress frameworks to model the pathways from economic disadvantage to negative child outcomes via family processes. Future research in this area should expand definitions of family and household to incorporate…

  3. Medium-term electric power demand forecasting based on economic-electricity transmission model

    Science.gov (United States)

    Li, Wenfeng; Bao, Fangmin; Bai, Hongkun; Liu, Wei; Liu, Yongmin; Mao, Yubin; Wang, Jiangbo; Liu, Junhui

    2018-06-01

    Electric demand forecasting is a basic work to ensure the safe operation of power system. Based on the theories of experimental economics and econometrics, this paper introduces Prognoz Platform 7.2 intelligent adaptive modeling platform, and constructs the economic electricity transmission model that considers the economic development scenarios and the dynamic adjustment of industrial structure to predict the region's annual electricity demand, and the accurate prediction of the whole society's electricity consumption is realized. Firstly, based on the theories of experimental economics and econometrics, this dissertation attempts to find the economic indicator variables that drive the most economical growth of electricity consumption and availability, and build an annual regional macroeconomic forecast model that takes into account the dynamic adjustment of industrial structure. Secondly, it innovatively put forward the economic electricity directed conduction theory and constructed the economic power transfer function to realize the group forecast of the primary industry + rural residents living electricity consumption, urban residents living electricity, the second industry electricity consumption, the tertiary industry electricity consumption; By comparing with the actual value of economy and electricity in Henan province in 2016, the validity of EETM model is proved, and the electricity consumption of the whole province from 2017 to 2018 is predicted finally.

  4. Multi-Attribute Modelling of Economic and Ecological Impacts of Cropping Systems

    NARCIS (Netherlands)

    Bohanec, M.; Dzeroski, S.; Znidarsic, M.; Messéan, A.; Scatasta, S.; Wesseler, J.H.H.

    2004-01-01

    Modelling of economic and ecological impacts of genetically modified crops is a demanding task. We present some preliminary attempts made for the purpose of the ECOGEN project "Soil ecological and economic evaluation of genetically modified crops". One of the goals of the project is to develop a

  5. An economic theory-based explanatory model of agricultural land-use patterns

    NARCIS (Netherlands)

    Diogo, V.; Koomen, E.; Kuhlman, T.

    2015-01-01

    An economic theory-based land-use modelling framework is presented aiming to explain the causal link between economic decisions and resulting spatial patterns of agricultural land use. The framework assumes that farmers pursue utility maximisation in agricultural production systems, while

  6. Firm dynamic analysis for urban land use and economic growth modelling

    NARCIS (Netherlands)

    Che'Man, N.; Sabri, S.; Hosni, N.; Timmermans, H.J.P.

    2013-01-01

    In urban growth processes, urbanisation is highly influenced by economic growth which triggers the dynamics of economic agents and land uses. This is consisted of complex subsystems which need sophisticated methods like agent-based modelling and simulation to understand the pattern, behaviour and

  7. Foreword to the Special Issue on "Dynamic Models in Economics and Finance"

    Science.gov (United States)

    Gardini, Laura; Kubin, Ingrid; Tramontana, Fabio; Wagener, Florian

    2018-05-01

    International workshops on Dynamic Models in Economics and Finance (MDEF) take place every two years in Urbino (Italy); since the inception of the series in 2000, there have been nine editions. The subject has become a central topic for scholars working on economic dynamics. In 2016 the workshop was held under the auspices of University of Urbino "Carlo Bo" , DESP1

  8. Multi-basin, Multi-sector Drought Economic Impact Model in Python: Development and Applications

    Science.gov (United States)

    Gutenson, J. L.; Zhu, L.; Ernest, A. N. S.; Oubeidillah, A.; Bearden, B.; Johnson, T. G.

    2015-12-01

    Drought is one of the most economically disastrous natural hazards, one whose impacts are exacerbated by the lack of abrupt onset and offset that define tornados and hurricanes. In the United States, about 30 billion dollars losses is caused by drought in 2012, resulting in widespread economic impacts for societies, industries, agriculture, and recreation. And in California, the drought cost statewide economic losses about 2.2 billion, with a total loss of 17,100 seasonal and part-time jobs. Driven by a variety of factors including climate change, population growth, increased water demands, alteration to land cover, drought occurs widely all over the world. Drought economic consequence assessment tool are greatly needed to allow decision makers and stakeholders to anticipate and manage effectively. In this study, current drought economic impact modeling methods were reviewed. Most of these models only deal with the impact in the agricultural sector with a focus on a single basin; few of these models analyze long term impact. However, drought impacts are rarely restricted to basin boundaries, and cascading economic impacts are likely to be significant. A holistic approach to multi-basin, multi-sector drought economic impact assessment is needed.In this work, we developed a new model for drought economic impact assessment, Drought Economic Impact Model in Python (PyDEM). This model classified all business establishments into thirteen categories based on NAICS, and using a continuous dynamic social accounting matrix approach, coupled with calculation of the indirect consequences for the local and regional economies and the various resilience. In addition, Environmental Policy Integrated Climate model was combined for analyzing drought caused soil erosion together with agriculture production, and then the long term impacts of drought were achieved. A visible output of this model was presented in GIS. In this presentation, Choctawhatchee-Pea-Yellow River Basins, Alabama

  9. Ecological-economic modeling for biodiversity management: potential, pitfalls, and prospects

    NARCIS (Netherlands)

    Wätzold, F.; Drechsler, M.; Armstrong, C.W.; Baumgärtner, S.; Grimm, V.; Huth, A.; Perrings, C.; Possingham, H.P.; Shogren, J.F.; Skonhoft, A.; Verboom-Vasiljev, J.; Wissel, C.

    2006-01-01

    Ecologists and economists both use models to help develop strategies for biodiversity management. The practical use of disciplinary models, however, can be limited because ecological models tend not to address the socioeconomic dimension of biodiversity management, whereas economic models tend to

  10. Economics as a factor in models of behavioral motivation and change.

    Science.gov (United States)

    Montoya, I D; Atkinson, J S; Trevino, R A

    2000-02-01

    This note first presents a summary of four main behavioral models that are used to explain behavioral motivation and change. Three models are based on psychosocial theory. They are: 1) the Theory of Reasoned Action, 2) the Theory of Planned Behavior, and 3) the Theory of Stages-of-Change. The fourth model is based on economic theory and is known as the Rational Addiction Model. Each model is analyzed for its strengths and weaknesses. The note concludes by arguing for the usefulness of integrating the economic and the psychosocial models to study drug use. Specific examples and suggestions are presented.

  11. Green and economic fleet replacement modeling : part I.

    Science.gov (United States)

    2011-10-01

    "The purpose of this study was to gain a better understanding of how equipment replacement decisions are supported with data collection and : quantitative models at state DOTs, and to determine if models found in the research literature offer any bet...

  12. Discounting the future: influence of the economic model.

    Science.gov (United States)

    West, R R

    1996-06-01

    To consider the effect of the economic discount rate on health care policy and the rationale for discounting the collective future of society generally. A review of the concept of discounting the future vis à vis the present from the points of view of individuals (who pass on) and of societies (that continue) and reconsideration of the application of discounting to typical public health scenarios. A public health service, within a basically stable society, which can reasonably anticipate a nearly certain future. Discounting necessarily overvalues the "here and now" compared with the future. While applications of discount rates, typical of those employed in health economic studies in recent years, may seem rational in health care programmes directed at middle aged employed people, they do not for the young and the elderly, important recipients of health care. The consequences of discounting do not accord with the aims and objectives of public health. The "time preferences" of transient individuals within a stable society do not provide a rational basis for time preference of a stable society collectively. Discounting inevitably encourages "short termism" and hence biases public policy decision making. The neoclassical theory that gave rise to the concept of discounting requires revision.

  13. Model integration and the economics of nuclear power

    International Nuclear Information System (INIS)

    Lundgren, S.

    1985-01-01

    The author proposes and applies a specific approach to model integration, i.e. the merger of two or several independently developed models. The approach is intended for integrations of activity analysis sector models and applied general equilibrium models. Model integration makes it possible to extend the range of applicability of applied general equilibrium models by exploiting the information contained in sector models. It also makes it possible to evaluate the validity of the partial equilibrium analyses in which sector models often are employed. The proposed approach is used to integrate a sector model of electricity and heat production with a general equilibrium model of the Swedish economy. Both models have been constructed within the research programme. The author uses the integrated model to look at two issues concerning the role of nuclear power on the Swedish electricity market: What are the likely consequences of a nuclear power discontinuation and how does the nuclear power investment programme of the 1970's and the early 1980's compare with a socially efficient one. (Author)

  14. Characterizing economic trends by Bayesian stochastic model specification search

    DEFF Research Database (Denmark)

    Grassi, Stefano; Proietti, Tommaso

    We extend a recently proposed Bayesian model selection technique, known as stochastic model specification search, for characterising the nature of the trend in macroeconomic time series. In particular, we focus on autoregressive models with possibly time-varying intercept and slope and decide on ...

  15. Stability and the structure of continuous-time economic models

    NARCIS (Netherlands)

    Nieuwenhuis, H.J.; Schoonbeek, L.

    In this paper we investigate the relationship between the stability of macroeconomic, or macroeconometric, continuous-time models and the structure of the matrices appearing in these models. In particular, we concentrate on dominant-diagonal structures. We derive general stability results for models

  16. ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system

    International Nuclear Information System (INIS)

    Duan, Wenjun; Yu, Qingbo; Wang, Kun; Qin, Qin; Hou, Limin; Yao, Xin; Wu, Tianwei

    2015-01-01

    Highlights: • An integrated system of coal gasification with slag waste heat recovery was proposed. • The goal of BF slag heat saving and emission reduction was achieved by this system. • The optimal parameters were obtained and the waste heat recovery rate reached 83.08%. • About 6.64 kmol/min syngas was produced when using one ton BF slag to provide energy. - Abstract: This article presented a model for the system of coal gasification with steam and blast furnace slag waste heat recovery by using the ASPEN Plus as the simulating and modeling tool. Constrained by mass and energy balance for the entire system, the model included the gasifier used to product syngas at the chemical equilibrium based on the Gibbs free energy minimization approach and the boiler used to recover the heat of the blast furnace slag (BF slag) and syngas. Two parameters of temperature and steam to coal ratio (S/C) were considered to account for their impacts on the Datong coal (DT coal) gasification process. The carbon gasification efficiency (CE), cold gasification efficiency (CGE), syngas product efficiency (PE) and the heating value of syngas produced by 1 kg pulverized coal (HV) were adopted as the indicators to examine the gasification performance. The optimal operating temperature and S/C were 800 °C and 1.5, respectively. At this condition, CE reached above 90% and the maximum values of the CGE, PE and HV were all obtained. Under the optimal operating conditions, 1000 kg/min BF slag, about 40.41 kg/min DT pulverized coal and 77.94 kg/min steam were fed into the gasifier and approximate 6.64 kmol/min syngas could be generated. Overall, the coal was converted to clean syngas by gasification reaction and the BF slag waste heat was also recovered effectively (reached up to 83.08%) in this system, achieving the objective of energy saving and emission reduction

  17. Simulation of the SSC refrigeration system using the ASPEN/SP process simulator

    International Nuclear Information System (INIS)

    Rasson, J.; Dweck, J.

    1990-01-01

    The SSC Magnet must be maintained at a superconducting temperature of 4 K. The proposed refrigeration cooling processes consist of fairly simple closed cycles which take advantage of the Joule-Thompson effect via a series of expansions and compressions of helium gas which has been precooled by liquid nitrogen. The processes currently under consideration consist of three cycles, the 20 K shield cooling, the 4.0 K helium refrigerator and the helium liquefier. The process units which are to be employed are compressors, turbines, expanders, mixers, flashes, two stream heat exchangers and multiple stream heat exchangers. The cycles are to be operated at or near steady state. Due to the large number of competing cooling sector designs to be considered and the high capital and operating costs of the proposed processes, the SSC Laboratory requires a software tool for the validation and optimization of the individual designs and for the performance of cost-benefit analyses among competing designs. Since these processes are steady state flow processes involving primarily standard unit operations, a decision was made to investigate the application of a commercial process simulator to the task. Several months of internal evaluations by the SSC Laboratory revealed that while the overall structure and calculation approach of a number of the commercial simulators were appropriate for this task, all were lacking essential capabilities in the areas of thermodynamic property calculations for cryogenic systems and modeling of complex, multiple stream heat exchangers. An acceptable thermodynamic model was provided and a series of simple, but three software vendors. Based on the results of the benchmark tests, the ASPEN/SP process simulator was selected for future modeling work. 2 refs., 4 figs

  18. Analysis of Economic Burden of Seasonal Influenza: An Actuarial Based Conceptual Model

    Directory of Open Access Journals (Sweden)

    S. S. N. Perera

    2017-01-01

    Full Text Available Analysing the economic burden of the seasonal influenza is highly essential due to the large number of outbreaks in recent years. Mathematical and actuarial models can be considered as management tools to understand the dynamical behavior, predict the risk, and compute it. This study is an attempt to develop conceptual model to investigate the economic burden due to seasonal influenza. The compartment SIS (susceptible-infected-susceptible model is used to capture the dynamical behavior of influenza. Considering the current investment and future medical care expenditure as premium payment and benefit (claim, respectively, the insurance and actuarial based conceptual model is proposed to model the present economic burden due to the spread of influenza. Simulation is carried out to demonstrate the variation of the present economic burden with respect to model parameters. The sensitivity of the present economic burden is studied with respect to the risk of disease spread. The basic reproduction is used to identify the risk of disease spread. Impact of the seasonality is studied by introducing the seasonally varying infection rate. The proposed model provides theoretical background to investigate the economic burden of seasonal influenza.

  19. Towards low carbon business park energy systems: Classification of techno-economic energy models

    International Nuclear Information System (INIS)

    Timmerman, Jonas; Vandevelde, Lieven; Van Eetvelde, Greet

    2014-01-01

    To mitigate climate destabilisation, human-induced greenhouse gas emissions urgently need to be curbed. A major share of these emissions originates from the industry and energy sectors. Hence, a low carbon shift in industrial and business park energy systems is called for. Low carbon business parks minimise energy-related carbon dioxide emissions by maximal exploitation of local renewable energy production, enhanced energy efficiency, and inter-firm heat exchange, combined in a collective energy system. The holistic approach of techno-economic energy models facilitates the design of such systems, while yielding an optimal trade-off between energetic, economic and environmental performances. However, no models custom-tailored for industrial park energy systems are detected in literature. In this paper, existing energy model classifications are scanned for adequate model characteristics and accordingly, a confined number of models are selected and described. Subsequently, a practical typology is proposed, existing of energy system evolution, optimisation, simulation, accounting and integration models, and key model features are compared. Finally, important features for a business park energy model are identified. - Highlights: • A holistic perspective on (low carbon) business park energy systems is introduced. • A new categorisation of techno-economic energy models is proposed. • Model characteristics are described per model category. • Essential model features for business park energy system modelling are identified. • A strategy towards a techno-economic energy model for business parks is proposed

  20. Simulating Quantile Models with Applications to Economics and Management

    Science.gov (United States)

    Machado, José A. F.

    2010-05-01

    The massive increase in the speed of computers over the past forty years changed the way that social scientists, applied economists and statisticians approach their trades and also the very nature of the problems that they could feasibly tackle. The new methods that use intensively computer power go by the names of "computer-intensive" or "simulation". My lecture will start with bird's eye view of the uses of simulation in Economics and Statistics. Then I will turn out to my own research on uses of computer- intensive methods. From a methodological point of view the question I address is how to infer marginal distributions having estimated a conditional quantile process, (Counterfactual Decomposition of Changes in Wage Distributions using Quantile Regression," Journal of Applied Econometrics 20, 2005). Illustrations will be provided of the use of the method to perform counterfactual analysis in several different areas of knowledge.

  1. Danish wind turbines: Technical-economic feasibility of commercial models

    International Nuclear Information System (INIS)

    Falchetta, M.

    1992-01-01

    This feasibility study examines the principal technical and economic (investment-manufacturing-installation-operation unit costs, supply and demand) characteristics of wind turbines being commercialized in Denmark. The general configuration of the 150 to 450 kW range machines currently being manufactured can be described as that of a three bladed fibreglass rotor, of from 24 to 35 meters in diameter, and mounted on a tower of from 29 to 41 meters in height. The electrical system consists of one asynchronous generator or a two generator system with a power ratio of 1 to 5 between the two generators. The cost analysis reveals that the Danish wind turbines are competitively priced, with per kWh costs varying from $0. 0675 to $0. 040 for operating wind speeds ranging from 5 to 7 m/sec, and that their overall design and performance characteristics make them suitable for Italian site conditions

  2. Adaptive institutions? Peasant institutions and natural models facing climatic and economic changes in the Colombian Andes

    NARCIS (Netherlands)

    Feola, Giuseppe

    2017-01-01

    In the Colombian Andes, peasants have co-evolved with their environment for centuries, but it is uncertain whether traditional informal institutions and natural models are adapting to current and possibly unprecedented economic and climatic disturbances. This study investigated institutional

  3. Characterizing economic trends by Bayesian stochastic model specifi cation search

    OpenAIRE

    Grassi, Stefano; Proietti, Tommaso

    2010-01-01

    We apply a recently proposed Bayesian model selection technique, known as stochastic model specification search, for characterising the nature of the trend in macroeconomic time series. We illustrate that the methodology can be quite successfully applied to discriminate between stochastic and deterministic trends. In particular, we formulate autoregressive models with stochastic trends components and decide on whether a specific feature of the series, i.e. the underlying level and/or the rate...

  4. Colocalization of low-methylesterified pectins and Pb deposits in the apoplast of aspen roots exposed to lead

    International Nuclear Information System (INIS)

    Rabęda, Irena; Bilski, Henryk; Mellerowicz, Ewa J.; Napieralska, Anna; Suski, Szymon; Woźny, Adam; Krzesłowska, Magdalena

    2015-01-01

    Low-methylesterified homogalacturonans have been suggested to play a role in the binding and immobilization of Pb in CW. Using root apices of hybrid aspen, a plant with a high phytoremediation potential, as a model, we demonstrated that the in situ distribution pattern of low-methylesterified homogalacturonan, pectin epitope (JIM5-P), reflects the pattern of Pb occurrence. The region which indicated high JIM5-P level corresponded with “Pb accumulation zone”. Moreover, JIM5-P was especially abundant in cell junctions, CWs lining the intercellular spaces and the corners of intercellular spaces indicating the highest accumulation of Pb. Furthermore, JIM5-P and Pb commonly co-localized. The observations indicate that low-methylesterified homogalacturonan is the CW polymer that determines the capacity of CW for Pb sequestration. Our results suggest a promising directions for CW modification for enhancing the efficiency of plant roots in Pb accumulation, an important aspect in the phytoremediation of soils contaminated with trace metals. - Highlights: • Co-localization of low-methylesterified pectins and Pb was analysed in situ. • The pattern of Pb accumulation matched low-methylesterified pectins distribution. • Low-methylesterified pectins and Pb commonly co-localized in cell walls. • Low-methylesterified pectins revealed an important compound in Pb sequestration. • We suggest a new direction in enhancing plant efficiency for phytoremediation. - The distribution of lead in developing tissues of aspen root tips exposed to short-term lead treatment mimics the distribution of low-methylesterified pectin epitope

  5. MODEL PENENTUAN HARGA SAHAM: PENGUJIAN CAPITAL ASSET PRICING MODEL MELALUI PENGUJIAN ECONOMIC VALUE ADDED

    Directory of Open Access Journals (Sweden)

    Suripto Suripto

    2017-03-01

    Full Text Available This research tested the influence of characteristics of the firms and of EVA (Eco-nomic Value Added to stock of returns. This Research sample was company Self-100 ValueCreator of year 2001 until 2006. Result of research indicated that company size measure,profitability, capital structure (characteristics of the firms and EVA by stimulant had aneffect on significant to stock of returns, but by partial only characteristics company. Condi-tion of company fundamentals had an effect on significance to stock of returns. This indica-tion that investor still considered factors of fundamentals was having investment. EVA didnot have an effect on significant to stock of returns. This finding indicated that Model deter-mination of stock of returns (CAPM Irrelevant determined the level of EVA and also indicatedthat CAPM (Capital Assets Pricing Model was not relevant in determining stock of returns inIndonesian Stock Exchange.

  6. Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

    Science.gov (United States)

    Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

    2010-01-01

    The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

  7. Polypropylene /Aspen/ liquid polybutadienes composites: maximization of impact strength, tensile and modulus by statistical experimental design

    Czech Academy of Sciences Publication Activity Database

    Kokta, B. V.; Fortelný, Ivan; Kruliš, Zdeněk; Horák, Zdeněk; Michálková, Danuše

    2005-01-01

    Roč. 99, - (2005), s. 10-11 ISSN 0009-2770. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. 10.5.2005-12.5.2005, Bratislava] Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * Aspen-PP composite Subject RIV: CD - Macromolecular Chemistry

  8. Effect of citric acid modification of aspen wood on sorption of copper ion

    Science.gov (United States)

    James D. McSweeny; Roger M. Rowell; Soo Hong Min

    2006-01-01

    Milled aspen wood was thermochemically modified with citric acid for the purpose of improving the copper (Cu2+) ion sorption capacity of the wood when tested in 24-hour equilibrium batch tests. The wood-citric acid adducts provided additional carboxyl groups to those in the native wood and substantially increased Cu2+ ion uptake of the modified wood compared with that...

  9. Variable performance of outbreak defoliators on aspen clones exposed to elevated CO2 and O3

    Science.gov (United States)

    Daniel A. Herms; William J. Mattson; David N. Karowe; Mark D. Coleman; Terry M. Trier; Bruce A. Birr; J. G. Isebrands

    1996-01-01

    Increasing atmospheric concentrations of ozone and CO2 affect many aspects of tree physiology. However, their effects on tree resistance to insects have received relatively little attention. The objectives of this study were to test the effects of elevated CO2 and ozone on the resistance of three quaking aspen (...

  10. Soil properties and aspen development five years after compaction and forest floor removal

    Science.gov (United States)

    Douglas M. Stone; John D. Elioff

    1998-01-01

    Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

  11. Continental-scale assessment of genetic diversity and population structure in quaking aspen (Populus tremuloides)

    Science.gov (United States)

    Colin M. Callahan; Carol A. Rowe; Ronald J. Ryel; John D. Shaw; Michael D. Madritch; Karen E. Mock

    2013-01-01

    Aspen populations in the south-western portion of the range are consistent with expectations for a historically stable edge, with low within-population diversity, significant geographical population structuring, and little evidence of northward expansion. Structuring within the southwestern cluster may result from distinct gene pools separated during the Pleistocene...

  12. Is the wide distribution of aspen a result of its stress tolerance?

    Science.gov (United States)

    V. J. Lieffers; S. M. Landhausser; E. H. Hogg

    2001-01-01

    Populus tremuloides is distributed from drought-prone fringes of the Great Plains to extremely cold sites at arctic treeline. To occupy these conditions aspen appears to be more tolerant of stress than the other North American species of the genus Populus. Cold winters, cold soil conditions during the growing season, periodic drought, insect defoliation, and...

  13. Increased saccharification yields from aspen biomass upon treatment with enzymatically generated peracetic acid.

    Science.gov (United States)

    Duncan, Shona; Jing, Qing; Katona, Adrian; Kazlauskas, Romas J; Schilling, Jonathan; Tschirner, Ulrike; Aldajani, Waleed Wafa

    2010-03-01

    The recalcitrance of lignocellulosic biomass to enzymatic release of sugars (saccharification) currently limits its use as feedstock for biofuels. Enzymatic hydrolysis of untreated aspen wood releases only 21.8% of the available sugars due primarily to the lignin barrier. Nature uses oxidative enzymes to selectively degrade lignin in lignocellulosic biomass, but thus far, natural enzymes have been too slow for industrial use. In this study, oxidative pretreatment with commercial peracetic acid (470 mM) removed 40% of the lignin (from 19.9 to 12.0 wt.% lignin) from aspen and enhanced the sugar yields in subsequent enzymatic hydrolysis to about 90%. Increasing the amount of lignin removed correlated with increasing yields of sugar release. Unfortunately, peracetic acid is expensive, and concentrated forms can be hazardous. To reduce costs and hazards associated with using commercial peracetic acid, we used a hydrolase to catalyze the perhydrolysis of ethyl acetate generating 60-70 mM peracetic acid in situ as a pretreatment to remove lignin from aspen wood. A single pretreatment was insufficient, but multiple cycles (up to eight) removed up to 61.7% of the lignin enabling release of >90% of the sugars during saccharification. This value corresponds to a predicted 581 g of fermentable sugars from 1 kg of aspen wood. Improvements in the enzyme stability are needed before the enzymatically generated peracetic acid is a commercially viable alternative.

  14. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  15. Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

    Science.gov (United States)

    Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

    2017-12-01

    Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

  16. Root growth and physiology of potted and field-grown trembling aspen exposed to tropospheric ozone

    Science.gov (United States)

    M.D. Coleman; R.E. Dickson; J.G. Isebrands; D.F. Karnosky

    1996-01-01

    We studied root growth and respiration of potted plants and field-grown aspen trees (Populus tremuloides Michx.) exposed to ambient or twice-ambient ozone. Root dry weight of potted plants decreased up to 45% after 12 weeks of ozone treatment, and root system respiration decreased by 27%. The ozone-induced decrease in root system respiration of...

  17. Jobs and Economic Development Impact (JEDI) Model: Offshore Wind User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, E.; Goldberg, M.; Keyser, D.

    2013-06-01

    The Offshore Wind Jobs and Economic Development Impact (JEDI) model, developed by NREL and MRG & Associates, is a spreadsheet based input-output tool. JEDI is meant to be a user friendly and transparent tool to estimate potential economic impacts supported by the development and operation of offshore wind projects. This guide describes how to use the model as well as technical information such as methodology, limitations, and data sources.

  18. Links between fluid mechanics and quantum mechanics: a model for information in economics?

    Science.gov (United States)

    Haven, Emmanuel

    2016-05-28

    This paper tallies the links between fluid mechanics and quantum mechanics, and attempts to show whether those links can aid in beginning to build a formal template which is usable in economics models where time is (a)symmetric and memory is absent or present. An objective of this paper is to contemplate whether those formalisms can allow us to model information in economics in a novel way. © 2016 The Author(s).

  19. A Dynamic Economic Model with Discrete Time and Consumer Sentiment

    Directory of Open Access Journals (Sweden)

    L. I. Dobrescu

    2009-01-01

    is replaced by a (quasi periodic motion. We associate the difference stochastic equation to the model by randomizing the control parameter d and by adding one stochastic control. Numerical simulations are made for the deterministic and stochastic models, for different values of the control parameter d.

  20. Computer model for economic study of unbleached kraft paperboard production

    Science.gov (United States)

    Peter J. Ince

    1984-01-01

    Unbleached kraft paperboard is produced from wood fiber in an industrial papermaking process. A highly specific and detailed model of the process is presented. The model is also presented as a working computer program. A user of the computer program will provide data on physical parameters of the process and on prices of material inputs and outputs. The program is then...