WorldWideScience

Sample records for policy simulation models

  1. Useful models for simulating policies to induce technological change

    International Nuclear Information System (INIS)

    Rivers, Nic; Jaccard, Mark

    2006-01-01

    Conventional top-down and bottom-up energy-economy models have limitations that affect their usefulness to policy-makers. Efforts to develop hybrid models, that incorporate valuable aspects of these two frameworks, may be more useful by representing technologies in the energy-economy explicitly while also representing more realistically the way in which businesses and consumers choose between those technologies. This representation allows for the realistic simulation of a wide range of technology-specific regulations and fiscal incentives alongside economy-wide fiscal incentives and disincentives. These policies can be assessed based on the costs required to reach a goal in the medium term, as well as on the degree to which they induce technological change that affects costs over long time periods

  2. Exploratory Modeling and the use of Simulation for Policy Analysis

    Science.gov (United States)

    1992-01-01

    and the Use of Simulation for Policy Analysis Steven C. Barikes Prepared for the United States Army R A N D Approved for public release; distribution...Research, Vol. 39, No. 3, May-June 1991, pp. 355-365. Lipton, Richard J ., Thomas G. Marr, and J . Douglas Welsh, "Computational Approaches to Discovering...the Visual Cortex, John Wiley & Sons, New York, 1985. / -30- Rothenberg, J ., N. Z. Shapiro, and C. Hefley, "A Propagative’ Approach to Sensitivity

  3. The role of public policies in reducing smoking prevalence: results from the Michigan SimSmoke tobacco policy simulation model.

    Science.gov (United States)

    Levy, David T; Huang, An-Tsun; Havumaki, Joshua S; Meza, Rafael

    2016-05-01

    Michigan has implemented several of the tobacco control policies recommended by the World Health Organization MPOWER goals. We consider the effect of those policies and additional policies consistent with MPOWER goals on smoking prevalence and smoking-attributable deaths (SADs). The SimSmoke tobacco control policy simulation model is used to examine the effect of past policies and a set of additional policies to meet the MPOWER goals. The model is adapted to Michigan using state population, smoking, and policy data starting in 1993. SADs are estimated using standard attribution methods. Upon validating the model, SimSmoke is used to distinguish the effect of policies implemented since 1993 against a counterfactual with policies kept at their 1993 levels. The model is then used to project the effect of implementing stronger policies beginning in 2014. SimSmoke predicts smoking prevalence accurately between 1993 and 2010. Since 1993, a relative reduction in smoking rates of 22 % by 2013 and of 30 % by 2054 can be attributed to tobacco control policies. Of the 22 % reduction, 44 % is due to taxes, 28 % to smoke-free air laws, 26 % to cessation treatment policies, and 2 % to youth access. Moreover, 234,000 SADs are projected to be averted by 2054. With additional policies consistent with MPOWER goals, the model projects that, by 2054, smoking prevalence can be further reduced by 17 % with 80,000 deaths averted relative to the absence of those policies. Michigan SimSmoke shows that tobacco control policies, including cigarette taxes, smoke-free air laws, and cessation treatment policies, have substantially reduced smoking and SADs. Higher taxes, strong mass media campaigns, and cessation treatment policies would further reduce smoking prevalence and SADs.

  4. Selecting Policy Indicators and Developing Simulation Models for the National School Lunch and Breakfast Programs (Summary)

    OpenAIRE

    Lisa Dragoset; Anne Gordon

    2010-01-01

    This brief describes exploratory work to develop a simulation model to predict the potential implications of changes that may be coming in policies and practices related to school meals and school food environments.

  5. Systems Thinking and Simulation Modeling to Inform Childhood Obesity Policy and Practice.

    Science.gov (United States)

    Powell, Kenneth E; Kibbe, Debra L; Ferencik, Rachel; Soderquist, Chris; Phillips, Mary Ann; Vall, Emily Anne; Minyard, Karen J

    In 2007, 31.7% of Georgia adolescents in grades 9-12 were overweight or obese. Understanding the impact of policies and interventions on obesity prevalence among young people can help determine statewide public health and policy strategies. This article describes a systems model, originally launched in 2008 and updated in 2014, that simulates the impact of policy interventions on the prevalence of childhood obesity in Georgia through 2034. In 2008, using information from peer-reviewed reports and quantitative estimates by experts in childhood obesity, physical activity, nutrition, and health economics and policy, a group of legislators, legislative staff members, and experts trained in systems thinking and system dynamics modeling constructed a model simulating the impact of policy interventions on the prevalence of childhood obesity in Georgia through 2034. Use of the 2008 model contributed to passage of a bill requiring annual fitness testing of schoolchildren and stricter enforcement of physical education requirements. We updated the model in 2014. With no policy change, the updated model projects that the prevalence of obesity among children and adolescents aged ≤18 in Georgia would hold at 18% from 2014 through 2034. Mandating daily school physical education (which would reduce prevalence to 12%) and integrating moderate to vigorous physical activity into elementary classrooms (which would reduce prevalence to 10%) would have the largest projected impact. Enacting all policies simultaneously would lower the prevalence of childhood obesity from 18% to 3%. Systems thinking, especially with simulation models, facilitates understanding of complex health policy problems. Using a simulation model to educate legislators, educators, and health experts about the policies that have the greatest short- and long-term impact should encourage strategic investment in low-cost, high-return policies.

  6. How to enhance the future use of energy policy simulation models through ex post validation

    International Nuclear Information System (INIS)

    Qudrat-Ullah, Hassan

    2017-01-01

    Although simulation and modeling in general and system dynamics models in particular has long served the energy policy domain, ex post validation of these energy policy models is rarely addressed. In fact, ex post validation is a valuable area of research because it offers modelers a chance to enhance the future use of their simulation models by validating them against the field data. This paper contributes by presenting (i) a system dynamics simulation model, which was developed and used to do a three dimensional, socio-economical and environmental long-term assessment of Pakistan's energy policy in 1999, (ii) a systematic analysis of the 15-years old predictive scenarios produced by a system dynamics simulation model through ex post validation. How did the model predictions compare with the actual data? We report that the ongoing crisis of the electricity sector of Pakistan is unfolding, as the model-based scenarios had projected. - Highlights: • Argues that increased use of energy policy models is dependent on their credibility validation. • An ex post validation process is presented as a solution to build confidence in models. • A unique system dynamics model, MDESRAP, is presented. • The root mean square percentage error and Thiel's inequality statistics are applied. • The dynamic model, MDESRAP, is presented as an ex ante and ex post validated model.

  7. A multiple perspective modeling and simulation approach for renewable energy policy evaluation

    Science.gov (United States)

    Alyamani, Talal M.

    Environmental issues and reliance on fossil fuel sources, including coal, oil, and natural gas, are the two most common energy issues that are currently faced by the United States (U.S.). Incorporation of renewable energy sources, a non-economical option in electricity generation compared to conventional sources that burn fossil fuels, single handedly promises a viable solution for both of these issues. Several energy policies have concordantly been suggested to reduce the financial burden of adopting renewable energy technologies and make such technologies competitive with conventional sources throughout the U.S. This study presents a modeling and analysis approach for comprehensive evaluation of renewable energy policies with respect to their benefits to various related stakeholders--customers, utilities, governmental and environmental agencies--where the debilitating impacts, advantages, and disadvantages of such policies can be assessed and quantified at the state level. In this work, a novel simulation framework is presented to help policymakers promptly assess and evaluate policies from different perspectives of its stakeholders. The proposed framework is composed of four modules: 1) a database that collates the economic, operational, and environmental data; 2) elucidation of policy, which devises the policy for the simulation model; 3) a preliminary analysis, which makes predictions for consumption, supply, and prices; and 4) a simulation model. After the validity of the proposed framework is demonstrated, a series of planned Florida and Texas renewable energy policies are implemented into the presented framework as case studies. Two solar and one energy efficiency programs are selected as part of the Florida case study. A utility rebate and federal tax credit programs are selected as part of the Texas case study. The results obtained from the simulation and conclusions drawn on the assessment of current energy policies are presented with respect to the

  8. Knowledge mobilisation for policy development: implementing systems approaches through participatory dynamic simulation modelling.

    Science.gov (United States)

    Freebairn, Louise; Rychetnik, Lucie; Atkinson, Jo-An; Kelly, Paul; McDonnell, Geoff; Roberts, Nick; Whittall, Christine; Redman, Sally

    2017-10-02

    Evidence-based decision-making is an important foundation for health policy and service planning decisions, yet there remain challenges in ensuring that the many forms of available evidence are considered when decisions are being made. Mobilising knowledge for policy and practice is an emergent process, and one that is highly relational, often messy and profoundly context dependent. Systems approaches, such as dynamic simulation modelling can be used to examine both complex health issues and the context in which they are embedded, and to develop decision support tools. This paper reports on the novel use of participatory simulation modelling as a knowledge mobilisation tool in Australian real-world policy settings. We describe how this approach combined systems science methodology and some of the core elements of knowledge mobilisation best practice. We describe the strategies adopted in three case studies to address both technical and socio-political issues, and compile the experiential lessons derived. Finally, we consider the implications of these knowledge mobilisation case studies and provide evidence for the feasibility of this approach in policy development settings. Participatory dynamic simulation modelling builds on contemporary knowledge mobilisation approaches for health stakeholders to collaborate and explore policy and health service scenarios for priority public health topics. The participatory methods place the decision-maker at the centre of the process and embed deliberative methods and co-production of knowledge. The simulation models function as health policy and programme dynamic decision support tools that integrate diverse forms of evidence, including research evidence, expert knowledge and localised contextual information. Further research is underway to determine the impact of these methods on health service decision-making.

  9. Simulation modelling as a tool for knowledge mobilisation in health policy settings: a case study protocol.

    Science.gov (United States)

    Freebairn, L; Atkinson, J; Kelly, P; McDonnell, G; Rychetnik, L

    2016-09-21

    Evidence-informed decision-making is essential to ensure that health programs and services are effective and offer value for money; however, barriers to the use of evidence persist. Emerging systems science approaches and advances in technology are providing new methods and tools to facilitate evidence-based decision-making. Simulation modelling offers a unique tool for synthesising and leveraging existing evidence, data and expert local knowledge to examine, in a robust, low risk and low cost way, the likely impact of alternative policy and service provision scenarios. This case study will evaluate participatory simulation modelling to inform the prevention and management of gestational diabetes mellitus (GDM). The risks associated with GDM are well recognised; however, debate remains regarding diagnostic thresholds and whether screening and treatment to reduce maternal glucose levels reduce the associated risks. A diagnosis of GDM may provide a leverage point for multidisciplinary lifestyle modification interventions. This research will apply and evaluate a simulation modelling approach to understand the complex interrelation of factors that drive GDM rates, test options for screening and interventions, and optimise the use of evidence to inform policy and program decision-making. The study design will use mixed methods to achieve the objectives. Policy, clinical practice and research experts will work collaboratively to develop, test and validate a simulation model of GDM in the Australian Capital Territory (ACT). The model will be applied to support evidence-informed policy dialogues with diverse stakeholders for the management of GDM in the ACT. Qualitative methods will be used to evaluate simulation modelling as an evidence synthesis tool to support evidence-based decision-making. Interviews and analysis of workshop recordings will focus on the participants' engagement in the modelling process; perceived value of the participatory process, perceived

  10. A simulation model for reliability-based appraisal of an energy policy: The case of Lebanon

    International Nuclear Information System (INIS)

    Hamdan, H.A.; Ghajar, R.F.; Chedid, R.B.

    2012-01-01

    The Lebanese Electric Power System (LEPS) has been suffering from technical and financial deficiencies for decades and mirrors the problems encountered in many developing countries suffering from inadequate or no power systems planning resulting in incomplete and ill-operating infrastructure, and suffering from effects of political instability, huge debts, unavailability of financing desired projects and inefficiency in operation. The upgrade and development of the system necessitate the adoption of a comprehensive energy policy that introduces solutions to a diversity of problems addressing the technical, financial, administrative and governance aspects of the system. In this paper, an energy policy for Lebanon is proposed and evaluated based on integration between energy modeling and financial modeling. The paper utilizes the Load Modification Technique (LMT) as a probabilistic tool to assess the impact of policy implementation on energy production, overall cost, technical/commercial losses and reliability. Scenarios reflecting implementation of policy projects are assessed and their impacts are compared with business-as-usual scenarios which assume no new investment is to take place in the sector. Conclusions are drawn on the usefulness of the proposed evaluation methodology and the effectiveness of the adopted energy policy for Lebanon and other developing countries suffering from similar power system problems. - Highlights: ► Evaluation methodology based on a probabilistic simulation tool is proposed. ► A business-as-usual scenario for a given study period of the LEPS was modeled. ► Mitigation scenarios reflecting implementation of the energy policy are modeled. ► Policy simulated and compared with business-as-usual scenarios of the LEPS. ► Results reflect usefulness of proposed methodology and the adopted energy policy.

  11. Emission policies and the Nigerian economy. Simulations from a dynamic applied general equilibrium model

    International Nuclear Information System (INIS)

    Nwaobi, Godwin Chukwudum

    2004-01-01

    Recently, there has been growing concern that human activities may be affecting the global climate through growing atmospheric concentrations of greenhouse gases (GHG). Such warming could have major impacts on economic activity and society. For the Nigerian case, the study uses multisector dynamic applied general equilibrium model to quantify the economy-wide, distributional and environmental costs of policies to curb GHG emissions. The simulation results indicate effectiveness of carbon tax, tradable permit and backstop technology policies in curbing GHG emissions but with distorted economy-wide income distributional effects. However, the model was found to be sensitive to three key exogenous variable and parameters tested: lower GDP growth rate, changed interfuel substitution elasticity and autonomous energy efficiency factor. Unlike the first test, the last two tests only had improved environmental effect but stable economy wide effect. This then suggest that domestic energy conservation measures could be a second best alternative

  12. Evaluation of realised energy savings with simulation models. A new policy tool for the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Boonekamp, P.G.M. [ECN Policy Studies, Petten (Netherlands)

    2013-01-15

    This report describes a new analysis tool for the evaluation of realised energy savings, and effects of savings policy, in the Netherlands. It aims to meet the information needs of policymakers, both at national and EU level, using the monitoring results of the NL Agency. The system builds on the Protocol Monitoring Energy Savings to calculate realised savings. The innovation consists of the option to adjust energy models per sector, as already used for scenario analysis, to simulate past developments. The simulations can estimate total savings and assess the contribution of policy measures. The detailed simulation approach also enables the decomposition of energy trends into volume-effects due to growth, structural effects such as fuel substitution and import/exports, and various saving effects. As the modeling system is already used for the analysis of future trends, it enables a good comparison between ex-ante (expected) savings and ex-post (realised) savings. Finally, the system enables a faster delivery of calculation results than presently is the case.

  13. Intelligent simulation of aquatic environment economic policy coupled ABM and SD models.

    Science.gov (United States)

    Wang, Huihui; Zhang, Jiarui; Zeng, Weihua

    2018-03-15

    Rapid urbanization and population growth have resulted in serious water shortage and pollution of the aquatic environment, which are important reasons for the complex increase in environmental deterioration in the region. This study examines the environmental consequences and economic impacts of water resource shortages under variant economic policies; however, this requires complex models that jointly consider variant agents and sectors within a systems perspective. Thus, we propose a complex system model that couples multi-agent based models (ABM) and system dynamics (SD) models to simulate the impact of alternative economic policies on water use and pricing. Moreover, this model took the constraint of the local water resources carrying capacity into consideration. Results show that to achieve the 13th Five Year Plan targets in Dianchi, water prices for local residents and industries should rise to 3.23 and 4.99 CNY/m 3 , respectively. The corresponding sewage treatment fees for residents and industries should rise to 1.50 and 2.25 CNY/m 3 , respectively, assuming comprehensive adjustment of industrial structure and policy. At the same time, the local government should exercise fine-scale economic policy combined with emission fees assessed for those exceeding a standard, and collect fines imposed as punishment for enterprises that exceed emission standards. When fines reach 500,000 CNY, the total number of enterprises that exceed emission standards in the basin can be controlled within 1%. Moreover, it is suggested that the volume of water diversion in Dianchi should be appropriately reduced to 3.06×10 8 m 3 . The reduced expense of water diversion should provide funds to use for the construction of recycled water facilities. Then the local rise in the rate of use of recycled water should reach 33%, and 1.4 CNY/m 3 for the price of recycled water could be provided to ensure the sustainable utilization of local water resources. Copyright © 2017 Elsevier B

  14. A Model-Based Framework for Legal Policy Simulation and Compliance Checking

    OpenAIRE

    Soltana, Ghanem

    2017-01-01

    Information systems implementing requirements from laws and regulations, such as taxes and social benefits, need to be thoroughly verified to demonstrate their compliance. Several Verification and Validation (V&V) techniques, such as reliability testing, and modeling and simulation, can be used for assessing that such systems meet their legal. Typically, one has to model the expected (legal) behavior of the system in a form that can be executed (simulated), subject the resulting models and th...

  15. Modeling and Simulation of Bus Dispatching Policy for Timed Transfers on Signalized Networks

    Science.gov (United States)

    Cho, Hsun-Jung; Lin, Guey-Shii

    2007-12-01

    The major work of this study is to formulate the system cost functions and to integrate the bus dispatching policy with signal control. The integrated model mainly includes the flow dispersion model for links, signal control model for nodes, and dispatching control model for transfer terminals. All such models are inter-related for transfer operations in one-center transit network. The integrated model that combines dispatching policies with flexible signal control modes can be applied to assess the effectiveness of transfer operations. It is found that, if bus arrival information is reliable, an early dispatching decision made at the mean bus arrival times is preferable. The costs for coordinated operations with slack times are relatively low at the optimal common headway when applying adaptive route control. Based on such findings, a threshold function of bus headway for justifying an adaptive signal route control under various time values of auto drivers is developed.

  16. Impact of different policies on unhealthy dietary behaviors in an urban adult population: an agent-based simulation model.

    Science.gov (United States)

    Zhang, Donglan; Giabbanelli, Philippe J; Arah, Onyebuchi A; Zimmerman, Frederick J

    2014-07-01

    Unhealthy eating is a complex-system problem. We used agent-based modeling to examine the effects of different policies on unhealthy eating behaviors. We developed an agent-based simulation model to represent a synthetic population of adults in Pasadena, CA, and how they make dietary decisions. Data from the 2007 Food Attitudes and Behaviors Survey and other empirical studies were used to calibrate the parameters of the model. Simulations were performed to contrast the potential effects of various policies on the evolution of dietary decisions. Our model showed that a 20% increase in taxes on fast foods would lower the probability of fast-food consumption by 3 percentage points, whereas improving the visibility of positive social norms by 10%, either through community-based or mass-media campaigns, could improve the consumption of fruits and vegetables by 7 percentage points and lower fast-food consumption by 6 percentage points. Zoning policies had no significant impact. Interventions emphasizing healthy eating norms may be more effective than directly targeting food prices or regulating local food outlets. Agent-based modeling may be a useful tool for testing the population-level effects of various policies within complex systems.

  17. Rural-urban migration: policy simulations in a dual economy model of Bangladesh.

    Science.gov (United States)

    Ahmed, S

    1986-03-01

    The process of rural-urban migration in Bangladesh is analyzed using a dual economy model. The focus is on the period 1976-1985. The main purpose of the paper is to examine alternative policies designed to reduce the level of such migration without adversely affecting the country's economy.

  18. Simulation tools for developing policies for complex systems: modeling the health and safety of refugee communities.

    Science.gov (United States)

    Anderson, James; Chaturvedi, Alok; Cibulskis, Mike

    2007-12-01

    The U.S. Committee for Refugees and Immigrants estimated that there were over 33 million refugees and internally displaced persons (IDPs) in the world at the beginning of 2005. IDP/Refugee communities behave in complex ways making it difficult to make policy decisions regarding the provision of humanitarian aid and health and safety. This paper reports the construction of an agent-based model that has been used to study humanitarian assistance policies executed by governments and NGOs that provide for the health and safety of refugee communities. Agent-based modeling (ABM) was chosen because the more widely used alternatives impose unrealistic restrictions and assumptions on the system being modeled and primarily apply to aggregate data. We created intelligent agents representing institutions, organizations, individuals, infrastructure, and governments and analyzed the resulting interactions and emergent behavior using a Central Composite Design of Experiments with five factors. The resulting model allows policy makers and analysts to create scenarios, to make rapid changes in parameters, and provides a test bed for concepts and strategies. Policies can be examined to see how refugee communities might respond to alternative courses of action and how these actions are likely to affect the health and well-being of the community.

  19. Oligopolistic competition in wholesale electricity markets: Large-scale simulation and policy analysis using complementarity models

    Science.gov (United States)

    Helman, E. Udi

    This dissertation conducts research into the large-scale simulation of oligopolistic competition in wholesale electricity markets. The dissertation has two parts. Part I is an examination of the structure and properties of several spatial, or network, equilibrium models of oligopolistic electricity markets formulated as mixed linear complementarity problems (LCP). Part II is a large-scale application of such models to the electricity system that encompasses most of the United States east of the Rocky Mountains, the Eastern Interconnection. Part I consists of Chapters 1 to 6. The models developed in this part continue research into mixed LCP models of oligopolistic electricity markets initiated by Hobbs [67] and subsequently developed by Metzler [87] and Metzler, Hobbs and Pang [88]. Hobbs' central contribution is a network market model with Cournot competition in generation and a price-taking spatial arbitrage firm that eliminates spatial price discrimination by the Cournot firms. In one variant, the solution to this model is shown to be equivalent to the "no arbitrage" condition in a "pool" market, in which a Regional Transmission Operator optimizes spot sales such that the congestion price between two locations is exactly equivalent to the difference in the energy prices at those locations (commonly known as locational marginal pricing). Extensions to this model are presented in Chapters 5 and 6. One of these is a market model with a profit-maximizing arbitrage firm. This model is structured as a mathematical program with equilibrium constraints (MPEC), but due to the linearity of its constraints, can be solved as a mixed LCP. Part II consists of Chapters 7 to 12. The core of these chapters is a large-scale simulation of the U.S. Eastern Interconnection applying one of the Cournot competition with arbitrage models. This is the first oligopolistic equilibrium market model to encompass the full Eastern Interconnection with a realistic network representation (using

  20. Developing Flexible Discrete Event Simulation Models in an Uncertain Policy Environment

    Science.gov (United States)

    Miranda, David J.; Fayez, Sam; Steele, Martin J.

    2011-01-01

    On February 1st, 2010 U.S. President Barack Obama submitted to Congress his proposed budget request for Fiscal Year 2011. This budget included significant changes to the National Aeronautics and Space Administration (NASA), including the proposed cancellation of the Constellation Program. This change proved to be controversial and Congressional approval of the program's official cancellation would take many months to complete. During this same period an end-to-end discrete event simulation (DES) model of Constellation operations was being built through the joint efforts of Productivity Apex Inc. (PAl) and Science Applications International Corporation (SAIC) teams under the guidance of NASA. The uncertainty in regards to the Constellation program presented a major challenge to the DES team, as to: continue the development of this program-of-record simulation, while at the same time remain prepared for possible changes to the program. This required the team to rethink how it would develop it's model and make it flexible enough to support possible future vehicles while at the same time be specific enough to support the program-of-record. This challenge was compounded by the fact that this model was being developed through the traditional DES process-orientation which lacked the flexibility of object-oriented approaches. The team met this challenge through significant pre-planning that led to the "modularization" of the model's structure by identifying what was generic, finding natural logic break points, and the standardization of interlogic numbering system. The outcome of this work resulted in a model that not only was ready to be easily modified to support any future rocket programs, but also a model that was extremely structured and organized in a way that facilitated rapid verification. This paper discusses in detail the process the team followed to build this model and the many advantages this method provides builders of traditional process-oriented discrete

  1. A dynamic simulation model for assessing the overall impact of incentive policies on power system reliability, costs and environment

    International Nuclear Information System (INIS)

    Ibanez-Lopez, A.S.; Martinez-Val, J.M.; Moratilla-Soria, B.Y.

    2017-01-01

    The liberalization of power markets has entailed dramatic changes in power system planning worldwide. The inception of new alternative technologies, smart grids and distributed generation and storage is expected to make system planning even more challenging. Government policies still play a major role in the evolution of a country's power generation mix, even in those countries with liberalized markets. This paper presents a System Dynamics model aimed at assessing the overall technical, economic and environmental impact of renewable energy incentives and capacity payment policies. The model has been used to simulate Spain's power industry in order to assess the impact of electric power policies with the goal of getting insights regarding how to achieve an optimum power generation mix. The main conclusions of the present paper are (i) the necessity of specific regulatory actions in Spain in order to keep adequate reliability levels, avoid price spikes and boom and bust investment cycles as well as to deploy specific technologies, (ii) the fact that capacity payments are a better instrument for keeping adequate reserve margins and avoiding power price spikes than renewable energy incentives and (iii) the evidence that both instruments entail additional system costs over the base case scenario. - Highlights: • A System Dynamics model of Spain's power generation mix is proposed. • The overall policy impact on system costs, environment and reliability is assessed. • Current policies are not enough to keep adequate reliability levels. • Capacity payments are an adequate instrument for guaranteeing system reliability. • RES incentives do not solve reliability issues and entail greater system costs.

  2. Contribution to the economic impact assessment of policy options to regulate animal cloning for food production with an economic simulation model

    OpenAIRE

    Koen Dillen; Emanuele Ferrari; Pascal Tillie; George Philippidis; Sophie Helaine

    2013-01-01

    The EU is currently evaluating different policy options towards the use of cloning or products derived from cloned animals in the food chain. This study presents a first attempt to quantify the likely effects of different policy scenarios on international trade and EU domestic production. In the context of the Impact Asessment process the JRC was requested to simulate via a modelling study the economic impact of selected policy options. Based on a literature review and the specific constra...

  3. Interactive use of simulation models for collaborative knowledge construction: the case of flood policy decision-making

    NARCIS (Netherlands)

    Leskens, Anne

    2015-01-01

    There is an increasing use of interactive flood simulation models in work sessions with practitioners, which is supposed to be more effective than feeding static model results from conventional simulation models into the decision-making process. These interactive simulation models rely on fast and

  4. Essays in energy policy and planning modeling under uncertainty: Value of information, optimistic biases, and simulation of capacity markets

    Science.gov (United States)

    Hu, Ming-Che

    Optimization and simulation are popular operations research and systems analysis tools for energy policy modeling. This dissertation addresses three important questions concerning the use of these tools for energy market (and electricity market) modeling and planning under uncertainty. (1) What is the value of information and cost of disregarding different sources of uncertainty for the U.S. energy economy? (2) Could model-based calculations of the performance (social welfare) of competitive and oligopolistic market equilibria be optimistically biased due to uncertainties in objective function coefficients? (3) How do alternative sloped demand curves perform in the PJM capacity market under economic and weather uncertainty? How does curve adjustment and cost dynamics affect the capacity market outcomes? To address the first question, two-stage stochastic optimization is utilized in the U.S. national MARKAL energy model; then the value of information and cost of ignoring uncertainty are estimated for three uncertainties: carbon cap policy, load growth and natural gas prices. When an uncertainty is important, then explicitly considering those risks when making investments will result in better performance in expectation (positive expected cost of ignoring uncertainty). Furthermore, eliminating the uncertainty would improve strategies even further, meaning that improved forecasts of future conditions are valuable ( i.e., a positive expected value of information). Also, the value of policy coordination shows the difference between a strategy developed under the incorrect assumption of no carbon cap and a strategy correctly anticipating imposition of such a cap. For the second question, game theory models are formulated and the existence of optimistic (positive) biases in market equilibria (both competitive and oligopoly markets) are proved, in that calculated social welfare and producer profits will, in expectation, exceed the values that will actually be received

  5. A Monetary Policy Simulation Game

    Science.gov (United States)

    Lengwiler, Yvan

    2004-01-01

    The author presents a computer game that puts the player in the role of a central bank governor. The game is a stochastic simulation of a standard reduced form macro model, and the user interacts with this simulation by manipulating the interest rate. The problem the player faces is in many ways quite realistic--just as a real monetary authority,…

  6. The Food and Agricultural Policy Simulator

    OpenAIRE

    Salathe, Larry E.; Price, J. Michael; Gadson, Kenneth E.

    1982-01-01

    This article describes the structure and dynamic properties of the Food and Agricultural Policy Simulator (FAPSIM), an annual econometric model of the US agricultural sector F APSIM estimates a simultaneous price-quantity equilibrium solution for a set of individual commodity models developed for beef, pork, dairy, chickens, eggs, turkeys, corn, oats, barley, gram sorghum, wheat, soybeans, and cotton F APSIM also endogenously determines farm production expenses, cash receipts, net farm Income...

  7. The 1993 timber assessment market model: structure, projections, and policy simulations.

    Science.gov (United States)

    Darius M. Adams; Richard W. Haynes

    1996-01-01

    The 1993 timber assessment market model (TAMM) is a spatial model of the solidwood and timber inventory elements of the U.S. forest products sector. The TAMM model provides annual projections of volumes and prices in the solidwood products and sawtimber stumpage markets and estimates of total timber harvest and inventory by geographic region for periods of up to 50...

  8. The thyroid cancer policy model: A mathematical simulation model of papillary thyroid carcinoma in The U.S. population.

    Directory of Open Access Journals (Sweden)

    Carrie Lubitz

    Full Text Available Thyroid cancer affects over ½ million people in the U.S. and the incidence of thyroid cancer has increased worldwide at a rate higher than any other cancer, while survival has remained largely unchanged. The aim of this research was to develop, calibrate and verify a mathematical disease model to simulate the natural history of papillary thyroid cancer, which will serve as a platform to assess the effectiveness of clinical and cancer control interventions.Herein, we modeled the natural pre-clinical course of both benign and malignant thyroid nodules with biologically relevant health states from normal to detected nodule. Using established calibration techniques, optimal parameter sets for tumor growth characteristics, development rate, and detection rate were used to fit Surveillance Epidemiology and End Results (SEER incidence data and other calibration targets.Model outputs compared to calibration targets demonstrating sufficient calibration fit and model validation are presented including primary targets of SEER incidence data and size distribution at detection of malignancy. Additionally, we show the predicted underlying benign and malignant prevalence of nodules in the population, the probability of detection based on size of nodule, and estimates of growth over time in both benign and malignant nodules.This comprehensive model provides a dynamic platform employable for future comparative effectiveness research. Future model analyses will test and assess various clinical management strategies to improve patient outcomes related to thyroid cancer and optimize resource utilization for patients with thyroid nodules.

  9. The Brazil SimSmoke policy simulation model: the effect of strong tobacco control policies on smoking prevalence and smoking-attributable deaths in a middle income nation.

    Science.gov (United States)

    Levy, David; de Almeida, Liz Maria; Szklo, Andre

    2012-01-01

    Brazil has reduced its smoking rate by about 50% in the last 20 y. During that time period, strong tobacco control policies were implemented. This paper estimates the effect of these stricter policies on smoking prevalence and associated premature mortality, and the effect that additional policies may have. The model was developed using the SimSmoke tobacco control policy model. Using policy, population, and smoking data for Brazil, the model assesses the effect on premature deaths of cigarette taxes, smoke-free air laws, mass media campaigns, marketing restrictions, packaging requirements, cessation treatment programs, and youth access restrictions. We estimate the effect of past policies relative to a counterfactual of policies kept to 1989 levels, and the effect of stricter future policies. Male and female smoking prevalence in Brazil have fallen by about half since 1989, which represents a 46% (lower and upper bounds: 28%-66%) relative reduction compared to the 2010 prevalence under the counterfactual scenario of policies held to 1989 levels. Almost half of that 46% reduction is explained by price increases, 14% by smoke-free air laws, 14% by marketing restrictions, 8% by health warnings, 6% by mass media campaigns, and 10% by cessation treatment programs. As a result of the past policies, a total of almost 420,000 (260,000-715,000) deaths had been averted by 2010, increasing to almost 7 million (4.5 million-10.3 million) deaths projected by 2050. Comparing future implementation of a set of stricter policies to a scenario with 2010 policies held constant, smoking prevalence by 2050 could be reduced by another 39% (29%-54%), and 1.3 million (0.9 million-2.0 million) out of 9 million future premature deaths could be averted. Brazil provides one of the outstanding public health success stories in reducing deaths due to smoking, and serves as a model for other low and middle income nations. However, a set of stricter policies could further reduce smoking and save

  10. Modeling environmental policy

    International Nuclear Information System (INIS)

    Martin, W.E.; McDonald, L.A.

    1997-01-01

    The eight book chapters demonstrate the link between the physical models of the environment and the policy analysis in support of policy making. Each chapter addresses an environmental policy issue using a quantitative modeling approach. The volume addresses three general areas of environmental policy - non-point source pollution in the agricultural sector, pollution generated in the extractive industries, and transboundary pollutants from burning fossil fuels. The book concludes by discussing the modeling efforts and the use of mathematical models in general. Chapters are entitled: modeling environmental policy: an introduction; modeling nonpoint source pollution in an integrated system (agri-ecological); modeling environmental and trade policy linkages: the case of EU and US agriculture; modeling ecosystem constraints in the Clean Water Act: a case study in Clearwater National Forest (subject to discharge from metal mining waste); costs and benefits of coke oven emission controls; modeling equilibria and risk under global environmental constraints (discussing energy and environmental interrelations); relative contribution of the enhanced greenhouse effect on the coastal changes in Louisiana; and the use of mathematical models in policy evaluations: comments. The paper on coke area emission controls has been abstracted separately for the IEA Coal Research CD-ROM

  11. FSSIM, a bio-economic farm model for simulating the response of EU farming systems to agricultural and environmental policies

    NARCIS (Netherlands)

    Louhichi, K.; Kanellopoulos, A.; Janssen, S.J.C.; Flichman, G.; Blanco, M.; Hengsdijk, H.; Heckelei, T.; Berentsen, P.; Oude Lansink, A.G.J.M.; Ittersum, van M.K.

    2010-01-01

    The disciplinary nature of most existing farm models as well as the issue specific orientation of most of the studies in agricultural systems research are main reasons for the limited use and re-use of bio-economic modelling for the ex-ante integrated assessment of policy decisions. The objective of

  12. Simulating the impact of policy, energy prices and technological progress on the passenger car fleet in Austria-A model based analysis 2010-2050

    International Nuclear Information System (INIS)

    Kloess, Maximilian; Mueller, Andreas

    2011-01-01

    This paper investigates the effects of policy, fuel prices and technological progress on the Austrian passenger car fleet in terms of energy consumption and greenhouse gas (GHG) emissions. To analyse these effects a simulation model is used. We model the car fleet from a bottom-up perspective, with a detailed coverage of vehicle specifications and propulsion technologies. The model focuses on the technological trend toward electrified propulsion systems and their potential effects on the fleet's energy consumption and GHG emissions. To represent the impact of prices and income on the development of the fleet, we combine the fleet model with top-down demand models. We developed two scenarios for the time frame 2010-2050, using two different sets of assumptions for regulatory development and conditions of increasing fossil fuel prices and continuous technological progress in vehicle propulsion technologies. The results indicate that material cuts in energy consumption and GHG emissions can be achieved with changes to the political framework for passenger cars. Appropriate taxation of fuels and cars can stabilise demand for individual motorised transport and lead to an improvement in vehicle efficiency by fostering the adoption of efficient vehicle propulsion technologies and low carbon fuels. - Highlights: → We present a simulation model for future energy demand and greenhouse gas emissions in passenger car transport. → We develop scenarios up to 2050 assuming two different policy schemes. → Policy strongly affects energy demand and greenhouse gas emissions in passenger car transport. → Policy can slow down growth in demand for passenger car transport. → Policy can promote the diffusion of more efficient propulsion technologies and low carbon fuels.

  13. Social Security reform: evaluating current proposals. Latest results of the EBRI-SSASIM2 policy simulation model.

    Science.gov (United States)

    Copeland, C; VanDerhei, J; Salisbury, D L

    1999-06-01

    The present Social Security program has been shown to be financially unsustainable in the future without modification to the current program. The purpose of this Issue Brief, EBRI's fourth in a series on Social Security reform, is threefold: to illustrate new features of the EBRI-SSASIM2 policy simulation model not available in earlier EBRI publications, to expand quantitative analysis to specific proposals, and to evaluate the uncertainty involved in proposals that rely on equity investment. This analysis compares the Gregg/Breaux-Kolbe/Stenholm (GB-KS) and Moynihan/Kerrey proposals with three generic or "traditional" reforms: increasing taxes, reducing benefits, and/or increasing the retirement age. Both proposals would create individual accounts by "carving out" funds from current Social Security payroll taxes. This analysis also examines other proposed changes that would "add on" to existing Social Security funds through the use of general revenue transfers and/or investment in the equities market. President Clinton has proposed a general revenue transfer and the collective investment of some of the OASDI trust fund assets in equities. Reps. Archer and Shaw have proposed a general revenue tax credit to establish individual accounts that would be invested partially in the equities markets. When comparing Social Security reform proposals that would specifically alter benefit levels, the Moynihan/Kerrey bill compares quite favorably with the other proposals in both benefit levels and payback ratios, when individuals elect to use the individual account option. In contrast, the GB-KS bills do not compare quite as favorably for their benefit levels, but do compare favorably in terms of payback ratios. An important comparison in these bills is the administrative costs of managing the individual accounts, since benefits can be lowered by up to 23 percent when going from the assumed low to high administrative costs. Moreover, allowing individuals to decide whether to

  14. Simulating Policy Processes through Electronic Mail.

    Science.gov (United States)

    Flynn, John P.

    1987-01-01

    Focuses on the use of electronic mail for teaching and learning about social welfare policy processes and compares electronic mail as a simulation medium to more structured computer applications. (Author)

  15. The Structural Underpinnings of Policy Learning: A Classroom Policy Simulation

    Science.gov (United States)

    Bird, Stephen

    This paper investigates the relationship between the centrality of individual actors in a social network structure and their policy learning performance. In a dynamic comparable to real-world policy networks, results from a classroom simulation demonstrate a strong relationship between centrality in social learning networks and grade performance. Previous research indicates that social network centrality should have a positive effect on learning in other contexts and this link is tested in a policy learning context. Second, the distinction between collaborative learning versus information diffusion processes in policy learning is examined. Third, frequency of interaction is analyzed to determine whether consistent, frequent tics have a greater impact on the learning process. Finally, the data arc analyzed to determine if the benefits of centrality have limitations or thresholds when benefits no longer accrue. These results demonstrate the importance of network structure, and support a collaborative conceptualization of the policy learning process.

  16. Estimating the Potential Impact of Tobacco Control Policies on Adverse Maternal and Child Health Outcomes in the United States Using the SimSmoke Tobacco Control Policy Simulation Model.

    Science.gov (United States)

    Levy, David; Mohlman, Mary Katherine; Zhang, Yian

    2016-05-01

    Numerous studies document the causal relationship between prenatal smoking and adverse maternal and child health (MCH) outcomes. Studies also reveal the impact that tobacco control policies have on prenatal smoking. The purpose of this study is to estimate the effect of tobacco control policies on prenatal smoking prevalence and adverse MCH outcomes. The US SimSmoke simulation model was extended to consider adverse MCH outcomes. The model estimates prenatal smoking prevalence and, applying standard attribution methods, uses estimates of MCH prevalence and relative smoking risks to estimate smoking-attributable MCH outcomes over time. The model then estimates the effect of tobacco control policies on adverse birth outcomes averted. Different tobacco control policies have varying impacts on the number of smoking-attributable adverse MCH birth outcomes. Higher cigarette taxes and comprehensive marketing bans individually have the biggest impact with a 5% to 10% reduction across all outcomes for the period from 2015 to 2065. The policies with the lowest impact (2%-3% decrease) during this period are cessation treatment, health warnings, and complete smoke-free laws. Combinations of all policies with each tax level lead to 23% to 28% decreases across all outcomes. Our findings demonstrate the substantial impact of strong tobacco control policies for preventing adverse MCH outcomes, including long-term health implications for children exposed to low birth weight and preterm birth. These benefits are often overlooked in discussions of tobacco control. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. The Model of Gas Supply Capacity Simulation In Regional Energy Security Framework: Policy Studies PT. X Cirebon Area

    Science.gov (United States)

    Nuryadin; Ronny Rahman Nitibaskara, Tb; Herdiansyah, Herdis; Sari, Ravita

    2017-10-01

    The needs of energy are increasing every year. The unavailability of energy will cause economic losses and weaken energy security. To overcome the availability of gas supply in the future, planning are cruacially needed. Therefore, it is necessary to approach the system, so that the process of gas distribution is running properly. In this research, system dynamic method will be used to measure how much supply capacity planning is needed until 2050, with parameters of demand in industrial, household and commercial sectors. From the model obtained PT.X Cirebon area in 2031 was not able to meet the needs of gas customers in the Cirebon region, as well as with Businnes as usual scenario, the ratio of gas fulfillment only until 2027. The implementation of the national energy policy that is the use of NRE as government intervention in the model is produced up to 2035 PT.X Cirebon area is still able to supply the gas needs of its customers.

  18. External Shocks and Macroeconomic Policy: Simulations with EUROMON

    OpenAIRE

    M. Demertzis; L. de Haan

    2001-01-01

    We carry out a number of policy simulations with DNB's multicountry model, EUROMON. With these simulations we aim to analyse the effectiveness of monetary and fiscal expansion in light of the current global downturn in the US and the Euro area. We thus run two types of simulations in which we examine first, the real and nominal effects of the interest rate reductions implemented over the past year (2002) in both the US and the EU and second compare, the effects of similar macro policies appli...

  19. Using Collaborative Simulation Modeling to Develop a Web-Based Tool to Support Policy-Level Decision Making About Breast Cancer Screening Initiation Age

    Directory of Open Access Journals (Sweden)

    Elizabeth S. Burnside MD, MPH, MS

    2017-07-01

    Full Text Available Background: There are no publicly available tools designed specifically to assist policy makers to make informed decisions about the optimal ages of breast cancer screening initiation for different populations of US women. Objective: To use three established simulation models to develop a web-based tool called Mammo OUTPuT. Methods: The simulation models use the 1970 US birth cohort and common parameters for incidence, digital screening performance, and treatment effects. Outcomes include breast cancers diagnosed, breast cancer deaths averted, breast cancer mortality reduction, false-positive mammograms, benign biopsies, and overdiagnosis. The Mammo OUTPuT tool displays these outcomes for combinations of age at screening initiation (every year from 40 to 49, annual versus biennial interval, lifetime versus 10-year horizon, and breast density, compared to waiting to start biennial screening at age 50 and continuing to 74. The tool was piloted by decision makers (n = 16 who completed surveys. Results: The tool demonstrates that benefits in the 40s increase linearly with earlier initiation age, without a specific threshold age. Likewise, the harms of screening increase monotonically with earlier ages of initiation in the 40s. The tool also shows users how the balance of benefits and harms varies with breast density. Surveys revealed that 100% of users (16/16 liked the appearance of the site; 94% (15/16 found the tool helpful; and 94% (15/16 would recommend the tool to a colleague. Conclusions: This tool synthesizes a representative subset of the most current CISNET (Cancer Intervention and Surveillance Modeling Network simulation model outcomes to provide policy makers with quantitative data on the benefits and harms of screening women in the 40s. Ultimate decisions will depend on program goals, the population served, and informed judgments about the weight of benefits and harms.

  20. Monetary policy and macroeconomic management: A simulation ...

    African Journals Online (AJOL)

    The dynamic nexus between money supply, fiscal deficit, inflation, output and exchange rate management has generated much debate in economic literature in Nigeria in recent times. To contribute to this debate, this paper uses 3SLS estimation technique as well as carried out policy simulation experiment to investigate ...

  1. Adapting a Markov Monte Carlo simulation model for forecasting the number of Coronary Artery Revascularisation Procedures in an era of rapidly changing technology and policy

    Directory of Open Access Journals (Sweden)

    Knuiman Matthew

    2008-06-01

    Full Text Available Abstract Background Treatments for coronary heart disease (CHD have evolved rapidly over the last 15 years with considerable change in the number and effectiveness of both medical and surgical treatments. This period has seen the rapid development and uptake of statin drugs and coronary artery revascularization procedures (CARPs that include Coronary Artery Bypass Graft procedures (CABGs and Percutaneous Coronary Interventions (PCIs. It is difficult in an era of such rapid change to accurately forecast requirements for treatment services such as CARPs. In a previous paper we have described and outlined the use of a Markov Monte Carlo simulation model for analyzing and predicting the requirements for CARPs for the population of Western Australia (Mannan et al, 2007. In this paper, we expand on the use of this model for forecasting CARPs in Western Australia with a focus on the lack of adequate performance of the (standard model for forecasting CARPs in a period during the mid 1990s when there were considerable changes to CARP technology and implementation policy and an exploration and demonstration of how the standard model may be adapted to achieve better performance. Methods Selected key CARP event model probabilities are modified based on information relating to changes in the effectiveness of CARPs from clinical trial evidence and an awareness of trends in policy and practice of CARPs. These modified model probabilities and the ones obtained by standard methods are used as inputs in our Markov simulation model. Results The projected numbers of CARPs in the population of Western Australia over 1995–99 only improve marginally when modifications to model probabilities are made to incorporate an increase in effectiveness of PCI procedures. However, the projected numbers improve substantially when, in addition, further modifications are incorporated that relate to the increased probability of a PCI procedure and the reduced probability of a CABG

  2. Adapting a Markov Monte Carlo simulation model for forecasting the number of coronary artery revascularisation procedures in an era of rapidly changing technology and policy.

    Science.gov (United States)

    Mannan, Haider R; Knuiman, Matthew; Hobbs, Michael

    2008-06-25

    Treatments for coronary heart disease (CHD) have evolved rapidly over the last 15 years with considerable change in the number and effectiveness of both medical and surgical treatments. This period has seen the rapid development and uptake of statin drugs and coronary artery revascularization procedures (CARPs) that include Coronary Artery Bypass Graft procedures (CABGs) and Percutaneous Coronary Interventions (PCIs). It is difficult in an era of such rapid change to accurately forecast requirements for treatment services such as CARPs. In a previous paper we have described and outlined the use of a Markov Monte Carlo simulation model for analyzing and predicting the requirements for CARPs for the population of Western Australia (Mannan et al, 2007). In this paper, we expand on the use of this model for forecasting CARPs in Western Australia with a focus on the lack of adequate performance of the (standard) model for forecasting CARPs in a period during the mid 1990s when there were considerable changes to CARP technology and implementation policy and an exploration and demonstration of how the standard model may be adapted to achieve better performance. Selected key CARP event model probabilities are modified based on information relating to changes in the effectiveness of CARPs from clinical trial evidence and an awareness of trends in policy and practice of CARPs. These modified model probabilities and the ones obtained by standard methods are used as inputs in our Markov simulation model. The projected numbers of CARPs in the population of Western Australia over 1995-99 only improve marginally when modifications to model probabilities are made to incorporate an increase in effectiveness of PCI procedures. However, the projected numbers improve substantially when, in addition, further modifications are incorporated that relate to the increased probability of a PCI procedure and the reduced probability of a CABG procedure stemming from changed CARP preference

  3. Selecting Policy Indicators and Developing Simulation Models for the National School Lunch and Breakfast Programs. Final Report. Special Nutrition Programs Report Series. Special Nutrition Programs Report No. CN-10-PRED

    Science.gov (United States)

    Dragoset, Lisa; Gordon, Anne

    2010-01-01

    This report describes work using nationally representative 2005 data from the School Nutrition Dietary Assessment-III (SNDA-III) study to develop a simulation model to predict the potential implications of changes in policies or practices related to school meals and school food environments. The model focuses on three domains of outcomes: (1) the…

  4. Simulation modeling and arena

    CERN Document Server

    Rossetti, Manuel D

    2015-01-01

    Emphasizes a hands-on approach to learning statistical analysis and model building through the use of comprehensive examples, problems sets, and software applications With a unique blend of theory and applications, Simulation Modeling and Arena®, Second Edition integrates coverage of statistical analysis and model building to emphasize the importance of both topics in simulation. Featuring introductory coverage on how simulation works and why it matters, the Second Edition expands coverage on static simulation and the applications of spreadsheets to perform simulation. The new edition als

  5. Environmental management policy analysis using complex system simulation

    International Nuclear Information System (INIS)

    Van Eeckhout, E.; Roberts, D.; Oakes, R.; Shieh, A.; Hardie, W.; Pope, P.

    1999-01-01

    The two primary modules of Envirosim (the model of Los Alamos TA-55 and the WIPP transport/storage model) have been combined into one application, with the simulated waste generated by TA-55 operations being fed to storage, packaging, and transport simulation entities. Three simulation scenarios were executed which demonstrate the usefulness of Envirosim as a policy analysis tool for use in planning shipments to WIPP. A graphical user interface (GUI) has been implemented using IDL (Interactive Data Language) which allows the analyst to easily view simulation results. While IDL is not necessarily the graphics interface that would be selected for a production version of Envirosim, it does provide some powerful data manipulation capabilities, and it runs on a variety of platforms

  6. Aviation Safety Simulation Model

    Science.gov (United States)

    Houser, Scott; Yackovetsky, Robert (Technical Monitor)

    2001-01-01

    The Aviation Safety Simulation Model is a software tool that enables users to configure a terrain, a flight path, and an aircraft and simulate the aircraft's flight along the path. The simulation monitors the aircraft's proximity to terrain obstructions, and reports when the aircraft violates accepted minimum distances from an obstruction. This model design facilitates future enhancements to address other flight safety issues, particularly air and runway traffic scenarios. This report shows the user how to build a simulation scenario and run it. It also explains the model's output.

  7. Irrigation water policy analysis using a business simulation game

    Science.gov (United States)

    Buchholz, M.; Holst, G.; Musshoff, O.

    2016-10-01

    Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

  8. Cost-effectiveness of breast cancer screening policies using simulation.

    Science.gov (United States)

    Gocgun, Y; Banjevic, D; Taghipour, S; Montgomery, N; Harvey, B J; Jardine, A K S; Miller, A B

    2015-08-01

    In this paper, we study breast cancer screening policies using computer simulation. We developed a multi-state Markov model for breast cancer progression, considering both the screening and treatment stages of breast cancer. The parameters of our model were estimated through data from the Canadian National Breast Cancer Screening Study as well as data in the relevant literature. Using computer simulation, we evaluated various screening policies to study the impact of mammography screening for age-based subpopulations in Canada. We also performed sensitivity analysis to examine the impact of certain parameters on number of deaths and total costs. The analysis comparing screening policies reveals that a policy in which women belonging to the 40-49 age group are not screened, whereas those belonging to the 50-59 and 60-69 age groups are screened once every 5 years, outperforms others with respect to cost per life saved. Our analysis also indicates that increasing the screening frequencies for the 50-59 and 60-69 age groups decrease mortality, and that the average number of deaths generally decreases with an increase in screening frequency. We found that screening annually for all age groups is associated with the highest costs per life saved. Our analysis thus reveals that cost per life saved increases with an increase in screening frequency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. From Predictive Models to Instructional Policies

    Science.gov (United States)

    Rollinson, Joseph; Brunskill, Emma

    2015-01-01

    At their core, Intelligent Tutoring Systems consist of a student model and a policy. The student model captures the state of the student and the policy uses the student model to individualize instruction. Policies require different properties from the student model. For example, a mastery threshold policy requires the student model to have a way…

  10. Pilot Study: Impact of Computer Simulation on Students' Economic Policy Performance. Pilot Study.

    Science.gov (United States)

    Domazlicky, Bruce; France, Judith

    Fiscal and monetary policies taught in macroeconomic principles courses are concepts that might require both lecture and simulation methods. The simulation models, which apply the principles gleened from comparative statistics to a dynamic world, may give students an appreciation for the problems facing policy makers. This paper is a report of a…

  11. Simulation in Complex Modelling

    DEFF Research Database (Denmark)

    Nicholas, Paul; Ramsgaard Thomsen, Mette; Tamke, Martin

    2017-01-01

    This paper will discuss the role of simulation in extended architectural design modelling. As a framing paper, the aim is to present and discuss the role of integrated design simulation and feedback between design and simulation in a series of projects under the Complex Modelling framework. Complex...... performance, engage with high degrees of interdependency and allow the emergence of design agency and feedback between the multiple scales of architectural construction. This paper presents examples for integrated design simulation from a series of projects including Lace Wall, A Bridge Too Far and Inflated...... Restraint developed for the research exhibition Complex Modelling, Meldahls Smedie Gallery, Copenhagen in 2016. Where the direct project aims and outcomes have been reported elsewhere, the aim for this paper is to discuss overarching strategies for working with design integrated simulation....

  12. Scientific Modeling and simulations

    CERN Document Server

    Diaz de la Rubia, Tomás

    2009-01-01

    Showcases the conceptual advantages of modeling which, coupled with the unprecedented computing power through simulations, allow scientists to tackle the formibable problems of our society, such as the search for hydrocarbons, understanding the structure of a virus, or the intersection between simulations and real data in extreme environments

  13. Computer Modeling and Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pronskikh, V. S. [Fermilab

    2014-05-09

    Verification and validation of computer codes and models used in simulation are two aspects of the scientific practice of high importance and have recently been discussed by philosophers of science. While verification is predominantly associated with the correctness of the way a model is represented by a computer code or algorithm, validation more often refers to model’s relation to the real world and its intended use. It has been argued that because complex simulations are generally not transparent to a practitioner, the Duhem problem can arise for verification and validation due to their entanglement; such an entanglement makes it impossible to distinguish whether a coding error or model’s general inadequacy to its target should be blamed in the case of the model failure. I argue that in order to disentangle verification and validation, a clear distinction between computer modeling (construction of mathematical computer models of elementary processes) and simulation (construction of models of composite objects and processes by means of numerical experimenting with them) needs to be made. Holding on to that distinction, I propose to relate verification (based on theoretical strategies such as inferences) to modeling and validation, which shares the common epistemology with experimentation, to simulation. To explain reasons of their intermittent entanglement I propose a weberian ideal-typical model of modeling and simulation as roles in practice. I suggest an approach to alleviate the Duhem problem for verification and validation generally applicable in practice and based on differences in epistemic strategies and scopes

  14. Automated Simulation Model Generation

    NARCIS (Netherlands)

    Huang, Y.

    2013-01-01

    One of today's challenges in the field of modeling and simulation is to model increasingly larger and more complex systems. Complex models take long to develop and incur high costs. With the advances in data collection technologies and more popular use of computer-aided systems, more data has become

  15. AEGIS geologic simulation model

    International Nuclear Information System (INIS)

    Foley, M.G.

    1982-01-01

    The Geologic Simulation Model (GSM) is used by the AEGIS (Assessment of Effectiveness of Geologic Isolation Systems) program at the Pacific Northwest Laboratory to simulate the dynamic geology and hydrology of a geologic nuclear waste repository site over a million-year period following repository closure. The GSM helps to organize geologic/hydrologic data; to focus attention on active natural processes by requiring their simulation; and, through interactive simulation and calibration, to reduce subjective evaluations of the geologic system. During each computer run, the GSM produces a million-year geologic history that is possible for the region and the repository site. In addition, the GSM records in permanent history files everything that occurred during that time span. Statistical analyses of data in the history files of several hundred simulations are used to classify typical evolutionary paths, to establish the probabilities associated with deviations from the typical paths, and to determine which types of perturbations of the geologic/hydrologic system, if any, are most likely to occur. These simulations will be evaluated by geologists familiar with the repository region to determine validity of the results. Perturbed systems that are determined to be the most realistic, within whatever probability limits are established, will be used for the analyses that involve radionuclide transport and dose models. The GSM is designed to be continuously refined and updated. Simulation models are site specific, and, although the submodels may have limited general applicability, the input data equirements necessitate detailed characterization of each site before application

  16. Validation of simulation models

    DEFF Research Database (Denmark)

    Rehman, Muniza; Pedersen, Stig Andur

    2012-01-01

    In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety...

  17. Dynamic energy models and carbon mitigation policies

    Science.gov (United States)

    Tilley, Luke A.

    In this dissertation I examine a specific class of energy models and their implications for carbon mitigation policies. The class of models includes a production function capable of reproducing the empirically observed phenomenon of short run rigidity of energy use in response to energy price changes and long run exibility of energy use in response to energy price changes. I use a theoretical model, parameterized using empirical data, to simulate economic performance under several tax regimes where taxes are levied on capital income, investment, and energy. I also investigate transitions from one tax regime to another. I find that energy taxes intended to reduce energy use can successfully achieve those goals with minimal or even positive impacts on macroeconomic performance. But the transition paths to new steady states are lengthy, making political commitment to such policies very challenging.

  18. 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.

  19. Modeling of global biomass policies

    International Nuclear Information System (INIS)

    Gielen, Dolf; Fujino, Junichi; Hashimoto, Seiji; Moriguchi, Yuichi

    2003-01-01

    This paper discusses the BEAP model and its use for the analysis of biomass policies for CO 2 emission reduction. The model considers competing land use, trade and leakage effects, and competing emission reduction strategies. Two policy scenarios are presented. In case of a 2040 time horizon the results suggest that a combination of afforestation and limited use of biomass for energy and materials constitutes the most attractive set of strategies. In case of a 'continued Kyoto' scenario including afforestation permit trade, the results suggest 5.1 Gt emission reduction based on land use change in 2020, two thirds of the total emission reduction by then. In case of global emission reduction, land use, land use change and forestry (LULUCF) accounts for one quarter of the emission reduction. However these results depend on the modeling time horizon. In case of a broader time horizon, maximized biomass production is more attractive than LULUCF. This result can be interpreted as a warning against a market based trading scheme for LULUCF credits. The model results suggest that the bioenergy market is dominated by transportation fuels and heating, and to a lesser extent feedstocks. Bioelectricity does not gain a significant market share in case competing CO 2 -free electricity options such as CO 2 capture and sequestration and nuclear are considered. To some extent trade in agricultural food products such as beef and cereals will be affected by CO 2 policies

  20. Modeling of global biomass policies

    International Nuclear Information System (INIS)

    Gielen, D.; Fujino, Junichi; Hashimoto, Seiji; Moriguchi, Yuichi

    2003-01-01

    This paper discusses the BEAP model and its use for the analysis of biomass policies for CO 2 emission reduction. The model considers competing land use, trade and leakage effects, and competing emission reduction strategies. Two policy scenarios are presented. In case of a 2040 time horizon the results suggest that a combination of afforestation and limited use of biomass for energy and materials constitutes the most attractive set of strategies. In case of a 'continued Kyoto' scenario including afforestation permit trade, the results suggest 5.1 Gt emission reduction based on land use change in 2020, two thirds of the total emission reduction by then. In case of global emission reduction, land use, land use change and forestry (LULUCF) accounts for one quarter of the emission reduction. However these results depend on the modeling time horizon. In case of a broader time horizon, maximized biomass production is more attractive than LULUCF. This result can be interpreted as a warning against a market based trading scheme for LULUCF credits. The model results suggest that the bioenergy market is dominated by transportation fuels and heating, and to a lesser extent feedstocks. Bioelectricity does not gain a significant market share in case competing CO 2 -free electricity options such as CO 2 capture and sequestration and nuclear are considered. To some extent trade in agricultural food products such as beef and cereals will be affected by CO 2 policies. (Author)

  1. Models and simulations

    International Nuclear Information System (INIS)

    Lee, M.J.; Sheppard, J.C.; Sullenberger, M.; Woodley, M.D.

    1983-09-01

    On-line mathematical models have been used successfully for computer controlled operation of SPEAR and PEP. The same model control concept is being implemented for the operation of the LINAC and for the Damping Ring, which will be part of the Stanford Linear Collider (SLC). The purpose of this paper is to describe the general relationships between models, simulations and the control system for any machine at SLAC. The work we have done on the development of the empirical model for the Damping Ring will be presented as an example

  2. PSH Transient Simulation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-21

    PSH Transient Simulation Modeling presentation from the WPTO FY14 - FY16 Peer Review. Transient effects are an important consideration when designing a PSH system, yet numerical techniques for hydraulic transient analysis still need improvements for adjustable-speed (AS) reversible pump-turbine applications.

  3. Wake modeling and simulation

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Madsen Aagaard, Helge; Larsen, Torben J.

    We present a consistent, physically based theory for the wake meandering phenomenon, which we consider of crucial importance for the overall description of wind turbine loadings in wind farms. In its present version the model is confined to single wake situations. The model philosophy does, howev...... methodology has been implemented in the aeroelastic code HAWC2, and example simulations of wake situations, from the small Tjæreborg wind farm, have been performed showing satisfactory agreement between predictions and measurements...

  4. Simulation modeling and analysis in safety. II

    International Nuclear Information System (INIS)

    Ayoub, M.A.

    1981-01-01

    The paper introduces and illustrates simulation modeling as a viable approach for dealing with complex issues and decisions in safety and health. The author details two studies: evaluation of employee exposure to airborne radioactive materials and effectiveness of the safety organization. The first study seeks to define a policy to manage a facility used in testing employees for radiation contamination. An acceptable policy is one that would permit the testing of all employees as defined under regulatory requirements, while not exceeding available resources. The second study evaluates the relationship between safety performance and the characteristics of the organization, its management, its policy, and communication patterns among various functions and levels. Both studies use models where decisions are reached based on the prevailing conditions and occurrence of key events within the simulation environment. Finally, several problem areas suitable for simulation studies are highlighted. (Auth.)

  5. Software-Engineering Process Simulation (SEPS) model

    Science.gov (United States)

    Lin, C. Y.; Abdel-Hamid, T.; Sherif, J. S.

    1992-01-01

    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments.

  6. 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...

  7. Simulation - modeling - experiment

    International Nuclear Information System (INIS)

    2004-01-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  8. Wake modeling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.; Aagaard Madsen, H.; Larsen, T.J.; Troldborg, N.

    2008-07-15

    We present a consistent, physically based theory for the wake meandering phenomenon, which we consider of crucial importance for the overall description of wind turbine loadings in wind farms. In its present version the model is confined to single wake situations. The model philosophy does, however, have the potential to include also mutual wake interaction phenomenons. The basic conjecture behind the dynamic wake meandering (DWM) model is that wake transportation in the atmospheric boundary layer is driven by the large scale lateral- and vertical turbulence components. Based on this conjecture a stochastic model of the downstream wake meandering is formulated. In addition to the kinematic formulation of the dynamics of the 'meandering frame of reference', models characterizing the mean wake deficit as well as the added wake turbulence, described in the meandering frame of reference, are an integrated part the DWM model complex. For design applications, the computational efficiency of wake deficit prediction is a key issue. A computationally low cost model is developed for this purpose. Likewise, the character of the added wake turbulence, generated by the up-stream turbine in the form of shed and trailed vorticity, has been approached by a simple semi-empirical model essentially based on an eddy viscosity philosophy. Contrary to previous attempts to model wake loading, the DWM approach opens for a unifying description in the sense that turbine power- and load aspects can be treated simultaneously. This capability is a direct and attractive consequence of the model being based on the underlying physical process, and it potentially opens for optimization of wind farm topology, of wind farm operation as well as of control strategies for the individual turbine. To establish an integrated modeling tool, the DWM methodology has been implemented in the aeroelastic code HAWC2, and example simulations of wake situations, from the small Tjaereborg wind farm, have

  9. Biomolecular modelling and simulations

    CERN Document Server

    Karabencheva-Christova, Tatyana

    2014-01-01

    Published continuously since 1944, the Advances in Protein Chemistry and Structural Biology series is the essential resource for protein chemists. Each volume brings forth new information about protocols and analysis of proteins. Each thematically organized volume is guest edited by leading experts in a broad range of protein-related topics. Describes advances in biomolecular modelling and simulations Chapters are written by authorities in their field Targeted to a wide audience of researchers, specialists, and students The information provided in the volume is well supported by a number of high quality illustrations, figures, and tables.

  10. The role of public policies in reducing smoking: the Minnesota SimSmoke tobacco policy model.

    Science.gov (United States)

    Levy, David T; Boyle, Raymond G; Abrams, David B

    2012-11-01

    Following the landmark lawsuit and settlement with the tobacco industry, Minnesota pursued the implementation of stricter tobacco control policies, including tax increases, mass media campaigns, smokefree air laws, and cessation treatment policies. Modeling is used to examine policy effects on smoking prevalence and smoking-attributable deaths. To estimate the effect of tobacco control policies in Minnesota on smoking prevalence and smoking-attributable deaths using the SimSmoke simulation model. Minnesota data starting in 1993 are applied to SimSmoke, a simulation model used to examine the effect of tobacco control policies over time on smoking initiation and cessation. Upon validating the model against smoking prevalence, SimSmoke is used to distinguish the effect of policies implemented since 1993 on smoking prevalence. Using standard attribution methods, SimSmoke also estimates deaths averted as a result of the policies. SimSmoke predicts smoking prevalence accurately between 1993 and 2011. Since 1993, a relative reduction in smoking rates of 29% by 2011 and of 41% by 2041 can be attributed to tobacco control policies, mainly tax increases, smokefree air laws, media campaigns, and cessation treatment programs. Moreover, 48,000 smoking-attributable deaths will be averted by 2041. Minnesota SimSmoke demonstrates that tobacco control policies, especially taxes, have substantially reduced smoking prevalence and smoking-attributable deaths. Taxes, smokefree air laws, mass media, cessation treatment policies, and youth-access enforcement contributed to the decline in prevalence and deaths averted, with the strongest component being taxes. With stronger policies, for example, increasing cigarette taxes to $4.00 per pack, Minnesota's smoking rate could be reduced by another 13%, and 7200 deaths could be averted by 2041. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Drug Policy: the "Dutch Model"

    NARCIS (Netherlands)

    van Ooijen-Houben, M.M.J.; Kleemans, E.R.

    2015-01-01

    Dutch drug policy, once considered pragmatic and lenient and rooted in a generally tolerant attitude toward drug use, has slowly but surely shifted from a primarily public health focus to an increasing focus on law enforcement. The "coffee shop" policy and the policy toward MDMA/ecstasy are

  12. A hybrid society model for simulating residential electricity consumption

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Minjie [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); State Power Economic Research Institute, Beijing (China); Hu, Zhaoguang [State Power Economic Research Institute, Beijing (China); Wu, Junyong; Zhou, Yuhui [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China)

    2008-12-15

    In this paper, a hybrid social model of econometric model and social influence model is proposed for evaluating the influence of pricing policy and public education policy on residential habit of electricity using in power resources management. And, a hybrid society simulation platform based on the proposed model, called residential electricity consumption multi-agent systems (RECMAS), is designed for simulating residential electricity consumption by multi-agent system. RECMAS is composed of consumer agent, power supplier agent, and policy maker agent. It provides the policy makers with a useful tool to evaluate power price policies and public education campaigns in different scenarios. According to an influenced diffusion mechanism, RECMAS can simulate the residential electricity demand-supply chain and analyze impacts of the factors on residential electricity consumption. Finally, the proposed method is used to simulate urban residential electricity consumption in China. (author)

  13. A hybrid society model for simulating residential electricity consumption

    International Nuclear Information System (INIS)

    Xu, Minjie; Hu, Zhaoguang; Wu, Junyong; Zhou, Yuhui

    2008-01-01

    In this paper, a hybrid social model of econometric model and social influence model is proposed for evaluating the influence of pricing policy and public education policy on residential habit of electricity using in power resources management. And, a hybrid society simulation platform based on the proposed model, called residential electricity consumption multi-agent systems (RECMAS), is designed for simulating residential electricity consumption by multi-agent system. RECMAS is composed of consumer agent, power supplier agent, and policy maker agent. It provides the policy makers with a useful tool to evaluate power price policies and public education campaigns in different scenarios. According to an influenced diffusion mechanism, RECMAS can simulate the residential electricity demand-supply chain and analyze impacts of the factors on residential electricity consumption. Finally, the proposed method is used to simulate urban residential electricity consumption in China. (author)

  14. Policy, Personalities and Pedagogy: The Use of Simulation Games to Teach and Learn about Development Policy

    Science.gov (United States)

    Prinsen, Gerard; Overton, John

    2011-01-01

    Simulation games have a long history in education and are well suited to learning about negotiation, power, relationships and uncertain outcomes. This paper reflects on the experience of using a semester-long simulation game to introduce postgraduate students to development policy. It focuses on three issues identified in the literature--realism,…

  15. 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.

  16. Towards increased policy relevance in energy modeling

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Ramesohl, Stephan; Boyd, Gale

    2003-07-29

    Historically, most energy models were reasonably equipped to assess the impact of a subsidy or change in taxation, but are often insufficient to assess the impact of more innovative policy instruments. We evaluate the models used to assess future energy use, focusing on industrial energy use. We explore approaches to engineering-economic analysis that could help improve the realism and policy relevance of engineering-economic modeling frameworks. We also explore solutions to strengthen the policy usefulness of engineering-economic analysis that can be built from a framework of multi-disciplinary cooperation. We focus on the so-called ''engineering-economic'' (or ''bottom-up'') models, as they include the amount of detail that is commonly needed to model policy scenarios. We identify research priorities for the modeling framework, technology representation in models, policy evaluation and modeling of decision-making behavior.

  17. Simulation of an integrated age replacement and spare provisioning policy using SLAM

    International Nuclear Information System (INIS)

    Zohrul Kabir, A.B.M.; Farrash, S.H.A.

    1996-01-01

    This paper presents a SLAM simulation model for determining a jointly optimal age replacement and spare part provisioning policy. The policy, referred to as a stocking policy, is formulated by combining age replacement policy with a continuous review (s, S) type inventory policy, where s is the stock reorder level and S is the maximum stock level. The optimal values of the decision variables are obtained by minimizing the total cost of replacement and inventory. The simulation procedure outlined in the paper can be used to model any operating situation having either a single item or a number of identical items. Results from a number of case problems specifically constructed by 5-factor second order rotatory design have been presented and the effects of different cost elements, item failure characteristics and lead time characteristics have been highlighted. For all case problems, optimal (s, S) policies to support the Barlow-Proschan age policy have also been determined. Simulation results clearly indicate the separate optimizations of replacement and spare provisioning policies do not ensure global optimality when total system cost has to be minimized

  18. Optimal Policy in OG Models

    DEFF Research Database (Denmark)

    Ghiglino, Christian; Tvede, Mich

    for generations, through fiscal policy, i.e. monetary transfers and taxes. Both situations with and without time discounting are considered. It is shown that if the discount factor is suffciently close to one then the optimal policy stabilizes the economy, i.e. the equilibrium path has the turnpike property...

  19. Optimal Policy in OG Models

    DEFF Research Database (Denmark)

    Ghiglino, Christian; Tvede, Mich

    2000-01-01

    for generations, through fiscal policy, i.e., monetary transfers and taxes. Situations both with and without time discounting are considered. It is shown that if the discount factor is sufficiently close to one then the optimal policy stabilizes the economy, i.e. the equilibrium path has the turnpike property...

  20. Notes on modeling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Antonio [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-10

    These notes present a high-level overview of how modeling and simulation are carried out by practitioners. The discussion is of a general nature; no specific techniques are examined but the activities associated with all modeling and simulation approaches are briefly addressed. There is also a discussion of validation and verification and, at the end, a section on why modeling and simulation are useful.

  1. Demographic Consequences of Gender Discrimination in China: Simulation Analysis of Policy Options

    OpenAIRE

    Quanbao, Jiang; Shuzhuo, Li; Marcus W., Feldman

    2011-01-01

    The large number of missing females in China, a consequence of gender discrimination, is having and will continue to have a profound effect on the country's population development. In this paper, we analyze the causes of this gender discrimination in terms of institutions, culture and, economy, and suggest public policies that might help eliminate gender discrimination. Using a population simulation model, we study the effect of public policies on the sex ratio at birth and excess female chil...

  2. Simulation Model of a Transient

    DEFF Research Database (Denmark)

    Jauch, Clemens; Sørensen, Poul; Bak-Jensen, Birgitte

    2005-01-01

    This paper describes the simulation model of a controller that enables an active-stall wind turbine to ride through transient faults. The simulated wind turbine is connected to a simple model of a power system. Certain fault scenarios are specified and the turbine shall be able to sustain operati...

  3. Cognitive models embedded in system simulation models

    International Nuclear Information System (INIS)

    Siegel, A.I.; Wolf, J.J.

    1982-01-01

    If we are to discuss and consider cognitive models, we must first come to grips with two questions: (1) What is cognition; (2) What is a model. Presumably, the answers to these questions can provide a basis for defining a cognitive model. Accordingly, this paper first places these two questions into perspective. Then, cognitive models are set within the context of computer simulation models and a number of computer simulations of cognitive processes are described. Finally, pervasive issues are discussed vis-a-vis cognitive modeling in the computer simulation context

  4. Exploiting Modelling and Simulation in Support of Cyber Defence

    NARCIS (Netherlands)

    Klaver, M.H.A.; Boltjes, B.; Croom-Jonson, S.; Jonat, F.; Çankaya, Y.

    2014-01-01

    The rapidly evolving environment of Cyber threats against the NATO Alliance has necessitated a renewed focus on the development of Cyber Defence policy and capabilities. The NATO Modelling and Simulation Group is looking for ways to leverage Modelling and Simulation experience in research, analysis

  5. General introduction to simulation models

    DEFF Research Database (Denmark)

    Hisham Beshara Halasa, Tariq; Boklund, Anette

    2012-01-01

    trials. However, if simulation models would be used, good quality input data must be available. To model FMD, several disease spread models are available. For this project, we chose three simulation model; Davis Animal Disease Spread (DADS), that has been upgraded to DTU-DADS, InterSpread Plus (ISP......Monte Carlo simulation can be defined as a representation of real life systems to gain insight into their functions and to investigate the effects of alternative conditions or actions on the modeled system. Models are a simplification of a system. Most often, it is best to use experiments and field...... trials to investigate the effect of alternative conditions or actions on a specific system. Nonetheless, field trials are expensive and sometimes not possible to conduct, as in case of foot-and-mouth disease (FMD). Instead, simulation models can be a good and cheap substitute for experiments and field...

  6. An electricity and environmental policy model

    International Nuclear Information System (INIS)

    Hanson, D.A.

    1993-01-01

    This paper describes work being done to simulate the 1990 Clean Air Act Amendments (CAAA), Title IV, Acidic Deposition Control, which introduced tradable, bankable SO 2 emission allowances. The Title IV simulations are compared with three other scenarios on a regional basis in order to calculate the following: the absolute cost savings of the tradable/ bankable approach, the relative cost savings of the tradable/ bankable approach derived from a baseline of no controls, the environmental improvement, measured in terms of SO 2 emission reduction, that will be achieved under Title IV compared with a more rigid command-and-control regulation with the same cost. Hence, the simulations illustrate the basic point that more efficient market-based regulation can either reduce costs or can provide enhanced environmental quality, or both. It is important for policy formation to get a handle on relative magnitudes. The National Acid Precipitation Assessment Program (NAPAP) 1990 Assessment suggested a 25% cost saving from tradable emission allowances relative to command-and-control. Both the relative savings potential and the absolute savings potential matter because a small relative savings in a large regulatory program may still be worth pursuing. Regional cost reductions and environmental improvements are of particular interest. However, this study goes further to characterize likely SO 2 emission trading patterns within and among utility operating systems. The study also characterizes the coal market and the induced sulfur premiums over time and the market price path for SO 2 emission allowances. It is shown that the sulfur premium is equivalent to the SO 2 allowance price. This paper focuses on the methodology and on the new electric utility planning and compliance model which was designed for the study

  7. Simulation - modeling - experiment; Simulation - modelisation - experience

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  8. An evaluation model for low carbon island policy: The case of Taiwan's green transportation policy

    International Nuclear Information System (INIS)

    Trappey, Amy J.C.; Trappey, Charles; Hsiao, C.T.; Ou, Jerry J.R.; Li, S.J.; Chen, Kevin W.P.

    2012-01-01

    Conserving energy and reducing carbon emissions have become the common responsibility of the international community. During the year 2010, the Taiwan government planned a four-year project budgeted at 300 million US dollars, called “The Penghu Low Carbon Island Development Project.” The policy objective is to use Penghu Island (population 85,000) as a test platform to evaluate new ways to conserve energy and reduce carbon emissions before attempting to replicate the policies on Taiwan Island. For Taiwan, a zero carbon island green transportation policy will regulate the total number of electric scooters, the total number of gasoline motorcycles, influence government subsidy incentives, and create the need for new motorcycle license issuing and control. These factors interact with each other to form a complex and dynamic system that impacts policy as well as the current way of life. In this study, a system dynamics approach is designed to construct a model for evaluating the green transportation policy on Penghu Island. Simulations are conducted to model green transportation system behavior and related policy effects in a smaller, controlled environment before creating policies for Taiwan Island that will impact the lives of over 23 million people. - Highlights: ► Provides an overview of Taiwan's Penghu Low Carbon Island Development Project. ► Develops a systems dynamics approach for green transportation policy assessment. ► Provides causal analysis of social, economic, and environmental factors. ► Demonstrates that the proposed policy cannot meet the CO 2 reduction goals. ► Alternative policies can be evaluated using the proposed approach.

  9. Computational Models Used to Assess US Tobacco Control Policies.

    Science.gov (United States)

    Feirman, Shari P; Glasser, Allison M; Rose, Shyanika; Niaura, Ray; Abrams, David B; Teplitskaya, Lyubov; Villanti, Andrea C

    2017-11-01

    Simulation models can be used to evaluate existing and potential tobacco control interventions, including policies. The purpose of this systematic review was to synthesize evidence from computational models used to project population-level effects of tobacco control interventions. We provide recommendations to strengthen simulation models that evaluate tobacco control interventions. Studies were eligible for review if they employed a computational model to predict the expected effects of a non-clinical US-based tobacco control intervention. We searched five electronic databases on July 1, 2013 with no date restrictions and synthesized studies qualitatively. Six primary non-clinical intervention types were examined across the 40 studies: taxation, youth prevention, smoke-free policies, mass media campaigns, marketing/advertising restrictions, and product regulation. Simulation models demonstrated the independent and combined effects of these interventions on decreasing projected future smoking prevalence. Taxation effects were the most robust, as studies examining other interventions exhibited substantial heterogeneity with regard to the outcomes and specific policies examined across models. Models should project the impact of interventions on overall tobacco use, including nicotine delivery product use, to estimate preventable health and cost-saving outcomes. Model validation, transparency, more sophisticated models, and modeling policy interactions are also needed to inform policymakers to make decisions that will minimize harm and maximize health. In this systematic review, evidence from multiple studies demonstrated the independent effect of taxation on decreasing future smoking prevalence, and models for other tobacco control interventions showed that these strategies are expected to decrease smoking, benefit population health, and are reasonable to implement from a cost perspective. Our recommendations aim to help policymakers and researchers minimize harm and

  10. Effects of national energy policies on carbon dioxide emissions in a European internal electricity market: Results from a simulation model of the European power systems

    OpenAIRE

    Hoster, Frank

    1997-01-01

    This article considers the economic and environmental (in terms of CO2) effects of national energy policies in a European Single Market for electricity. It was found that the combined CO2/Energy-tax proposed by the European Commission would be able to stabilise the current volume of CO2-emissions in the electricity sector. A national single handed effort in introducing a CO2-tax to reduce the emissions was found to be ineffective in the long term and would be in addition allocative inefficien...

  11. Policy modeling for industrial energy use

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Park, Hi-Chun; Lee, Sang-Gon; Jung, Yonghun; Kato, Hiroyuki; Ramesohl, Stephan; Boyd, Gale; Eichhammer, Wolfgang; Nyboer, John; Jaccard, Mark; Nordqvist, Joakim; Boyd, Christopher; Klee, Howard; Anglani, Norma; Biermans, Gijs

    2003-03-01

    The international workshop on Policy Modeling for Industrial Energy Use was jointly organized by EETA (Professional Network for Engineering Economic Technology Analysis) and INEDIS (International Network for Energy Demand Analysis in the Industrial Sector). The workshop has helped to layout the needs and challenges to include policy more explicitly in energy-efficiency modeling. The current state-of-the-art models have a proven track record in forecasting future trends under conditions similar to those faced in the recent past. However, the future of energy policy in a climate-restrained world is likely to demand different and additional services to be provided by energy modelers. In this workshop some of the international models used to make energy consumption forecasts have been discussed as well as innovations to enable the modeling of policy scenarios. This was followed by the discussion of future challenges, new insights in the data needed to determine the inputs into energy model s, and methods to incorporate decision making and policy in the models. Based on the discussion the workshop participants came to the following conclusions and recommendations: Current energy models are already complex, and it is already difficult to collect the model inputs. Hence, new approaches should be transparent and not lead to extremely complex models that try to ''do everything''. The model structure will be determined by the questions that need to be answered. A good understanding of the decision making framework of policy makers and clear communication on the needs are essential to make any future energy modeling effort successful. There is a need to better understand the effects of policy on future energy use, emissions and the economy. To allow the inclusion of policy instruments in models, evaluation of programs and instruments is essential, and need to be included in the policy instrument design. Increased efforts are needed to better understand the

  12. 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

  13. Progress in modeling and simulation.

    Science.gov (United States)

    Kindler, E

    1998-01-01

    For the modeling of systems, the computers are more and more used while the other "media" (including the human intellect) carrying the models are abandoned. For the modeling of knowledges, i.e. of more or less general concepts (possibly used to model systems composed of instances of such concepts), the object-oriented programming is nowadays widely used. For the modeling of processes existing and developing in the time, computer simulation is used, the results of which are often presented by means of animation (graphical pictures moving and changing in time). Unfortunately, the object-oriented programming tools are commonly not designed to be of a great use for simulation while the programming tools for simulation do not enable their users to apply the advantages of the object-oriented programming. Nevertheless, there are exclusions enabling to use general concepts represented at a computer, for constructing simulation models and for their easy modification. They are described in the present paper, together with true definitions of modeling, simulation and object-oriented programming (including cases that do not satisfy the definitions but are dangerous to introduce misunderstanding), an outline of their applications and of their further development. In relation to the fact that computing systems are being introduced to be control components into a large spectrum of (technological, social and biological) systems, the attention is oriented to models of systems containing modeling components.

  14. Stochastic modeling analysis and simulation

    CERN Document Server

    Nelson, Barry L

    1995-01-01

    A coherent introduction to the techniques for modeling dynamic stochastic systems, this volume also offers a guide to the mathematical, numerical, and simulation tools of systems analysis. Suitable for advanced undergraduates and graduate-level industrial engineers and management science majors, it proposes modeling systems in terms of their simulation, regardless of whether simulation is employed for analysis. Beginning with a view of the conditions that permit a mathematical-numerical analysis, the text explores Poisson and renewal processes, Markov chains in discrete and continuous time, se

  15. FASTBUS simulation models in VHDL

    International Nuclear Information System (INIS)

    Appelquist, G.

    1992-11-01

    Four hardware simulation models implementing the FASTBUS protocol are described. The models are written in the VHDL hardware description language to obtain portability, i.e. without relations to any specific simulator. They include two complete FASTBUS devices, a full-duplex segment interconnect and ancillary logic for the segment. In addition, master and slave models using a high level interface to describe FASTBUS operations, are presented. With these models different configurations of FASTBUS systems can be evaluated and the FASTBUS transactions of new devices can be verified. (au)

  16. Model reduction for circuit simulation

    CERN Document Server

    Hinze, Michael; Maten, E Jan W Ter

    2011-01-01

    Simulation based on mathematical models plays a major role in computer aided design of integrated circuits (ICs). Decreasing structure sizes, increasing packing densities and driving frequencies require the use of refined mathematical models, and to take into account secondary, parasitic effects. This leads to very high dimensional problems which nowadays require simulation times too large for the short time-to-market demands in industry. Modern Model Order Reduction (MOR) techniques present a way out of this dilemma in providing surrogate models which keep the main characteristics of the devi

  17. POLICY ISSUES ASSOCIATED WITH USING SIMULATION TO ASSESS ENVIRONMENTAL IMPACTS

    Energy Technology Data Exchange (ETDEWEB)

    Uchitel, Kirsten; Tanana, Heather

    2014-11-01

    This report examines the relationship between simulation-based science and judicial assessments of simulations or models supporting evaluations of environmental harms or risks, considering both how it exists currently and how it might be shaped in the future. This report considers the legal standards relevant to judicial assessments of simulation-based science and provides examples of the judicial application of those legal standards. Next, this report discusses the factors that inform whether there is a correlation between the sophistication of a challenged simulation and judicial support for that simulation. Finally, this report examines legal analysis of the broader issues that must be addressed for simulation-based science to be better understood and utilized in the context of judicial challenge and evaluation. !

  18. Greenhouse simulation models.

    NARCIS (Netherlands)

    Bot, G.P.A.

    1989-01-01

    A model is a representation of a real system to describe some properties i.e. internal factors of that system (out-puts) as function of some external factors (inputs). It is impossible to describe the relation between all internal factors (if even all internal factors could be defined) and all

  19. Maintaining environmental quality while expanding biomass production: Sub-regional U.S. policy simulations

    International Nuclear Information System (INIS)

    Egbendewe-Mondzozo, Aklesso; Swinton, Scott M.; Izaurralde, R. César; Manowitz, David H.; Zhang, Xuesong

    2013-01-01

    This paper evaluates environmental policy effects on ligno-cellulosic biomass production and environmental outcomes using an integrated bioeconomic optimization model. The environmental policy integrated climate (EPIC) model is used to simulate crop yields and environmental indicators in current and future potential bioenergy cropping systems based on weather, topographic and soil data. The crop yield and environmental outcome parameters from EPIC are combined with biomass transport costs and economic parameters in a representative farmer profit-maximizing mathematical optimization model. The model is used to predict the impact of alternative policies on biomass production and environmental outcomes. We find that without environmental policy, rising biomass prices initially trigger production of annual crop residues, resulting in increased greenhouse gas emissions, soil erosion, and nutrient losses to surface and ground water. At higher biomass prices, perennial bioenergy crops replace annual crop residues as biomass sources, resulting in lower environmental impacts. Simulations of three environmental policies namely a carbon price, a no-till area subsidy, and a fertilizer tax reveal that only the carbon price policy systematically mitigates environmental impacts. The fertilizer tax is ineffectual and too costly to farmers. The no-till subsidy is effective only at low biomass prices and is too costly to government. - Highlights: ► Bioeconomic optimization model predicts how biomass production affects environment. ► Rising biomass production could impair climate and water quality. ► Environmental protection policies compared as biomass supply grows. ► Carbon price protects the environment cost-effectively as biomass supply expands

  20. Time to refine key climate policy models

    Science.gov (United States)

    Barron, Alexander R.

    2018-05-01

    Ambition regarding climate change at the national level is critical but is often calibrated with the projected costs — as estimated by a small suite of energy-economic models. Weaknesses in several key areas in these models will continue to distort policy design unless collectively addressed by a diversity of researchers.

  1. Modeling Hepatitis C treatment policy.

    Energy Technology Data Exchange (ETDEWEB)

    Kuypers, Marshall A.; Lambert, Gregory Joseph; Moore, Thomas W.; Glass, Robert John,; Finley, Patrick D.; Ross, David; Chartier, Maggie

    2013-09-01

    Chronic infection with Hepatitis C virus (HCV) results in cirrhosis, liver cancer and death. As the nations largest provider of care for HCV, US Veterans Health Administration (VHA) invests extensive resources in the diagnosis and treatment of the disease. This report documents modeling and analysis of HCV treatment dynamics performed for the VHA aimed at improving service delivery efficiency. System dynamics modeling of disease treatment demonstrated the benefits of early detection and the role of comorbidities in disease progress and patient mortality. Preliminary modeling showed that adherence to rigorous treatment protocols is a primary determinant of treatment success. In depth meta-analysis revealed correlations of adherence and various psycho-social factors. This initial meta-analysis indicates areas where substantial improvement in patient outcomes can potentially result from VA programs which incorporate these factors into their design.

  2. A VRLA battery simulation model

    International Nuclear Information System (INIS)

    Pascoe, Phillip E.; Anbuky, Adnan H.

    2004-01-01

    A valve regulated lead acid (VRLA) battery simulation model is an invaluable tool for the standby power system engineer. The obvious use for such a model is to allow the assessment of battery performance. This may involve determining the influence of cells suffering from state of health (SOH) degradation on the performance of the entire string, or the running of test scenarios to ascertain the most suitable battery size for the application. In addition, it enables the engineer to assess the performance of the overall power system. This includes, for example, running test scenarios to determine the benefits of various load shedding schemes. It also allows the assessment of other power system components, either for determining their requirements and/or vulnerabilities. Finally, a VRLA battery simulation model is vital as a stand alone tool for educational purposes. Despite the fundamentals of the VRLA battery having been established for over 100 years, its operating behaviour is often poorly understood. An accurate simulation model enables the engineer to gain a better understanding of VRLA battery behaviour. A system level multipurpose VRLA battery simulation model is presented. It allows an arbitrary battery (capacity, SOH, number of cells and number of strings) to be simulated under arbitrary operating conditions (discharge rate, ambient temperature, end voltage, charge rate and initial state of charge). The model accurately reflects the VRLA battery discharge and recharge behaviour. This includes the complex start of discharge region known as the coup de fouet

  3. A Policy Language for Modelling Recommendations

    Science.gov (United States)

    Abou El Kalam, Anas; Balbiani, Philippe

    While current and emergent applications become more and more complex, most of existing security policies and models only consider a yes/no response to the access requests. Consequently, modelling, formalizing and implementing permissions, obligations and prohibitions do not cover the richness of all the possible scenarios. In fact, several applications have access rules with the recommendation access modality. In this paper we focus on the problem of formalizing security policies with recommendation needs. The aim is to provide a generic domain-independent formal system for modelling not only permissions, prohibitions and obligations, but also recommendations. In this respect, we present our logic-based language, the semantics, the truth conditions, our axiomatic as well as inference rules. We also give a representative use case with our specification of recommendation requirements. Finally, we explain how our logical framework could be used to query the security policy and to check its consistency.

  4. Sensitivity Analysis of Simulation Models

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2009-01-01

    This contribution presents an overview of sensitivity analysis of simulation models, including the estimation of gradients. It covers classic designs and their corresponding (meta)models; namely, resolution-III designs including fractional-factorial two-level designs for first-order polynomial

  5. Computer Based Modelling and Simulation

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 3. Computer Based Modelling and Simulation - Modelling Deterministic Systems. N K Srinivasan. General Article Volume 6 Issue 3 March 2001 pp 46-54. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Validity of information security policy models

    Directory of Open Access Journals (Sweden)

    Joshua Onome Imoniana

    Full Text Available Validity is concerned with establishing evidence for the use of a method to be used with a particular set of population. Thus, when we address the issue of application of security policy models, we are concerned with the implementation of a certain policy, taking into consideration the standards required, through attribution of scores to every item in the research instrument. En today's globalized economic scenarios, the implementation of information security policy, in an information technology environment, is a condition sine qua non for the strategic management process of any organization. Regarding this topic, various studies present evidences that, the responsibility for maintaining a policy rests primarily with the Chief Security Officer. The Chief Security Officer, in doing so, strives to enhance the updating of technologies, in order to meet all-inclusive business continuity planning policies. Therefore, for such policy to be effective, it has to be entirely embraced by the Chief Executive Officer. This study was developed with the purpose of validating specific theoretical models, whose designs were based on literature review, by sampling 10 of the Automobile Industries located in the ABC region of Metropolitan São Paulo City. This sampling was based on the representativeness of such industries, particularly with regards to each one's implementation of information technology in the region. The current study concludes, presenting evidence of the discriminating validity of four key dimensions of the security policy, being such: the Physical Security, the Logical Access Security, the Administrative Security, and the Legal & Environmental Security. On analyzing the Alpha of Crombach structure of these security items, results not only attest that the capacity of those industries to implement security policies is indisputable, but also, the items involved, homogeneously correlate to each other.

  7. Impact of Different Policies on Unhealthy Dietary Behaviors in an Adult Population of Los Angeles County: An Agent-Based Simulation Model

    OpenAIRE

    Zhang, Donglan

    2014-01-01

    A typical American diet is comprised of too much high-calorie foods and insufficient fruits and vegetables. Many theories and models targeting unhealthy dietary behaviors focus exclusively on people as individuals, while behavior theories such as multi-level theory of population health emphasize the social component in human cognitive habits and behaviors, providing an alternative paradigm to understand dietary behaviors. This dissertation incorporates those behavioral theories into an agent-...

  8. Vehicle dynamics modeling and simulation

    CERN Document Server

    Schramm, Dieter; Bardini, Roberto

    2014-01-01

    The authors examine in detail the fundamentals and mathematical descriptions of the dynamics of automobiles. In this context different levels of complexity will be presented, starting with basic single-track models up to complex three-dimensional multi-body models. A particular focus is on the process of establishing mathematical models on the basis of real cars and the validation of simulation results. The methods presented are explained in detail by means of selected application scenarios.

  9. Code modernization and modularization of APEX and SWAT watershed simulation models

    Science.gov (United States)

    SWAT (Soil and Water Assessment Tool) and APEX (Agricultural Policy / Environmental eXtender) are respectively large and small watershed simulation models derived from EPIC Environmental Policy Integrated Climate), a field-scale agroecology simulation model. All three models are coded in FORTRAN an...

  10. Numerical simulation of Higgs models

    International Nuclear Information System (INIS)

    Jaster, A.

    1995-10-01

    The SU(2) Higgs and the Schwinger model on the lattice were analysed. Numerical simulations of the SU(2) Higgs model were performed to study the finite temperature electroweak phase transition. With the help of the multicanonical method the distribution of an order parameter at the phase transition point was measured. This was used to obtain the order of the phase transition and the value of the interface tension with the histogram method. Numerical simulations were also performed at zero temperature to perform renormalization. The measured values for the Wilson loops were used to determine the static potential and from this the renormalized gauge coupling. The Schwinger model was simulated at different gauge couplings to analyse the properties of the Kaplan-Shamir fermions. The prediction that the mass parameter gets only multiplicative renormalization was tested and verified. (orig.)

  11. Stochastic models: theory and simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Field, Richard V., Jr.

    2008-03-01

    Many problems in applied science and engineering involve physical phenomena that behave randomly in time and/or space. Examples are diverse and include turbulent flow over an aircraft wing, Earth climatology, material microstructure, and the financial markets. Mathematical models for these random phenomena are referred to as stochastic processes and/or random fields, and Monte Carlo simulation is the only general-purpose tool for solving problems of this type. The use of Monte Carlo simulation requires methods and algorithms to generate samples of the appropriate stochastic model; these samples then become inputs and/or boundary conditions to established deterministic simulation codes. While numerous algorithms and tools currently exist to generate samples of simple random variables and vectors, no cohesive simulation tool yet exists for generating samples of stochastic processes and/or random fields. There are two objectives of this report. First, we provide some theoretical background on stochastic processes and random fields that can be used to model phenomena that are random in space and/or time. Second, we provide simple algorithms that can be used to generate independent samples of general stochastic models. The theory and simulation of random variables and vectors is also reviewed for completeness.

  12. A Simple Forecasting Model Linking Macroeconomic Policy to Industrial Employment Demand.

    Science.gov (United States)

    Malley, James R.; Hady, Thomas F.

    A study detailed further a model linking monetary and fiscal policy to industrial employment in metropolitan and nonmetropolitan areas of four United States regions. The model was used to simulate the impacts on area and regional employment of three events in the economy: changing real gross national product (GNP) via monetary policy, holding the…

  13. Plasma modelling and numerical simulation

    International Nuclear Information System (INIS)

    Van Dijk, J; Kroesen, G M W; Bogaerts, A

    2009-01-01

    Plasma modelling is an exciting subject in which virtually all physical disciplines are represented. Plasma models combine the electromagnetic, statistical and fluid dynamical theories that have their roots in the 19th century with the modern insights concerning the structure of matter that were developed throughout the 20th century. The present cluster issue consists of 20 invited contributions, which are representative of the state of the art in plasma modelling and numerical simulation. These contributions provide an in-depth discussion of the major theories and modelling and simulation strategies, and their applications to contemporary plasma-based technologies. In this editorial review, we introduce and complement those papers by providing a bird's eye perspective on plasma modelling and discussing the historical context in which it has surfaced. (editorial review)

  14. Agri‐environmental Policies to Meet Consumer Preferences in Japan: An Economic‐Biophysical Model Approach

    Directory of Open Access Journals (Sweden)

    Tetsuya Uetake

    2014-08-01

    Full Text Available Promoting environmentally friendly farming products is crucial to meeting consumer demand. Although governments implement policy measures to improve the environmental performance of the agriculture sector, theirimpacts are difficult to assess. This study analyses the performance of agri‐environmental policies in Japan, by using the OECD’s policy impact model and reference level framework. In particular, it identifies the environmental impacts of three simulated agri‐environmental policies based on farms’ characteristics. The results suggest that a policy mix of regulation and an incentive payment would reduce environmental impacts, suggesting that targeted approaches could improve the cost‐effectiveness of agri‐environmental policies.

  15. Merging Energy Policy Decision Support, Education, and Communication: The 'World Energy' Simulation Role-Playing Game

    Science.gov (United States)

    Rooney-varga, J. N.; Franck, T.; Jones, A.; Sterman, J.; Sawin, E.

    2013-12-01

    To meet international goals for climate change mitigation and adaptation, as well as energy access and equity, there is an urgent need to explore and define energy policy paths forward. Despite this need, students, citizens, and decision-makers often hold deeply flawed mental models of the energy and climate systems. Here we describe a simulation role-playing game, World Energy, that provides an immersive learning experience in which participants can create their own path forward for global energy policy and learn about the impact of their policy choices on carbon dioxide emissions, temperature rise, energy supply mix, energy prices, and energy demand. The game puts players in the decision-making roles of advisors to the United Nations Sustainable Energy for All Initiative (drawn from international leaders from industry, governments, intergovernmental organizations, and citizens groups) and, using a state-of-the-art decision-support simulator, asks them to negotiate a plan for global energy policy. We use the En-ROADS (Energy Rapid Overview and Decision Support) simulator, which runs on a laptop computer in <0.1 sec. En-ROADS enables users to specify many factors, including R&D-driven cost reductions in fossil fuel-based, renewable, or carbon-neutral energy technologies; taxes and subsidies for different energy sources; performance standards and energy efficiency; emissions prices; policies to address other greenhouse gas emissions (e.g., methane, nitrous oxide, chlorofluorocarbons, etc.); and assumptions about GDP and population. In World Energy, participants must balance climate change mitigation goals with equity, prices and access to energy, and the political feasibility of policies. Initial results indicate participants gain insights into the dynamics of the energy and climate systems and greater understanding of the potential impacts policies.

  16. Modelling mobility aspects of security policies

    NARCIS (Netherlands)

    Hartel, Pieter H.; van Eck, Pascal; Etalle, Sandro; Wieringa, Roelf J.; Barthe, G.; Burdy, L.; Huisman, Marieke; Lanet, J.-L.; Muntean, T.

    Security policies are rules that constrain the behaviour of a system. Different, largely unrelated sets of rules typically govern the physical and logical worlds. However, increased hardware and software mobility forces us to consider those rules in an integrated fashion. We present SPIN models of

  17. Model for Simulation Atmospheric Turbulence

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik

    1976-01-01

    A method that produces realistic simulations of atmospheric turbulence is developed and analyzed. The procedure makes use of a generalized spectral analysis, often called a proper orthogonal decomposition or the Karhunen-Loève expansion. A set of criteria, emphasizing a realistic appearance...... eigenfunctions and estimates of the distributions of the corresponding expansion coefficients. The simulation method utilizes the eigenfunction expansion procedure to produce preliminary time histories of the three velocity components simultaneously. As a final step, a spectral shaping procedure is then applied....... The method is unique in modeling the three velocity components simultaneously, and it is found that important cross-statistical features are reasonably well-behaved. It is concluded that the model provides a practical, operational simulator of atmospheric turbulence....

  18. Simulation Models for Socioeconomic Inequalities in Health: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Niko Speybroeck

    2013-11-01

    Full Text Available Background: The emergence and evolution of socioeconomic inequalities in health involves multiple factors interacting with each other at different levels. Simulation models are suitable for studying such complex and dynamic systems and have the ability to test the impact of policy interventions in silico. Objective: To explore how simulation models were used in the field of socioeconomic inequalities in health. Methods: An electronic search of studies assessing socioeconomic inequalities in health using a simulation model was conducted. Characteristics of the simulation models were extracted and distinct simulation approaches were identified. As an illustration, a simple agent-based model of the emergence of socioeconomic differences in alcohol abuse was developed. Results: We found 61 studies published between 1989 and 2013. Ten different simulation approaches were identified. The agent-based model illustration showed that multilevel, reciprocal and indirect effects of social determinants on health can be modeled flexibly. Discussion and Conclusions: Based on the review, we discuss the utility of using simulation models for studying health inequalities, and refer to good modeling practices for developing such models. The review and the simulation model example suggest that the use of simulation models may enhance the understanding and debate about existing and new socioeconomic inequalities of health frameworks.

  19. Stabilising the global greenhouse. A simulation model

    International Nuclear Information System (INIS)

    Michaelis, P.

    1993-01-01

    This paper investigates the economic implications of a comprehensive approach to greenhouse policies that strives to stabilise the atmospheric concentration of greenhouse gases at an ecolocially determined threshold level. In a theoretical optimisation model conditions for an efficient allocation of abatement effort among pollutants and over time are derived. The model is empirically specified and adapted to a dynamic Gams-algorithm. By various simulation runs for the period of 1990 to 2110, the economics of greenhouse gas accumulation are explored. In particular, the long-run cost associated with the above stabilisation target are evaluated for three different policy scenarios: i) A comprehensive approach that covers all major greenhouse gases simultaneously, ii) a piecemeal approach that is limited to reducing CO 2 emissions, and iii) a ten-year moratorium that postpones abatement effort until new scientific evidence on the greenhouse effect will become available. Comparing the simulation results suggests that a piecemeal approach would considerably increase total cost, whereas a ten-year moratorium might be reasonable even if the probability of 'good news' is comparatively small. (orig.)

  20. Validation process of simulation model

    International Nuclear Information System (INIS)

    San Isidro, M. J.

    1998-01-01

    It is presented a methodology on empirical validation about any detailed simulation model. This king of validation it is always related with an experimental case. The empirical validation has a residual sense, because the conclusions are based on comparisons between simulated outputs and experimental measurements. This methodology will guide us to detect the fails of the simulation model. Furthermore, it can be used a guide in the design of posterior experiments. Three steps can be well differentiated: Sensitivity analysis. It can be made with a DSA, differential sensitivity analysis, and with a MCSA, Monte-Carlo sensitivity analysis. Looking the optimal domains of the input parameters. It has been developed a procedure based on the Monte-Carlo methods and Cluster techniques, to find the optimal domains of these parameters. Residual analysis. This analysis has been made on the time domain and on the frequency domain, it has been used the correlation analysis and spectral analysis. As application of this methodology, it is presented the validation carried out on a thermal simulation model on buildings, Esp., studying the behavior of building components on a Test Cell of LECE of CIEMAT. (Author) 17 refs

  1. Modeling and Simulation for Safeguards

    International Nuclear Information System (INIS)

    Swinhoe, Martyn T.

    2012-01-01

    The purpose of this talk is to give an overview of the role of modeling and simulation in Safeguards R and D and introduce you to (some of) the tools used. Some definitions are: (1) Modeling - the representation, often mathematical, of a process, concept, or operation of a system, often implemented by a computer program; (2) Simulation - the representation of the behavior or characteristics of one system through the use of another system, especially a computer program designed for the purpose; and (3) Safeguards - the timely detection of diversion of significant quantities of nuclear material. The role of modeling and simulation are: (1) Calculate amounts of material (plant modeling); (2) Calculate signatures of nuclear material etc. (source terms); and (3) Detector performance (radiation transport and detection). Plant modeling software (e.g. FACSIM) gives the flows and amount of material stored at all parts of the process. In safeguards this allow us to calculate the expected uncertainty of the mass and evaluate the expected MUF. We can determine the measurement accuracy required to achieve a certain performance.

  2. Modeling and Simulation of Nanoindentation

    Science.gov (United States)

    Huang, Sixie; Zhou, Caizhi

    2017-11-01

    Nanoindentation is a hardness test method applied to small volumes of material which can provide some unique effects and spark many related research activities. To fully understand the phenomena observed during nanoindentation tests, modeling and simulation methods have been developed to predict the mechanical response of materials during nanoindentation. However, challenges remain with those computational approaches, because of their length scale, predictive capability, and accuracy. This article reviews recent progress and challenges for modeling and simulation of nanoindentation, including an overview of molecular dynamics, the quasicontinuum method, discrete dislocation dynamics, and the crystal plasticity finite element method, and discusses how to integrate multiscale modeling approaches seamlessly with experimental studies to understand the length-scale effects and microstructure evolution during nanoindentation tests, creating a unique opportunity to establish new calibration procedures for the nanoindentation technique.

  3. The Timber Resource Inventory Model (TRIM): a projection model for timber supply and policy analysis.

    Science.gov (United States)

    P.L. Tedder; R.N. La Mont; J.C. Kincaid

    1987-01-01

    TRIM (Timber Resource Inventory Model) is a yield table projection system developed for timber supply projections and policy analysis. TRIM simulates timber growth, inventories, management and area changes, and removals over the projection period. Programs in the TRIM system, card-by-card descriptions of required inputs, table formats, and sample results are presented...

  4. Assessment of Molecular Modeling & Simulation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-01-03

    This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.

  5. NRTA simulation by modeling PFPF

    International Nuclear Information System (INIS)

    Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo; Shibata, Junichi; Totsu, Noriko

    2003-01-01

    In PFPF, NRTA system has been applied since 1991. It has been confirmed by evaluating facility material accountancy data provided from operator in each IIV that a significant MUF was not generated. In case of throughput of PFPF scale, MUF can be evaluated with a sufficient detection probability by the present NRTA evaluation manner. However, by increasing of throughput, the uncertainty of material accountancy will increase, and the detection probability will decline. The relationship between increasing of throughput and declining of detection probability and the maximum throughput upon application of following measures with a sufficient detection probability were evaluated by simulation of NRTA system. This simulation was performed by modeling of PFPF. Measures for increasing detection probability are shown as follows. Shortening of the evaluation interval. Segmentation of evaluation area. This report shows the results of these simulations. (author)

  6. Pricing Policy on Business Performance: A Study on Organizational Strategy Simulator

    Directory of Open Access Journals (Sweden)

    Murilo Alvarenga Oliveira

    2012-06-01

    Full Text Available This study presents an analysis of the relationship between different pricing policies and the results obtained with them within on Business Games. Beginning from a theoretical review that seeks to reunite concepts about pricing, policy and price definitions, it is proposed a model analysis of pricing decisions made by teams that participate in a Business Game. From the applying of this model on data collected in the game, it seeks to classify the pricing policies applied by the teams. Then the results are discussed and its relationship to literature is referred. There are also comments on the decision make default demonstrated by the teams participating in the game. The results obtained here confirm the literature, indicating the price policy as a helpful and valid tool to support marketing strategies. They also show the adhesion between the simulated environment in a Business Game and the features found in the real world, confirming the trend toward adoption of organizational strategy simulators as instruments in teaching and research in Administration.

  7. The Crucible simulation: Behavioral simulation improves clinical leadership skills and understanding of complex health policy change.

    Science.gov (United States)

    Cohen, Daniel; Vlaev, Ivo; McMahon, Laurie; Harvey, Sarah; Mitchell, Andy; Borovoi, Leah; Darzi, Ara

    2017-05-11

    The Health and Social Care Act 2012 represents the most complex National Health Service reforms in history. High-quality clinical leadership is important for successful implementation of health service reform. However, little is known about the effectiveness of current leadership training. This study describes the use of a behavioral simulation to improve the knowledge and leadership of a cohort of medical doctors expected to take leadership roles in the National Health Service. A day-long behavioral simulation (The Crucible) was developed and run based on a fictitious but realistic health economy. Participants completed pre- and postsimulation questionnaires generating qualitative and quantitative data. Leadership skills, knowledge, and behavior change processes described by the "theory of planned behavior" were self-assessed pre- and postsimulation. Sixty-nine medical doctors attended. Participants deemed the simulation immersive and relevant. Significant improvements were shown in perceived knowledge, capability, attitudes, subjective norms, intentions, and leadership competency following the program. Nearly one third of participants reported that they had implemented knowledge and skills from the simulation into practice within 4 weeks. This study systematically demonstrates the effectiveness of behavioral simulation for clinical management training and understanding of health policy reform. Potential future uses and strategies for analysis are discussed. High-quality care requires understanding of health systems and strong leadership. Policymakers should consider the use of behavioral simulation to improve understanding of health service reform and development of leadership skills in clinicians, who readily adopt skills from simulation into everyday practice.

  8. Projecting the effects of long-term care policy on the labor market participation of primary informal family caregivers of elderly with disability: insights from a dynamic simulation model.

    Science.gov (United States)

    Ansah, John P; Matchar, David B; Malhotra, Rahul; Love, Sean R; Liu, Chang; Do, Young

    2016-03-23

    Using Singapore as a case study, this paper aims to understand the effects of the current long-term care policy and various alternative policy options on the labor market participation of primary informal family caregivers of elderly with disability. A model of the long-term care system in Singapore was developed using System Dynamics methodology. Under the current long-term care policy, by 2030, 6.9 percent of primary informal family caregivers (0.34 percent of the domestic labor supply) are expected to withdraw from the labor market. Alternative policy options reduce primary informal family caregiver labor market withdrawal; however, the number of workers required to scale up long-term care services is greater than the number of caregivers who can be expected to return to the labor market. Policymakers may face a dilemma between admitting more foreign workers to provide long-term care services and depending on primary informal family caregivers.

  9. System Dynamics Simulation of Large-Scale Generation System for Designing Wind Power Policy in China

    Directory of Open Access Journals (Sweden)

    Linna Hou

    2015-01-01

    Full Text Available This paper focuses on the impacts of renewable energy policy on a large-scale power generation system, including thermal power, hydropower, and wind power generation. As one of the most important clean energy, wind energy has been rapidly developed in the world. But in recent years there is a serious waste of wind power equipment and investment in China leading to many problems in the industry from wind power planning to its integration. One way overcoming the difficulty is to analyze the influence of wind power policy on a generation system. This paper builds a system dynamics (SD model of energy generation to simulate the results of wind energy generation policies based on a complex system. And scenario analysis method is used to compare the effectiveness and efficiency of these policies. The case study shows that the combinations of lower portfolio goal and higher benchmark price and those of higher portfolio goal and lower benchmark price have large differences in both effectiveness and efficiency. On the other hand, the combinations of uniformly lower or higher portfolio goal and benchmark price have similar efficiency, but different effectiveness. Finally, an optimal policy combination can be chosen on the basis of policy analysis in the large-scale power system.

  10. Demographic Consequences of Gender Discrimination in China: Simulation Analysis of Policy Options

    Science.gov (United States)

    Quanbao, Jiang; Marcus W., Feldman

    2013-01-01

    The large number of missing females in China, a consequence of gender discrimination, is having and will continue to have a profound effect on the country's population development. In this paper, we analyze the causes of this gender discrimination in terms of institutions, culture and, economy, and suggest public policies that might help eliminate gender discrimination. Using a population simulation model, we study the effect of public policies on the sex ratio at birth and excess female child mortality, and the effect of gender discrimination on China's population development. We find that gender discrimination will decrease China's population size, number of births, and working age population, accelerate population aging and exacerbate the male marriage squeeze. These results provide theoretical support for suggesting that the government enact and implement public policies aimed at eliminating gender discrimination. PMID:24363477

  11. Demographic Consequences of Gender Discrimination in China: Simulation Analysis of Policy Options.

    Science.gov (United States)

    Quanbao, Jiang; Shuzhuo, Li; Marcus W, Feldman

    2011-08-01

    The large number of missing females in China, a consequence of gender discrimination, is having and will continue to have a profound effect on the country's population development. In this paper, we analyze the causes of this gender discrimination in terms of institutions, culture and, economy, and suggest public policies that might help eliminate gender discrimination. Using a population simulation model, we study the effect of public policies on the sex ratio at birth and excess female child mortality, and the effect of gender discrimination on China's population development. We find that gender discrimination will decrease China's population size, number of births, and working age population, accelerate population aging and exacerbate the male marriage squeeze. These results provide theoretical support for suggesting that the government enact and implement public policies aimed at eliminating gender discrimination.

  12. Repository simulation model: Final report

    International Nuclear Information System (INIS)

    1988-03-01

    This report documents the application of computer simulation for the design analysis of the nuclear waste repository's waste handling and packaging operations. The Salt Repository Simulation Model was used to evaluate design alternatives during the conceptual design phase of the Salt Repository Project. Code development and verification was performed by the Office of Nuclear Waste Isolation (ONWL). The focus of this report is to relate the experience gained during the development and application of the Salt Repository Simulation Model to future repository design phases. Design of the repository's waste handling and packaging systems will require sophisticated analysis tools to evaluate complex operational and logistical design alternatives. Selection of these design alternatives in the Advanced Conceptual Design (ACD) and License Application Design (LAD) phases must be supported by analysis to demonstrate that the repository design will cost effectively meet DOE's mandated emplacement schedule and that uncertainties in the performance of the repository's systems have been objectively evaluated. Computer simulation of repository operations will provide future repository designers with data and insights that no other analytical form of analysis can provide. 6 refs., 10 figs

  13. 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.

  14. Simulating spin models on GPU

    Science.gov (United States)

    Weigel, Martin

    2011-09-01

    Over the last couple of years it has been realized that the vast computational power of graphics processing units (GPUs) could be harvested for purposes other than the video game industry. This power, which at least nominally exceeds that of current CPUs by large factors, results from the relative simplicity of the GPU architectures as compared to CPUs, combined with a large number of parallel processing units on a single chip. To benefit from this setup for general computing purposes, the problems at hand need to be prepared in a way to profit from the inherent parallelism and hierarchical structure of memory accesses. In this contribution I discuss the performance potential for simulating spin models, such as the Ising model, on GPU as compared to conventional simulations on CPU.

  15. Standard for Models and Simulations

    Science.gov (United States)

    Steele, Martin J.

    2016-01-01

    This NASA Technical Standard establishes uniform practices in modeling and simulation to ensure essential requirements are applied to the design, development, and use of models and simulations (MS), while ensuring acceptance criteria are defined by the program project and approved by the responsible Technical Authority. It also provides an approved set of requirements, recommendations, and criteria with which MS may be developed, accepted, and used in support of NASA activities. As the MS disciplines employed and application areas involved are broad, the common aspects of MS across all NASA activities are addressed. The discipline-specific details of a given MS should be obtained from relevant recommended practices. The primary purpose is to reduce the risks associated with MS-influenced decisions by ensuring the complete communication of the credibility of MS results.

  16. Transport Choice Modeling for the Evaluation of New Transport Policies

    Directory of Open Access Journals (Sweden)

    Ander Pijoan

    2018-04-01

    Full Text Available Quantifying the impact of the application of sustainable transport policies is essential in order to mitigate effects of greenhouse gas emissions produced by the transport sector. One of the most common approaches used for this purpose is that of traffic modelling and simulation, which consists of emulating the operation of an entire road network. This article presents the results of fitting 8 well known data science methods for transport choice modelling, the area in which more research is needed. The models have been trained with information from Biscay province in Spain in order to match as many of its commuters as possible. Results show that the best models correctly forecast more than 51% of the trips recorded. Finally, the results have been validated with a second data set from the Silesian Voivodeship in Poland, showing that all models indeed maintain their forecasting ability.

  17. Assessing policies towards sustainable transport in Europe: an integrated model

    International Nuclear Information System (INIS)

    Zachariadis, Theodoros

    2005-01-01

    A transport simulation and forecast model is presented, which is designed for the assessment of policy options aiming to achieve sustainability in transportation. Starting from a simulation of the economic behaviour of consumers and producers within a microeconomic optimisation framework and the resulting calculation of the modal split, the allocation of the vehicle stock into vintages and technological groups is modelled. In a third step, a technology-oriented algorithm, which incorporates the relevant state-of-the-art knowledge in Europe, calculates emissions of air pollutants and greenhouse gases as well as appropriate indicators for traffic congestion, noise and road accidents. The paper outlines the methodology and the basic data sources used in connection with work done so far in Europe, presents the outlook according to a 'reference case' run for the 15 current European Union Member States up to 2030, displays aggregate results from a number of alternative scenarios and outlines elements of future work

  18. Verifying and Validating Simulation Models

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    This presentation is a high-level discussion of the Verification and Validation (V&V) of computational models. Definitions of V&V are given to emphasize that “validation” is never performed in a vacuum; it accounts, instead, for the current state-of-knowledge in the discipline considered. In particular comparisons between physical measurements and numerical predictions should account for their respective sources of uncertainty. The differences between error (bias), aleatoric uncertainty (randomness) and epistemic uncertainty (ignorance, lack-of- knowledge) are briefly discussed. Four types of uncertainty in physics and engineering are discussed: 1) experimental variability, 2) variability and randomness, 3) numerical uncertainty and 4) model-form uncertainty. Statistical sampling methods are available to propagate, and analyze, variability and randomness. Numerical uncertainty originates from the truncation error introduced by the discretization of partial differential equations in time and space. Model-form uncertainty is introduced by assumptions often formulated to render a complex problem more tractable and amenable to modeling and simulation. The discussion concludes with high-level guidance to assess the “credibility” of numerical simulations, which stems from the level of rigor with which these various sources of uncertainty are assessed and quantified.

  19. Advances in Intelligent Modelling and Simulation Simulation Tools and Applications

    CERN Document Server

    Oplatková, Zuzana; Carvalho, Marco; Kisiel-Dorohinicki, Marek

    2012-01-01

    The human capacity to abstract complex systems and phenomena into simplified models has played a critical role in the rapid evolution of our modern industrial processes and scientific research. As a science and an art, Modelling and Simulation have been one of the core enablers of this remarkable human trace, and have become a topic of great importance for researchers and practitioners. This book was created to compile some of the most recent concepts, advances, challenges and ideas associated with Intelligent Modelling and Simulation frameworks, tools and applications. The first chapter discusses the important aspects of a human interaction and the correct interpretation of results during simulations. The second chapter gets to the heart of the analysis of entrepreneurship by means of agent-based modelling and simulations. The following three chapters bring together the central theme of simulation frameworks, first describing an agent-based simulation framework, then a simulator for electrical machines, and...

  20. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

    Sørensen, Kim; Condra, Thomas Joseph; Houbak, Niels

    2004-01-01

    In the present work a framework for optimizing the design of boilers for dynamic operation has been developed. A cost function to be minimized during the optimization has been formulated and for the present design variables related to the Boiler Volume and the Boiler load Gradient (i.e. ring rate...... on the boiler) have been dened. Furthermore a number of constraints related to: minimum and maximum boiler load gradient, minimum boiler size, Shrinking and Swelling and Steam Space Load have been dened. For dening the constraints related to the required boiler volume a dynamic model for simulating the boiler...... performance has been developed. Outputs from the simulations are shrinking and swelling of water level in the drum during for example a start-up of the boiler, these gures combined with the requirements with respect to allowable water level uctuations in the drum denes the requirements with respect to drum...

  1. SEMI Modeling and Simulation Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Hermina, W.L.

    2000-10-02

    With the exponential growth in the power of computing hardware and software, modeling and simulation is becoming a key enabler for the rapid design of reliable Microsystems. One vision of the future microsystem design process would include the following primary software capabilities: (1) The development of 3D part design, through standard CAD packages, with automatic design rule checks that guarantee the manufacturability and performance of the microsystem. (2) Automatic mesh generation, for 3D parts as manufactured, that permits computational simulation of the process steps, and the performance and reliability analysis for the final microsystem. (3) Computer generated 2D layouts for process steps that utilize detailed process models to generate the layout and process parameter recipe required to achieve the desired 3D part. (4) Science-based computational tools that can simulate the process physics, and the coupled thermal, fluid, structural, solid mechanics, electromagnetic and material response governing the performance and reliability of the microsystem. (5) Visualization software that permits the rapid visualization of 3D parts including cross-sectional maps, performance and reliability analysis results, and process simulation results. In addition to these desired software capabilities, a desired computing infrastructure would include massively parallel computers that enable rapid high-fidelity analysis, coupled with networked compute servers that permit computing at a distance. We now discuss the individual computational components that are required to achieve this vision. There are three primary areas of focus: design capabilities, science-based capabilities and computing infrastructure. Within each of these areas, there are several key capability requirements.

  2. Photovoltaic array performance simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, D. F.

    1986-09-15

    The experience of the solar industry confirms that, despite recent cost reductions, the profitability of photovoltaic (PV) systems is often marginal and the configuration and sizing of a system is a critical problem for the design engineer. Construction and evaluation of experimental systems are expensive and seldom justifiable. A mathematical model or computer-simulation program is a desirable alternative, provided reliable results can be obtained. Sandia National Laboratories, Albuquerque (SNLA), has been studying PV-system modeling techniques in an effort to develop an effective tool to be used by engineers and architects in the design of cost-effective PV systems. This paper reviews two of the sources of error found in previous PV modeling programs, presents the remedies developed to correct these errors, and describes a new program that incorporates these improvements.

  3. Simulated annealing model of acupuncture

    Science.gov (United States)

    Shang, Charles; Szu, Harold

    2015-05-01

    The growth control singularity model suggests that acupuncture points (acupoints) originate from organizers in embryogenesis. Organizers are singular points in growth control. Acupuncture can cause perturbation of a system with effects similar to simulated annealing. In clinical trial, the goal of a treatment is to relieve certain disorder which corresponds to reaching certain local optimum in simulated annealing. The self-organizing effect of the system is limited and related to the person's general health and age. Perturbation at acupoints can lead a stronger local excitation (analogous to higher annealing temperature) compared to perturbation at non-singular points (placebo control points). Such difference diminishes as the number of perturbed points increases due to the wider distribution of the limited self-organizing activity. This model explains the following facts from systematic reviews of acupuncture trials: 1. Properly chosen single acupoint treatment for certain disorder can lead to highly repeatable efficacy above placebo 2. When multiple acupoints are used, the result can be highly repeatable if the patients are relatively healthy and young but are usually mixed if the patients are old, frail and have multiple disorders at the same time as the number of local optima or comorbidities increases. 3. As number of acupoints used increases, the efficacy difference between sham and real acupuncture often diminishes. It predicted that the efficacy of acupuncture is negatively correlated to the disease chronicity, severity and patient's age. This is the first biological - physical model of acupuncture which can predict and guide clinical acupuncture research.

  4. Operations planning simulation: Model study

    Science.gov (United States)

    1974-01-01

    The use of simulation modeling for the identification of system sensitivities to internal and external forces and variables is discussed. The technique provides a means of exploring alternate system procedures and processes, so that these alternatives may be considered on a mutually comparative basis permitting the selection of a mode or modes of operation which have potential advantages to the system user and the operator. These advantages are measurements is system efficiency are: (1) the ability to meet specific schedules for operations, mission or mission readiness requirements or performance standards and (2) to accomplish the objectives within cost effective limits.

  5. The Effect of a Reduced Allowance and Pension Taper Rate: Policy Simulations Using the Melbourne Institute Tax and Transfer Simulator

    OpenAIRE

    Guyonne Kalb; Hsein Kew

    2002-01-01

    This paper presents the results of two policy simulations for couples with and without children. The first policy involves a reduction of the highest withdrawal rate from 70 to 60 per cent. The second policy reduces all withdrawal rates of 70 and 50 per cent to 30 per cent. A comparison is made between the two policies to determine the magnitude of the impact on government expenditure and labour supply responses. Both policies have the effect of increasing the net income of those who are eith...

  6. Simulation of Farmers’ Response to Irrigation Water Pricing and Rationing Policies (Case Study: Zabol City

    Directory of Open Access Journals (Sweden)

    abouzar parhizkari

    2014-10-01

    Full Text Available Considering that agricultural sector is the largest consumer of water, presenting integrated management for water resources and formulating effective policies to increase water productivity in this sector is essential. Therefore, using economic modeling , this study simulated the farmers’ responses to irrigation water pricing and rationing policies in Zabol city. To achieve the study purpose, the State Wide Agricultural Production Model and Positive Mathematical Programming were applied. The required data for the years 2010-2011 was collected by completing questionnaires and collecting data sets from the relevant agencies of Zabol city in personal attendance. The results showed that imposing irrigation water pricing and rationing policies in Zabol city leads to a reduction in the total cultivated area by 9/54 and 5/14 percent and a reduction in the water consumption by 6/23 and 7/01 percent, compared to the base year. Ultimately, irrigation water rationing policy, considering frugality of 18/9 million m3 of water, as the appropriate solution for the sustainability of water resources of Zabol city was proposed.

  7. Impulse pumping modelling and simulation

    International Nuclear Information System (INIS)

    Pierre, B; Gudmundsson, J S

    2010-01-01

    Impulse pumping is a new pumping method based on propagation of pressure waves. Of particular interest is the application of impulse pumping to artificial lift situations, where fluid is transported from wellbore to wellhead using pressure waves generated at wellhead. The motor driven element of an impulse pumping apparatus is therefore located at wellhead and can be separated from the flowline. Thus operation and maintenance of an impulse pump are facilitated. The paper describes the different elements of an impulse pumping apparatus, reviews the physical principles and details the modelling of the novel pumping method. Results from numerical simulations of propagation of pressure waves in water-filled pipelines are then presented for illustrating impulse pumping physical principles, and validating the described modelling with experimental data.

  8. Simulation model of a PWR power plant

    International Nuclear Information System (INIS)

    Larsen, N.

    1987-03-01

    A simulation model of a hypothetical PWR power plant is described. A large number of disturbances and failures in plant function can be simulated. The model is written as seven modules to the modular simulation system for continuous processes DYSIM and serves also as a user example of this system. The model runs in Fortran 77 on the IBM-PC-AT. (author)

  9. Simulating the dynamic effect of land use and transport policies on the health of populations.

    Science.gov (United States)

    McClure, Roderick J; Adriazola-Steil, Claudia; Mulvihill, Christine; Fitzharris, Michael; Salmon, Paul; Bonnington, C Paul; Stevenson, Mark

    2015-04-01

    We identified the features of a land use-transportation system that optimizes the health and well-being of the population. We developed a quantitative system dynamics model to represent relationships among land use, transport, economic development, and population health. Simulation experiments were conducted over a 10-year simulation period to compare the effect of different baseline conditions and land use-transport policies on the number of motor vehicle crash deaths and disability-adjusted life years lost. Optimal reduction in the public health burden attributable to land transport was demonstrated when transport safety risk reduction policies were combined with land use and transport polices that minimized reliance on individual motorized transport and maximized use of active transport modes. The model's results were particularly sensitive to the level of development that characterized each city at the start of the simulation period. Local, national, and international decision-makers are encouraged to address transport, land use, and health as an integrated whole to achieve the desired societal benefits of traffic safety, population health, and social equity.

  10. Business-as-Unusual: Existing policies in energy model baselines

    International Nuclear Information System (INIS)

    Strachan, Neil

    2011-01-01

    Baselines are generally accepted as a key input assumption in long-term energy modelling, but energy models have traditionally been poor on identifying baselines assumptions. Notably, transparency on the current policy content of model baselines is now especially critical as long-term climate mitigation policies have been underway for a number of years. This paper argues that the range of existing energy and emissions policies are an integral part of any long-term baseline, and hence already represent a 'with-policy' baseline, termed here a Business-as-Unusual (BAuU). Crucially, existing energy policies are not a sunk effort; as impacts of existing policy initiatives are targeted at future years, they may be revised through iterative policy making, and their quantitative effectiveness requires ex-post verification. To assess the long-term role of existing policies in energy modelling, currently identified UK policies are explicitly stripped out of the UK MARKAL Elastic Demand (MED) optimisation energy system model, to generate a BAuU (with-policy) and a REF (without policy) baseline. In terms of long-term mitigation costs, policy-baseline assumptions are comparable to another key exogenous modelling assumption - that of global fossil fuel prices. Therefore, best practice in energy modelling would be to have both a no-policy reference baseline, and a current policy reference baseline (BAuU). At a minimum, energy modelling studies should have a transparent assessment of the current policy contained within the baseline. Clearly identifying and comparing policy-baseline assumptions are required for cost effective and objective policy making, otherwise energy models will underestimate the true cost of long-term emissions reductions.

  11. Modelling climate change policies : an application of ENERGY2020

    International Nuclear Information System (INIS)

    Timilsina, G.; Bhargava, A.; Backus, G.

    2005-01-01

    Researches and policy-makers are increasingly analyzing the economic impacts of the Kyoto Protocol at national, regional and global levels. The analyses are generally based on numerical models integrating energy, environment and the economy. Most models range from partial equilibrium types to complex multi-sector general equilibrium models, and typically represent the energy sector at an aggregate level, which limits their ability to reflect details of different sectors. In Canada, a model called ENERGY2020 has been widely used by the federal and provincial governments to analyze the sectoral and provincial impacts of implementing the Kyoto Protocol. ENERGY2020 uses stocks and flows simulation that captures the physical aspects of the processes utilizing energy, as well as the qualitative choice theory which captures human behavioural aspects. The model also has a database containing 20 years of time-series on all economic, environmental and energy variables, enabling the model to derive most parameters endogenously through econometric estimations. It has the capacity to analyze consumer and business responses over a wide range of policy initiatives such as energy environment taxes, regulatory standards for buildings, equipment and motor vehicles, grants, rebates and subsidy initiatives, consumer awareness initiatives, technology improvements, moratoriums and mandated cut-backs. It is also capable of producing long-term energy market forecasts as well as analyzing the impacts of policies in the markets. It was concluded that the model's application will serve as a useful analytical tool for a range of issues, and may be useful to developing countries and economies in transition. 6 refs., 5 figs

  12. Model-Driven Configuration of SELinux Policies

    Science.gov (United States)

    Agreiter, Berthold; Breu, Ruth

    The need for access control in computer systems is inherent. However, the complexity to configure such systems is constantly increasing which affects the overall security of a system negatively. We think that it is important to define security requirements on a non-technical level while taking the application domain into respect in order to have a clear and separated view on security configuration (i.e. unblurred by technical details). On the other hand, security functionality has to be tightly integrated with the system and its development process in order to provide comprehensive means of enforcement. In this paper, we propose a systematic approach based on model-driven security configuration to leverage existing operating system security mechanisms (SELinux) for realising access control. We use UML models and develop a UML profile to satisfy these needs. Our goal is to exploit a comprehensive protection mechanism while rendering its security policy manageable by a domain specialist.

  13. The Relevance of Using Mathematical Models in Macroeconomic Policies Theory

    Directory of Open Access Journals (Sweden)

    Nora Mihail

    2006-11-01

    Full Text Available The article presents a look of the principal’s mathematical models – starting with Theil, Hansen and Tinbergen work – and their results used to analysis and design macroeconomic policies. In modeling field changes are very fast in theoretical aspects of modeling the many problems of macroeconomic policies and in using in practice the different political models elaboration. The article points out the problems of static and dynamic theory used in macro-policies modeling.

  14. The Relevance of Using Mathematical Models in Macroeconomic Policies Theory

    Directory of Open Access Journals (Sweden)

    Nora Mihail

    2006-09-01

    Full Text Available The article presents a look of the principal’s mathematical models – starting with Theil, Hansen and Tinbergen work – and their results used to analysis and design macroeconomic policies. In modeling field changes are very fast in theoretical aspects of modeling the many problems of macroeconomic policies and in using in practice the different political models elaboration. The article points out the problems of static and dynamic theory used in macro-policies modeling.

  15. Renewable energy policy evaluation using real option model. The case of Taiwan

    International Nuclear Information System (INIS)

    Lee, Shun-Chung; Shih, Li-Hsing

    2010-01-01

    This study presents a policy benefit evaluation model that integrates cost efficiency curve information on renewable power generation technologies into real options analysis (ROA) methods. The proposed model evaluates quantitatively the policy value provided by developing renewable energy (RE) in the face of uncertain fossil fuel prices and RE policy-related factors. The economic intuition underlying the policy-making process is elucidated, while empirical analysis illustrates the option value embedded in the current development policy in Taiwan for wind power. In addition to revealing the benefits that RE development provides when considering real options, analytical results indicate that ROA is a highly effective means of quantifying how policy planning uncertainty including managerial flexibility influences RE development. In addition to assessing the policy value of current RE development policy, this study also compares policy values in terms of internalized external costs and varying feed-in tariff (FIT). Simulation results demonstrate that the RE development policy with internalized CO 2 emission costs is appropriate policy planning from sustainability point of view. Furthermore, relationship between varying FIT and policy values can be shown quantitatively and appropriate FIT level could be determined accordingly. (author)

  16. Galaxy Alignments: Theory, Modelling & Simulations

    Science.gov (United States)

    Kiessling, Alina; Cacciato, Marcello; Joachimi, Benjamin; Kirk, Donnacha; Kitching, Thomas D.; Leonard, Adrienne; Mandelbaum, Rachel; Schäfer, Björn Malte; Sifón, Cristóbal; Brown, Michael L.; Rassat, Anais

    2015-11-01

    The shapes of galaxies are not randomly oriented on the sky. During the galaxy formation and evolution process, environment has a strong influence, as tidal gravitational fields in the large-scale structure tend to align nearby galaxies. Additionally, events such as galaxy mergers affect the relative alignments of both the shapes and angular momenta of galaxies throughout their history. These "intrinsic galaxy alignments" are known to exist, but are still poorly understood. This review will offer a pedagogical introduction to the current theories that describe intrinsic galaxy alignments, including the apparent difference in intrinsic alignment between early- and late-type galaxies and the latest efforts to model them analytically. It will then describe the ongoing efforts to simulate intrinsic alignments using both N-body and hydrodynamic simulations. Due to the relative youth of this field, there is still much to be done to understand intrinsic galaxy alignments and this review summarises the current state of the field, providing a solid basis for future work.

  17. Information Security Policy Modeling for Network Security Systems

    Directory of Open Access Journals (Sweden)

    Dmitry Sergeevich Chernyavskiy

    2014-12-01

    Full Text Available Policy management for network security systems (NSSs is one of the most topical issues of network security management. Incorrect configurations of NSSs lead to system outages and appearance of vulnerabilities. Moreover, policy management process is a time-consuming task, which includes significant amount of manual work. These factors reduce efficiency of NSSs’ utilization. The paper discusses peculiarities of policy management process and existing approaches to policy modeling, presents a model aimed to formalize policies for NSSs independently on NSSs’ platforms and select the most effective NSSs for implementation of the policies.

  18. Examining Policies to Reduce Homelessness Using a General Equilibrium Model of the Housing Market

    OpenAIRE

    Mansur, Erin; Quigley, John M.; Raphael, Steven; Smolensky, Eugene

    2003-01-01

    In this paper, we use a general equilibrium simulation model to assess the potential impacts on homelessness of various housing-market policy interventions. We calibrate the model to the four largest metropolitan areas in California. We explore the welfare con- sequences and the effects on homelessness of three housing-market policy interventions: extending housing vouchers to all low-income households, subsidizing all landlords, and subsidizing those landlords who supply low-income housing. ...

  19. Interaction between Fiscal and Monetary Policy in a Dynamic Nonlinear Model

    Science.gov (United States)

    Bertella, Mario A.; Rego, Henio A.; Neris, Celso; Silva, Jonathas N.; Podobnik, Boris; Stanley, H. Eugene

    2015-01-01

    The objective of this study is to verify the dynamics between fiscal policy, measured by public debt, and monetary policy, measured by a reaction function of a central bank. Changes in monetary policies due to deviations from their targets always generate fiscal impacts. We examine two policy reaction functions: the first related to inflation targets and the second related to economic growth targets. We find that the condition for stable equilibrium is more restrictive in the first case than in the second. We then apply our simulation model to Brazil and United Kingdom and find that the equilibrium is unstable in the Brazilian case but stable in the UK case. PMID:25799581

  20. Interaction between fiscal and monetary policy in a dynamic nonlinear model.

    Science.gov (United States)

    Bertella, Mario A; Rego, Henio A; Neris, Celso; Silva, Jonathas N; Podobnik, Boris; Stanley, H Eugene

    2015-01-01

    The objective of this study is to verify the dynamics between fiscal policy, measured by public debt, and monetary policy, measured by a reaction function of a central bank. Changes in monetary policies due to deviations from their targets always generate fiscal impacts. We examine two policy reaction functions: the first related to inflation targets and the second related to economic growth targets. We find that the condition for stable equilibrium is more restrictive in the first case than in the second. We then apply our simulation model to Brazil and United Kingdom and find that the equilibrium is unstable in the Brazilian case but stable in the UK case.

  1. Managing emergency department overcrowding via ambulance diversion: A discrete event simulation model

    Directory of Open Access Journals (Sweden)

    Chih-Hao Lin

    2015-01-01

    Conclusion: An input–throughput–output simulation model is proposed for simulating ED operation. Effectiveness of several AD strategies on relieving ED overcrowding was assessed via computer simulations based on this model. By appropriate parameter settings, the model can represent medical resource providers of different scales. It is also feasible to expand the simulations to evaluate the effect of AD strategies on a community basis. The results may offer insights for making effective AD policies.

  2. Affective Policy Performance Evaluation Model: A Case of an International Trade Policy Implementation

    Directory of Open Access Journals (Sweden)

    Inwon Kang

    2018-01-01

    Full Text Available Firms often superficially adopt policies because of governmental rules and regulations, so as to avoid penalties or to gain benefits. However, the evaluation and characterization of those kinds of adoptions as policy performance distorts the true level of policy performance: social sustainability. This study proposes an affective policy performance evaluation model. The attitudes of employees toward adopting a policy are characterized into genuine and superficial compliance. Their behaviors are explained through voluntary and opportunistic adoptions. In order to validate the proposed model, a survey was conducted on an international trade policy target group (n = 216 for the Strategic Trade Control System (STCS, in order to understand their attitudes toward adopting the policy. The survey data was analyzed by a structural equation modeling method. The measures of the factors in the proposed model are adopted and modified from existing studies. The most effective resources of policy implementation on the firms’ genuine and superficial compliance and ultimately on the firms’ voluntary policy adoption are revealed through the analysis. Based on the results, this study presents a strategy for allocating and managing policy implementation resources to exclusively encourage firms’ trade policy adoptions.

  3. THE MARK I BUSINESS SYSTEM SIMULATION MODEL

    Science.gov (United States)

    of a large-scale business simulation model as a vehicle for doing research in management controls. The major results of the program were the...development of the Mark I business simulation model and the Simulation Package (SIMPAC). SIMPAC is a method and set of programs facilitating the construction...of large simulation models. The object of this document is to describe the Mark I Corporation model, state why parts of the business were modeled as they were, and indicate the research applications of the model. (Author)

  4. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  5. Benchmark simulation models, quo vadis?

    Science.gov (United States)

    Jeppsson, U; Alex, J; Batstone, D J; Benedetti, L; Comas, J; Copp, J B; Corominas, L; Flores-Alsina, X; Gernaey, K V; Nopens, I; Pons, M-N; Rodríguez-Roda, I; Rosen, C; Steyer, J-P; Vanrolleghem, P A; Volcke, E I P; Vrecko, D

    2013-01-01

    As the work of the IWA Task Group on Benchmarking of Control Strategies for wastewater treatment plants (WWTPs) is coming to an end, it is essential to disseminate the knowledge gained. For this reason, all authors of the IWA Scientific and Technical Report on benchmarking have come together to provide their insights, highlighting areas where knowledge may still be deficient and where new opportunities are emerging, and to propose potential avenues for future development and application of the general benchmarking framework and its associated tools. The paper focuses on the topics of temporal and spatial extension, process modifications within the WWTP, the realism of models, control strategy extensions and the potential for new evaluation tools within the existing benchmark system. We find that there are major opportunities for application within all of these areas, either from existing work already being done within the context of the benchmarking simulation models (BSMs) or applicable work in the wider literature. Of key importance is increasing capability, usability and transparency of the BSM package while avoiding unnecessary complexity.

  6. How Does Environmental Regulation Affect Industrial Transformation? A Study Based on the Methodology of Policy Simulation

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2016-01-01

    Full Text Available The difference of factor input structure determines different response to environmental regulation. This paper constructs a theoretical model including environmental regulation, factor input structure, and industrial transformation and conducts a policy simulation based on the difference of influencing mechanism of environmental regulation considering industrial heterogeneity. The findings show that the impact of environmental regulation on industrial transformation presents comparison of distortion effect of resource allocation and technology effect. Environmental regulation will promote industrial transformation when technology effect of environmental regulation is stronger than distortion effect of resource allocation. Particularly, command-control environmental regulation has a significant incentive effect and spillover effect of technological innovation on cleaning industries, but these effects do not exist in pollution-intensive industries. Command-control environmental regulation promotes industrial transformation. The result of simulation showed that environmental regulation of market incentives is similar to that of command-control.

  7. Simulation modelling of fynbos ecosystems: Systems analysis and conceptual models

    CSIR Research Space (South Africa)

    Kruger, FJ

    1985-03-01

    Full Text Available -animal interactions. An additional two models, which expand aspects of the FYNBOS model, are described: a model for simulating canopy processes; and a Fire Recovery Simulator. The canopy process model will simulate ecophysiological processes in more detail than FYNBOS...

  8. The "Statecraft" Simulation and Foreign Policy Attitudes among Undergraduate Students

    Science.gov (United States)

    Saiya, Nilay

    2016-01-01

    Professors of international relations are increasingly realizing that simulations can be a fun and effective way of teaching the complexities of the field to their students. One popular simulation that has emerged in recent years--the "Statecraft" simulation--is now used by more than 190 colleges and universities worldwide. Despite…

  9. An introduction to enterprise modeling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ostic, J.K.; Cannon, C.E. [Los Alamos National Lab., NM (United States). Technology Modeling and Analysis Group

    1996-09-01

    As part of an ongoing effort to continuously improve productivity, quality, and efficiency of both industry and Department of Energy enterprises, Los Alamos National Laboratory is investigating various manufacturing and business enterprise simulation methods. A number of enterprise simulation software models are being developed to enable engineering analysis of enterprise activities. In this document the authors define the scope of enterprise modeling and simulation efforts, and review recent work in enterprise simulation at Los Alamos National Laboratory as well as at other industrial, academic, and research institutions. References of enterprise modeling and simulation methods and a glossary of enterprise-related terms are provided.

  10. Simulation and Modeling Methodologies, Technologies and Applications

    CERN Document Server

    Filipe, Joaquim; Kacprzyk, Janusz; Pina, Nuno

    2014-01-01

    This book includes extended and revised versions of a set of selected papers from the 2012 International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH 2012) which was sponsored by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC) and held in Rome, Italy. SIMULTECH 2012 was technically co-sponsored by the Society for Modeling & Simulation International (SCS), GDR I3, Lionphant Simulation, Simulation Team and IFIP and held in cooperation with AIS Special Interest Group of Modeling and Simulation (AIS SIGMAS) and the Movimento Italiano Modellazione e Simulazione (MIMOS).

  11. Structured building model reduction toward parallel simulation

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Justin R. [Cornell University; Hencey, Brondon M. [Cornell University

    2013-08-26

    Building energy model reduction exchanges accuracy for improved simulation speed by reducing the number of dynamical equations. Parallel computing aims to improve simulation times without loss of accuracy but is poorly utilized by contemporary simulators and is inherently limited by inter-processor communication. This paper bridges these disparate techniques to implement efficient parallel building thermal simulation. We begin with a survey of three structured reduction approaches that compares their performance to a leading unstructured method. We then use structured model reduction to find thermal clusters in the building energy model and allocate processing resources. Experimental results demonstrate faster simulation and low error without any interprocessor communication.

  12. Evaluating Energy Efficiency Policies with Energy-Economy Models

    Energy Technology Data Exchange (ETDEWEB)

    Mundaca, Luis; Neij, Lena; Worrell, Ernst; McNeil, Michael A.

    2010-08-01

    The growing complexities of energy systems, environmental problems and technology markets are driving and testing most energy-economy models to their limits. To further advance bottom-up models from a multidisciplinary energy efficiency policy evaluation perspective, we review and critically analyse bottom-up energy-economy models and corresponding evaluation studies on energy efficiency policies to induce technological change. We use the household sector as a case study. Our analysis focuses on decision frameworks for technology choice, type of evaluation being carried out, treatment of market and behavioural failures, evaluated policy instruments, and key determinants used to mimic policy instruments. Although the review confirms criticism related to energy-economy models (e.g. unrealistic representation of decision-making by consumers when choosing technologies), they provide valuable guidance for policy evaluation related to energy efficiency. Different areas to further advance models remain open, particularly related to modelling issues, techno-economic and environmental aspects, behavioural determinants, and policy considerations.

  13. A physiological production model for cacao : results of model simulations

    NARCIS (Netherlands)

    Zuidema, P.A.; Leffelaar, P.A.

    2002-01-01

    CASE2 is a physiological model for cocoa (Theobroma cacao L.) growth and yield. This report introduces the CAcao Simulation Engine for water-limited production in a non-technical way and presents simulation results obtained with the model.

  14. Simulation modeling and analysis with Arena

    CERN Document Server

    Altiok, Tayfur

    2007-01-01

    Simulation Modeling and Analysis with Arena is a highly readable textbook which treats the essentials of the Monte Carlo discrete-event simulation methodology, and does so in the context of a popular Arena simulation environment.” It treats simulation modeling as an in-vitro laboratory that facilitates the understanding of complex systems and experimentation with what-if scenarios in order to estimate their performance metrics. The book contains chapters on the simulation modeling methodology and the underpinnings of discrete-event systems, as well as the relevant underlying probability, statistics, stochastic processes, input analysis, model validation and output analysis. All simulation-related concepts are illustrated in numerous Arena examples, encompassing production lines, manufacturing and inventory systems, transportation systems, and computer information systems in networked settings.· Introduces the concept of discrete event Monte Carlo simulation, the most commonly used methodology for modeli...

  15. A review of Agent Based Modeling for agricultural policy evaluation

    NARCIS (Netherlands)

    Kremmydas, Dimitris; Athanasiadis, I.N.; Rozakis, Stelios

    2018-01-01

    Farm level scale policy analysis is receiving increased attention due to a changing agricultural policy orientation. Agent based models (ABM) are farm level models that have appeared in the end of 1990's, having several differences from traditional farm level models, like the consideration of

  16. Network Modeling and Simulation A Practical Perspective

    CERN Document Server

    Guizani, Mohsen; Khan, Bilal

    2010-01-01

    Network Modeling and Simulation is a practical guide to using modeling and simulation to solve real-life problems. The authors give a comprehensive exposition of the core concepts in modeling and simulation, and then systematically address the many practical considerations faced by developers in modeling complex large-scale systems. The authors provide examples from computer and telecommunication networks and use these to illustrate the process of mapping generic simulation concepts to domain-specific problems in different industries and disciplines. Key features: Provides the tools and strate

  17. Policy Game, Online Game--Simulated: Applying the Ecology of Policy Game to Virtual World

    Science.gov (United States)

    Park, Yong Jin

    2012-01-01

    Teaching communication policy to young college students can be a challenge. Students often consider law and policy as difficult, abstract, or even unrelated to their lives. Yet experienced teachers note that students--especially those who are first exposed to regulatory concepts--benefit when they actively participate, engage, and deliberate for…

  18. Modelling and simulation of a heat exchanger

    Science.gov (United States)

    Xia, Lei; Deabreu-Garcia, J. Alex; Hartley, Tom T.

    1991-01-01

    Two models for two different control systems are developed for a parallel heat exchanger. First by spatially lumping a heat exchanger model, a good approximate model which has a high system order is produced. Model reduction techniques are applied to these to obtain low order models that are suitable for dynamic analysis and control design. The simulation method is discussed to ensure a valid simulation result.

  19. Modeling and simulation of large HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Jin, H.; Sood, V.K.

    1993-01-01

    This paper addresses the complexity and the amount of work in preparing simulation data and in implementing various converter control schemes and the excessive simulation time involved in modelling and simulation of large HVDC systems. The Power Electronic Circuit Analysis program (PECAN) is used to address these problems and a large HVDC system with two dc links is simulated using PECAN. A benchmark HVDC system is studied to compare the simulation results with those from other packages. The simulation time and results are provided in the paper.

  20. Discharge Fee Policy Analysis: A Computable General Equilibrium (CGE) Model of Water Resources and Water Environments

    OpenAIRE

    Guohua Fang; Ting Wang; Xinyi Si; Xin Wen; Yu Liu

    2016-01-01

    To alleviate increasingly serious water pollution and shortages in developing countries, various kinds of policies have been implemented by local governments. It is vital to quantify and evaluate the performance and potential economic impacts of these policies. This study develops a Computable General Equilibrium (CGE) model to simulate the regional economic and environmental effects of discharge fees. Firstly, water resources and water environment factors are separated from the input and out...

  1. An expert system for national economy model simulations

    Directory of Open Access Journals (Sweden)

    Roljić Lazo

    2002-01-01

    Full Text Available There are some fundamental economic uncertainties. We cannot forecast economic events with a very high scientific precision. It is very clear that there does not exist a unique 'general' model, which can yield all answers to a wide range of macroeconomic issues. Therefore, we use several different kinds of models on segments of the macroeconomic problem. Different models can distinguish/solve economy desegregation, time series analysis and other subfactors involved in macroeconomic problem solving. A major issue becomes finding a meaningful method to link these econometric models. Macroeconomic models were linked through development of an Expert System for National Economy Model Simulations (ESNEMS. ESNEMS consists of five parts: (1 small-scale short-term national econometric model, (2 Methodology of Interactive Nonlinear Goal Programming (MINGP, (3 data-base of historical macro-economic aggregates, (4 software interface for interactive communications between a model and a decision maker, and (5 software for solving problems. ESNEMS was developed to model the optimum macro-economic policy of a developing country (SFRY-formerly Yugoslavia. Most econometric models are very complex. Optimizing of the economic policy is typically defined as a nonlinear goal programming problem. To solve/optimize these models, a new methodology, MINGP, was developed as a part of ESNEMS. MINGP is methodologically based on linear goal programming and feasible directions method. Using Euler's Homogeneous Function Theorem, MINGP linearizes nonlinear homogeneous functions. The highest priorities in minimizing the objective function are the growth of gross domestic product and the decrease of inflation. In the core of the optimization model, MINGP, there is a small-scale econometric model. This model was designed through analysis of the causal relations in the SFRY's social reproduction process of the past 20 years. The objective of the econometric model is to simulate

  2. Simulating Deforestation in Minas Gerais, Brazil, under Changing Government Policies and Socioeconomic Conditions.

    Science.gov (United States)

    Stan, Kayla; Sanchez-Azofeifa, Arturo; Espírito-Santo, Mário; Portillo-Quintero, Carlos

    2015-01-01

    Agricultural expansion is causing deforestation in Minas Gerais, Brazil, converting savanna and tropical dry forest to farmland, and in 2012, Brazil's Forest Code was revised with the government reducing deforestation restrictions. Understanding the effects of policy change on rates and locations of natural ecosystem loss is imperative. In this paper, deforestation in Minas Gerais was simulated annually until 2020 using Dinamica Environment for Geoprocessing Objects (Dinamica EGO). This system is a state-of-the-art land use and cover change (LUCC) model which incorporates government policy, landscape maps, and other biophysical and anthropogenic datasets. Three studied scenarios: (i) business as usual, (ii) increased deforestation, and (iii) decreased deforestation showed more transition to agriculture from shrubland compared to forests, and consistent locations for most deforestation. The probability of conversion to agriculture is strongly tied to areas with the smallest patches of original biome remaining. Increases in agricultural revenue are projected to continue with a loss of 25% of the remaining Cerrado land in the next decade if profit is maximized. The addition of biodiversity value as a tax on land sale prices, estimated at over $750,000,000 USD using the cost of extracting and maintaining current species ex-situ, can save more than 1 million hectares of shrubland with minimal effects on the economy of the State of Minas Gerais. With environmental policy determining rates of deforestation and economics driving the location of land clearing, site-specific protection or market accounting of externalities is needed to balance economic development and conservation.

  3. A Simulation of Readiness-Based Sparing Policies

    Science.gov (United States)

    2017-06-01

    variant of a greedy heuristic algorithm to set stock levels and estimate overall WS availability. Our discrete event simulation is then used to test the...variant of a greedy heuristic algorithm to set stock levels and estimate overall WS availability. Our discrete event simulation is then used to test the...WS Type with 22 Individual WS at a Representative Site.....................................................................................31

  4. Experiences with a dialogue process between policy makers and global modellers

    International Nuclear Information System (INIS)

    Van Daalen, C.E.; Thissen, W.A.H.; Berk, M.M.

    1998-01-01

    Between 1995 and 1997, a series of five workshops, henceforth called the Delft process, took place with the aim to explore and enhance use of the IMAGE 2 model to support international climate negotiations. The IMAGE 2 model is a multi-disciplinary, integrated model designed to simulate the dynamics of the global society-biosphere-climate system. The workshops facilitated a dialogue between policy makers and scientists involved in the development and applications of the IMAGE 2 model. In this way, policy makers would benefit from the policy makers on how to improve the policy relevance of the IMAGE 2 model. The evaluation at the end of the workshop series showed that participants have used information from the workshop at international negotiation conferences and in preparation of policy documents. The process shows that creating a forum for direct science-policy interactions can be very useful and productive, and has confirmed the importance of creating an open and constructive atmosphere between policy makers, and between policy makers and analysts, to enhance utilisation of scientific knowledge. The authors' analysis also suggests that many factors have to be 'in the right position at the right time and place' to achieve such a success, and that it is difficult to prevent the occurrence of biases in processes like this. 33 refs

  5. Hopf bifurcation and chaos in macroeconomic models with policy lag

    International Nuclear Information System (INIS)

    Liao Xiaofeng; Li Chuandong; Zhou Shangbo

    2005-01-01

    In this paper, we consider the macroeconomic models with policy lag, and study how lags in policy response affect the macroeconomic stability. The local stability of the nonzero equilibrium of this equation is investigated by analyzing the corresponding transcendental characteristic equation of its linearized equation. Some general stability criteria involving the policy lag and the system parameter are derived. By choosing the policy lag as a bifurcation parameter, the model is found to undergo a sequence of Hopf bifurcation. The direction and stability of the bifurcating periodic solutions are determined by using the normal form theory and the center manifold theorem. Moreover, we show that the government can stabilize the intrinsically unstable economy if the policy lag is sufficiently short, but the system become locally unstable when the policy lag is too long. We also find the chaotic behavior in some range of the policy lag

  6. Pharmaceutical expenditure forecast model to support health policy decision making

    OpenAIRE

    R?muzat, C?cile; Urbinati, Duccio; Kornfeld, ?sa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aball?a, Samuel; Mzoughi, Olfa; Toumi, Mondher

    2014-01-01

    Background and objective: With constant incentives for healthcare payers to contain their pharmaceutical budgets, modelling policy decision impact became critical. The objective of this project was to test the impact of various policy decisions on pharmaceutical budget (developed for the European Commission for the project ‘European Union (EU) Pharmaceutical expenditure forecast’ – http://ec.europa.eu/health/healthcare/key_documents/index_en.htm).Methods: A model was built to assess policy sc...

  7. Modeling and Simulation of Low Voltage Arcs

    NARCIS (Netherlands)

    Ghezzi, L.; Balestrero, A.

    2010-01-01

    Modeling and Simulation of Low Voltage Arcs is an attempt to improve the physical understanding, mathematical modeling and numerical simulation of the electric arcs that are found during current interruptions in low voltage circuit breakers. An empirical description is gained by refined electrical

  8. Diversity modelling for electrical power system simulation

    International Nuclear Information System (INIS)

    Sharip, R M; Abu Zarim, M A U A

    2013-01-01

    This paper considers diversity of generation and demand profiles against the different future energy scenarios and evaluates these on a technical basis. Compared to previous studies, this research applied a forecasting concept based on possible growth rates from publically electrical distribution scenarios concerning the UK. These scenarios were created by different bodies considering aspects such as environment, policy, regulation, economic and technical. In line with these scenarios, forecasting is on a long term timescale (up to every ten years from 2020 until 2050) in order to create a possible output of generation mix and demand profiles to be used as an appropriate boundary condition for the network simulation. The network considered is a segment of rural LV populated with a mixture of different housing types. The profiles for the 'future' energy and demand have been successfully modelled by applying a forecasting method. The network results under these profiles shows for the cases studied that even though the value of the power produced from each Micro-generation is often in line with the demand requirements of an individual dwelling there will be no problems arising from high penetration of Micro-generation and demand side management for each dwellings considered. The results obtained highlight the technical issues/changes for energy delivery and management to rural customers under the future energy scenarios

  9. Diversity modelling for electrical power system simulation

    Science.gov (United States)

    Sharip, R. M.; Abu Zarim, M. A. U. A.

    2013-12-01

    This paper considers diversity of generation and demand profiles against the different future energy scenarios and evaluates these on a technical basis. Compared to previous studies, this research applied a forecasting concept based on possible growth rates from publically electrical distribution scenarios concerning the UK. These scenarios were created by different bodies considering aspects such as environment, policy, regulation, economic and technical. In line with these scenarios, forecasting is on a long term timescale (up to every ten years from 2020 until 2050) in order to create a possible output of generation mix and demand profiles to be used as an appropriate boundary condition for the network simulation. The network considered is a segment of rural LV populated with a mixture of different housing types. The profiles for the 'future' energy and demand have been successfully modelled by applying a forecasting method. The network results under these profiles shows for the cases studied that even though the value of the power produced from each Micro-generation is often in line with the demand requirements of an individual dwelling there will be no problems arising from high penetration of Micro-generation and demand side management for each dwellings considered. The results obtained highlight the technical issues/changes for energy delivery and management to rural customers under the future energy scenarios.

  10. Maryland's Model Policy to Address Bullying, Harassment, or Intimidation

    Science.gov (United States)

    Maryland State Department of Education, 2016

    2016-01-01

    In accordance with the provisions of Section 7-424.1 of the Education Article of the Annotated Code of Maryland, the Maryland State Board of Education has developed and adopted a Model Policy to address bullying, harassment, or intimidation. This report presents the Model Policy, which is organized into the following eight points: (1) Prohibition…

  11. Uncertainty and endogenous technical change in climate policy models

    International Nuclear Information System (INIS)

    Baker, Erin; Shittu, Ekundayo

    2008-01-01

    Until recently endogenous technical change and uncertainty have been modeled separately in climate policy models. In this paper, we review the emerging literature that considers both these elements together. Taken as a whole the literature indicates that explicitly including uncertainty has important quantitative and qualitative impacts on optimal climate change technology policy. (author)

  12. APEX model simulation of edge-of-field water quality benefits from upland buffers

    Science.gov (United States)

    For maximum usefulness, simulation models must be able to estimate the effectiveness of management practices not represented in the dataset used for model calibration. This study focuses on the ability of the Agricultural Policy Environmental eXtender (APEX) to simulate upland buffer effectiveness f...

  13. Model improvements to simulate charging in SEM

    Science.gov (United States)

    Arat, K. T.; Klimpel, T.; Hagen, C. W.

    2018-03-01

    Charging of insulators is a complex phenomenon to simulate since the accuracy of the simulations is very sensitive to the interaction of electrons with matter and electric fields. In this study, we report model improvements for a previously developed Monte-Carlo simulator to more accurately simulate samples that charge. The improvements include both modelling of low energy electron scattering and charging of insulators. The new first-principle scattering models provide a more realistic charge distribution cloud in the material, and a better match between non-charging simulations and experimental results. Improvements on charging models mainly focus on redistribution of the charge carriers in the material with an induced conductivity (EBIC) and a breakdown model, leading to a smoother distribution of the charges. Combined with a more accurate tracing of low energy electrons in the electric field, we managed to reproduce the dynamically changing charging contrast due to an induced positive surface potential.

  14. Modelling inspection policies for building maintenance.

    Science.gov (United States)

    Christer, A H

    1982-08-01

    A method of assessing the potential of an inspection maintenance policy as opposed to an existing breakdown maintenance policy for a building complex is developed. The method is based upon information likely to be available and specific subjective assessments which could be made available. Estimates of the expected number of defects identified at an inspection and the consequential cost saving are presented as functions of the inspection frequency.

  15. Protection for the U.S. Automobile Industry: A Joint Class Simulation in Trade Policy.

    Science.gov (United States)

    Hess, Peter N.; Ortmayer, Louis M.

    A description of a joint class simulation in trade policy undertaken by an international economics class and a political science class at Davidson College (Pennsylvania) is presented in three sections. Section I describes the structure of the simulation. Students were divided into groups of United States auto manufacturers, the United Auto…

  16. Modeling policy mix to improve the competitiveness of Indonesian palm oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Silitonga, R. Y.H.; Siswanto, J.; Simatupang, T.; Bahagia, S.N.

    2016-07-01

    The purpose of this research is to develop a model that will explain the impact of government policies to the competitiveness of palm oil industry. The model involves two commodities in this industry, namely crude palm oil (CPO) and refined palm oil (RPO), each has different added value. The model built will define the behavior of government in controlling palm oil industry, and their interactions with macro-environment, in order to improve the competitiveness of the industry. Therefore the first step was to map the main activities in this industry using value chain analysis. After that a conceptual model was built, where the output of the model is competitiveness of the industry based on market share. The third step was model formulation. The model is then utilized to simulate the policy mix given by government in improving the competitiveness of Palm Oil Industry. The model was developed using only some policies which give direct impact to the competitiveness of the industry. For macro environment input, only price is considered in this model. The model can simulate the output of the industry for various government policies mix given to the industry. This research develops a model that can represent the structure and relationship between industry, government and macro environment, using value chain analysis and hierarchical multilevel system approach. (Author)

  17. Modeling policy mix to improve the competitiveness of Indonesian palm oil industry

    Directory of Open Access Journals (Sweden)

    Roland Y H Silitonga

    2016-04-01

    Full Text Available Purpose: The purpose of this research is to develop a model that will explain the impact of government policies to the competitiveness of palm oil industry. The model involves two commodities in this industry, namely crude palm oil (CPO and refined palm oil (RPO, each has different added value. Design/methodology/approach: The model built will define the behavior of government in controlling palm oil industry, and their interactions with macro-environment, in order to improve the competitiveness of the industry. Therefore the first step was to map the main activities in this industry using value chain analysis. After that a conceptual model was built, where the output of the model is competitiveness of the industry based on market share. The third step was model formulation. The model is then utilized to simulate the policy mix given by government in improving the competitiveness of Palm Oil Industry. Research limitations/implications: The model was developed using only some policies which give direct impact to the competitiveness of the industry. For macro environment input, only price is considered in this model. Practical implications: The model can simulate the output of the industry for various government policies mix given to the industry. Originality/value: This research develops a model that can represent the structure and relationship between industry, government and macro environment, using value chain analysis and hierarchical multilevel system approach.

  18. Moving communities toward policy change: APPEAL's 4-prong policy change model.

    Science.gov (United States)

    Tong, Elisa K; Lew, Rod

    2013-09-01

    Policy change is recognized for underlying much of the success of tobacco control. However, there is little evidence and attention on how Asian American and Native Hawaiian and Pacific Islander (AA and NHPI) communities may engage in policy change. Challenges for AA and NHPI communities include the racial/ethnic and geographic diversity, and tobacco data accurately representing the communities. Over the past decade, the Asian Pacific Partners for Empowerment, Advocacy and Leadership (APPEAL) has worked to develop and implement policy change for AA and NHPI communities. This article describes APPEAL's 4-prong policy change model, in the context of its overall strategic framework for policy change with communities that accounts for varying levels of readiness and leadership capacity, and targets four different levels of policy change (community, mainstream institution, legislative, and corporate). The health promotion implication of this framework for tobacco control policy engagement is for improving understanding of effective pathways to policy change, promoting innovative methods for policy analysis, and translating them into effective implementation and sustainability of policy initiatives. The APPEAL strategic framework can transcend into other communities and health topics that ultimately may contribute to the elimination of health disparities.

  19. Moving Communities Toward Policy Change: APPEAL’s 4-Prong Policy Change Model

    Science.gov (United States)

    Tong, Elisa K.; Lew, Rod

    2014-01-01

    Policy change is recognized for underlying much of the success of tobacco control. However, there is little evidence and attention on how Asian American and Native Hawaiian and Pacific Islander (AA and NHPI) communities may engage in policy change. Challenges for AA and NHPI communities include the racial/ethnic and geographic diversity, and tobacco data accurately representing the communities. Over the past decade, the Asian Pacific Partners for Empowerment, Advocacy and Leadership (APPEAL) has worked to develop and implement policy change for AA and NHPI communities. This article describes APPEAL’s 4-prong policy change model, in the context of its overall strategic framework for policy change with communities that accounts for varying levels of readiness and leadership capacity, and targets four different levels of policy change (community, mainstream institution, legislative, and corporate). The health promotion implication of this framework for tobacco control policy engagement is for improving understanding of effective pathways to policy change, promoting innovative methods for policy analysis, and translating them into effective implementation and sustainability of policy initiatives. The APPEAL strategic framework can transcend into other communities and health topics that ultimately may contribute to the elimination of health disparities. PMID:23707962

  20. Cash Management Policies By Evolutionary Models: A Comparison Using The MILLER-ORR Model

    Directory of Open Access Journals (Sweden)

    Marcelo Botelho da Costa Moraes

    2013-10-01

    Full Text Available This work aims to apply genetic algorithms (GA and particle swarm optimization (PSO to managing cash balance, comparing performance results between computational models and the Miller-Orr model. Thus, the paper proposes the application of computational evolutionary models to minimize the total cost of cash balance maintenance, obtaining the parameters for a cash management policy, using assumptions presented in the literature, considering the cost of maintenance and opportunity for cost of cash. For such, we developed computational experiments from cash flows simulated to implement the algorithms. For a control purpose, an algorithm has been developed that uses the Miller-Orr model defining the lower bound parameter, which is not obtained by the original model. The results indicate that evolutionary algorithms present better results than the Miller-Orr model, with prevalence for PSO algorithm in results.

  1. Policy modeling for energy efficiency improvement in US industry

    International Nuclear Information System (INIS)

    Worrell, Ernst; Price, Lynn; Ruth, Michael

    2001-01-01

    We are at the beginning of a process of evaluating and modeling the contribution of policies to improve energy efficiency. Three recent policy studies trying to assess the impact of energy efficiency policies in the United States are reviewed. The studies represent an important step in the analysis of climate change mitigation strategies. All studies model the estimated policy impact, rather than the policy itself. Often the policy impacts are based on assumptions, as the effects of a policy are not certain. Most models only incorporate economic (or price) tools, which recent studies have proven to be insufficient to estimate the impacts, costs and benefits of mitigation strategies. The reviewed studies are a first effort to capture the effects of non-price policies. The studies contribute to a better understanding of the role of policies in improving energy efficiency and mitigating climate change. All policy scenarios results in substantial energy savings compared to the baseline scenario used, as well as substantial net benefits to the U.S. economy

  2. Whole-building Hygrothermal Simulation Model

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2003-01-01

    An existing integrated simulation tool for dynamic thermal simulation of building was extended with a transient model for moisture release and uptake in building materials. Validation of the new model was begun with comparison against measurements in an outdoor test cell furnished with single...... materials. Almost quasi-steady, cyclic experiments were used to compare the indoor humidity variation and the numerical results of the integrated simulation tool with the new moisture model. Except for the case with chipboard as furnishing, the predictions of indoor humidity with the detailed model were...

  3. Towards policy relevant environmental modeling: contextual validity and pragmatic models

    Science.gov (United States)

    Miles, Scott B.

    2000-01-01

    "What makes for a good model?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of modeling. One particular domain that is wrestling with this question is the multidisciplinary field of environmental modeling. Examples of environmental models range from models of contaminated ground water flow to the economic impact of natural disasters, such as earthquakes. One of the distinguishing claims of the field is the relevancy of environmental modeling to policy and environment-related decision-making in general. A pervasive view by both scientists and decision-makers is that a "good" model is one that is an accurate predictor. Thus, determining whether a model is "accurate" or "correct" is done by comparing model output to empirical observations. The expected outcome of this process, usually referred to as "validation" or "ground truthing," is a stamp on the model in question of "valid" or "not valid" that serves to indicate whether or not the model will be reliable before it is put into service in a decision-making context. In this paper, I begin by elaborating on the prevailing view of model validation and why this view must change. Drawing from concepts coming out of the studies of science and technology, I go on to propose a contextual view of validity that can overcome the problems associated with "ground truthing" models as an indicator of model goodness. The problem of how we talk about and determine model validity has much to do about how we perceive the utility of environmental models. In the remainder of the paper, I argue that we should adopt ideas of pragmatism in judging what makes for a good model and, in turn, developing good models. From such a perspective of model goodness, good environmental models should facilitate communication, convey—not bury or "eliminate"—uncertainties, and, thus, afford the active building of consensus decisions, instead

  4. Simulation modeling for the health care manager.

    Science.gov (United States)

    Kennedy, Michael H

    2009-01-01

    This article addresses the use of simulation software to solve administrative problems faced by health care managers. Spreadsheet add-ins, process simulation software, and discrete event simulation software are available at a range of costs and complexity. All use the Monte Carlo method to realistically integrate probability distributions into models of the health care environment. Problems typically addressed by health care simulation modeling are facility planning, resource allocation, staffing, patient flow and wait time, routing and transportation, supply chain management, and process improvement.

  5. Protein Simulation Data in the Relational Model.

    Science.gov (United States)

    Simms, Andrew M; Daggett, Valerie

    2012-10-01

    High performance computing is leading to unprecedented volumes of data. Relational databases offer a robust and scalable model for storing and analyzing scientific data. However, these features do not come without a cost-significant design effort is required to build a functional and efficient repository. Modeling protein simulation data in a relational database presents several challenges: the data captured from individual simulations are large, multi-dimensional, and must integrate with both simulation software and external data sites. Here we present the dimensional design and relational implementation of a comprehensive data warehouse for storing and analyzing molecular dynamics simulations using SQL Server.

  6. A Dynamic Linear Modeling Approach to Public Policy Change

    DEFF Research Database (Denmark)

    Loftis, Matthew; Mortensen, Peter Bjerre

    2017-01-01

    Theories of public policy change, despite their differences, converge on one point of strong agreement. The relationship between policy and its causes can and does change over time. This consensus yields numerous empirical implications, but our standard analytical tools are inadequate for testing...... them. As a result, the dynamic and transformative relationships predicted by policy theories have been left largely unexplored in time-series analysis of public policy. This paper introduces dynamic linear modeling (DLM) as a useful statistical tool for exploring time-varying relationships in public...... policy. The paper offers a detailed exposition of the DLM approach and illustrates its usefulness with a time series analysis of U.S. defense policy from 1957-2010. The results point the way for a new attention to dynamics in the policy process and the paper concludes with a discussion of how...

  7. Modeling and simulation of blood collection systems.

    Science.gov (United States)

    Alfonso, Edgar; Xie, Xiaolan; Augusto, Vincent; Garraud, Olivier

    2012-03-01

    This paper addresses the modeling and simulation of blood collection systems in France for both fixed site and mobile blood collection with walk in whole blood donors and scheduled plasma and platelet donors. Petri net models are first proposed to precisely describe different blood collection processes, donor behaviors, their material/human resource requirements and relevant regulations. Petri net models are then enriched with quantitative modeling of donor arrivals, donor behaviors, activity times and resource capacity. Relevant performance indicators are defined. The resulting simulation models can be straightforwardly implemented with any simulation language. Numerical experiments are performed to show how the simulation models can be used to select, for different walk in donor arrival patterns, appropriate human resource planning and donor appointment strategies.

  8. Prostitution and Human Trafficking : A model-based exploration and policy analysis

    NARCIS (Netherlands)

    Kovari, A.; Pruyt, E.

    2012-01-01

    The meeting of the oldest profession with modern slavery is the topic of this paper. After a brief introduction to prostitution and prostitution-related human trafficking, this paper focuses on the Dutch policy debate. A System Dynamics simulation model related to the Dutch situation developed to

  9. Modeling and Simulation of Matrix Converter

    DEFF Research Database (Denmark)

    Liu, Fu-rong; Klumpner, Christian; Blaabjerg, Frede

    2005-01-01

    This paper discusses the modeling and simulation of matrix converter. Two models of matrix converter are presented: one is based on indirect space vector modulation and the other is based on power balance equation. The basis of these two models is• given and the process on modeling is introduced...

  10. Simulation models for tokamak plasmas

    International Nuclear Information System (INIS)

    Dimits, A.M.; Cohen, B.I.

    1992-01-01

    Two developments in the nonlinear simulation of tokamak plasmas are described: (A) Simulation algorithms that use quasiballooning coordinates have been implemented in a 3D fluid code and a 3D partially linearized (Δf) particle code. In quasiballooning coordinates, one of the coordinate directions is closely aligned with that of the magnetic field, allowing both optimal use of the grid resolution for structures highly elongated along the magnetic field as well as implementation of the correct periodicity conditions with no discontinuities in the toroidal direction. (B) Progress on the implementation of a likeparticle collision operator suitable for use in partially linearized particle codes is reported. The binary collision approach is shown to be unusable for this purpose. The algorithm under development is a complete version of the test-particle plus source-field approach that was suggested and partially implemented by Xu and Rosenbluth

  11. A model management system for combat simulation

    OpenAIRE

    Dolk, Daniel R.

    1986-01-01

    The design and implementation of a model management system to support combat modeling is discussed. Structured modeling is introduced as a formalism for representing mathematical models. A relational information resource dictionary system is developed which can accommodate structured models. An implementation is described. Structured modeling is then compared to Jackson System Development (JSD) as a methodology for facilitating discrete event simulation. JSD is currently better at representin...

  12. HVDC System Characteristics and Simulation Models

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.I.; Han, B.M.; Jang, G.S. [Electric Enginnering and Science Research Institute, Seoul (Korea)

    2001-07-01

    This report deals with the AC-DC power system simulation method by PSS/E and EUROSTAG for the development of a strategy for the reliable operation of the Cheju-Haenam interconnected system. The simulation using both programs is performed to analyze HVDC simulation models. In addition, the control characteristics of the Cheju-Haenam HVDC system as well as Cheju AC system characteristics are described in this work. (author). 104 figs., 8 tabs.

  13. Physically realistic modeling of maritime training simulation

    OpenAIRE

    Cieutat , Jean-Marc

    2003-01-01

    Maritime training simulation is an important matter of maritime teaching, which requires a lot of scientific and technical skills.In this framework, where the real time constraint has to be maintained, all physical phenomena cannot be studied; the most visual physical phenomena relating to the natural elements and the ship behaviour are reproduced only. Our swell model, based on a surface wave simulation approach, permits to simulate the shape and the propagation of a regular train of waves f...

  14. Systematic modelling and simulation of refrigeration systems

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.; Jakobsen, Arne

    1998-01-01

    The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose...... of the simulation, to select appropriate component models and to set up the equations in a well-arranged way. In this paper the outline of such a method is proposed and examples showing the use of this method for simulation of refrigeration systems are given....

  15. Service Coordination Policies and Models: National Status.

    Science.gov (United States)

    Harbin, Gloria L.; Bruder, M.; Mazzarella, C.; Gabbard, G.; Reynolds, C.

    This report discusses the findings of a study that investigated state coordination of early intervention services for infants, toddlers, and young children with disabilities. State Part C coordinators participated in a survey that sought their perceptions of values under girding service coordination, approach to service coordination, policies,…

  16. Deriving simulators for hybrid Chi models

    NARCIS (Netherlands)

    Beek, van D.A.; Man, K.L.; Reniers, M.A.; Rooda, J.E.; Schiffelers, R.R.H.

    2006-01-01

    The hybrid Chi language is formalism for modeling, simulation and verification of hybrid systems. The formal semantics of hybrid Chi allows the definition of provably correct implementations for simulation, verification and realtime control. This paper discusses the principles of deriving an

  17. Modeling and simulation for RF system design

    CERN Document Server

    Frevert, Ronny; Jancke, Roland; Knöchel, Uwe; Schwarz, Peter; Kakerow, Ralf; Darianian, Mohsen

    2005-01-01

    Focusing on RF specific modeling and simulation methods, and system and circuit level descriptions, this work contains application-oriented training material. Accompanied by a CD- ROM, it combines the presentation of a mixed-signal design flow, an introduction into VHDL-AMS and Verilog-A, and the application of commercially available simulators.

  18. Magnetosphere Modeling: From Cartoons to Simulations

    Science.gov (United States)

    Gombosi, T. I.

    2017-12-01

    Over the last half a century physics-based global computer simulations became a bridge between experiment and basic theory and now it represents the "third pillar" of geospace research. Today, many of our scientific publications utilize large-scale simulations to interpret observations, test new ideas, plan campaigns, or design new instruments. Realistic simulations of the complex Sun-Earth system have been made possible by the dramatically increased power of both computing hardware and numerical algorithms. Early magnetosphere models were based on simple E&M concepts (like the Chapman-Ferraro cavity) and hydrodynamic analogies (bow shock). At the beginning of the space age current system models were developed culminating in the sophisticated Tsyganenko-type description of the magnetic configuration. The first 3D MHD simulations of the magnetosphere were published in the early 1980s. A decade later there were several competing global models that were able to reproduce many fundamental properties of the magnetosphere. The leading models included the impact of the ionosphere by using a height-integrated electric potential description. Dynamic coupling of global and regional models started in the early 2000s by integrating a ring current and a global magnetosphere model. It has been recognized for quite some time that plasma kinetic effects play an important role. Presently, global hybrid simulations of the dynamic magnetosphere are expected to be possible on exascale supercomputers, while fully kinetic simulations with realistic mass ratios are still decades away. In the 2010s several groups started to experiment with PIC simulations embedded in large-scale 3D MHD models. Presently this integrated MHD-PIC approach is at the forefront of magnetosphere simulations and this technique is expected to lead to some important advances in our understanding of magnetosheric physics. This talk will review the evolution of magnetosphere modeling from cartoons to current systems

  19. Modeling and simulation of complex systems a framework for efficient agent-based modeling and simulation

    CERN Document Server

    Siegfried, Robert

    2014-01-01

    Robert Siegfried presents a framework for efficient agent-based modeling and simulation of complex systems. He compares different approaches for describing structure and dynamics of agent-based models in detail. Based on this evaluation the author introduces the "General Reference Model for Agent-based Modeling and Simulation" (GRAMS). Furthermore he presents parallel and distributed simulation approaches for execution of agent-based models -from small scale to very large scale. The author shows how agent-based models may be executed by different simulation engines that utilize underlying hard

  20. The Optimization of the Local Public Policies’ Development Process Through Modeling And Simulation

    Directory of Open Access Journals (Sweden)

    Minodora URSĂCESCU

    2012-06-01

    Full Text Available The local public policies development in Romania represents an empirically realized measure, the strategic management practices in this domain not being based on a scientific instrument capable to anticipate and evaluate the results of implementing a local public policy in a logic of needs-policies-effects type. Beginning from this motivation, the purpose of the paper resides in the reconceptualization of the public policies process on functioning principles of the dynamic systems with inverse connection, by means of mathematical modeling and techniques simulation. Therefore, the research is oriented in the direction of developing an optimization method for the local public policies development process, using as instruments the mathematical modeling and the techniques simulation. The research’s main results are on the one side constituted by generating a new process concept of the local public policies, and on the other side by proposing the conceptual model of a complex software product which will permit the parameterized modeling in a virtual environment of these policies development process. The informatic product’s finality resides in modeling and simulating each local public policy type, taking into account the respective policy’s characteristics, but also the value of their appliance environment parameters in a certain moment.

  1. NUMERICAL SIMULATION AND MODELING OF UNSTEADY FLOW ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... objective of this study is to control the simulation of unsteady flows around structures. ... Aerospace, our results were in good agreement with experimental .... Two-Equation Eddy-Viscosity Turbulence Models for Engineering.

  2. SEIR model simulation for Hepatitis B

    Science.gov (United States)

    Side, Syafruddin; Irwan, Mulbar, Usman; Sanusi, Wahidah

    2017-09-01

    Mathematical modelling and simulation for Hepatitis B discuss in this paper. Population devided by four variables, namely: Susceptible, Exposed, Infected and Recovered (SEIR). Several factors affect the population in this model is vaccination, immigration and emigration that occurred in the population. SEIR Model obtained Ordinary Differential Equation (ODE) non-linear System 4-D which then reduces to 3-D. SEIR model simulation undertaken to predict the number of Hepatitis B cases. The results of the simulation indicates the number of Hepatitis B cases will increase and then decrease for several months. The result of simulation using the number of case in Makassar also found the basic reproduction number less than one, that means, Makassar city is not an endemic area of Hepatitis B.

  3. Maintenance Personnel Performance Simulation (MAPPS) model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Knee, H.E.; Haas, P.M.

    1984-01-01

    A stochastic computer model for simulating the actions and behavior of nuclear power plant maintenance personnel is described. The model considers personnel, environmental, and motivational variables to yield predictions of maintenance performance quality and time to perform. The mode has been fully developed and sensitivity tested. Additional evaluation of the model is now taking place

  4. Computer simulations of the random barrier model

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Dyre, Jeppe

    2002-01-01

    A brief review of experimental facts regarding ac electronic and ionic conduction in disordered solids is given followed by a discussion of what is perhaps the simplest realistic model, the random barrier model (symmetric hopping model). Results from large scale computer simulations are presented...

  5. Turbine modelling for real time simulators

    International Nuclear Information System (INIS)

    Oliveira Barroso, A.C. de; Araujo Filho, F. de

    1992-01-01

    A model for vapor turbines and its peripherals has been developed. All the important variables have been included and emphasis has been given for the computational efficiency to obtain a model able to simulate all the modeled equipment. (A.C.A.S.)

  6. Use of queue modelling in the analysis of elective patient treatment governed by a maximum waiting time policy

    DEFF Research Database (Denmark)

    Kozlowski, Dawid; Worthington, Dave

    2015-01-01

    chain and discrete event simulation models, to provide an insightful analysis of the public hospital performance under the policy rules. The aim of this paper is to support the enhancement of the quality of elective patient care, to be brought about by better understanding of the policy implications...... on the utilization of public hospital resources. This paper illustrates the use of a queue modelling approach in the analysis of elective patient treatment governed by the maximum waiting time policy. Drawing upon the combined strengths of analytic and simulation approaches we develop both continuous-time Markov...

  7. Economic and Environmental Effects of Public Transport Subsidy Policies: a Spatial CGE Model of Beijing

    Directory of Open Access Journals (Sweden)

    Ping Xu

    2018-01-01

    Full Text Available Public transport plays an important role in the environment. This study established a Spatial Computable General Equilibrium (SCGE model to examine the economic and environmental effects of public transport subsidy policies. The model includes firms, consumers, and traffic modules in one framework. Statistical data from Beijing were used in calibration to obtain benchmark equilibrium. Based on the equilibrium, simulations compared citywide social welfare, jobs-housing spatial population distribution, and environmental outputs under four subsidy policies: fare subsidy, cash grants, road expansion, and public transport speedup. Based on the results regarding the effects of public transport policies, conclusions can be drawn about which policies will have greater overall social influence and should therefore be used.

  8. Theory, modeling, and simulation annual report, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report briefly discusses research on the following topics: development of electronic structure methods; modeling molecular processes in clusters; modeling molecular processes in solution; modeling molecular processes in separations chemistry; modeling interfacial molecular processes; modeling molecular processes in the atmosphere; methods for periodic calculations on solids; chemistry and physics of minerals; graphical user interfaces for computational chemistry codes; visualization and analysis of molecular simulations; integrated computational chemistry environment; and benchmark computations.

  9. Modeling and simulation with operator scaling

    OpenAIRE

    Cohen, Serge; Meerschaert, Mark M.; Rosiński, Jan

    2010-01-01

    Self-similar processes are useful in modeling diverse phenomena that exhibit scaling properties. Operator scaling allows a different scale factor in each coordinate. This paper develops practical methods for modeling and simulating stochastic processes with operator scaling. A simulation method for operator stable Levy processes is developed, based on a series representation, along with a Gaussian approximation of the small jumps. Several examples are given to illustrate practical application...

  10. Development of a Computational Simulation Model for Conflict Management in Team Building

    Directory of Open Access Journals (Sweden)

    W. M. Wang

    2011-05-01

    Full Text Available Conflict management is one of the most important issues in leveraging organizational competitiveness. However, traditional social scientists built theories or models in this area which were mostly expressed in words and diagrams are insufficient. Social science research based on computational modeling and simulation is beginning to augment traditional theory building. Simulation provides a method for people to try their actions out in a way that is cost effective, faster, appropriate, flexible, and ethical. In this paper, a computational simulation model for conflict management in team building is presented. The model is designed and used to explore the individual performances related to the combination of individuals who have a range of conflict handling styles, under various types of resources and policies. The model is developed based on agent-based modeling method. Each of the agents has one of the five conflict handling styles: accommodation, compromise, competition, contingency, and learning. There are three types of scenarios: normal, convex, and concave. There are two types of policies: no policy, and a reward and punishment policy. Results from running the model are also presented. The simulation has led us to derive two implications concerning conflict management. First, a concave type of resource promotes competition, while convex type of resource promotes compromise and collaboration. Second, the performance ranking of different styles can be influenced by introducing different policies. On the other hand, it is possible for us to promote certain style by introducing different policies.

  11. Simulating Deforestation in Minas Gerais, Brazil, under Changing Government Policies and Socioeconomic Conditions.

    Directory of Open Access Journals (Sweden)

    Kayla Stan

    Full Text Available Agricultural expansion is causing deforestation in Minas Gerais, Brazil, converting savanna and tropical dry forest to farmland, and in 2012, Brazil's Forest Code was revised with the government reducing deforestation restrictions. Understanding the effects of policy change on rates and locations of natural ecosystem loss is imperative. In this paper, deforestation in Minas Gerais was simulated annually until 2020 using Dinamica Environment for Geoprocessing Objects (Dinamica EGO. This system is a state-of-the-art land use and cover change (LUCC model which incorporates government policy, landscape maps, and other biophysical and anthropogenic datasets. Three studied scenarios: (i business as usual, (ii increased deforestation, and (iii decreased deforestation showed more transition to agriculture from shrubland compared to forests, and consistent locations for most deforestation. The probability of conversion to agriculture is strongly tied to areas with the smallest patches of original biome remaining. Increases in agricultural revenue are projected to continue with a loss of 25% of the remaining Cerrado land in the next decade if profit is maximized. The addition of biodiversity value as a tax on land sale prices, estimated at over $750,000,000 USD using the cost of extracting and maintaining current species ex-situ, can save more than 1 million hectares of shrubland with minimal effects on the economy of the State of Minas Gerais. With environmental policy determining rates of deforestation and economics driving the location of land clearing, site-specific protection or market accounting of externalities is needed to balance economic development and conservation.

  12. Modeling of magnetic particle suspensions for simulations

    CERN Document Server

    Satoh, Akira

    2017-01-01

    The main objective of the book is to highlight the modeling of magnetic particles with different shapes and magnetic properties, to provide graduate students and young researchers information on the theoretical aspects and actual techniques for the treatment of magnetic particles in particle-based simulations. In simulation, we focus on the Monte Carlo, molecular dynamics, Brownian dynamics, lattice Boltzmann and stochastic rotation dynamics (multi-particle collision dynamics) methods. The latter two simulation methods can simulate both the particle motion and the ambient flow field simultaneously. In general, specialized knowledge can only be obtained in an effective manner under the supervision of an expert. The present book is written to play such a role for readers who wish to develop the skill of modeling magnetic particles and develop a computer simulation program using their own ability. This book is therefore a self-learning book for graduate students and young researchers. Armed with this knowledge,...

  13. Modelling Options for Policy Impact Analysis on African Dairy Farms

    Directory of Open Access Journals (Sweden)

    Oghaiki Asaah NDAMBI

    2008-01-01

    Full Text Available Studies on the priorities for agricultural research in Eastern and CentralAfrica concluded that milk is the most important commodity for research anddevelopment in the region, based on its potential contribution to the agriculturalGDP. It has been presumed that, the right policies, marketing systems and technicalsupport must be sought for dairy development in Africa. In order to determine theright development pattern, appropriate analytical tools must be applied. The TIPICAL(Technology Impact Policy Impact model was used to analyse the impact ofdifferent policies on two typical dairy farming systems in Uganda, which accountfor more than 70% of milk produced in the country. Seven influential policy areaswere also identified: provision of veterinary services, consumption promotion,marketing promotion, input provision, credit access improvement, milk qualityimprovement and genetic improvement. In general, the policy impacts are very littleon farms with local cows but can be magnified up to threefold, if the farms havegraded cows. Policies which improve farmers’ accessibility to markets have thegreatest impacts. The results obtained from this model were compared to thoseusing the EXTRAPOLATE model. This comparison shows that both models couldcomplement each other in analysing policy impacts on African dairy farms.However, differences in results from the models indicate that more focus should bemade on farmers’ willingness to adopt new technology.

  14. Policy harmonized approach for the EU agricultural sector modelling

    Directory of Open Access Journals (Sweden)

    G. SALPUTRA

    2008-12-01

    Full Text Available Policy harmonized (PH approach allows for the quantitative assessment of the impact of various elements of EU CAP direct support schemes, where the production effects of direct payments are accounted through reaction prices formed by producer price and policy price add-ons. Using the AGMEMOD model the impacts of two possible EU agricultural policy scenarios upon beef production have been analysed – full decoupling with a switch from historical to regional Single Payment scheme or alternatively with re-distribution of country direct payment envelopes via introduction of EU-wide flat area payment. The PH approach, by systematizing and harmonizing the management and use of policy data, ensures that projected differential policy impacts arising from changes in common EU policies reflect the likely actual differential impact as opposed to differences in how “common” policies are implemented within analytical models. In the second section of the paper the AGMEMOD model’s structure is explained. The policy harmonized evaluation method is presented in the third section. Results from an application of the PH approach are presented and discussed in the paper’s penultimate section, while section 5 concludes.;

  15. Modelling and Simulation of Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    velocity can be approximated by a Gaussian Markov process. Known approximate results for the first-passage density or equivalently, the distribution of the extremes of wave loads are presented and compared with rather precise simulation results. It is demonstrated that the approximate results......A simple model of the wave load on slender members of offshore structures is described. The wave elevation of the sea state is modelled by a stationary Gaussian process. A new procedure to simulate realizations of the wave loads is developed. The simulation method assumes that the wave particle...

  16. Modelling and Simulation of Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1985-01-01

    velocity can be approximated by a Gaussian Markov process. Known approximate results for the first passage density or equivalently, the distribution of the extremes of wave loads are presented and compared with rather precise simulation results. It is demonstrated that the approximate results......A simple model of the wave load on stender members of offshore structures is described . The wave elevation of the sea stateis modelled by a stationary Gaussian process. A new procedure to simulate realizations of the wave loads is developed. The simulation method assumes that the wave particle...

  17. Modeling and simulation of discrete event systems

    CERN Document Server

    Choi, Byoung Kyu

    2013-01-01

    Computer modeling and simulation (M&S) allows engineers to study and analyze complex systems. Discrete-event system (DES)-M&S is used in modern management, industrial engineering, computer science, and the military. As computer speeds and memory capacity increase, so DES-M&S tools become more powerful and more widely used in solving real-life problems. Based on over 20 years of evolution within a classroom environment, as well as on decades-long experience in developing simulation-based solutions for high-tech industries, Modeling and Simulation of Discrete-Event Systems is the only book on

  18. Minimum-complexity helicopter simulation math model

    Science.gov (United States)

    Heffley, Robert K.; Mnich, Marc A.

    1988-01-01

    An example of a minimal complexity simulation helicopter math model is presented. Motivating factors are the computational delays, cost, and inflexibility of the very sophisticated math models now in common use. A helicopter model form is given which addresses each of these factors and provides better engineering understanding of the specific handling qualities features which are apparent to the simulator pilot. The technical approach begins with specification of features which are to be modeled, followed by a build up of individual vehicle components and definition of equations. Model matching and estimation procedures are given which enable the modeling of specific helicopters from basic data sources such as flight manuals. Checkout procedures are given which provide for total model validation. A number of possible model extensions and refinement are discussed. Math model computer programs are defined and listed.

  19. A linear programming model to optimize diets in environmental policy scenarios.

    Science.gov (United States)

    Moraes, L E; Wilen, J E; Robinson, P H; Fadel, J G

    2012-03-01

    The objective was to develop a linear programming model to formulate diets for dairy cattle when environmental policies are present and to examine effects of these policies on diet formulation and dairy cattle nitrogen and mineral excretions as well as methane emissions. The model was developed as a minimum cost diet model. Two types of environmental policies were examined: a tax and a constraint on methane emissions. A tax was incorporated to simulate a greenhouse gas emissions tax policy, and prices of carbon credits in the current carbon markets were attributed to the methane production variable. Three independent runs were made, using carbon dioxide equivalent prices of $5, $17, and $250/t. A constraint was incorporated into the model to simulate the second type of environmental policy, reducing methane emissions by predetermined amounts. The linear programming formulation of this second alternative enabled the calculation of marginal costs of reducing methane emissions. Methane emission and manure production by dairy cows were calculated according to published equations, and nitrogen and mineral excretions were calculated by mass conservation laws. Results were compared with respect to the values generated by a base least-cost model. Current prices of the carbon credit market did not appear onerous enough to have a substantive incentive effect in reducing methane emissions and altering diet costs of our hypothetical dairy herd. However, when emissions of methane were assumed to be reduced by 5, 10, and 13.5% from the base model, total diet costs increased by 5, 19.1, and 48.5%, respectively. Either these increased costs would be passed onto the consumer or dairy producers would go out of business. Nitrogen and potassium excretions were increased by 16.5 and 16.7% with a 13.5% reduction in methane emissions from the base model. Imposing methane restrictions would further increase the demand for grains and other human-edible crops, which is not a progressive

  20. Policy improvement by a model-free Dyna architecture.

    Science.gov (United States)

    Hwang, Kao-Shing; Lo, Chia-Yue

    2013-05-01

    The objective of this paper is to accelerate the process of policy improvement in reinforcement learning. The proposed Dyna-style system combines two learning schemes, one of which utilizes a temporal difference method for direct learning; the other uses relative values for indirect learning in planning between two successive direct learning cycles. Instead of establishing a complicated world model, the approach introduces a simple predictor of average rewards to actor-critic architecture in the simulation (planning) mode. The relative value of a state, defined as the accumulated differences between immediate reward and average reward, is used to steer the improvement process in the right direction. The proposed learning scheme is applied to control a pendulum system for tracking a desired trajectory to demonstrate its adaptability and robustness. Through reinforcement signals from the environment, the system takes the appropriate action to drive an unknown dynamic to track desired outputs in few learning cycles. Comparisons are made between the proposed model-free method, a connectionist adaptive heuristic critic, and an advanced method of Dyna-Q learning in the experiments of labyrinth exploration. The proposed method outperforms its counterparts in terms of elapsed time and convergence rate.

  1. Computer Based Modelling and Simulation

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. Computer Based ... universities, and later did system analysis, ... sonal computers (PC) and low cost software packages and tools. They can serve as useful learning experience through student projects. Models are .... Let us consider a numerical example: to calculate the velocity of a trainer aircraft ...

  2. Thermal unit availability modeling in a regional simulation model

    International Nuclear Information System (INIS)

    Yamayee, Z.A.; Port, J.; Robinett, W.

    1983-01-01

    The System Analysis Model (SAM) developed under the umbrella of PNUCC's System Analysis Committee is capable of simulating the operation of a given load/resource scenario. This model employs a Monte-Carlo simulation to incorporate uncertainties. Among uncertainties modeled is thermal unit availability both for energy simulation (seasonal) and capacity simulations (hourly). This paper presents the availability modeling in the capacity and energy models. The use of regional and national data in deriving the two availability models, the interaction between the two and modifications made to the capacity model in order to reflect regional practices is presented. A sample problem is presented to show the modification process. Results for modeling a nuclear unit using NERC-GADS is presented

  3. Plasma disruption modeling and simulation

    International Nuclear Information System (INIS)

    Hassanein, A.

    1994-01-01

    Disruptions in tokamak reactors are considered a limiting factor to successful operation and reliable design. The behavior of plasma-facing components during a disruption is critical to the overall integrity of the reactor. Erosion of plasma facing-material (PFM) surfaces due to thermal energy dump during the disruption can severely limit the lifetime of these components and thus diminish the economic feasibility of the reactor. A comprehensive understanding of the interplay of various physical processes during a disruption is essential for determining component lifetime and potentially improving the performance of such components. There are three principal stages in modeling the behavior of PFM during a disruption. Initially, the incident plasma particles will deposit their energy directly on the PFM surface, heating it to a very high temperature where ablation occurs. Models for plasma-material interactions have been developed and used to predict material thermal evolution during the disruption. Within a few microseconds after the start of the disruption, enough material is vaporized to intercept most of the incoming plasma particles. Models for plasma-vapor interactions are necessary to predict vapor cloud expansion and hydrodynamics. Continuous heating of the vapor cloud above the material surface by the incident plasma particles will excite, ionize, and cause vapor atoms to emit thermal radiation. Accurate models for radiation transport in the vapor are essential for calculating the net radiated flux to the material surface which determines the final erosion thickness and consequently component lifetime. A comprehensive model that takes into account various stages of plasma-material interaction has been developed and used to predict erosion rates during reactor disruption, as well during induced disruption in laboratory experiments

  4. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2......: a zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  5. A virtual laboratory notebook for simulation models.

    Science.gov (United States)

    Winfield, A J

    1998-01-01

    In this paper we describe how we have adopted the laboratory notebook as a metaphor for interacting with computer simulation models. This 'virtual' notebook stores the simulation output and meta-data (which is used to record the scientist's interactions with the simulation). The meta-data stored consists of annotations (equivalent to marginal notes in a laboratory notebook), a history tree and a log of user interactions. The history tree structure records when in 'simulation' time, and from what starting point in the tree changes are made to the parameters by the user. Typically these changes define a new run of the simulation model (which is represented as a new branch of the history tree). The tree shows the structure of the changes made to the simulation and the log is required to keep the order in which the changes occurred. Together they form a record which you would normally find in a laboratory notebook. The history tree is plotted in simulation parameter space. This shows the scientist's interactions with the simulation visually and allows direct manipulation of the parameter information presented, which in turn is used to control directly the state of the simulation. The interactions with the system are graphical and usually involve directly selecting or dragging data markers and other graphical control devices around in parameter space. If the graphical manipulators do not provide precise enough control then textual manipulation is still available which allows numerical values to be entered by hand. The Virtual Laboratory Notebook, by providing interesting interactions with the visual view of the history tree, provides a mechanism for giving the user complex and novel ways of interacting with biological computer simulation models.

  6. Bridging experiments, models and simulations

    DEFF Research Database (Denmark)

    Carusi, Annamaria; Burrage, Kevin; Rodríguez, Blanca

    2012-01-01

    Computational models in physiology often integrate functional and structural information from a large range of spatiotemporal scales from the ionic to the whole organ level. Their sophistication raises both expectations and skepticism concerning how computational methods can improve our...... understanding of living organisms and also how they can reduce, replace, and refine animal experiments. A fundamental requirement to fulfill these expectations and achieve the full potential of computational physiology is a clear understanding of what models represent and how they can be validated. The present...... that contributes to defining the specific aspects of cardiac electrophysiology the MSE system targets, rather than being only an external test, and that this is driven by advances in experimental and computational methods and the combination of both....

  7. Role of the national energy system modelling in the process of the policy development

    OpenAIRE

    Merse Stane; Urbancic Andreja; Sucic Boris; Pusnik Matevz

    2012-01-01

    Strategic planning and decision making, nonetheless making energy policies and strategies, is very extensive process and has to follow multiple and often contradictory objectives. During the preparation of the new Slovenian Energy Programme proposal, complete update of the technology and sector oriented bottom up model of Reference Energy and Environmental System of Slovenia (REES-SLO) has been done. During the redevelopment of the REES-SLO model trade-off between the simulation and opt...

  8. Global climate change policies. An analysis of CDM policies with an adapted GTAP model

    International Nuclear Information System (INIS)

    Wang, Shunli

    2004-01-01

    In the context of the relationships between spatial-economic interaction and global warming just discussed, this study aims to analyze the Clean Development Mechanisms (CDM) policies from an economic point of view. The research question of this study is formulated as follows: What will be the impacts of clirnate change policies, in particular CDM policies, on the economic performance of (groups of) countries in our global economic system, taking spatial interaction and general equilibrium effects into account? The purpose of addressing the issue of economic performance for (groups of) countries in the economic system is not just to identify winners and losers from international treaties. Rather, winning or losing may even determine the implementation and willingness of individual countries to participate in international environmental treaties, as illustrated by the recent withdrawal of the US from the Kyoto Protocol. By analyzing the economic impacts of an international environmental treaty for individual (groups of) countries, the framework that will be used to analyze this research question may be useful to determine the attractiveness of some global environmental policies, both for the world as a whole and for individual (groups of) countries. The research question will be answered by dividing it into six subquestions: (1) What is the position of CDM policies in the broad context of climate policy regimes?; (2) How should the relationship between human behavior and the physical environment be ideally modeled from an economic perspective? (3) How should the spatial dimension be incorporated in this framework of interaction between the economic and ecological system?; (4) How can climate change issues be incorporated in general equilibrium models in general, and in GTAP-E (extension of the Global Trade Analysis Project) in particular?; (5) How can CDM policies be implemented in the GTAP-E model?; and (6) What are the impacts of these climate change policies on

  9. The French nuclear policy. A model for security policy in North-East Asia

    International Nuclear Information System (INIS)

    Choe, K.

    1998-01-01

    Between the end of the second world war and the collapse of the Berlin wall, the French diplomacy was based on the nuclear policy in a solid and coherent way. This nuclear policy was an 'incarnation' of the national security conception, allowing France to recover its political, military and economical rank on the international scene. The most important characteristic of the French nuclear policy concerns the commercialization of the nuclear energy which aims to ensuring the national security through the building up of a financial, technological and political 'reserve'. In front of the domination of the USA and USSR during the cold war era, NE Asia had a similar geostrategic configuration as Western Europe. It concerns in particular the massive application of nuclear energy for both military and industrial purposes. The bases of the security policy in this region refers to the real use of the nuclear weapon by the USA against Japan in 1945. The French nuclear policy may be considered as a model for the building of the security policy of NE Asia, in particular through the commercialization of the nuclear technology between the countries in concern. This nuclear approach would allow the countries of these region to change their present day national defense policy into an economical and military cooperation. (J.S.)

  10. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    2003-01-01

    , and the total stress level (i.e. stresses introduced due to internal pressure plus stresses introduced due to temperature gradients) must always be kept below the allowable stress level. In this way, the increased water-/steam space that should allow for better dynamic performance, in the end causes limited...... freedom with respect to dynamic operation of the plant. By means of an objective function including as well the price of the plant as a quantification of the value of dynamic operation of the plant an optimization is carried out. The dynamic model of the boiler plant is applied to define parts...

  11. Impact of Minimum Driveway Spacing Policies on Safety Performance: An Integrated Traffic Micro-Simulation and Automated Conflict Analysis

    Directory of Open Access Journals (Sweden)

    Chu C. Minh

    2014-09-01

    Full Text Available A key strategy for successful access management is the adoption of driveway spacing guidelines that consider both safety and operations. The goal is to provide sufficient distance from one driveway to the next so that drivers can perceive and react to the conditions at each potential conflict point in succession. State DOTs across the country have adopted different driveway spacing standards that vary according to the access class and characteristics of the adjacent roadway, such as type of roadway, posted speed limit, and traffic volume. Utilizing the VISSIM microscopic traffic simulation tool and FHWA's Surrogate Safety Assessment Model (SSAM, this research examined safety implications of four different driveway spacing policies representing 13 states. The analysis involved calibrating the VISSIM model for an arterial roadway corridor in West Columbia, SC, and then using the calibrated model to simulate various operational changes to the corridor, including speed limits, traffic volumes, and the associated minimum driveway spacing criteria for the four different policies. SSAM was used to analyze vehicle trajectories derived from VISSIM to determine the number of conflict points. Experimental results indicate that posted speed limit and traffic volume are the primary impact factors for driveway safety, and thus, these parameters should be considered in establishing minimum driveway spacing. Findings from this study indicate that there are significant differences in safety impacts between the different driveway spacing policies adopted by various state DOTs.

  12. Advanced training simulator models. Implementation and validation

    International Nuclear Information System (INIS)

    Borkowsky, Jeffrey; Judd, Jerry; Belblidia, Lotfi; O'farrell, David; Andersen, Peter

    2008-01-01

    Modern training simulators are required to replicate plant data for both thermal-hydraulic and neutronic response. Replication is required such that reactivity manipulation on the simulator properly trains the operator for reactivity manipulation at the plant. This paper discusses advanced models which perform this function in real-time using the coupled code system THOR/S3R. This code system models the all fluids systems in detail using an advanced, two-phase thermal-hydraulic a model. The nuclear core is modeled using an advanced, three-dimensional nodal method and also by using cycle-specific nuclear data. These models are configured to run interactively from a graphical instructor station or handware operation panels. The simulator models are theoretically rigorous and are expected to replicate the physics of the plant. However, to verify replication, the models must be independently assessed. Plant data is the preferred validation method, but plant data is often not available for many important training scenarios. In the absence of data, validation may be obtained by slower-than-real-time transient analysis. This analysis can be performed by coupling a safety analysis code and a core design code. Such a coupling exists between the codes RELAP5 and SIMULATE-3K (S3K). RELAP5/S3K is used to validate the real-time model for several postulated plant events. (author)

  13. Regularization modeling for large-eddy simulation

    NARCIS (Netherlands)

    Geurts, Bernardus J.; Holm, D.D.

    2003-01-01

    A new modeling approach for large-eddy simulation (LES) is obtained by combining a "regularization principle" with an explicit filter and its inversion. This regularization approach allows a systematic derivation of the implied subgrid model, which resolves the closure problem. The central role of

  14. Analytical system dynamics modeling and simulation

    CERN Document Server

    Fabien, Brian C

    2008-01-01

    This book offering a modeling technique based on Lagrange's energy method includes 125 worked examples. Using this technique enables one to model and simulate systems as diverse as a six-link, closed-loop mechanism or a transistor power amplifier.

  15. Hybrid simulation models of production networks

    CERN Document Server

    Kouikoglou, Vassilis S

    2001-01-01

    This book is concerned with a most important area of industrial production, that of analysis and optimization of production lines and networks using discrete-event models and simulation. The book introduces a novel approach that combines analytic models and discrete-event simulation. Unlike conventional piece-by-piece simulation, this method observes a reduced number of events between which the evolution of the system is tracked analytically. Using this hybrid approach, several models are developed for the analysis of production lines and networks. The hybrid approach combines speed and accuracy for exceptional analysis of most practical situations. A number of optimization problems, involving buffer design, workforce planning, and production control, are solved through the use of hybrid models.

  16. Developing policy analytics for public health strategy and decisions-the Sheffield alcohol policy model framework.

    Science.gov (United States)

    Brennan, Alan; Meier, Petra; Purshouse, Robin; Rafia, Rachid; Meng, Yang; Hill-Macmanus, Daniel

    This paper sets out the development of a methodological framework for detailed evaluation of public health strategies for alcohol harm reduction to meet UK policy-makers needs. Alcohol is known to cause substantial harms, and controlling its affordability and availability are effective policy options. Analysis and synthesis of a variety of public and commercial data sources is needed to evaluate impact on consumers, health services, crime, employers and industry, so a sound evaluation of impact is important. We discuss the iterative process to engage with stakeholders, identify evidence/data and develop analytic approaches and produce a final model structure. We set out a series of steps in modelling impact including: classification and definition of population subgroups of interest, identification and definition of harms and outcomes for inclusion, classification of modifiable components of risk and their baseline values, specification of the baseline position on policy variables especially prices, estimating effects of changing policy variables on risk factors including price elasticities, quantifying risk functions relating risk factors to harms including 47 health conditions, crimes, absenteeism and unemployment, and monetary valuation. The most difficult model structuring decisions are described, as well as the final results framework used to provide decision support to national level policymakers in the UK. In the discussion we explore issues around the relationship between modelling and policy debates, valuation and scope, limitations of evidence/data, how the framework can be adapted to other countries and decisions. We reflect on the approach taken and outline ongoing plans for further development.

  17. Dynamic modeling and simulation of wind turbines

    International Nuclear Information System (INIS)

    Ghafari Seadat, M.H.; Kheradmand Keysami, M.; Lari, H.R.

    2002-01-01

    Using wind energy for generating electricity in wind turbines is a good way for using renewable energies. It can also help to protect the environment. The main objective of this paper is dynamic modeling by energy method and simulation of a wind turbine aided by computer. In this paper, the equations of motion are extracted for simulating the system of wind turbine and then the behavior of the system become obvious by solving the equations. The turbine is considered with three blade rotor in wind direction, induced generator that is connected to the network and constant revolution for simulation of wind turbine. Every part of the wind turbine should be simulated for simulation of wind turbine. The main parts are blades, gearbox, shafts and generator

  18. Regional model simulations of New Zealand climate

    Science.gov (United States)

    Renwick, James A.; Katzfey, Jack J.; Nguyen, Kim C.; McGregor, John L.

    1998-03-01

    Simulation of New Zealand climate is examined through the use of a regional climate model nested within the output of the Commonwealth Scientific and Industrial Research Organisation nine-level general circulation model (GCM). R21 resolution GCM output is used to drive a regional model run at 125 km grid spacing over the Australasian region. The 125 km run is used in turn to drive a simulation at 50 km resolution over New Zealand. Simulations with a full seasonal cycle are performed for 10 model years. The focus is on the quality of the simulation of present-day climate, but results of a doubled-CO2 run are discussed briefly. Spatial patterns of mean simulated precipitation and surface temperatures improve markedly as horizontal resolution is increased, through the better resolution of the country's orography. However, increased horizontal resolution leads to a positive bias in precipitation. At 50 km resolution, simulated frequency distributions of daily maximum/minimum temperatures are statistically similar to those of observations at many stations, while frequency distributions of daily precipitation appear to be statistically different to those of observations at most stations. Modeled daily precipitation variability at 125 km resolution is considerably less than observed, but is comparable to, or exceeds, observed variability at 50 km resolution. The sensitivity of the simulated climate to changes in the specification of the land surface is discussed briefly. Spatial patterns of the frequency of extreme temperatures and precipitation are generally well modeled. Under a doubling of CO2, the frequency of precipitation extremes changes only slightly at most locations, while air frosts become virtually unknown except at high-elevation sites.

  19. Landscape Modelling and Simulation Using Spatial Data

    Directory of Open Access Journals (Sweden)

    Amjed Naser Mohsin AL-Hameedawi

    2017-08-01

    Full Text Available In this paper a procedure was performed for engendering spatial model of landscape acclimated to reality simulation. This procedure based on combining spatial data and field measurements with computer graphics reproduced using Blender software. Thereafter that we are possible to form a 3D simulation based on VIS ALL packages. The objective was to make a model utilising GIS, including inputs to the feature attribute data. The objective of these efforts concentrated on coordinating a tolerable spatial prototype, circumscribing facilitation scheme and outlining the intended framework. Thus; the eventual result was utilized in simulation form. The performed procedure contains not only data gathering, fieldwork and paradigm providing, but extended to supply a new method necessary to provide the respective 3D simulation mapping production, which authorises the decision makers as well as investors to achieve permanent acceptance an independent navigation system for Geoscience applications.

  20. Testing simulation and structural models with applications to energy demand

    Science.gov (United States)

    Wolff, Hendrik

    2007-12-01

    This dissertation deals with energy demand and consists of two parts. Part one proposes a unified econometric framework for modeling energy demand and examples illustrate the benefits of the technique by estimating the elasticity of substitution between energy and capital. Part two assesses the energy conservation policy of Daylight Saving Time and empirically tests the performance of electricity simulation. In particular, the chapter "Imposing Monotonicity and Curvature on Flexible Functional Forms" proposes an estimator for inference using structural models derived from economic theory. This is motivated by the fact that in many areas of economic analysis theory restricts the shape as well as other characteristics of functions used to represent economic constructs. Specific contributions are (a) to increase the computational speed and tractability of imposing regularity conditions, (b) to provide regularity preserving point estimates, (c) to avoid biases existent in previous applications, and (d) to illustrate the benefits of our approach via numerical simulation results. The chapter "Can We Close the Gap between the Empirical Model and Economic Theory" discusses the more fundamental question of whether the imposition of a particular theory to a dataset is justified. I propose a hypothesis test to examine whether the estimated empirical model is consistent with the assumed economic theory. Although the proposed methodology could be applied to a wide set of economic models, this is particularly relevant for estimating policy parameters that affect energy markets. This is demonstrated by estimating the Slutsky matrix and the elasticity of substitution between energy and capital, which are crucial parameters used in computable general equilibrium models analyzing energy demand and the impacts of environmental regulations. Using the Berndt and Wood dataset, I find that capital and energy are complements and that the data are significantly consistent with duality

  1. Quantitative interface models for simulating microstructure evolution

    International Nuclear Information System (INIS)

    Zhu, J.Z.; Wang, T.; Zhou, S.H.; Liu, Z.K.; Chen, L.Q.

    2004-01-01

    To quantitatively simulate microstructural evolution in real systems, we investigated three different interface models: a sharp-interface model implemented by the software DICTRA and two diffuse-interface models which use either physical order parameters or artificial order parameters. A particular example is considered, the diffusion-controlled growth of a γ ' precipitate in a supersaturated γ matrix in Ni-Al binary alloys. All three models use the thermodynamic and kinetic parameters from the same databases. The temporal evolution profiles of composition from different models are shown to agree with each other. The focus is on examining the advantages and disadvantages of each model as applied to microstructure evolution in alloys

  2. A queuing model for road traffic simulation

    International Nuclear Information System (INIS)

    Guerrouahane, N.; Aissani, D.; Bouallouche-Medjkoune, L.; Farhi, N.

    2015-01-01

    We present in this article a stochastic queuing model for the raod traffic. The model is based on the M/G/c/c state dependent queuing model, and is inspired from the deterministic Godunov scheme for the road traffic simulation. We first propose a variant of M/G/c/c state dependent model that works with density-flow fundamental diagrams rather than density-speed relationships. We then extend this model in order to consider upstream traffic demand as well as downstream traffic supply. Finally, we show how to model a whole raod by concatenating raod sections as in the deterministic Godunov scheme

  3. Clock error models for simulation and estimation

    International Nuclear Information System (INIS)

    Meditch, J.S.

    1981-10-01

    Mathematical models for the simulation and estimation of errors in precision oscillators used as time references in satellite navigation systems are developed. The results, based on all currently known oscillator error sources, are directly implementable on a digital computer. The simulation formulation is sufficiently flexible to allow for the inclusion or exclusion of individual error sources as desired. The estimation algorithms, following from Kalman filter theory, provide directly for the error analysis of clock errors in both filtering and prediction

  4. Modeling and simulation goals and accomplishments

    International Nuclear Information System (INIS)

    Turinsky, P.

    2013-01-01

    The CASL (Consortium for Advanced Simulation of Light Water Reactors) mission is to develop and apply the Virtual Reactor simulator (VERA) to optimise nuclear power in terms of capital and operating costs, of nuclear waste production and of nuclear safety. An efficient and reliable virtual reactor simulator relies on 3-dimensional calculations, accurate physics models and code coupling. Advances in computer hardware, along with comparable advances in numerical solvers make the VERA project achievable. This series of slides details the VERA project and presents the specificities and performance of the codes involved in the project and ends by listing the computing needs

  5. Optimal Pricing and Advertising Policies for New Product Oligopoly Models

    OpenAIRE

    Gerald L. Thompson; Jinn-Tsair Teng

    1984-01-01

    In this paper our previous work on monopoly and oligopoly new product models is extended by the addition of pricing as well as advertising control variables. These models contain Bass's demand growth model, and the Vidale-Wolfe and Ozga advertising models, as well as the production learning curve model and an exponential demand function. The problem of characterizing an optimal pricing and advertising policy over time is an important question in the field of marketing as well as in the areas ...

  6. Applications of system dynamics modelling to support health policy.

    Science.gov (United States)

    Atkinson, Jo-An M; Wells, Robert; Page, Andrew; Dominello, Amanda; Haines, Mary; Wilson, Andrew

    2015-07-09

    The value of systems science modelling methods in the health sector is increasingly being recognised. Of particular promise is the potential of these methods to improve operational aspects of healthcare capacity and delivery, analyse policy options for health system reform and guide investments to address complex public health problems. Because it lends itself to a participatory approach, system dynamics modelling has been a particularly appealing method that aims to align stakeholder understanding of the underlying causes of a problem and achieve consensus for action. The aim of this review is to determine the effectiveness of system dynamics modelling for health policy, and explore the range and nature of its application. A systematic search was conducted to identify articles published up to April 2015 from the PubMed, Web of Knowledge, Embase, ScienceDirect and Google Scholar databases. The grey literature was also searched. Papers eligible for inclusion were those that described applications of system dynamics modelling to support health policy at any level of government. Six papers were identified, comprising eight case studies of the application of system dynamics modelling to support health policy. No analytic studies were found that examined the effectiveness of this type of modelling. Only three examples engaged multidisciplinary stakeholders in collective model building. Stakeholder participation in model building reportedly facilitated development of a common 'mental map' of the health problem, resulting in consensus about optimal policy strategy and garnering support for collaborative action. The paucity of relevant papers indicates that, although the volume of descriptive literature advocating the value of system dynamics modelling is considerable, its practical application to inform health policy making is yet to be routinely applied and rigorously evaluated. Advances in software are allowing the participatory model building approach to be extended to

  7. The knowledge-based economy modeled, measured, simulated

    CERN Document Server

    Leydesdorff, Loet

    2006-01-01

    "Challenging, theoretically rich yet anchored in detailed empirical analysis, Loet Leydesdorff's exploration of the dynamics of the knowledge-economy is a major contribution to the field. Drawing on his expertise in science and technology studies, systems theory, and his internationally respected work on the 'triple helix', the book provides a radically new modelling and simulation of knowledge systems, capturing the articulation of structure, communication, and agency therein. This work will be of immense interest to both theorists of the knowledge-economy and practitioners in science policy." Andrew Webster Science & Technology Studies, University of York, UK

  8. Simulation Modeling of Software Development Processes

    Science.gov (United States)

    Calavaro, G. F.; Basili, V. R.; Iazeolla, G.

    1996-01-01

    A simulation modeling approach is proposed for the prediction of software process productivity indices, such as cost and time-to-market, and the sensitivity analysis of such indices to changes in the organization parameters and user requirements. The approach uses a timed Petri Net and Object Oriented top-down model specification. Results demonstrate the model representativeness, and its usefulness in verifying process conformance to expectations, and in performing continuous process improvement and optimization.

  9. Effect of the one-child policy on influenza transmission in China: a stochastic transmission model.

    Directory of Open Access Journals (Sweden)

    Fengchen Liu

    Full Text Available BACKGROUND: China's one-child-per-couple policy, introduced in 1979, led to profound demographic changes for nearly a quarter of the world's population. Several decades later, the consequences include decreased fertility rates, population aging, decreased household sizes, changes in family structure, and imbalanced sex ratios. The epidemiology of communicable diseases may have been affected by these changes since the transmission dynamics of infectious diseases depend on demographic characteristics of the population. Of particular interest is influenza because China and Southeast Asia lie at the center of a global transmission network of influenza. Moreover, changes in household structure may affect influenza transmission. Is it possible that the pronounced demographic changes that have occurred in China have affected influenza transmission? METHODS AND FINDINGS: To address this question, we developed a continuous-time, stochastic, individual-based simulation model for influenza transmission. With this model, we simulated 30 years of influenza transmission and compared influenza transmission rates in populations with and without the one-child policy control. We found that the average annual attack rate is reduced by 6.08% (SD 2.21% in the presence of the one-child policy compared to a population in which no demographic changes occurred. There was no discernible difference in the secondary attack rate, -0.15% (SD 1.85%, between the populations with and without a one-child policy. We also forecasted influenza transmission over a ten-year time period in a population with a two-child policy under a hypothesis that a two-child-per-couple policy will be carried out in 2015, and found a negligible difference in the average annual attack rate compared to the population with the one-child policy. CONCLUSIONS: This study found that the average annual attack rate is slightly lowered in a population with a one-child policy, which may have resulted from a

  10. Validation of the simulator neutronics model

    International Nuclear Information System (INIS)

    Gregory, M.V.

    1984-01-01

    The neutronics model in the SRP reactor training simulator computes the variation with time of the neutron population in the reactor core. The power output of a reactor is directly proportional to the neutron population, thus in a very real sense the neutronics model determines the response of the simulator. The geometrical complexity of the reactor control system in SRP reactors requires the neutronics model to provide a detailed, 3D representation of the reactor core. Existing simulator technology does not allow such a detailed representation to run in real-time in a minicomputer environment, thus an entirely different approach to the problem was required. A prompt jump method has been developed in answer to this need

  11. Analyzing Strategic Business Rules through Simulation Modeling

    Science.gov (United States)

    Orta, Elena; Ruiz, Mercedes; Toro, Miguel

    Service Oriented Architecture (SOA) holds promise for business agility since it allows business process to change to meet new customer demands or market needs without causing a cascade effect of changes in the underlying IT systems. Business rules are the instrument chosen to help business and IT to collaborate. In this paper, we propose the utilization of simulation models to model and simulate strategic business rules that are then disaggregated at different levels of an SOA architecture. Our proposal is aimed to help find a good configuration for strategic business objectives and IT parameters. The paper includes a case study where a simulation model is built to help business decision-making in a context where finding a good configuration for different business parameters and performance is too complex to analyze by trial and error.

  12. A model to create an efficient and equitable admission policy for patients arriving to the cardiothoracic ICU.

    Science.gov (United States)

    Yang, Muer; Fry, Michael J; Raikhelkar, Jayashree; Chin, Cynthia; Anyanwu, Anelechi; Brand, Jordan; Scurlock, Corey

    2013-02-01

    To develop queuing and simulation-based models to understand the relationship between ICU bed availability and operating room schedule to maximize the use of critical care resources and minimize case cancellation while providing equity to patients and surgeons. Retrospective analysis of 6-month unit admission data from a cohort of cardiothoracic surgical patients, to create queuing and simulation-based models of ICU bed flow. Three different admission policies (current admission policy, shortest-processing-time policy, and a dynamic policy) were then analyzed using simulation models, representing 10 yr worth of potential admissions. Important output data consisted of the "average waiting time," a proxy for unit efficiency, and the "maximum waiting time," a surrogate for patient equity. A cardiothoracic surgical ICU in a tertiary center in New York, NY. Six hundred thirty consecutive cardiothoracic surgical patients admitted to the cardiothoracic surgical ICU. None. Although the shortest-processing-time admission policy performs best in terms of unit efficiency (0.4612 days), it did so at expense of patient equity prolonging surgical waiting time by as much as 21 days. The current policy gives the greatest equity but causes inefficiency in unit bed-flow (0.5033 days). The dynamic policy performs at a level (0.4997 days) 8.3% below that of the shortest-processing-time in average waiting time; however, it balances this with greater patient equity (maximum waiting time could be shortened by 4 days compared to the current policy). Queuing theory and computer simulation can be used to model case flow through a cardiothoracic operating room and ICU. A dynamic admission policy that looks at current waiting time and expected ICU length of stay allows for increased equity between patients with only minimum losses of efficiency. This dynamic admission policy would seem to be a superior in maximizing case-flow. These results may be generalized to other surgical ICUs.

  13. Simulating school closure policies for cost effective pandemic decision making

    Directory of Open Access Journals (Sweden)

    Araz Ozgur M

    2012-06-01

    Full Text Available Abstract Background Around the globe, school closures were used sporadically to mitigate the 2009 H1N1 influenza pandemic. However, such closures can detrimentally impact economic and social life. Methods Here, we couple a decision analytic approach with a mathematical model of influenza transmission to estimate the impact of school closures in terms of epidemiological and cost effectiveness. Our method assumes that the transmissibility and the severity of the disease are uncertain, and evaluates several closure and reopening strategies that cover a range of thresholds in school-aged prevalence (SAP and closure durations. Results Assuming a willingness to pay per quality adjusted life-year (QALY threshold equal to the US per capita GDP ($46,000, we found that the cost effectiveness of these strategies is highly dependent on the severity and on a willingness to pay per QALY. For severe pandemics, the preferred strategy couples the earliest closure trigger (0.5% SAP with the longest duration closure (24 weeks considered. For milder pandemics, the preferred strategies also involve the earliest closure trigger, but are shorter duration (12 weeks for low transmission rates and variable length for high transmission rates. Conclusions These findings highlight the importance of obtaining early estimates of pandemic severity and provide guidance to public health decision-makers for effectively tailoring school closures strategies in response to a newly emergent influenza pandemic.

  14. Tobacco Town: Computational Modeling of Policy Options to Reduce Tobacco Retailer Density.

    Science.gov (United States)

    Luke, Douglas A; Hammond, Ross A; Combs, Todd; Sorg, Amy; Kasman, Matt; Mack-Crane, Austen; Ribisl, Kurt M; Henriksen, Lisa

    2017-05-01

    To identify the behavioral mechanisms and effects of tobacco control policies designed to reduce tobacco retailer density. We developed the Tobacco Town agent-based simulation model to examine 4 types of retailer reduction policies: (1) random retailer reduction, (2) restriction by type of retailer, (3) limiting proximity of retailers to schools, and (4) limiting proximity of retailers to each other. The model examined the effects of these policies alone and in combination across 4 different types of towns, defined by 2 levels of population density (urban vs suburban) and 2 levels of income (higher vs lower). Model results indicated that reduction of retailer density has the potential to decrease accessibility of tobacco products by driving up search and purchase costs. Policy effects varied by town type: proximity policies worked better in dense, urban towns whereas retailer type and random retailer reduction worked better in less-dense, suburban settings. Comprehensive retailer density reduction policies have excellent potential to reduce the public health burden of tobacco use in communities.

  15. Evaluating business models for microgrids: Interactions of technology and policy

    International Nuclear Information System (INIS)

    Hanna, Ryan; Ghonima, Mohamed; Kleissl, Jan; Tynan, George; Victor, David G.

    2017-01-01

    Policy makers are increasingly focused on strategies to decentralize the electricity grid. We analyze the business model for one mode of decentralization—microgrids—and quantify the economics for self-supply of electricity and thermal energy and explicitly resolve technological as well as policy variables. We offer a tool, based on the Distributed Energy Resources Customer Adoption Model (DER-CAM) modeling framework, that determines the cost-minimal capacity and operation of distributed energy resources in a microgrid, and apply it in southern California to three “iconic” microgrid types which represent typical commercial adopters: a large commercial building, critical infrastructure, and campus. We find that optimal investment leads to some deployment of renewables but that natural gas technologies underpin the most robust business cases—due in part to relatively cheap gas and high electricity rates. This finding contrasts sharply with most policy advocacy, which has focused on the potentials for decentralization of the grid to encourage deployment of renewables. Decentralization could radically reduce customer energy costs, but without the right policy framework it could create large numbers of small decentralized sources of gas-based carbon emissions that will be difficult to control if policy makers want to achieve deep cuts in greenhouse gas emissions. - Highlights: • We offer a modeling tool to study technology and policy variables for microgrids. • We construct comprehensive load profiles for three likely adopters of microgrids. • Investment in natural gas generators is key to enabling business models. • Solar PV and storage are optimal but as supplements to gas generation. • Business models are highly robust to sensitivity in technology and policy variables.

  16. New exploration on TMSR: modelling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Si, S.; Chen, Q.; Bei, H.; Zhao, J., E-mail: ssy@snerdi.com.cn [Shanghai Nuclear Engineering Research & Design Inst., Shanghai (China)

    2015-07-01

    A tightly coupled multi-physics model for MSR (Molten Salt Reactor) system involving the reactor core and the rest of the primary loop has been developed and employed in an in-house developed computer code TANG-MSR. In this paper, the computer code is used to simulate the behavior of steady state operation and transient for our redesigned TMSR. The presented simulation results demonstrate that the models employed in TANG-MSR can capture major physics phenomena in MSR and the redesigned TMSR has excellent performance of safety and sustainability. (author)

  17. Nuclear reactor core modelling in multifunctional simulators

    International Nuclear Information System (INIS)

    Puska, E.K.

    1999-01-01

    The thesis concentrates on the development of nuclear reactor core models for the APROS multifunctional simulation environment and the use of the core models in various kinds of applications. The work was started in 1986 as a part of the development of the entire APROS simulation system. The aim was to create core models that would serve in a reliable manner in an interactive, modular and multifunctional simulator/plant analyser environment. One-dimensional and three-dimensional core neutronics models have been developed. Both models have two energy groups and six delayed neutron groups. The three-dimensional finite difference type core model is able to describe both BWR- and PWR-type cores with quadratic fuel assemblies and VVER-type cores with hexagonal fuel assemblies. The one- and three-dimensional core neutronics models can be connected with the homogeneous, the five-equation or the six-equation thermal hydraulic models of APROS. The key feature of APROS is that the same physical models can be used in various applications. The nuclear reactor core models of APROS have been built in such a manner that the same models can be used in simulator and plant analyser applications, as well as in safety analysis. In the APROS environment the user can select the number of flow channels in the three-dimensional reactor core and either the homogeneous, the five- or the six-equation thermal hydraulic model for these channels. The thermal hydraulic model and the number of flow channels have a decisive effect on the calculation time of the three-dimensional core model and thus, at present, these particular selections make the major difference between a safety analysis core model and a training simulator core model. The emphasis on this thesis is on the three-dimensional core model and its capability to analyse symmetric and asymmetric events in the core. The factors affecting the calculation times of various three-dimensional BWR, PWR and WWER-type APROS core models have been

  18. Nuclear reactor core modelling in multifunctional simulators

    Energy Technology Data Exchange (ETDEWEB)

    Puska, E.K. [VTT Energy, Nuclear Energy, Espoo (Finland)

    1999-06-01

    The thesis concentrates on the development of nuclear reactor core models for the APROS multifunctional simulation environment and the use of the core models in various kinds of applications. The work was started in 1986 as a part of the development of the entire APROS simulation system. The aim was to create core models that would serve in a reliable manner in an interactive, modular and multifunctional simulator/plant analyser environment. One-dimensional and three-dimensional core neutronics models have been developed. Both models have two energy groups and six delayed neutron groups. The three-dimensional finite difference type core model is able to describe both BWR- and PWR-type cores with quadratic fuel assemblies and VVER-type cores with hexagonal fuel assemblies. The one- and three-dimensional core neutronics models can be connected with the homogeneous, the five-equation or the six-equation thermal hydraulic models of APROS. The key feature of APROS is that the same physical models can be used in various applications. The nuclear reactor core models of APROS have been built in such a manner that the same models can be used in simulator and plant analyser applications, as well as in safety analysis. In the APROS environment the user can select the number of flow channels in the three-dimensional reactor core and either the homogeneous, the five- or the six-equation thermal hydraulic model for these channels. The thermal hydraulic model and the number of flow channels have a decisive effect on the calculation time of the three-dimensional core model and thus, at present, these particular selections make the major difference between a safety analysis core model and a training simulator core model. The emphasis on this thesis is on the three-dimensional core model and its capability to analyse symmetric and asymmetric events in the core. The factors affecting the calculation times of various three-dimensional BWR, PWR and WWER-type APROS core models have been

  19. Understanding Public Policy Making through the Work of Committees: Utilizing a Student-Led Congressional Hearing Simulation

    Science.gov (United States)

    Rinfret, Sara R.; Pautz, Michelle C.

    2015-01-01

    In an effort to help students better understand the complexity of making environmental policy and the role of policy actors in this process, we developed a mock congressional hearing simulation. In this congressional hearing, students in two environmental policy courses take on the roles of members of Congress and various interest groups to…

  20. THE SHEFFIELD ALCOHOL POLICY MODEL - A MATHEMATICAL DESCRIPTION.

    Science.gov (United States)

    Brennan, Alan; Meier, Petra; Purshouse, Robin; Rafia, Rachid; Meng, Yang; Hill-Macmanus, Daniel; Angus, Colin; Holmes, John

    2014-09-30

    This methodology paper sets out a mathematical description of the Sheffield Alcohol Policy Model version 2.0, a model to evaluate public health strategies for alcohol harm reduction in the UK. Policies that can be appraised include a minimum price per unit of alcohol, restrictions on price discounting, and broader public health measures. The model estimates the impact on consumers, health services, crime, employers, retailers and government tax revenues. The synthesis of public and commercial data sources to inform the model structure is described. A detailed algebraic description of the model is provided. This involves quantifying baseline levels of alcohol purchasing and consumption by age and gender subgroups, estimating the impact of policies on consumption, for example, using evidence on price elasticities of demand for alcohol, quantification of risk functions relating alcohol consumption to harms including 47 health conditions, crimes, absenteeism and unemployment, and finally monetary valuation of the consequences. The results framework, shown for a minimum price per unit of alcohol, has been used to provide policy appraisals for the UK government policy-makers. In discussion and online appendix, we explore issues around valuation and scope, limitations of evidence/data, how the framework can be adapted to other countries and decisions, and ongoing plans for further development. © 2014 The Authors. Health Economics published by John Wiley & Sons Ltd. © 2014 The Authors. Health Economics published by John Wiley & Sons Ltd.

  1. Kanban simulation model for production process optimization

    Directory of Open Access Journals (Sweden)

    Golchev Riste

    2015-01-01

    Full Text Available A long time has passed since the KANBAN system has been established as an efficient method for coping with the excessive inventory. Still, the possibilities for its improvement through its integration with other different approaches should be investigated further. The basic research challenge of this paper is to present benefits of KANBAN implementation supported with Discrete Event Simulation (DES. In that direction, at the beginning, the basics of KANBAN system are presented with emphasis on the information and material flow, together with a methodology for implementation of KANBAN system. Certain analysis on combining the simulation with this methodology is presented. The paper is concluded with a practical example which shows that through understanding the philosophy of the implementation methodology of KANBAN system and the simulation methodology, a simulation model can be created which can serve as a basis for a variety of experiments that can be conducted within a short period of time, resulting with production process optimization.

  2. Vermont Yankee simulator BOP model upgrade

    International Nuclear Information System (INIS)

    Alejandro, R.; Udbinac, M.J.

    2006-01-01

    The Vermont Yankee simulator has undergone significant changes in the 20 years since the original order was placed. After the move from the original Unix to MS Windows environment, and upgrade to the latest version of SimPort, now called MASTER, the platform was set for an overhaul and replacement of major plant system models. Over a period of a few months, the VY simulator team, in partnership with WSC engineers, replaced outdated legacy models of the main steam, condenser, condensate, circulating water, feedwater and feedwater heaters, and main turbine and auxiliaries. The timing was ideal, as the plant was undergoing a power up-rate, so the opportunity was taken to replace the legacy models with industry-leading, true on-line object oriented graphical models. Due to the efficiency of design and ease of use of the MASTER tools, VY staff performed the majority of the modeling work themselves with great success, with only occasional assistance from WSC, in a relatively short time-period, despite having to maintain all of their 'regular' simulator maintenance responsibilities. This paper will provide a more detailed view of the VY simulator, including how it is used and how it has benefited from the enhancements and upgrades implemented during the project. (author)

  3. Evaluating energy efficiency policies with energy-economy models

    NARCIS (Netherlands)

    Mundaca, L.; Neij, L.; Worrell, E.; McNeil, M.

    2010-01-01

    The growing complexities of energy systems, environmental problems, and technology markets are driving and testing most energy-economy models to their limits. To further advance bottom-up models from a multidisciplinary energy efficiency policy evaluation perspective, we review and critically

  4. Simulating stakeholder support in a policy process: An application to river management

    NARCIS (Netherlands)

    Valkering, Pieter; Rotmans, Jan; Krywkow, Jorg; van der Veen, A.

    2005-01-01

    The authors present an agent-based model representing a policy process among stakeholders of river management. For evaluating the different river management alternatives, the agent-based model is coupled to an integrated river model that describes the impacts of river management, such as flood risk,

  5. Data driven mathematical models for policy making

    OpenAIRE

    Nannyonga, Betty

    2011-01-01

    This thesis consists of two papers. 1. Betty Nannyonga, D.J.T. Sumpter, J.Y.T. Mugisha and L.S. Luboobi: The Dynamics,causes and possible prevention of Hepaititis E outbreaks. 2. Betty Nannyonga, D.J.T. Sumpter, andStam Nicolis: A dynamical systems approach tosocial and economic development. The first paper deals with a deterministic approach of modelling a Hepatitis E outbreak whenmalaria is endemic in a population. We design three models based on the epidemiology ofHepatitis E, malaria, and...

  6. Modeling salmonella Dublin into the dairy herd simulation model Simherd

    DEFF Research Database (Denmark)

    Kudahl, Anne Braad

    2010-01-01

    Infection with Salmonella Dublin in the dairy herd and effects of the infection and relevant control measures are currently being modeled into the dairy herd simulation model called Simherd. The aim is to compare the effects of different control strategies against Salmonella Dublin on both within...... of the simulations will therefore be used for decision support in the national surveillance and eradication program against Salmonella Dublin. Basic structures of the model are programmed and will be presented at the workshop. The model is in a phase of face-validation by a group of Salmonella......-herd- prevalence and economy by simulations. The project Dublin on both within-herd- prevalence and economy by simulations. The project is a part of a larger national project "Salmonella 2007 - 2011" with the main objective to reduce the prevalence of Salmonella Dublin in Danish Dairy herds. Results...

  7. Urban adaptation to mega-drought: Anticipatory water modeling, policy, and planning in Phoenix

    Science.gov (United States)

    Gober, P.; Sampson, D. A.; Quay, R.; White, D. D.; Chow, W.

    2016-12-01

    There is increasing interest in using the results of water models for long-term planning and policy analysis. Achieving this goal requires more effective integration of human dimensions into water modeling and a paradigm shift in the way models are developed and used. A user-defined focus argues in favor of models that are designed to foster public debate and engagement about the difficult trade-offs that are inevitable in managing complex water systems. These models also emphasize decision making under uncertainty and anticipatory planning, and are developed through a collaborative and iterative process. This paper demonstrates the use of anticipatory modeling for long-term drought planning in Phoenix, one of the largest and fastest growing urban areas in the southwestern USA. WaterSim 5, an anticipatory water policy and planning model, was used to explore groundwater sustainability outcomes for mega-drought conditions across a range of policies, including population growth management, water conservation, water banking, direct reuse of RO reclaimed water, and water augmentation. Results revealed that business-as-usual population growth, per capita use trends, and management strategies may not be sustainable over the long term, even without mega-drought conditions as years of available groundwater supply decline over the simulation period from 2000 to 2060. Adding mega-drought increases the decline in aquifer levels and increases the variability in flows and uncertainty about future groundwater supplies. Simulations that combine drought management policies can return the region to sustainable. Results demonstrate the value of long-term planning and policy analysis for anticipating and adapting to environmental change.

  8. A universal simulator for ecological models

    DEFF Research Database (Denmark)

    Holst, Niels

    2013-01-01

    Software design is an often neglected issue in ecological models, even though bad software design often becomes a hindrance for re-using, sharing and even grasping an ecological model. In this paper, the methodology of agile software design was applied to the domain of ecological models. Thus...... the principles for a universal design of ecological models were arrived at. To exemplify this design, the open-source software Universal Simulator was constructed using C++ and XML and is provided as a resource for inspiration....

  9. Biological transportation networks: Modeling and simulation

    KAUST Repository

    Albi, Giacomo

    2015-09-15

    We present a model for biological network formation originally introduced by Cai and Hu [Adaptation and optimization of biological transport networks, Phys. Rev. Lett. 111 (2013) 138701]. The modeling of fluid transportation (e.g., leaf venation and angiogenesis) and ion transportation networks (e.g., neural networks) is explained in detail and basic analytical features like the gradient flow structure of the fluid transportation network model and the impact of the model parameters on the geometry and topology of network formation are analyzed. We also present a numerical finite-element based discretization scheme and discuss sample cases of network formation simulations.

  10. Reproducibility in Computational Neuroscience Models and Simulations

    Science.gov (United States)

    McDougal, Robert A.; Bulanova, Anna S.; Lytton, William W.

    2016-01-01

    Objective Like all scientific research, computational neuroscience research must be reproducible. Big data science, including simulation research, cannot depend exclusively on journal articles as the method to provide the sharing and transparency required for reproducibility. Methods Ensuring model reproducibility requires the use of multiple standard software practices and tools, including version control, strong commenting and documentation, and code modularity. Results Building on these standard practices, model sharing sites and tools have been developed that fit into several categories: 1. standardized neural simulators, 2. shared computational resources, 3. declarative model descriptors, ontologies and standardized annotations; 4. model sharing repositories and sharing standards. Conclusion A number of complementary innovations have been proposed to enhance sharing, transparency and reproducibility. The individual user can be encouraged to make use of version control, commenting, documentation and modularity in development of models. The community can help by requiring model sharing as a condition of publication and funding. Significance Model management will become increasingly important as multiscale models become larger, more detailed and correspondingly more difficult to manage by any single investigator or single laboratory. Additional big data management complexity will come as the models become more useful in interpreting experiments, thus increasing the need to ensure clear alignment between modeling data, both parameters and results, and experiment. PMID:27046845

  11. A SIMULATION MODEL OF THE GAS COMPLEX

    Directory of Open Access Journals (Sweden)

    Sokolova G. E.

    2016-06-01

    Full Text Available The article considers the dynamics of gas production in Russia, the structure of sales in the different market segments, as well as comparative dynamics of selling prices on these segments. Problems of approach to the creation of the gas complex using a simulation model, allowing to estimate efficiency of the project and determine the stability region of the obtained solutions. In the presented model takes into account the unit repayment of the loan, allowing with the first year of simulation to determine the possibility of repayment of the loan. The model object is a group of gas fields, which is determined by the minimum flow rate above which the project is cost-effective. In determining the minimum source flow rate for the norm of discount is taken as a generalized weighted average percentage on debt and equity taking into account risk premiums. He also serves as the lower barrier to internal rate of return below which the project is rejected as ineffective. Analysis of the dynamics and methods of expert evaluation allow to determine the intervals of variation of the simulated parameters, such as the price of gas and the exit gas complex at projected capacity. Calculated using the Monte Carlo method, for each random realization of the model simulated values of parameters allow to obtain a set of optimal for each realization of values minimum yield of wells, and also allows to determine the stability region of the solution.

  12. Object Oriented Modelling and Dynamical Simulation

    DEFF Research Database (Denmark)

    Wagner, Falko Jens; Poulsen, Mikael Zebbelin

    1998-01-01

    This report with appendix describes the work done in master project at DTU.The goal of the project was to develop a concept for simulation of dynamical systems based on object oriented methods.The result was a library of C++-classes, for use when both building componentbased models and when...

  13. Advanced feeder control using fast simulation models

    NARCIS (Netherlands)

    Verheijen, O.S.; Op den Camp, O.M.G.C.; Beerkens, R.G.C.; Backx, A.C.P.M.; Huisman, L.; Drummond, C.H.

    2005-01-01

    For the automatic control of glass quality in glass production, the relation between process variable and product or glass quality and process conditions/process input parameters must be known in detail. So far, detailed 3-D glass melting simulation models were used to predict the effect of process

  14. Modeling and Simulating Virtual Anatomical Humans

    NARCIS (Netherlands)

    Madehkhaksar, Forough; Luo, Zhiping; Pronost, Nicolas; Egges, Arjan

    2014-01-01

    This chapter presents human musculoskeletal modeling and simulation as a challenging field that lies between biomechanics and computer animation. One of the main goals of computer animation research is to develop algorithms and systems that produce plausible motion. On the other hand, the main

  15. Agent Based Modelling for Social Simulation

    NARCIS (Netherlands)

    Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

    2013-01-01

    This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course

  16. Freshwater Ecosystem Services in Mining Regions: Modelling Options for Policy Development Support

    Directory of Open Access Journals (Sweden)

    Daniel Mercado-Garcia

    2018-04-01

    Full Text Available The ecosystem services (ES approach offers an integrated perspective of social-ecological systems, suitable for holistic assessments of mining impacts. Yet for ES models to be policy-relevant, methodological consensus in mining contexts is needed. We review articles assessing ES in mining areas focusing on freshwater components and policy support potential. Twenty-six articles were analysed concerning (i methodological complexity (data types, number of parameters, processes and ecosystem–human integration level and (ii potential applicability for policy development (communication of uncertainties, scenario simulation, stakeholder participation and management recommendations. Articles illustrate mining impacts on ES through valuation exercises mostly. However, the lack of ground- and surface-water measurements, as well as insufficient representation of the connectivity among soil, water and humans, leave room for improvements. Inclusion of mining-specific environmental stressors models, increasing resolution of topographies, determination of baseline ES patterns and inclusion of multi-stakeholder perspectives are advantageous for policy support. We argue that achieving more holistic assessments exhorts practitioners to aim for high social-ecological connectivity using mechanistic models where possible and using inductive methods only where necessary. Due to data constraints, cause–effect networks might be the most feasible and best solution. Thus, a policy-oriented framework is proposed, in which data science is directed to environmental modelling for analysis of mining impacts on water ES.

  17. Thermohydraulic modeling and simulation of breeder reactors

    International Nuclear Information System (INIS)

    Agrawal, A.K.; Khatib-Rahbar, M.; Curtis, R.T.; Hetrick, D.L.; Girijashankar, P.V.

    1982-01-01

    This paper deals with the modeling and simulation of system-wide transients in LMFBRs. Unprotected events (i.e., the presumption of failure of the plant protection system) leading to core-melt are not considered in this paper. The existing computational capabilities in the area of protected transients in the US are noted. Various physical and numerical approximations that are made in these codes are discussed. Finally, the future direction in the area of model verification and improvements is discussed

  18. MONETARY POLICY TRANSMISSION MECHANISM AND TVP-VAR MODEL

    Directory of Open Access Journals (Sweden)

    Andreea ROŞOIU

    2013-12-01

    Full Text Available The transmission of monetary policy to the economy is a subject of major importance for central banks because, by using these measures, central banks can achieve their purpose of ensuring price stability without neglecting the objective of sustainable economic growth. In order to analyze the evolution of the monetary policy transmission mechanism in Romania, a time varying structural vector autoregression model is estimated, by using a Markov Chain Monte Carlo algorithm for the posterior evolution. The conclusions of the empirical study are: both systematic and non-systematic monetary policy have changed during the investigated period of time, the systematic response of the interest rate to shocks in inflation and unemployment being faster over the recent period. Also, non-policy shocks seem more important than interest rate shocks in explaining inflation and unemployment evolution.

  19. Optimal maintenance policies in incomplete repair models

    International Nuclear Information System (INIS)

    Kahle, Waltraud

    2007-01-01

    We consider an incomplete repair model, that is, the impact of repair is not minimal as in the homogeneous Poisson process and not 'as good as new' as in renewal processes but lies between these boundary cases. The repairs are assumed to impact the failure intensity following a virtual age process of the general form proposed by Kijima. In previous works field data from an industrial setting were used to fit several models. In most cases the estimated rate of occurrence of failures was that of an underlying exponential distribution of the time between failures. In this paper, it is shown that there exist maintenance schedules under which the failure behavior of the failure-repair process becomes a homogeneous Poisson process

  20. On dynamics in a Keynesian model of monetary stabilization policy with debt effect

    Science.gov (United States)

    Asada, Toichiro; Demetrian, Michal; Zimka, Rudolf

    2018-05-01

    In this paper, a four-dimensional model of flexible prices with the central bank's stabilization policy, describing the development of the firms' private debt, the output, the expected rate of inflation and the rate of interest is analyzed. Questions concerning the existence of limit cycles around its normal equilibrium point are investigated. The bifurcation equation is found. The formulae for the calculation of its coefficients are gained. A numerical example is presented by means of numerical simulations.

  1. Modeling Supermassive Black Holes in Cosmological Simulations

    Science.gov (United States)

    Tremmel, Michael

    My thesis work has focused on improving the implementation of supermassive black hole (SMBH) physics in cosmological hydrodynamic simulations. SMBHs are ubiquitous in mas- sive galaxies, as well as bulge-less galaxies and dwarfs, and are thought to be a critical component to massive galaxy evolution. Still, much is unknown about how SMBHs form, grow, and affect their host galaxies. Cosmological simulations are an invaluable tool for un- derstanding the formation of galaxies, self-consistently tracking their evolution with realistic merger and gas accretion histories. SMBHs are often modeled in these simulations (generally as a necessity to produce realistic massive galaxies), but their implementations are commonly simplified in ways that can limit what can be learned. Current and future observations are opening new windows into the lifecycle of SMBHs and their host galaxies, but require more detailed, physically motivated simulations. Within the novel framework I have developed, SMBHs 1) are seeded at early times without a priori assumptions of galaxy occupation, 2) grow in a way that accounts for the angular momentum of gas, and 3) experience realistic orbital evolution. I show how this model, properly tuned with a novel parameter optimiza- tion technique, results in realistic galaxies and SMBHs. Utilizing the unique ability of these simulations to capture the dynamical evolution of SMBHs, I present the first self-consistent prediction for the formation timescales of close SMBH pairs, precursors to SMBH binaries and merger events potentially detected by future gravitational wave experiments.

  2. Advances in NLTE Modeling for Integrated Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Scott, H A; Hansen, S B

    2009-07-08

    The last few years have seen significant progress in constructing the atomic models required for non-local thermodynamic equilibrium (NLTE) simulations. Along with this has come an increased understanding of the requirements for accurately modeling the ionization balance, energy content and radiative properties of different elements for a wide range of densities and temperatures. Much of this progress is the result of a series of workshops dedicated to comparing the results from different codes and computational approaches applied to a series of test problems. The results of these workshops emphasized the importance of atomic model completeness, especially in doubly excited states and autoionization transitions, to calculating ionization balance, and the importance of accurate, detailed atomic data to producing reliable spectra. We describe a simple screened-hydrogenic model that calculates NLTE ionization balance with surprising accuracy, at a low enough computational cost for routine use in radiation-hydrodynamics codes. The model incorporates term splitting, {Delta}n = 0 transitions, and approximate UTA widths for spectral calculations, with results comparable to those of much more detailed codes. Simulations done with this model have been increasingly successful at matching experimental data for laser-driven systems and hohlraums. Accurate and efficient atomic models are just one requirement for integrated NLTE simulations. Coupling the atomic kinetics to hydrodynamics and radiation transport constrains both discretizations and algorithms to retain energy conservation, accuracy and stability. In particular, the strong coupling between radiation and populations can require either very short timesteps or significantly modified radiation transport algorithms to account for NLTE material response. Considerations such as these continue to provide challenges for NLTE simulations.

  3. Analysis of Intelligent Transportation Systems Using Model-Driven Simulations

    Directory of Open Access Journals (Sweden)

    Alberto Fernández-Isabel

    2015-06-01

    Full Text Available Intelligent Transportation Systems (ITSs integrate information, sensor, control, and communication technologies to provide transport related services. Their users range from everyday commuters to policy makers and urban planners. Given the complexity of these systems and their environment, their study in real settings is frequently unfeasible. Simulations help to address this problem, but present their own issues: there can be unintended mistakes in the transition from models to code; their platforms frequently bias modeling; and it is difficult to compare works that use different models and tools. In order to overcome these problems, this paper proposes a framework for a model-driven development of these simulations. It is based on a specific modeling language that supports the integrated specification of the multiple facets of an ITS: people, their vehicles, and the external environment; and a network of sensors and actuators conveniently arranged and distributed that operates over them. The framework works with a model editor to generate specifications compliant with that language, and a code generator to produce code from them using platform specifications. There are also guidelines to help researchers in the application of this infrastructure. A case study on advanced management of traffic lights with cameras illustrates its use.

  4. An Integrative Behavioral Model of Information Security Policy Compliance

    Directory of Open Access Journals (Sweden)

    Sang Hoon Kim

    2014-01-01

    Full Text Available The authors found the behavioral factors that influence the organization members’ compliance with the information security policy in organizations on the basis of neutralization theory, Theory of planned behavior, and protection motivation theory. Depending on the theory of planned behavior, members’ attitudes towards compliance, as well as normative belief and self-efficacy, were believed to determine the intention to comply with the information security policy. Neutralization theory, a prominent theory in criminology, could be expected to provide the explanation for information system security policy violations. Based on the protection motivation theory, it was inferred that the expected efficacy could have an impact on intentions of compliance. By the above logical reasoning, the integrative behavioral model and eight hypotheses could be derived. Data were collected by conducting a survey; 194 out of 207 questionnaires were available. The test of the causal model was conducted by PLS. The reliability, validity, and model fit were found to be statistically significant. The results of the hypotheses tests showed that seven of the eight hypotheses were acceptable. The theoretical implications of this study are as follows: (1 the study is expected to play a role of the baseline for future research about organization members’ compliance with the information security policy, (2 the study attempted an interdisciplinary approach by combining psychology and information system security research, and (3 the study suggested concrete operational definitions of influencing factors for information security policy compliance through a comprehensive theoretical review. Also, the study has some practical implications. First, it can provide the guideline to support the successful execution of the strategic establishment for the implement of information system security policies in organizations. Second, it proves that the need of education and training

  5. An integrative behavioral model of information security policy compliance.

    Science.gov (United States)

    Kim, Sang Hoon; Yang, Kyung Hoon; Park, Sunyoung

    2014-01-01

    The authors found the behavioral factors that influence the organization members' compliance with the information security policy in organizations on the basis of neutralization theory, Theory of planned behavior, and protection motivation theory. Depending on the theory of planned behavior, members' attitudes towards compliance, as well as normative belief and self-efficacy, were believed to determine the intention to comply with the information security policy. Neutralization theory, a prominent theory in criminology, could be expected to provide the explanation for information system security policy violations. Based on the protection motivation theory, it was inferred that the expected efficacy could have an impact on intentions of compliance. By the above logical reasoning, the integrative behavioral model and eight hypotheses could be derived. Data were collected by conducting a survey; 194 out of 207 questionnaires were available. The test of the causal model was conducted by PLS. The reliability, validity, and model fit were found to be statistically significant. The results of the hypotheses tests showed that seven of the eight hypotheses were acceptable. The theoretical implications of this study are as follows: (1) the study is expected to play a role of the baseline for future research about organization members' compliance with the information security policy, (2) the study attempted an interdisciplinary approach by combining psychology and information system security research, and (3) the study suggested concrete operational definitions of influencing factors for information security policy compliance through a comprehensive theoretical review. Also, the study has some practical implications. First, it can provide the guideline to support the successful execution of the strategic establishment for the implement of information system security policies in organizations. Second, it proves that the need of education and training programs suppressing

  6. Long term modelling in a second rank world: application to climate policies

    International Nuclear Information System (INIS)

    Crassous, R.

    2008-11-01

    This research aims at the identification of the dissatisfaction reasons with respect to the existing climate models, at the design of an innovating modelling architecture which would respond to these dissatisfactions, and at proposing climate policy assessment pathways. The authors gives a critique assessment of the modelling activity within the field of climate policies, outlines the fact that the large number and the scattering of existing long term scenarios hides a weak control of uncertainties and of the inner consistency of the produced paths, as well as the very low number of modelling paradigms. After a deepened analysis of modelling practices, the author presents the IMACLIM-R modelling architecture which is presented on a world scale and includes 12 areas and 12 sectors, and allows the simulation of evolutions by 2050, and even 2100, with a one-year time step. The author describes a scenario without any climate policy, highlights reassessment possibilities for economical trajectories which would allow greenhouse gas concentration stabilisation on a long term basis through the application of IMACLIM-R innovations. He outlines adjustment and refinement possibilities for climate policies which would robustly limit the transition cost risks

  7. Mesoscopic modelling and simulation of soft matter.

    Science.gov (United States)

    Schiller, Ulf D; Krüger, Timm; Henrich, Oliver

    2017-12-20

    The deformability of soft condensed matter often requires modelling of hydrodynamical aspects to gain quantitative understanding. This, however, requires specialised methods that can resolve the multiscale nature of soft matter systems. We review a number of the most popular simulation methods that have emerged, such as Langevin dynamics, dissipative particle dynamics, multi-particle collision dynamics, sometimes also referred to as stochastic rotation dynamics, and the lattice-Boltzmann method. We conclude this review with a short glance at current compute architectures for high-performance computing and community codes for soft matter simulation.

  8. Numerical model simulation of atmospheric coolant plumes

    International Nuclear Information System (INIS)

    Gaillard, P.

    1980-01-01

    The effect of humid atmospheric coolants on the atmosphere is simulated by means of a three-dimensional numerical model. The atmosphere is defined by its natural vertical profiles of horizontal velocity, temperature, pressure and relative humidity. Effluent discharge is characterised by its vertical velocity and the temperature of air satured with water vapour. The subject of investigation is the area in the vicinity of the point of discharge, with due allowance for the wake effect of the tower and buildings and, where application, wind veer with altitude. The model equations express the conservation relationships for mometum, energy, total mass and water mass, for an incompressible fluid behaving in accordance with the Boussinesq assumptions. Condensation is represented by a simple thermodynamic model, and turbulent fluxes are simulated by introduction of turbulent viscosity and diffusivity data based on in-situ and experimental water model measurements. The three-dimensional problem expressed in terms of the primitive variables (u, v, w, p) is governed by an elliptic equation system which is solved numerically by application of an explicit time-marching algorithm in order to predict the steady-flow velocity distribution, temperature, water vapour concentration and the liquid-water concentration defining the visible plume. Windstill conditions are simulated by a program processing the elliptic equations in an axisymmetrical revolution coordinate system. The calculated visible plumes are compared with plumes observed on site with a view to validate the models [fr

  9. Climate: Policy, Modeling, and Federal Priorities (Invited)

    Science.gov (United States)

    Koonin, S.; Department Of Energy Office Of The Under SecretaryScience

    2010-12-01

    The Administration has set ambitious national goals to reduce our dependence on fossil fuels and reduce anthropogenic greenhouse gas (GHG) emissions. The US and other countries involved in the U.N. Framework Convention on Climate Change continue to work toward a goal of establishing a viable treaty that would encompass limits on emissions and codify actions that nations would take to reduce emissions. These negotiations are informed by the science of climate change and by our understanding of how changes in technology and the economy might affect the overall climate in the future. I will describe the present efforts within the U.S. Department of Energy, and the federal government more generally, to address issues related to climate change. These include state-of-the-art climate modeling and uncertainty assessment, economic and climate scenario planning based on best estimates of different technology trajectories, adaption strategies for climate change, and monitoring and reporting for treaty verification.

  10. Modeling, simulation and optimization of bipedal walking

    CERN Document Server

    Berns, Karsten

    2013-01-01

    The model-based investigation of motions of anthropomorphic systems is an important interdisciplinary research topic involving specialists from many fields such as Robotics, Biomechanics, Physiology, Orthopedics, Psychology, Neurosciences, Sports, Computer Graphics and Applied Mathematics. This book presents a study of basic locomotion forms such as walking and running is of particular interest due to the high demand on dynamic coordination, actuator efficiency and balance control. Mathematical models and numerical simulation and optimization techniques are explained, in combination with experimental data, which can help to better understand the basic underlying mechanisms of these motions and to improve them. Example topics treated in this book are Modeling techniques for anthropomorphic bipedal walking systems Optimized walking motions for different objective functions Identification of objective functions from measurements Simulation and optimization approaches for humanoid robots Biologically inspired con...

  11. Multiphase reacting flows modelling and simulation

    CERN Document Server

    Marchisio, Daniele L

    2007-01-01

    The papers in this book describe the most widely applicable modeling approaches and are organized in six groups covering from fundamentals to relevant applications. In the first part, some fundamentals of multiphase turbulent reacting flows are covered. In particular the introduction focuses on basic notions of turbulence theory in single-phase and multi-phase systems as well as on the interaction between turbulence and chemistry. In the second part, models for the physical and chemical processes involved are discussed. Among other things, particular emphasis is given to turbulence modeling strategies for multiphase flows based on the kinetic theory for granular flows. Next, the different numerical methods based on Lagrangian and/or Eulerian schemes are presented. In particular the most popular numerical approaches of computational fluid dynamics codes are described (i.e., Direct Numerical Simulation, Large Eddy Simulation, and Reynolds-Averaged Navier-Stokes approach). The book will cover particle-based meth...

  12. Advancing Material Models for Automotive Forming Simulations

    International Nuclear Information System (INIS)

    Vegter, H.; An, Y.; Horn, C.H.L.J. ten; Atzema, E.H.; Roelofsen, M.E.

    2005-01-01

    Simulations in automotive industry need more advanced material models to achieve highly reliable forming and springback predictions. Conventional material models implemented in the FEM-simulation models are not capable to describe the plastic material behaviour during monotonic strain paths with sufficient accuracy. Recently, ESI and Corus co-operate on the implementation of an advanced material model in the FEM-code PAMSTAMP 2G. This applies to the strain hardening model, the influence of strain rate, and the description of the yield locus in these models. A subsequent challenge is the description of the material after a change of strain path.The use of advanced high strength steels in the automotive industry requires a description of plastic material behaviour of multiphase steels. The simplest variant is dual phase steel consisting of a ferritic and a martensitic phase. Multiphase materials also contain a bainitic phase in addition to the ferritic and martensitic phase. More physical descriptions of strain hardening than simple fitted Ludwik/Nadai curves are necessary.Methods to predict plastic behaviour of single-phase materials use a simple dislocation interaction model based on the formed cells structures only. At Corus, a new method is proposed to predict plastic behaviour of multiphase materials have to take hard phases into account, which deform less easily. The resulting deformation gradients create geometrically necessary dislocations. Additional micro-structural information such as morphology and size of hard phase particles or grains is necessary to derive the strain hardening models for this type of materials.Measurements available from the Numisheet benchmarks allow these models to be validated. At Corus, additional measured values are available from cross-die tests. This laboratory test can attain critical deformations by large variations in blank size and processing conditions. The tests are a powerful tool in optimising forming simulations prior

  13. Production functions for climate policy modeling. An empirical analysis

    International Nuclear Information System (INIS)

    Van der Werf, Edwin

    2008-01-01

    Quantitative models for climate policy modeling differ in the production structure used and in the sizes of the elasticities of substitution. The empirical foundation for both is generally lacking. This paper estimates the parameters of 2-level CES production functions with capital, labour and energy as inputs, and is the first to systematically compare all nesting structures. Using industry-level data from 12 OECD countries, we find that the nesting structure where capital and labour are combined first, fits the data best, but for most countries and industries we cannot reject that all three inputs can be put into one single nest. These two nesting structures are used by most climate models. However, while several climate policy models use a Cobb-Douglas function for (part of the) production function, we reject elasticities equal to one, in favour of considerably smaller values. Finally we find evidence for factor-specific technological change. With lower elasticities and with factor-specific technological change, some climate policy models may find a bigger effect of endogenous technological change on mitigating the costs of climate policy. (author)

  14. Modelling and simulation of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Eborn, J.

    1998-02-01

    Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Integrated production and recycling of materials are trends that give rise to heterogenous systems, which are difficult to handle within one area of expertise. Model libraries are an excellent way to package engineering knowledge of systems and units to be reused by those who are not experts in modelling. Many commercial packages provide good model libraries, but they are usually domain-specific and closed. Heterogenous, multi-domain systems requires open model libraries written in general purpose modelling languages. This thesis describes a model database for thermal power plants written in the object-oriented modelling language OMOLA. The models are based on first principles. Subunits describe volumes with pressure and enthalpy dynamics and flows of heat or different media. The subunits are used to build basic units such as pumps, valves and heat exchangers which can be used to build system models. Several applications are described; a heat recovery steam generator, equipment for juice blending, steam generation in a sulphuric acid plant and a condensing steam plate heat exchanger. Model libraries for industrial use must be validated against measured data. The thesis describes how parameter estimation methods can be used for model validation. Results from a case-study on parameter optimization of a non-linear drum boiler model show how the technique can be used 32 refs, 21 figs

  15. Strategies simulation model for the gas business chain MEGAS

    International Nuclear Information System (INIS)

    Gonzalez, S.M. de; Uzcategui, R.; Brea, E.; Diaz, R.

    1994-01-01

    MEGAS is a simulation model representing fundamental parameters of Corpoven's natural gas and NGL production, handling, processing, transportation and distribution systems in the Venezuelan mid-east, as well as its financial implications. Various strategies regarding development, prices, costs, new business opportunities, production scenarios, demand and energy policies can be evaluated through this model in order to determine, after analyzing the economics results, a set of strategies to follow in the mid and long term. MEGAS could be also used to make risk analysis studies, considering that probabilistic parameters and variables like gas quality, production, demand, plant shutdowns and others are to be represented by their distinctive function. It is possible to set up a probabilistic function for each economic indicator or operating variables with an appropriate experiment design. MEGAS is based on a dynamic simulation language, which facilitates both the real system components representation and the main variables statistical data accumulation. It also allows graphical representation of results and the simulation animation. Demand and price forecasts, new projects, costs and capabilities of the systems are some of the model input data. MEGAS should be considered as a tool that eases the strategic planning of the business, making it possible for the Corporation to foresee changes, both in the domestic and international market, to predict how these changes could affect its business affairs and to visualize different return scenarios

  16. Validity of microgravity simulation models on earth

    DEFF Research Database (Denmark)

    Regnard, J; Heer, M; Drummer, C

    2001-01-01

    Many studies have used water immersion and head-down bed rest as experimental models to simulate responses to microgravity. However, some data collected during space missions are at variance or in contrast with observations collected from experimental models. These discrepancies could reflect...... incomplete knowledge of the characteristics inherent to each model. During water immersion, the hydrostatic pressure lowers the peripheral vascular capacity and causes increased thoracic blood volume and high vascular perfusion. In turn, these changes lead to high urinary flow, low vasomotor tone, and a high...

  17. Modeling policy issues in a world of imperfect competition

    DEFF Research Database (Denmark)

    Dierker, Egbert; Grodal, Birgit

    1998-01-01

    General equilibrium theory constitutes a sound basis for the discussion of policy issues if firms do not have market power. However, if firms influence prices strategically, the concept of profits loses its meaning due to the price normalization problem. Hence, it is unclear how to model the beha......General equilibrium theory constitutes a sound basis for the discussion of policy issues if firms do not have market power. However, if firms influence prices strategically, the concept of profits loses its meaning due to the price normalization problem. Hence, it is unclear how to model...... the behavior of oligopolistic firms. In order to provide a conceptual foundation for the analysis of policy issues in the case of imperfect competition, we discuss ways to formulate the objective of a strategic firm. In particular, we investigate the concept of real wealth maximization that is based on profits...

  18. Mathematical models and numerical simulation in electromagnetism

    CERN Document Server

    Bermúdez, Alfredo; Salgado, Pilar

    2014-01-01

    The book represents a basic support for a master course in electromagnetism oriented to numerical simulation. The main goal of the book is that the reader knows the boundary-value problems of partial differential equations that should be solved in order to perform computer simulation of electromagnetic processes. Moreover it includes a part devoted to electric circuit theory  based on ordinary differential equations. The book is mainly oriented to electric engineering applications, going from the general to the specific, namely, from the full Maxwell’s equations to the particular cases of electrostatics, direct current, magnetostatics and eddy currents models. Apart from standard exercises related to analytical calculus, the book includes some others oriented to real-life applications solved with MaxFEM free simulation software.

  19. 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.

  20. Simulation as a surgical teaching model.

    Science.gov (United States)

    Ruiz-Gómez, José Luis; Martín-Parra, José Ignacio; González-Noriega, Mónica; Redondo-Figuero, Carlos Godofredo; Manuel-Palazuelos, José Carlos

    2018-01-01

    Teaching of surgery has been affected by many factors over the last years, such as the reduction of working hours, the optimization of the use of the operating room or patient safety. Traditional teaching methodology fails to reduce the impact of these factors on surgeońs training. Simulation as a teaching model minimizes such impact, and is more effective than traditional teaching methods for integrating knowledge and clinical-surgical skills. Simulation complements clinical assistance with training, creating a safe learning environment where patient safety is not affected, and ethical or legal conflicts are avoided. Simulation uses learning methodologies that allow teaching individualization, adapting it to the learning needs of each student. It also allows training of all kinds of technical, cognitive or behavioural skills. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Modeling and simulation of photovoltaic solar panel

    International Nuclear Information System (INIS)

    Belarbi, M.; Haddouche, K.; Midoun, A.

    2006-01-01

    In this article, we present a new approach for estimating the model parameters of a photovoltaic solar panel according to the irradiance and temperature. The parameters of the one diode model are given from the knowledge of three operating points: short-circuit, open circuit, and maximum power. In the first step, the adopted approach concerns the resolution of the system of equations constituting the three operating points to write all the model parameters according to series resistance. Secondly, we make an iterative resolution at the optimal operating point by using the Newton-Raphson method to calculate the series resistance value as well as the model parameters. Once the panel model is identified, we consider other equations for taking into account the irradiance and temperature effect. The simulation results show the convergence speed of the model parameters and the possibility of visualizing the electrical behaviour of the panel according to the irradiance and temperature. Let us note that a sensitivity of the algorithm at the optimal operating point was observed owing to the fact that a small variation of the optimal voltage value leads to a very great variation of the identified parameters values. With the identified model, we can develop algorithms of maximum power point tracking, and make simulations of a solar water pumping system.(Author)

  2. Deep Drawing Simulations With Different Polycrystalline Models

    Science.gov (United States)

    Duchêne, Laurent; de Montleau, Pierre; Bouvier, Salima; Habraken, Anne Marie

    2004-06-01

    The goal of this research is to study the anisotropic material behavior during forming processes, represented by both complex yield loci and kinematic-isotropic hardening models. A first part of this paper describes the main concepts of the `Stress-strain interpolation' model that has been implemented in the non-linear finite element code Lagamine. This model consists of a local description of the yield locus based on the texture of the material through the full constraints Taylor's model. The texture evolution due to plastic deformations is computed throughout the FEM simulations. This `local yield locus' approach was initially linked to the classical isotropic Swift hardening law. Recently, a more complex hardening model was implemented: the physically-based microstructural model of Teodosiu. It takes into account intergranular heterogeneity due to the evolution of dislocation structures, that affects isotropic and kinematic hardening. The influence of the hardening model is compared to the influence of the texture evolution thanks to deep drawing simulations.

  3. Facebook's personal page modelling and simulation

    Science.gov (United States)

    Sarlis, Apostolos S.; Sakas, Damianos P.; Vlachos, D. S.

    2015-02-01

    In this paper we will try to define the utility of Facebook's Personal Page marketing method. This tool that Facebook provides, is modelled and simulated using iThink in the context of a Facebook marketing agency. The paper has leveraged the system's dynamic paradigm to conduct Facebook marketing tools and methods modelling, using iThink™ system to implement them. It uses the design science research methodology for the proof of concept of the models and modelling processes. The following model has been developed for a social media marketing agent/company, Facebook platform oriented and tested in real circumstances. This model is finalized through a number of revisions and iterators of the design, development, simulation, testing and evaluation processes. The validity and usefulness of this Facebook marketing model for the day-to-day decision making are authenticated by the management of the company organization. Facebook's Personal Page method can be adjusted, depending on the situation, in order to maximize the total profit of the company which is to bring new customers, keep the interest of the old customers and deliver traffic to its website.

  4. A simulation model for material accounting systems

    International Nuclear Information System (INIS)

    Coulter, C.A.; Thomas, K.E.

    1987-01-01

    A general-purpose model that was developed to simulate the operation of a chemical processing facility for nuclear materials has been extended to describe material measurement and accounting procedures as well. The model now provides descriptors for material balance areas, a large class of measurement instrument types and their associated measurement errors for various classes of materials, the measurement instruments themselves with their individual calibration schedules, and material balance closures. Delayed receipt of measurement results (as for off-line analytical chemistry assay), with interim use of a provisional measurement value, can be accurately represented. The simulation model can be used to estimate inventory difference variances for processing areas that do not operate at steady state, to evaluate the timeliness of measurement information, to determine process impacts of measurement requirements, and to evaluate the effectiveness of diversion-detection algorithms. Such information is usually difficult to obtain by other means. Use of the measurement simulation model is illustrated by applying it to estimate inventory difference variances for two material balance area structures of a fictitious nuclear material processing line

  5. Theory, modeling and simulation: Annual report 1993

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, T.H. Jr.; Garrett, B.C.

    1994-07-01

    Developing the knowledge base needed to address the environmental restoration issues of the US Department of Energy requires a fundamental understanding of molecules and their interactions in insolation and in liquids, on surfaces, and at interfaces. To meet these needs, the PNL has established the Environmental and Molecular Sciences Laboratory (EMSL) and will soon begin construction of a new, collaborative research facility devoted to advancing the understanding of environmental molecular science. Research in the Theory, Modeling, and Simulation program (TMS), which is one of seven research directorates in the EMSL, will play a critical role in understanding molecular processes important in restoring DOE`s research, development and production sites, including understanding the migration and reactions of contaminants in soils and groundwater, the development of separation process for isolation of pollutants, the development of improved materials for waste storage, understanding the enzymatic reactions involved in the biodegradation of contaminants, and understanding the interaction of hazardous chemicals with living organisms. The research objectives of the TMS program are to apply available techniques to study fundamental molecular processes involved in natural and contaminated systems; to extend current techniques to treat molecular systems of future importance and to develop techniques for addressing problems that are computationally intractable at present; to apply molecular modeling techniques to simulate molecular processes occurring in the multispecies, multiphase systems characteristic of natural and polluted environments; and to extend current molecular modeling techniques to treat complex molecular systems and to improve the reliability and accuracy of such simulations. The program contains three research activities: Molecular Theory/Modeling, Solid State Theory, and Biomolecular Modeling/Simulation. Extended abstracts are presented for 89 studies.

  6. Theory, modeling and simulation: Annual report 1993

    International Nuclear Information System (INIS)

    Dunning, T.H. Jr.; Garrett, B.C.

    1994-07-01

    Developing the knowledge base needed to address the environmental restoration issues of the US Department of Energy requires a fundamental understanding of molecules and their interactions in insolation and in liquids, on surfaces, and at interfaces. To meet these needs, the PNL has established the Environmental and Molecular Sciences Laboratory (EMSL) and will soon begin construction of a new, collaborative research facility devoted to advancing the understanding of environmental molecular science. Research in the Theory, Modeling, and Simulation program (TMS), which is one of seven research directorates in the EMSL, will play a critical role in understanding molecular processes important in restoring DOE's research, development and production sites, including understanding the migration and reactions of contaminants in soils and groundwater, the development of separation process for isolation of pollutants, the development of improved materials for waste storage, understanding the enzymatic reactions involved in the biodegradation of contaminants, and understanding the interaction of hazardous chemicals with living organisms. The research objectives of the TMS program are to apply available techniques to study fundamental molecular processes involved in natural and contaminated systems; to extend current techniques to treat molecular systems of future importance and to develop techniques for addressing problems that are computationally intractable at present; to apply molecular modeling techniques to simulate molecular processes occurring in the multispecies, multiphase systems characteristic of natural and polluted environments; and to extend current molecular modeling techniques to treat complex molecular systems and to improve the reliability and accuracy of such simulations. The program contains three research activities: Molecular Theory/Modeling, Solid State Theory, and Biomolecular Modeling/Simulation. Extended abstracts are presented for 89 studies

  7. NUMERICAL MODEL APPLICATION IN ROWING SIMULATOR DESIGN

    Directory of Open Access Journals (Sweden)

    Petr Chmátal

    2016-04-01

    Full Text Available The aim of the research was to carry out a hydraulic design of rowing/sculling and paddling simulator. Nowadays there are two main approaches in the simulator design. The first one includes a static water with no artificial movement and counts on specially cut oars to provide the same resistance in the water. The second approach, on the other hand uses pumps or similar devices to force the water to circulate but both of the designs share many problems. Such problems are affecting already built facilities and can be summarized as unrealistic feeling, unwanted turbulent flow and bad velocity profile. Therefore, the goal was to design a new rowing simulator that would provide nature-like conditions for the racers and provide an unmatched experience. In order to accomplish this challenge, it was decided to use in-depth numerical modeling to solve the hydraulic problems. The general measures for the design were taken in accordance with space availability of the simulator ́s housing. The entire research was coordinated with other stages of the construction using BIM. The detailed geometry was designed using a numerical model in Ansys Fluent and parametric auto-optimization tools which led to minimum negative hydraulic phenomena and decreased investment and operational costs due to the decreased hydraulic losses in the system.

  8. An applied general equilibrium model for Dutch agribusiness policy analysis

    NARCIS (Netherlands)

    Peerlings, J.

    1993-01-01

    The purpose of this thesis was to develop a basic static applied general equilibrium (AGE) model to analyse the effects of agricultural policy changes on Dutch agribusiness. In particular the effects on inter-industry transactions, factor demand, income, and trade are of

  9. Model-Driven Policy Framework for Data Centers

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Kentis, Angelos Mimidis; Soler, José

    2016-01-01

    . Moreover, the lack of simple solutions for managing the configuration and behavior of the DC components makes the DC hard to configure and slow in adapting to changes in business needs. In this paper, we propose a model-driven framework for policy-based management for DCs, to simplify not only the service...

  10. Mapping and modelling ecosystem services for science, policy and practice

    NARCIS (Netherlands)

    Burkhard, B.; Crossman, N.; Nedkov, S.; Petz, K.; Alkemade, R.

    2013-01-01

    Ecosystem services are a significant research and policy topic and there are many modelling and mapping approaches aimed at understanding the stocks, demands and flows of ecosystem services on different spatial and temporal scales. The integration of geo-biophysical processes and structure

  11. eShopper modeling and simulation

    Science.gov (United States)

    Petrushin, Valery A.

    2001-03-01

    The advent of e-commerce gives an opportunity to shift the paradigm of customer communication into a highly interactive mode. The new generation of commercial Web servers, such as the Blue Martini's server, combines the collection of data on a customer behavior with real-time processing and dynamic tailoring of a feedback page. The new opportunities for direct product marketing and cross selling are arriving. The key problem is what kind of information do we need to achieve these goals, or in other words, how do we model the customer? The paper is devoted to customer modeling and simulation. The focus is on modeling an individual customer. The model is based on the customer's transaction data, click stream data, and demographics. The model includes the hierarchical profile of a customer's preferences to different types of products and brands; consumption models for the different types of products; the current focus, trends, and stochastic models for time intervals between purchases; product affinity models; and some generalized features, such as purchasing power, sensitivity to advertising, price sensitivity, etc. This type of model is used for predicting the date of the next visit, overall spending, and spending for different types of products and brands. For some type of stores (for example, a supermarket) and stable customers, it is possible to forecast the shopping lists rather accurately. The forecasting techniques are discussed. The forecasting results can be used for on- line direct marketing, customer retention, and inventory management. The customer model can also be used as a generative model for simulating the customer's purchasing behavior in different situations and for estimating customer's features.

  12. Quantification model of the consequences of monetary policy shocks

    Directory of Open Access Journals (Sweden)

    Coralia Emilia POPA

    2017-11-01

    Full Text Available The monetary analysis based on the BVAR (Bayesian Vector Autoregression model is extremely important in the monetary policy implementation strategy, the information provided is important not only for the Central Bank, but also for the economic agents and the population. Therefore, conducting this analysis at the level of Romania helps to understand better the mechanism by which monetary policy is transmitted in order to achieve the set target, namely inflation targeting, but it also provides us with important information regarding the accession to the euro area. The model we are trying to test helps us understand through the correlations between the interest rate, GDP and the inflation rate how monetary policy responds to shocks. The model follows the methodology presented by Sims and Zha (1998 in the paper "Bayesian Methods for Dynamic Multivariate Models and Using the Bayesian Autoregressive Vector". In the analysis of this model, quarterly data for a minimum of three years, three variables are used to make the results relevant. The data needed to model the model are used in logarithmic form, except for the interest rate, and the outcome is applied to a differentiated premium operator. Of the variables used, the interest rate is the only one that does not allow seasonal adjustment.

  13. Modelling climate change under no-policy and policy emissions pathways

    International Nuclear Information System (INIS)

    Wigley, T.M.L.

    2003-01-01

    Future emissions under the SRES scenarios are described as examples of no-climate-policy scenarios. The production of policy scenarios is guided by Article 2 of the UN Framework Convention on Climate Change, which requires stabilization of greenhouse-gas concentrations. It is suggested that the choice of stabilization targets should be governed by the need to avoid dangerous interference with the climate system, while the choice of the pathway towards a given target should be determined by some form of cost-benefit analysis. The WRE (Wigley, Richels and Edmonds) concentration profiles are given as examples of stabilization pathways, and an alternative 'overshoot' pathway is introduced. Probabilistic projections (as probability density functions - pdfs) for global-mean temperature under the SRES scenarios are given. The relative importance of different sources of uncertainty is determined by removing individual sources of uncertainty and examining the change in the output temperature pdf. Emissions and climate sensitivity uncertainties dominate, while carbon cycle, aerosol forcing and ocean mixing uncertainties are shown to be small. It is shown that large uncertainties remain even if the emissions are prescribed. Uncertainties in regional climate change are defined by comparing normalized changes (i.e., changes per 1C global-mean warming) across multiple models and using the inter-model standard deviation as an uncertainty metric. Global-mean temperature projections for the policy case are given using the WRE profiles. Different stabilization targets are considered, and the overshoot case for 550ppm stabilization is used to quantify the effects of pathway differences. It is shown that large emissions reductions (from the no-policy to the policy case) will lead to only relatively small reductions in warming over the next 100 years

  14. Sustaining critical care: using evidence-based simulation to evaluate ICU management policies.

    Science.gov (United States)

    Mahmoudian-Dehkordi, Amin; Sadat, Somayeh

    2017-12-01

    Intensive Care Units (ICU) are costly yet critical hospital departments that should be available to care for patients needing highly specialized critical care. Shortage of ICU beds in many regions of the world and the constant fire-fighting to make these beds available through various ICU management policies motivated this study. The paper discusses the application of a generic system dynamics model of emergency patient flow in a typical hospital, populated with empirical evidence found in the medical and hospital administration literature, to explore the dynamics of intended and unintended consequences of such ICU management policies under a natural disaster crisis scenario. ICU management policies that can be implemented by a single hospital on short notice, namely premature transfer from ICU, boarding in ward, and general ward admission control, along with their possible combinations, are modeled and their impact on managerial and health outcome measures are investigated. The main insight out of the study is that the general ward admission control policy outperforms the rest of ICU management policies under such crisis scenarios with regards to reducing total mortality, which is counter intuitive for hospital administrators as this policy is not very effective at alleviating the symptoms of the problem, namely high ED and ICU occupancy rates that are closely monitored by hospital management particularly in times of crisis. A multivariate sensitivity analysis on parameters with diverse range of values in the literature found the superiority of the general ward admission control to hold true in every scenario.

  15. A collision model in plasma particle simulations

    International Nuclear Information System (INIS)

    Ma Yanyun; Chang Wenwei; Yin Yan; Yue Zongwu; Cao Lihua; Liu Daqing

    2000-01-01

    In order to offset the collisional effects reduced by using finite-size particles, β particle clouds are used in particle simulation codes (β is the ratio of charge or mass of modeling particles to real ones). The method of impulse approximation (strait line orbit approximation) is used to analyze the scattering cross section of β particle clouds plasmas. The authors can obtain the relation of the value of a and β and scattering cross section (a is the radius of β particle cloud). By using this relation the authors can determine the value of a and β so that the collisional effects of the modeling system is correspondent with the real one. The authors can also adjust the values of a and β so that the authors can enhance or reduce the collisional effects fictitiously. The results of simulation are in good agreement with the theoretical ones

  16. Macro Level Simulation Model Of Space Shuttle Processing

    Science.gov (United States)

    2000-01-01

    The contents include: 1) Space Shuttle Processing Simulation Model; 2) Knowledge Acquisition; 3) Simulation Input Analysis; 4) Model Applications in Current Shuttle Environment; and 5) Model Applications for Future Reusable Launch Vehicles (RLV's). This paper is presented in viewgraph form.

  17. High-Fidelity Roadway Modeling and Simulation

    Science.gov (United States)

    Wang, Jie; Papelis, Yiannis; Shen, Yuzhong; Unal, Ozhan; Cetin, Mecit

    2010-01-01

    Roads are an essential feature in our daily lives. With the advances in computing technologies, 2D and 3D road models are employed in many applications, such as computer games and virtual environments. Traditional road models were generated by professional artists manually using modeling software tools such as Maya and 3ds Max. This approach requires both highly specialized and sophisticated skills and massive manual labor. Automatic road generation based on procedural modeling can create road models using specially designed computer algorithms or procedures, reducing the tedious manual editing needed for road modeling dramatically. But most existing procedural modeling methods for road generation put emphasis on the visual effects of the generated roads, not the geometrical and architectural fidelity. This limitation seriously restricts the applicability of the generated road models. To address this problem, this paper proposes a high-fidelity roadway generation method that takes into account road design principles practiced by civil engineering professionals, and as a result, the generated roads can support not only general applications such as games and simulations in which roads are used as 3D assets, but also demanding civil engineering applications, which requires accurate geometrical models of roads. The inputs to the proposed method include road specifications, civil engineering road design rules, terrain information, and surrounding environment. Then the proposed method generates in real time 3D roads that have both high visual and geometrical fidelities. This paper discusses in details the procedures that convert 2D roads specified in shape files into 3D roads and civil engineering road design principles. The proposed method can be used in many applications that have stringent requirements on high precision 3D models, such as driving simulations and road design prototyping. Preliminary results demonstrate the effectiveness of the proposed method.

  18. Difficulties with True Interoperability in Modeling & Simulation

    Science.gov (United States)

    2011-12-01

    Standards in M&S cover multiple layers of technical abstraction. There are middleware specifica- tions, such as the High Level Architecture (HLA) ( IEEE Xplore ... IEEE Xplore Digital Library. 2010. 1516-2010 IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA) – Framework and Rules...using different communication protocols being able to allow da- 2642978-1-4577-2109-0/11/$26.00 ©2011 IEEE Report Documentation Page Form ApprovedOMB No

  19. Agent Based Modelling for Social Simulation

    OpenAIRE

    Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

    2013-01-01

    This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course of this project two workshops were organized. At these workshops, a wide range of experts, both ABM experts and domain experts, worked on several potential applications of ABM. The results and ins...

  20. Mathematical models for photovoltaic solar panel simulation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Airton A. dos; Gnoatto, Estor; Fischborn, Marcos; Kavanagh, Edward [Universidade Tecnologica Federal do Parana (UTFPR), Medianeira, PR (Brazil)], Emails: airton@utfpr.edu.br, gnoatto@utfpr.edu.br, fisch@utfpr.edu.br, kavanagh@utfpr.edu.br

    2008-07-01

    A photovoltaic generator is subject to several variations of solar intensity, ambient temperature or load, that change your point of operation. This way, your behavior should be analyzed by such alterations, to optimize your operation. The present work sought to simulate a photovoltaic generator, of polycrystalline silicon, by characteristics supplied by the manufacturer, and to compare the results of two mathematical models with obtained values of field, in the city of Cascavel, for a period of one year. (author)

  1. Condition-based maintenance effectiveness for series–parallel power generation system—A combined Markovian simulation model

    International Nuclear Information System (INIS)

    Azadeh, A.; Asadzadeh, S.M.; Salehi, N.; Firoozi, M.

    2015-01-01

    Condition-based maintenance (CBM) is an increasingly applicable policy in the competitive marketplace as a means of improving equipment reliability and efficiency. Not only has maintenance a close relationship with safety but its costs also make it even more attractive issue for researchers. This study proposes a model to evaluate the effectiveness of CBM policy compared to two other maintenance policies: Corrective Maintenance (CM) and Preventive Maintenance (PM). Maintenance policies are compared through two system performance indicators: reliability and cost. To estimate the reliability and costs of the system, the proposed Markovian discrete-event simulation model is developed under each of these policies. The applicability and usefulness of the proposed Markovian simulation model is illustrated for a series–parallel power generation system. The simulated characteristics of CBM system include its prognostics efficiency to estimate remaining useful life of the equipment. Results show that with an efficient prognostics, CBM policy is an effective strategy compared to other maintenance strategies. - Highlights: • A model is developed to evaluate the effectiveness of CBM policy. • Maintenance policies are compared through reliability and cost. • A Markovian simulation model is developed. • A series–parallel power generation system is considered. • CBM is an effective strategy compared to others

  2. Modeling energy market dynamics using discrete event system simulation

    International Nuclear Information System (INIS)

    Gutierrez-Alcaraz, G.; Sheble, G.B.

    2009-01-01

    This paper proposes the use of Discrete Event System Simulation to study the interactions among fuel and electricity markets and consumers, and the decision-making processes of fuel companies (FUELCOs), generation companies (GENCOs), and consumers in a simple artificial energy market. In reality, since markets can reach a stable equilibrium or fail, it is important to observe how they behave in a dynamic framework. We consider a Nash-Cournot model in which marketers are depicted as Nash-Cournot players that determine supply to meet end-use consumption. Detailed engineering considerations such as transportation network flows are omitted, because the focus is upon the selection and use of appropriate market models to provide answers to policy questions. (author)

  3. Carbon tax simulations using a household demand model

    International Nuclear Information System (INIS)

    Braennlund, Runar; Nordstroem, Jonas

    1999-01-01

    The main objective of this paper is to analyse consumer response due to changes in energy or environmental policy. To achieve the objective we formulate and estimate an econometric model for non-durable consumer demand in Sweden that utilises micro- as well as macro-data. The microeconomic model is conditional on male and female labour supply. A 100 percent increase of the Swedish CO 2 tax will, according to the simulations, result in an increased tax payment of SEK 630 or 0.7 percent of disposable income for the households with the lowest disposable incomes. The corresponding numbers for the richest households are SEK 990 and 0.3 percent 38 refs, 10 tabs

  4. Carbon tax simulations using a household demand model

    Energy Technology Data Exchange (ETDEWEB)

    Braennlund, Runar; Nordstroem, Jonas [Umeaa Univ. (Sweden). Dept. of Economics

    1999-11-01

    The main objective of this paper is to analyse consumer response due to changes in energy or environmental policy. To achieve the objective we formulate and estimate an econometric model for non-durable consumer demand in Sweden that utilises micro- as well as macro-data. The microeconomic model is conditional on male and female labour supply. A 100 percent increase of the Swedish CO{sub 2} tax will, according to the simulations, result in an increased tax payment of SEK 630 or 0.7 percent of disposable income for the households with the lowest disposable incomes. The corresponding numbers for the richest households are SEK 990 and 0.3 percent 38 refs, 10 tabs

  5. Carbon tax simulations using a household demand model

    Energy Technology Data Exchange (ETDEWEB)

    Braennlund, Runar; Nordstroem, Jonas [Umeaa Univ. (Sweden). Dept. of Economics

    1999-07-01

    The main objective of this paper is to analyse consumer response due to changes in energy or environmental policy. To achieve the objective we formulate and estimate an econometric model for non-durable consumer demand in Sweden that utilises micro- as well as macro-data. The microeconomic model is conditional on male and female labour supply. A 100 percent increase of the Swedish CO{sub 2} tax will, according to the simulations, result in an increased tax payment of SEK 630 or 0.7 percent of disposable income for the households with the lowest disposable incomes. The corresponding numbers for the richest households are SEK 990 and 0.3 percent 38 refs, 10 tabs.

  6. An integrated model to simulate sown area changes for major crops at a global scale

    Institute of Scientific and Technical Information of China (English)

    SHIBASAKI; Ryosuke

    2008-01-01

    Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is pre- sented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users’ decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions, while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS) global land cover product in 2001. Both validation approaches indicated reliability of the model for ad- dressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally, the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline. The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

  7. A Computable OLG Model for Gender and Growth Policy Analysis

    OpenAIRE

    Pierre-Richard Agénor

    2012-01-01

    This paper develops a computable Overlapping Generations (OLG) model for gender and growth policy analysis. The model accounts for human and physical capital accumulation (both public and private), intra- and inter-generational health persistence, fertility choices, and women's time allocation between market work, child rearing, and home production. Bargaining between spouses and gender bias, in the form of discrimination in the work place and mothers' time allocation between daughters and so...

  8. MODELING MONETARY POLICY RULES IN THE MENACOUNTRIES: ISSUES AND EVIDENCE

    OpenAIRE

    Mohamad Husam Helmi

    2011-01-01

    This paper estimates the monetary policy reaction function for two sets of MENAcountries: The inflation target countries, (Turkeyand Israel) and the exchange ratetarget countries, (Jordan and Morocco). We motivateour empirical analysis byanalyzing a simple Taylor rule. This model looks atthe effects of inflation andoutput on setting the interest rate by the centralbank. Furthermore, we extendedour model by adding the exchange rate and the foreign interest rate ...

  9. Advancing LGBT Elder Policy and Support Services: The Massachusetts Model.

    Science.gov (United States)

    Krinsky, Lisa; Cahill, Sean R

    2017-12-01

    The Massachusetts-based LGBT Aging Project has trained elder service providers in affirming and culturally competent care for LGBT older adults, supported development of LGBT-friendly meal programs, and advanced LGBT equality under aging policy. Working across sectors, this innovative model launched the country's first statewide Legislative Commission on Lesbian, Gay, Bisexual, and Transgender Aging. Advocates are working with policymakers to implement key recommendations, including cultural competency training and data collection in statewide networks of elder services. The LGBT Aging Project's success provides a template for improving services and policy for LGBT older adults throughout the country.

  10. Replenishment policy for an inventory model under inflation

    Science.gov (United States)

    Singh, Vikramjeet; Saxena, Seema; Singh, Pushpinder; Mishra, Nitin Kumar

    2017-07-01

    The purpose of replenishment is to keep the flow of inventory in the system. To determine an optimal replenishment policy is a great challenge in developing an inventory model. Inflation is defined as the rate at which the prices of goods and services are rising over a time period. The cost parameters are affected by the rate of inflation. High rate of inflation affects the organizations financial conditions. Based on the above backdrop the present paper proposes the retailers replenishment policy for deteriorating items with different cycle lengths under inflation. The shortages are partially backlogged. At last numerical examples validate the results.

  11. Sources of change in foreign policy. A review of foreign policy models for developing countries

    Directory of Open Access Journals (Sweden)

    Alba E. Gámez

    2005-05-01

    Full Text Available The study of what could be called the reorientation of State foreign policy is not a new phenomenon. Changes in alliances, economic partners and attitudes in the face of international issues have been reflected in myriad texts. Nevertheless, few theoretical frameworksdeal with this issue as an area of study in and of itself. Overcoming this situation would contribute to identifying and comparing the changes in attitude and discourse in the relations between countries, especially in the case of developing countries, and, by extension, thesources of these changes. This article reviews the different models for the analysis of foreign policy, using the conceptual framework of Hermann (1990 as its starting point. This framework suggests the existence of four graded levels of change which allow for studying forms of change which are subtle but important in foreign policy; it also offers a reasoned analysis for testing the relative importance of their sources. This conceptual framework can be situated in the traditional division of levels of analysis: the characteristics of the leader, bureaucratic proposer, internal adjustment, and external impact; and, while it does not provide a conclusive answer, it may be a useful tool in clarifying the ways of using empirical evidence and establishing the relative importance of the sources of change in foreign policy orientation.

  12. Modelling interplanetary CMEs using magnetohydrodynamic simulations

    Directory of Open Access Journals (Sweden)

    P. J. Cargill

    Full Text Available The dynamics of Interplanetary Coronal Mass Ejections (ICMEs are discussed from the viewpoint of numerical modelling. Hydrodynamic models are shown to give a good zero-order picture of the plasma properties of ICMEs, but they cannot model the important magnetic field effects. Results from MHD simulations are shown for a number of cases of interest. It is demonstrated that the strong interaction of the ICME with the solar wind leads to the ICME and solar wind velocities being close to each other at 1 AU, despite their having very different speeds near the Sun. It is also pointed out that this interaction leads to a distortion of the ICME geometry, making cylindrical symmetry a dubious assumption for the CME field at 1 AU. In the presence of a significant solar wind magnetic field, the magnetic fields of the ICME and solar wind can reconnect with each other, leading to an ICME that has solar wind-like field lines. This effect is especially important when an ICME with the right sense of rotation propagates down the heliospheric current sheet. It is also noted that a lack of knowledge of the coronal magnetic field makes such simulations of little use in space weather forecasts that require knowledge of the ICME magnetic field strength.

    Key words. Interplanetary physics (interplanetary magnetic fields Solar physics, astrophysics, and astronomy (flares and mass ejections Space plasma physics (numerical simulation studies

  13. Interactive Modelling and Simulation of Human Motion

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol

    menneskers led, der udviser både ikke-konveksitet og flere frihedsgrader • En generel og alsidig model for aktivering af bløde legemer. Modellen kan anvendes som et animations værktøj, men er lige så velegnet til simulering af menneskelige muskler, da den opfylder de grundlæggende fysiske principper......Dansk resumé Denne ph.d.-afhandling beskæftiger sig med modellering og simulation af menneskelig bevægelse. Emnerne i denne afhandling har mindst to ting til fælles. For det første beskæftiger de sig med menneskelig bevægelse. Selv om de udviklede modeller også kan benyttes til andre ting,er det...... primære fokus på at modellere den menneskelige krop. For det andet, beskæftiger de sig alle med simulering som et redskab til at syntetisere bevægelse og dermed skabe animationer. Dette er en vigtigt pointe, da det betyder, at vi ikke kun skaber værktøjer til animatorer, som de kan bruge til at lave sjove...

  14. MODELING AND SIMULATION OF A HYDROCRACKING UNIT

    Directory of Open Access Journals (Sweden)

    HASSAN A. FARAG

    2016-06-01

    Full Text Available Hydrocracking is used in the petroleum industry to convert low quality feed stocks into high valued transportation fuels such as gasoline, diesel, and jet fuel. The aim of the present work is to develop a rigorous steady state two-dimensional mathematical model which includes conservation equations of mass and energy for simulating the operation of a hydrocracking unit. Both the catalyst bed and quench zone have been included in this integrated model. The model equations were numerically solved in both axial and radial directions using Matlab software. The presented model was tested against a real plant data in Egypt. The results indicated that a very good agreement between the model predictions and industrial values have been reported for temperature profiles, concentration profiles, and conversion in both radial and axial directions at the hydrocracking unit. Simulation of the quench zone conversion and temperature profiles in the quench zone was also included and gave a low deviation from the actual ones. In concentration profiles, the percentage deviation in the first reactor was found to be 9.28 % and 9.6% for the second reactor. The effect of several parameters such as: Pellet Heat Transfer Coefficient, Effective Radial Thermal Conductivity, Wall Heat Transfer Coefficient, Effective Radial Diffusivity, and Cooling medium (quench zone has been included in this study. The variation of Wall Heat Transfer Coefficient, Effective Radial Diffusivity for the near-wall region, gave no remarkable changes in the temperature profiles. On the other hand, even small variations of Effective Radial Thermal Conductivity, affected the simulated temperature profiles significantly, and this effect could not be compensated by the variations of the other parameters of the model.

  15. On Improving 4-km Mesoscale Model Simulations

    Science.gov (United States)

    Deng, Aijun; Stauffer, David R.

    2006-03-01

    A previous study showed that use of analysis-nudging four-dimensional data assimilation (FDDA) and improved physics in the fifth-generation Pennsylvania State University National Center for Atmospheric Research Mesoscale Model (MM5) produced the best overall performance on a 12-km-domain simulation, based on the 18 19 September 1983 Cross-Appalachian Tracer Experiment (CAPTEX) case. However, reducing the simulated grid length to 4 km had detrimental effects. The primary cause was likely the explicit representation of convection accompanying a cold-frontal system. Because no convective parameterization scheme (CPS) was used, the convective updrafts were forced on coarser-than-realistic scales, and the rainfall and the atmospheric response to the convection were too strong. The evaporative cooling and downdrafts were too vigorous, causing widespread disruption of the low-level winds and spurious advection of the simulated tracer. In this study, a series of experiments was designed to address this general problem involving 4-km model precipitation and gridpoint storms and associated model sensitivities to the use of FDDA, planetary boundary layer (PBL) turbulence physics, grid-explicit microphysics, a CPS, and enhanced horizontal diffusion. Some of the conclusions include the following: 1) Enhanced parameterized vertical mixing in the turbulent kinetic energy (TKE) turbulence scheme has shown marked improvements in the simulated fields. 2) Use of a CPS on the 4-km grid improved the precipitation and low-level wind results. 3) Use of the Hong and Pan Medium-Range Forecast PBL scheme showed larger model errors within the PBL and a clear tendency to predict much deeper PBL heights than the TKE scheme. 4) Combining observation-nudging FDDA with a CPS produced the best overall simulations. 5) Finer horizontal resolution does not always produce better simulations, especially in convectively unstable environments, and a new CPS suitable for 4-km resolution is needed. 6

  16. Reactive transport models and simulation with ALLIANCES

    International Nuclear Information System (INIS)

    Leterrier, N.; Deville, E.; Bary, B.; Trotignon, L.; Hedde, T.; Cochepin, B.; Stora, E.

    2009-01-01

    Many chemical processes influence the evolution of nuclear waste storage. As a result, simulations based only upon transport and hydraulic processes fail to describe adequately some industrial scenarios. We need to take into account complex chemical models (mass action laws, kinetics...) which are highly non-linear. In order to simulate the coupling of these chemical reactions with transport, we use a classical Sequential Iterative Approach (SIA), with a fixed point algorithm, within the mainframe of the ALLIANCES platform. This approach allows us to use the various transport and chemical modules available in ALLIANCES, via an operator-splitting method based upon the structure of the chemical system. We present five different applications of reactive transport simulations in the context of nuclear waste storage: 1. A 2D simulation of the lixiviation by rain water of an underground polluted zone high in uranium oxide; 2. The degradation of the steel envelope of a package in contact with clay. Corrosion of the steel creates corrosion products and the altered package becomes a porous medium. We follow the degradation front through kinetic reactions and the coupling with transport; 3. The degradation of a cement-based material by the injection of an aqueous solution of zinc and sulphate ions. In addition to the reactive transport coupling, we take into account in this case the hydraulic retroaction of the porosity variation on the Darcy velocity; 4. The decalcification of a concrete beam in an underground storage structure. In this case, in addition to the reactive transport simulation, we take into account the interaction between chemical degradation and the mechanical forces (cracks...), and the retroactive influence on the structure changes on transport; 5. The degradation of the steel envelope of a package in contact with a clay material under a temperature gradient. In this case the reactive transport simulation is entirely directed by the temperature changes and

  17. Cleanliness Policy Implementation: Evaluating Retribution Model to Rise Public Satisfaction

    Science.gov (United States)

    Dailiati, Surya; Hernimawati; Prihati; Chintia Utami, Bunga

    2018-05-01

    This research is based on the principal issues concerning the evaluation of cleanliness retribution policy which has not been optimally be able to improve the Local Revenue of Pekanbaru City and has not improved the cleanliness of Pekanbaru City. It was estimated to be caused by the performance of Garden and Sanitation Department are not in accordance with the requirement of society of Pekanbaru City. The research method used in this study is a mixed method with sequential exploratory strategy. The data collection used are observation, interview and documentation for qualitative research as well as questionnaires for quantitative research. The collected data were analyzed with interactive model of Miles and Huberman for qualitative research and multiple regression analysis for quantitative research. The research result indicated that the model of cleanliness policy implementation that can increase of PAD Pekanbaru City and be able to improve people’s satisfaction divided into two (2) which are the evaluation model and the society satisfaction model. The evaluation model influence by criteria/variable of effectiveness, efficiency, adequacy, equity, responsiveness, and appropriateness, while the society satisfaction model influence by variables of society satisfaction, intentions, goals, plans, programs, and appropriateness of cleanliness retribution collection policy.

  18. Improving Safe Sleep Modeling in the Hospital through Policy Implementation.

    Science.gov (United States)

    Heitmann, Rachel; Nilles, Ester K; Jeans, Ashley; Moreland, Jackie; Clarke, Chris; McDonald, Morgan F; Warren, Michael D

    2017-11-01

    Introduction Sleep-related infant deaths are major contributors to Tennessee's high infant mortality rate. The purpose of this initiative was to evaluate the impact of policy-based efforts to improve modeling of safe sleep practices by health care providers in hospital settings across Tennessee. Methods Safe sleep policies were developed and implemented at 71 hospitals in Tennessee. Policies, at minimum, were required to address staff training on the American Academy of Pediatrics' safe sleep recommendations, correct modeling of infant safe sleep practices, and parent education. Hospital data on process measures related to training and results of crib audits were compiled for analysis. Results The overall observance of infants who were found with any risk factors for unsafe sleep decreased 45.6% (p ≤ 0.001) from the first crib audit to the last crib audit. Significant decreases were noted for specific risk factors, including infants found asleep not on their back, with a toy or object in the crib, and not sleeping in a crib. Significant improvements were observed at hospitals where printed materials or video were utilized for training staff compared to face-to-face training. Discussion Statewide implementation of the hospital policy intervention resulted in significant reductions in infants found in unsafe sleep situations. The most common risk factors for sleep-related infant deaths can be modeled in hospitals. This effort has the potential to reduce sleep-related infant deaths and ultimately infant mortality.

  19. Dynamic and adaptive policy models for coalition operations

    Science.gov (United States)

    Verma, Dinesh; Calo, Seraphin; Chakraborty, Supriyo; Bertino, Elisa; Williams, Chris; Tucker, Jeremy; Rivera, Brian; de Mel, Geeth R.

    2017-05-01

    It is envisioned that the success of future military operations depends on the better integration, organizationally and operationally, among allies, coalition members, inter-agency partners, and so forth. However, this leads to a challenging and complex environment where the heterogeneity and dynamism in the operating environment intertwines with the evolving situational factors that affect the decision-making life cycle of the war fighter. Therefore, the users in such environments need secure, accessible, and resilient information infrastructures where policy-based mechanisms adopt the behaviours of the systems to meet end user goals. By specifying and enforcing a policy based model and framework for operations and security which accommodates heterogeneous coalitions, high levels of agility can be enabled to allow rapid assembly and restructuring of system and information resources. However, current prevalent policy models (e.g., rule based event-condition-action model and its variants) are not sufficient to deal with the highly dynamic and plausibly non-deterministic nature of these environments. Therefore, to address the above challenges, in this paper, we present a new approach for policies which enables managed systems to take more autonomic decisions regarding their operations.

  20. Computer Models Simulate Fine Particle Dispersion

    Science.gov (United States)

    2010-01-01

    Through a NASA Seed Fund partnership with DEM Solutions Inc., of Lebanon, New Hampshire, scientists at Kennedy Space Center refined existing software to study the electrostatic phenomena of granular and bulk materials as they apply to planetary surfaces. The software, EDEM, allows users to import particles and obtain accurate representations of their shapes for modeling purposes, such as simulating bulk solids behavior, and was enhanced to be able to more accurately model fine, abrasive, cohesive particles. These new EDEM capabilities can be applied in many industries unrelated to space exploration and have been adopted by several prominent U.S. companies, including John Deere, Pfizer, and Procter & Gamble.

  1. Consolidation modelling for thermoplastic composites forming simulation

    Science.gov (United States)

    Xiong, H.; Rusanov, A.; Hamila, N.; Boisse, P.

    2016-10-01

    Pre-impregnated thermoplastic composites are widely used in the aerospace industry for their excellent mechanical properties, Thermoforming thermoplastic prepregs is a fast manufacturing process, the automotive industry has shown increasing interest in this manufacturing processes, in which the reconsolidation is an essential stage. The model of intimate contact is investigated as the consolidation model, compression experiments have been launched to identify the material parameters, several numerical tests show the influents of the temperature and pressure applied during processing. Finally, a new solid-shell prismatic element has been presented for the simulation of consolidation step in the thermoplastic composites forming process.

  2. Quantification of uncertainties of modeling and simulation

    International Nuclear Information System (INIS)

    Ma Zhibo; Yin Jianwei

    2012-01-01

    The principles of Modeling and Simulation (M and S) is interpreted by a functional relation, from which the total uncertainties of M and S are identified and sorted to three parts considered to vary along with the conceptual models' parameters. According to the idea of verification and validation, the space of the parameters is parted to verified and applied domains, uncertainties in the verified domain are quantified by comparison between numerical and standard results, and those in the applied domain are quantified by a newly developed extrapolating method. Examples are presented to demonstrate and qualify the ideas aimed to build a framework to quantify the uncertainties of M and S. (authors)

  3. Simulation models generator. Applications in scheduling

    Directory of Open Access Journals (Sweden)

    Omar Danilo Castrillón

    2013-08-01

    Rev.Mate.Teor.Aplic. (ISSN 1409-2433 Vol. 20(2: 231–241, July 2013 generador de modelos de simulacion 233 will, in order to have an approach to reality to evaluate decisions in order to take more assertive. To test prototype was used as the modeling example of a production system with 9 machines and 5 works as a job shop configuration, testing stops processing times and stochastic machine to measure rates of use of machines and time average jobs in the system, as measures of system performance. This test shows the goodness of the prototype, to save the user the simulation model building

  4. Modeling and simulation of reactive flows

    CERN Document Server

    Bortoli, De AL; Pereira, Felipe

    2015-01-01

    Modelling and Simulation of Reactive Flows presents information on modeling and how to numerically solve reactive flows. The book offers a distinctive approach that combines diffusion flames and geochemical flow problems, providing users with a comprehensive resource that bridges the gap for scientists, engineers, and the industry. Specifically, the book looks at the basic concepts related to reaction rates, chemical kinetics, and the development of reduced kinetic mechanisms. It considers the most common methods used in practical situations, along with equations for reactive flows, and va

  5. Nonlinear friction model for servo press simulation

    Science.gov (United States)

    Ma, Ninshu; Sugitomo, Nobuhiko; Kyuno, Takunori; Tamura, Shintaro; Naka, Tetsuo

    2013-12-01

    The friction coefficient was measured under an idealized condition for a pulse servo motion. The measured friction coefficient and its changing with both sliding distance and a pulse motion showed that the friction resistance can be reduced due to the re-lubrication during unloading process of the pulse servo motion. Based on the measured friction coefficient and its changes with sliding distance and re-lubrication of oil, a nonlinear friction model was developed. Using the newly developed the nonlinear friction model, a deep draw simulation was performed and the formability was evaluated. The results were compared with experimental ones and the effectiveness was verified.

  6. VAR IPP-IPC Model Simulation

    Directory of Open Access Journals (Sweden)

    Juan P. Pérez Monsalve

    2014-12-01

    Full Text Available This work analyzed the relationship of the two main Price indicators in the Colombian economy, the IPP and the IPC. For this purpose, we identified the theory comprising both indexes to then develop a vector autoregressive model, which shows the reaction to shocks both in itself as in the other variable, whose impact continues propagating in the long term. Additionally, the work presents a simulation of the VAR model through the Monte Carlo method, verifying the coincidence in distributions of probability and volatility levels, as well as the existence correlation over time

  7. The electricity portfolio simulation model (EPSim) technical description.

    Energy Technology Data Exchange (ETDEWEB)

    Drennen, Thomas E.; Klotz, Richard (Hobart and William Smith Colleges, Geneva, NY)

    2005-09-01

    Stakeholders often have competing interests when selecting or planning new power plants. The purpose of developing this preliminary Electricity Portfolio Simulation Model (EPSim) is to provide a first cut, dynamic methodology and approach to this problem, that can subsequently be refined and validated, that may help energy planners, policy makers, and energy students better understand the tradeoffs associated with competing electricity portfolios. EPSim allows the user to explore competing electricity portfolios annually from 2002 to 2025 in terms of five different criteria: cost, environmental impacts, energy dependence, health and safety, and sustainability. Four additional criteria (infrastructure vulnerability, service limitations, policy needs and science and technology needs) may be added in future versions of the model. Using an analytic hierarchy process (AHP) approach, users or groups of users apply weights to each of the criteria. The default energy assumptions of the model mimic Department of Energy's (DOE) electricity portfolio to 2025 (EIA, 2005). At any time, the user can compare alternative portfolios to this reference case portfolio.

  8. TMS modeling toolbox for realistic simulation.

    Science.gov (United States)

    Cho, Young Sun; Suh, Hyun Sang; Lee, Won Hee; Kim, Tae-Seong

    2010-01-01

    Transcranial magnetic stimulation (TMS) is a technique for brain stimulation using rapidly changing magnetic fields generated by coils. It has been established as an effective stimulation technique to treat patients suffering from damaged brain functions. Although TMS is known to be painless and noninvasive, it can also be harmful to the brain by incorrect focusing and excessive stimulation which might result in seizure. Therefore there is ongoing research effort to elucidate and better understand the effect and mechanism of TMS. Lately Boundary element method (BEM) and Finite element method (FEM) have been used to simulate the electromagnetic phenomenon of TMS. However, there is a lack of general tools to generate the models of TMS due to some difficulties in realistic modeling of the human head and TMS coils. In this study, we have developed a toolbox through which one can generate high-resolution FE TMS models. The toolbox allows creating FE models of the head with isotropic and anisotropic electrical conductivities in five different tissues of the head and the coils in 3D. The generated TMS model is importable to FE software packages such as ANSYS for further and efficient electromagnetic analysis. We present a set of demonstrative results of realistic simulation of TMS with our toolbox.

  9. Biomedical Simulation Models of Human Auditory Processes

    Science.gov (United States)

    Bicak, Mehmet M. A.

    2012-01-01

    Detailed acoustic engineering models that explore noise propagation mechanisms associated with noise attenuation and transmission paths created when using hearing protectors such as earplugs and headsets in high noise environments. Biomedical finite element (FE) models are developed based on volume Computed Tomography scan data which provides explicit external ear, ear canal, middle ear ossicular bones and cochlea geometry. Results from these studies have enabled a greater understanding of hearing protector to flesh dynamics as well as prioritizing noise propagation mechanisms. Prioritization of noise mechanisms can form an essential framework for exploration of new design principles and methods in both earplug and earcup applications. These models are currently being used in development of a novel hearing protection evaluation system that can provide experimentally correlated psychoacoustic noise attenuation. Moreover, these FE models can be used to simulate the effects of blast related impulse noise on human auditory mechanisms and brain tissue.

  10. Modeling and simulation of gamma camera

    International Nuclear Information System (INIS)

    Singh, B.; Kataria, S.K.; Samuel, A.M.

    2002-08-01

    Simulation techniques play a vital role in designing of sophisticated instruments and also for the training of operating and maintenance staff. Gamma camera systems have been used for functional imaging in nuclear medicine. Functional images are derived from the external counting of the gamma emitting radioactive tracer that after introduction in to the body mimics the behavior of native biochemical compound. The position sensitive detector yield the coordinates of the gamma ray interaction with the detector and are used to estimate the point of gamma ray emission within the tracer distribution space. This advanced imaging device is thus dependent on the performance of algorithm for coordinate computing, estimation of point of emission, generation of image and display of the image data. Contemporary systems also have protocols for quality control and clinical evaluation of imaging studies. Simulation of this processing leads to understanding of the basic camera design problems. This report describes a PC based package for design and simulation of gamma camera along with the options of simulating data acquisition and quality control of imaging studies. Image display and data processing the other options implemented in SIMCAM will be described in separate reports (under preparation). Gamma camera modeling and simulation in SIMCAM has preset configuration of the design parameters for various sizes of crystal detector with the option to pack the PMT on hexagon or square lattice. Different algorithm for computation of coordinates and spatial distortion removal are allowed in addition to the simulation of energy correction circuit. The user can simulate different static, dynamic, MUGA and SPECT studies. The acquired/ simulated data is processed for quality control and clinical evaluation of the imaging studies. Results show that the program can be used to assess these performances. Also the variations in performance parameters can be assessed due to the induced

  11. Energy modelling platforms for policy and strategy support

    International Nuclear Information System (INIS)

    Dyner, I.

    2000-01-01

    The energy field has been dominated by 'hard' modelling approaches by researchers from engineering and economics discipline. The recent trend towards a more liberalised environment moves away from central planning to market-based resource allocation, leading to the creation and use of strategic tools, with much 'softer' specifications, in the 'system-thinking' tradition. This paper presents the use of system dynamics in a generalised way, to provide a platform for integrated energy analysis. Issues of modularity and policy evolution are important in the design of the modelling platform to facilitate its use, and reuse. Hence the concepts of a platform, rather than a model, has to be implemented in a coherent way if it is to provide sustained value for ongoing support to both government policy and corporate strategy. (author)

  12. Desktop Modeling and Simulation: Parsimonious, yet Effective Discrete-Event Simulation Analysis

    Science.gov (United States)

    Bradley, James R.

    2012-01-01

    This paper evaluates how quickly students can be trained to construct useful discrete-event simulation models using Excel The typical supply chain used by many large national retailers is described, and an Excel-based simulation model is constructed of it The set of programming and simulation skills required for development of that model are then determined we conclude that six hours of training are required to teach the skills to MBA students . The simulation presented here contains all fundamental functionallty of a simulation model, and so our result holds for any discrete-event simulation model. We argue therefore that Industry workers with the same technical skill set as students having completed one year in an MBA program can be quickly trained to construct simulation models. This result gives credence to the efficacy of Desktop Modeling and Simulation whereby simulation analyses can be quickly developed, run, and analyzed with widely available software, namely Excel.

  13. Systematic simulations of modified gravity: chameleon models

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine; Li, Baojiu; Winther, Hans A.; Zhao, Gong-Bo

    2013-01-01

    In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have modified the N-body simulation code ecosmog to perform a total of 65 simulations for different models and parameter values, including the default ΛCDM. These simulations enable us to explore a significant portion of the parameter space. We have studied the effects of modified gravity on the matter power spectrum and mass function, and found a rich and interesting phenomenology where the difference with the ΛCDM paradigm cannot be reproduced by a linear analysis even on scales as large as k ∼ 0.05 hMpc −1 , since the latter incorrectly assumes that the modification of gravity depends only on the background matter density. Our results show that the chameleon screening mechanism is significantly more efficient than other mechanisms such as the dilaton and symmetron, especially in high-density regions and at early times, and can serve as a guidance to determine the parts of the chameleon parameter space which are cosmologically interesting and thus merit further studies in the future

  14. Systematic simulations of modified gravity: chameleon models

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Theorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Davis, Anne-Christine [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Li, Baojiu [Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Winther, Hans A. [Institute of Theoretical Astrophysics, University of Oslo, 0315 Oslo (Norway); Zhao, Gong-Bo, E-mail: philippe.brax@cea.fr, E-mail: a.c.davis@damtp.cam.ac.uk, E-mail: baojiu.li@durham.ac.uk, E-mail: h.a.winther@astro.uio.no, E-mail: gong-bo.zhao@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)

    2013-04-01

    In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have modified the N-body simulation code ecosmog to perform a total of 65 simulations for different models and parameter values, including the default ΛCDM. These simulations enable us to explore a significant portion of the parameter space. We have studied the effects of modified gravity on the matter power spectrum and mass function, and found a rich and interesting phenomenology where the difference with the ΛCDM paradigm cannot be reproduced by a linear analysis even on scales as large as k ∼ 0.05 hMpc{sup −1}, since the latter incorrectly assumes that the modification of gravity depends only on the background matter density. Our results show that the chameleon screening mechanism is significantly more efficient than other mechanisms such as the dilaton and symmetron, especially in high-density regions and at early times, and can serve as a guidance to determine the parts of the chameleon parameter space which are cosmologically interesting and thus merit further studies in the future.

  15. [Modeling and Simulation of Spectral Polarimetric BRDF].

    Science.gov (United States)

    Ling, Jin-jiang; Li, Gang; Zhang, Ren-bin; Tang, Qian; Ye, Qiu

    2016-01-01

    Under the conditions of the polarized light, The reflective surface of the object is affected by many factors, refractive index, surface roughness, and so the angle of incidence. For the rough surface in the different wavelengths of light exhibit different reflection characteristics of polarization, a spectral polarimetric BRDF based on Kirchhof theory is proposee. The spectral model of complex refraction index is combined with refraction index and extinction coefficient spectral model which were got by using the known complex refraction index at different value. Then get the spectral model of surface roughness derived from the classical surface roughness measuring method combined with the Fresnel reflection function. Take the spectral model of refraction index and roughness into the BRDF model, then the spectral polarimetirc BRDF model is proposed. Compare the simulation results of the refractive index varies with wavelength, roughness is constant, the refraction index and roughness both vary with wavelength and origin model with other papers, it shows that, the spectral polarimetric BRDF model can show the polarization characteristics of the surface accurately, and can provide a reliable basis for the application of polarization remote sensing, and other aspects of the classification of substances.

  16. Tokamak Simulation Code modeling of NSTX

    International Nuclear Information System (INIS)

    Jardin, S.C.; Kaye, S.; Menard, J.; Kessel, C.; Glasser, A.H.

    2000-01-01

    The Tokamak Simulation Code [TSC] is widely used for the design of new axisymmetric toroidal experiments. In particular, TSC was used extensively in the design of the National Spherical Torus eXperiment [NSTX]. The authors have now benchmarked TSC with initial NSTX results and find excellent agreement for plasma and vessel currents and magnetic flux loops when the experimental coil currents are used in the simulations. TSC has also been coupled with a ballooning stability code and with DCON to provide stability predictions for NSTX operation. TSC has also been used to model initial CHI experiments where a large poloidal voltage is applied to the NSTX vacuum vessel, causing a force-free current to appear in the plasma. This is a phenomenon that is similar to the plasma halo current that sometimes develops during a plasma disruption

  17. Integrating the simulation of domestic water demand behaviour to an urban water model using agent based modelling

    Science.gov (United States)

    Koutiva, Ifigeneia; Makropoulos, Christos

    2015-04-01

    The urban water system's sustainable evolution requires tools that can analyse and simulate the complete cycle including both physical and cultural environments. One of the main challenges, in this regard, is the design and development of tools that are able to simulate the society's water demand behaviour and the way policy measures affect it. The effects of these policy measures are a function of personal opinions that subsequently lead to the formation of people's attitudes. These attitudes will eventually form behaviours. This work presents the design of an ABM tool for addressing the social dimension of the urban water system. The created tool, called Urban Water Agents' Behaviour (UWAB) model, was implemented, using the NetLogo agent programming language. The main aim of the UWAB model is to capture the effects of policies and environmental pressures to water conservation behaviour of urban households. The model consists of agents representing urban households that are linked to each other creating a social network that influences the water conservation behaviour of its members. Household agents are influenced as well by policies and environmental pressures, such as drought. The UWAB model simulates behaviour resulting in the evolution of water conservation within an urban population. The final outcome of the model is the evolution of the distribution of different conservation levels (no, low, high) to the selected urban population. In addition, UWAB is implemented in combination with an existing urban water management simulation tool, the Urban Water Optioneering Tool (UWOT) in order to create a modelling platform aiming to facilitate an adaptive approach of water resources management. For the purposes of this proposed modelling platform, UWOT is used in a twofold manner: (1) to simulate domestic water demand evolution and (2) to simulate the response of the water system to the domestic water demand evolution. The main advantage of the UWAB - UWOT model

  18. Dealing with correlated choices: how a spin-glass model can help political parties select their policies.

    Science.gov (United States)

    Moore, M A; Katzgraber, Helmut G

    2014-10-01

    Starting from preferences on N proposed policies obtained via questionnaires from a sample of the electorate, an Ising spin-glass model in a field can be constructed from which a political party could find the subset of the proposed policies which would maximize its appeal, form a coherent choice in the eyes of the electorate, and have maximum overlap with the party's existing policies. We illustrate the application of the procedure by simulations of a spin glass in a random field on scale-free networks.

  19. Simulations, evaluations and models. Vol. 1

    International Nuclear Information System (INIS)

    Brehmer, B.; Leplat, J.

    1992-01-01

    Papers presented at the Fourth MOHAWC (Models of Human Activities in Work Context) workshop. The general theme was simulations, evaluations and models. The emphasis was on time in relation to the modelling of human activities in modern, high tech. work. Such work often requires people to control dynamic systems, and the behaviour and misbehaviour of these systems in time is a principle focus of work in, for example, a modern process plant. The papers report on microworlds and on their innovative uses, both in the form of experiments and in the form of a new form of use, that of testing a program which performs diagnostic reasoning. They present new aspects on the problem of time in process control, showing the importance of considering the time scales of dynamic tasks, both in individual decision making and in distributed decision making, and in providing new formalisms, both for the representation of time and for reasoning involving time in diagnosis. (AB)

  20. Process model simulations of the divergence effect

    Science.gov (United States)

    Anchukaitis, K. J.; Evans, M. N.; D'Arrigo, R. D.; Smerdon, J. E.; Hughes, M. K.; Kaplan, A.; Vaganov, E. A.

    2007-12-01

    We explore the extent to which the Vaganov-Shashkin (VS) model of conifer tree-ring formation can explain evidence for changing relationships between climate and tree growth over recent decades. The VS model is driven by daily environmental forcing (temperature, soil moisture, and solar radiation), and simulates tree-ring growth cell-by-cell as a function of the most limiting environmental control. This simplified representation of tree physiology allows us to examine using a selection of case studies whether instances of divergence may be explained in terms of changes in limiting environmental dependencies or transient climate change. Identification of model-data differences permits further exploration of the effects of tree-ring standardization, atmospheric composition, and additional non-climatic factors.

  1. Radiation Modeling with Direct Simulation Monte Carlo

    Science.gov (United States)

    Carlson, Ann B.; Hassan, H. A.

    1991-01-01

    Improvements in the modeling of radiation in low density shock waves with direct simulation Monte Carlo (DSMC) are the subject of this study. A new scheme to determine the relaxation collision numbers for excitation of electronic states is proposed. This scheme attempts to move the DSMC programs toward a more detailed modeling of the physics and more reliance on available rate data. The new method is compared with the current modeling technique and both techniques are compared with available experimental data. The differences in the results are evaluated. The test case is based on experimental measurements from the AVCO-Everett Research Laboratory electric arc-driven shock tube of a normal shock wave in air at 10 km/s and .1 Torr. The new method agrees with the available data as well as the results from the earlier scheme and is more easily extrapolated to di erent ow conditions.

  2. Traffic flow dynamics data, models and simulation

    CERN Document Server

    Treiber, Martin

    2013-01-01

    This textbook provides a comprehensive and instructive coverage of vehicular traffic flow dynamics and modeling. It makes this fascinating interdisciplinary topic, which to date was only documented in parts by specialized monographs, accessible to a broad readership. Numerous figures and problems with solutions help the reader to quickly understand and practice the presented concepts. This book is targeted at students of physics and traffic engineering and, more generally, also at students and professionals in computer science, mathematics, and interdisciplinary topics. It also offers material for project work in programming and simulation at college and university level. The main part, after presenting different categories of traffic data, is devoted to a mathematical description of the dynamics of traffic flow, covering macroscopic models which describe traffic in terms of density, as well as microscopic many-particle models in which each particle corresponds to a vehicle and its driver. Focus chapters on ...

  3. Biomechanics trends in modeling and simulation

    CERN Document Server

    Ogden, Ray

    2017-01-01

    The book presents a state-of-the-art overview of biomechanical and mechanobiological modeling and simulation of soft biological tissues. Seven well-known scientists working in that particular field discuss topics such as biomolecules, networks and cells as well as failure, multi-scale, agent-based, bio-chemo-mechanical and finite element models appropriate for computational analysis. Applications include arteries, the heart, vascular stents and valve implants as well as adipose, brain, collagenous and engineered tissues. The mechanics of the whole cell and sub-cellular components as well as the extracellular matrix structure and mechanotransduction are described. In particular, the formation and remodeling of stress fibers, cytoskeletal contractility, cell adhesion and the mechanical regulation of fibroblast migration in healing myocardial infarcts are discussed. The essential ingredients of continuum mechanics are provided. Constitutive models of fiber-reinforced materials with an emphasis on arterial walls ...

  4. Qualitative simulation in formal process modelling

    International Nuclear Information System (INIS)

    Sivertsen, Elin R.

    1999-01-01

    In relation to several different research activities at the OECD Halden Reactor Project, the usefulness of formal process models has been identified. Being represented in some appropriate representation language, the purpose of these models is to model process plants and plant automatics in a unified way to allow verification and computer aided design of control strategies. The present report discusses qualitative simulation and the tool QSIM as one approach to formal process models. In particular, the report aims at investigating how recent improvements of the tool facilitate the use of the approach in areas like process system analysis, procedure verification, and control software safety analysis. An important long term goal is to provide a basis for using qualitative reasoning in combination with other techniques to facilitate the treatment of embedded programmable systems in Probabilistic Safety Analysis (PSA). This is motivated from the potential of such a combination in safety analysis based on models comprising both software, hardware, and operator. It is anticipated that the research results from this activity will benefit V and V in a wide variety of applications where formal process models can be utilized. Examples are operator procedures, intelligent decision support systems, and common model repositories (author) (ml)

  5. Pharmaceutical expenditure forecast model to support health policy decision making.

    Science.gov (United States)

    Rémuzat, Cécile; Urbinati, Duccio; Kornfeld, Åsa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aballéa, Samuel; Mzoughi, Olfa; Toumi, Mondher

    2014-01-01

    With constant incentives for healthcare payers to contain their pharmaceutical budgets, modelling policy decision impact became critical. The objective of this project was to test the impact of various policy decisions on pharmaceutical budget (developed for the European Commission for the project 'European Union (EU) Pharmaceutical expenditure forecast' - http://ec.europa.eu/health/healthcare/key_documents/index_en.htm). A model was built to assess policy scenarios' impact on the pharmaceutical budgets of seven member states of the EU, namely France, Germany, Greece, Hungary, Poland, Portugal, and the United Kingdom. The following scenarios were tested: expanding the UK policies to EU, changing time to market access, modifying generic price and penetration, shifting the distribution chain of biosimilars (retail/hospital). Applying the UK policy resulted in dramatic savings for Germany (10 times the base case forecast) and substantial additional savings for France and Portugal (2 and 4 times the base case forecast, respectively). Delaying time to market was found be to a very powerful tool to reduce pharmaceutical expenditure. Applying the EU transparency directive (6-month process for pricing and reimbursement) increased pharmaceutical expenditure for all countries (from 1.1 to 4 times the base case forecast), except in Germany (additional savings). Decreasing the price of generics and boosting the penetration rate, as well as shifting distribution of biosimilars through hospital chain were also key methods to reduce pharmaceutical expenditure. Change in the level of reimbursement rate to 100% in all countries led to an important increase in the pharmaceutical budget. Forecasting pharmaceutical expenditure is a critical exercise to inform policy decision makers. The most important leverages identified by the model on pharmaceutical budget were driven by generic and biosimilar prices, penetration rate, and distribution. Reducing, even slightly, the prices of

  6. Pharmaceutical expenditure forecast model to support health policy decision making

    Science.gov (United States)

    Rémuzat, Cécile; Urbinati, Duccio; Kornfeld, Åsa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aballéa, Samuel; Mzoughi, Olfa; Toumi, Mondher

    2014-01-01

    Background and objective With constant incentives for healthcare payers to contain their pharmaceutical budgets, modelling policy decision impact became critical. The objective of this project was to test the impact of various policy decisions on pharmaceutical budget (developed for the European Commission for the project ‘European Union (EU) Pharmaceutical expenditure forecast’ – http://ec.europa.eu/health/healthcare/key_documents/index_en.htm). Methods A model was built to assess policy scenarios’ impact on the pharmaceutical budgets of seven member states of the EU, namely France, Germany, Greece, Hungary, Poland, Portugal, and the United Kingdom. The following scenarios were tested: expanding the UK policies to EU, changing time to market access, modifying generic price and penetration, shifting the distribution chain of biosimilars (retail/hospital). Results Applying the UK policy resulted in dramatic savings for Germany (10 times the base case forecast) and substantial additional savings for France and Portugal (2 and 4 times the base case forecast, respectively). Delaying time to market was found be to a very powerful tool to reduce pharmaceutical expenditure. Applying the EU transparency directive (6-month process for pricing and reimbursement) increased pharmaceutical expenditure for all countries (from 1.1 to 4 times the base case forecast), except in Germany (additional savings). Decreasing the price of generics and boosting the penetration rate, as well as shifting distribution of biosimilars through hospital chain were also key methods to reduce pharmaceutical expenditure. Change in the level of reimbursement rate to 100% in all countries led to an important increase in the pharmaceutical budget. Conclusions Forecasting pharmaceutical expenditure is a critical exercise to inform policy decision makers. The most important leverages identified by the model on pharmaceutical budget were driven by generic and biosimilar prices, penetration rate

  7. Traffic flow dynamics. Data, models and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Treiber, Martin [Technische Univ. Dresden (Germany). Inst. fuer Wirtschaft und Verkehr; Kesting, Arne [TomTom Development Germany GmbH, Berlin (Germany)

    2013-07-01

    First comprehensive textbook of this fascinating interdisciplinary topic which explains advances in a way that it is easily accessible to engineering, physics and math students. Presents practical applications of traffic theory such as driving behavior, stability analysis, stop-and-go waves, and travel time estimation. Presents the topic in a novel and systematic way by addressing both microscopic and macroscopic models with a focus on traffic instabilities. Revised and extended edition of the German textbook ''Verkehrsdynamik und -simulation''. This textbook provides a comprehensive and instructive coverage of vehicular traffic flow dynamics and modeling. It makes this fascinating interdisciplinary topic, which to date was only documented in parts by specialized monographs, accessible to a broad readership. Numerous figures and problems with solutions help the reader to quickly understand and practice the presented concepts. This book is targeted at students of physics and traffic engineering and, more generally, also at students and professionals in computer science, mathematics, and interdisciplinary topics. It also offers material for project work in programming and simulation at college and university level. The main part, after presenting different categories of traffic data, is devoted to a mathematical description of the dynamics of traffic flow, covering macroscopic models which describe traffic in terms of density, as well as microscopic many-particle models in which each particle corresponds to a vehicle and its driver. Focus chapters on traffic instabilities and model calibration/validation present these topics in a novel and systematic way. Finally, the theoretical framework is shown at work in selected applications such as traffic-state and travel-time estimation, intelligent transportation systems, traffic operations management, and a detailed physics-based model for fuel consumption and emissions.

  8. Simulation of socio-ecological impacts: Modeling a fishing village

    Science.gov (United States)

    Miller, Philip C.

    1982-03-01

    The interrelationship of society and environment is addressed here through the study of a remote fishing village of 750 people. An interdisciplinary study evaluated demographic, economic, and social aspects of the community, and simulation modeling was used to integrate these societal characteristics with environmental factors. The population of the village had grown gradually until the 1960's, when a decline began. Out-migration correlated with declining fish harvests and with increased communications with urban centers. Fishing had provided the greatest economic opportunity, followed by logging. A survey was conducted to investigate the costs and revenues of village fishermen. Diversification characterized the local fleet, and analysis showed that rates of return on investment in the current year were equal between vessel types. The variable levels and rate parameters of the demographic, economic, and social components of the model were specified through static and time series data. Sensitivity analysis to assess the effects of uncertainty, and validation tests against known historical changes were also conducted. Forecast scenarios identified the development options under several levels of fish abundance and investment. The weight given to ecological versus economic resource management registered disproportionate effects due to the interaction between investment and migration rates and resource stochasticity. This finding argues against a “golden mean” rule for evaluating policy trade-offs and argues for the importance of using a dynamic, socio-ecological perspective in designing development policies for rural communities.

  9. Simulation Model of Mobile Detection Systems

    International Nuclear Information System (INIS)

    Edmunds, T.; Faissol, D.; Yao, Y.

    2009-01-01

    In this paper, we consider a mobile source that we attempt to detect with man-portable, vehicle-mounted or boat-mounted radiation detectors. The source is assumed to transit an area populated with these mobile detectors, and the objective is to detect the source before it reaches a perimeter. We describe a simulation model developed to estimate the probability that one of the mobile detectors will come in to close proximity of the moving source and detect it. We illustrate with a maritime simulation example. Our simulation takes place in a 10 km by 5 km rectangular bay patrolled by boats equipped with 2-inch x 4-inch x 16-inch NaI detectors. Boats to be inspected enter the bay and randomly proceed to one of seven harbors on the shore. A source-bearing boat enters the mouth of the bay and proceeds to a pier on the opposite side. We wish to determine the probability that the source is detected and its range from target when detected. Patrol boats select the nearest in-bound boat for inspection and initiate an intercept course. Once within an operational range for the detection system, a detection algorithm is started. If the patrol boat confirms the source is not present, it selects the next nearest boat for inspection. Each run of the simulation ends either when a patrol successfully detects a source or when the source reaches its target. Several statistical detection algorithms have been implemented in the simulation model. First, a simple k-sigma algorithm, which alarms with the counts in a time window exceeds the mean background plus k times the standard deviation of background, is available to the user. The time window used is optimized with respect to the signal-to-background ratio for that range and relative speed. Second, a sequential probability ratio test [Wald 1947] is available, and configured in this simulation with a target false positive probability of 0.001 and false negative probability of 0.1. This test is utilized when the mobile detector maintains

  10. Simulation Model of Mobile Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, T; Faissol, D; Yao, Y

    2009-01-27

    In this paper, we consider a mobile source that we attempt to detect with man-portable, vehicle-mounted or boat-mounted radiation detectors. The source is assumed to transit an area populated with these mobile detectors, and the objective is to detect the source before it reaches a perimeter. We describe a simulation model developed to estimate the probability that one of the mobile detectors will come in to close proximity of the moving source and detect it. We illustrate with a maritime simulation example. Our simulation takes place in a 10 km by 5 km rectangular bay patrolled by boats equipped with 2-inch x 4-inch x 16-inch NaI detectors. Boats to be inspected enter the bay and randomly proceed to one of seven harbors on the shore. A source-bearing boat enters the mouth of the bay and proceeds to a pier on the opposite side. We wish to determine the probability that the source is detected and its range from target when detected. Patrol boats select the nearest in-bound boat for inspection and initiate an intercept course. Once within an operational range for the detection system, a detection algorithm is started. If the patrol boat confirms the source is not present, it selects the next nearest boat for inspection. Each run of the simulation ends either when a patrol successfully detects a source or when the source reaches its target. Several statistical detection algorithms have been implemented in the simulation model. First, a simple k-sigma algorithm, which alarms with the counts in a time window exceeds the mean background plus k times the standard deviation of background, is available to the user. The time window used is optimized with respect to the signal-to-background ratio for that range and relative speed. Second, a sequential probability ratio test [Wald 1947] is available, and configured in this simulation with a target false positive probability of 0.001 and false negative probability of 0.1. This test is utilized when the mobile detector maintains

  11. Policy Effects in Hyperbolic vs. Exponential Models of Consumption and Retirement.

    Science.gov (United States)

    Gustman, Alan L; Steinmeier, Thomas L

    2012-06-01

    This paper constructs a structural retirement model with hyperbolic preferences and uses it to estimate the effect of several potential Social Security policy changes. Estimated effects of policies are compared using two models, one with hyperbolic preferences and one with standard exponential preferences. Sophisticated hyperbolic discounters may accumulate substantial amounts of wealth for retirement. We find it is frequently difficult to distinguish empirically between models with the two types of preferences on the basis of asset accumulation paths or consumption paths around the period of retirement. Simulations suggest that, despite the much higher initial time preference rate, individuals with hyperbolic preferences may actually value a real annuity more than individuals with exponential preferences who have accumulated roughly equal amounts of assets. This appears to be especially true for individuals with relatively high time preference rates or who have low assets for whatever reason. This affects the tradeoff between current benefits and future benefits on which many of the retirement incentives of the Social Security system rest.Simulations involving increasing the early entitlement age and increasing the delayed retirement credit do not show a great deal of difference whether exponential or hyperbolic preferences are used, but simulations for eliminating the earnings test show a non-trivially greater effect when exponential preferences are used.

  12. Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities

    Science.gov (United States)

    Baylin-Stern, Adam C.

    This paper demonstrates how an U.S. application of CIMS, a technologically explicit and behaviourally realistic energy-economy simulation model which includes macro-economic feedbacks, can be used to derive estimates of elasticity of substitution (ESUB) and autonomous energy efficiency index (AEEI) parameters. The ability of economies to reduce greenhouse gas emissions depends on the potential for households and industry to decrease overall energy usage, and move from higher to lower emissions fuels. Energy economists commonly refer to ESUB estimates to understand the degree of responsiveness of various sectors of an economy, and use estimates to inform computable general equilibrium models used to study climate policies. Using CIMS, I have generated a set of future, 'pseudo-data' based on a series of simulations in which I vary energy and capital input prices over a wide range. I then used this data set to estimate the parameters for transcendental logarithmic production functions using regression techniques. From the production function parameter estimates, I calculated an array of elasticity of substitution values between input pairs. Additionally, this paper demonstrates how CIMS can be used to calculate price-independent changes in energy-efficiency in the form of the AEEI, by comparing energy consumption between technologically frozen and 'business as usual' simulations. The paper concludes with some ideas for model and methodological improvement, and how these might figure into future work in the estimation of ESUBs from CIMS. Keywords: Elasticity of substitution; hybrid energy-economy model; translog; autonomous energy efficiency index; rebound effect; fuel switching.

  13. CASTOR detector. Model, objectives and simulated performance

    International Nuclear Information System (INIS)

    Angelis, A. L. S.; Mavromanolakis, G.; Panagiotou, A. D.; Aslanoglou, X.; Nicolis, N.; Lobanov, M.; Erine, S.; Kharlov, Y. V.; Bogolyubsky, M. Y.; Kurepin, A. B.; Chileev, K.; Wlodarczyk, Z.

    2001-01-01

    It is presented a phenomenological model describing the formation and evolution of a Centauro fireball in the baryon-rich region in nucleus-nucleus interactions in the upper atmosphere and at the LHC. The small particle multiplicity and imbalance of electromagnetic and hadronic content characterizing a Centauro event and also the strongly penetrating particles (assumed to be strangelets) frequently accompanying them can be naturally explained. It is described the CASTOR calorimeter, a sub detector of the ALICE experiment dedicated to the search for Centauro in the very forward, baryon-rich region of central Pb+Pb collisions at the LHC. The basic characteristics and simulated performance of the calorimeter are presented

  14. Modelling and simulation of railway cable systems

    Energy Technology Data Exchange (ETDEWEB)

    Teichelmann, G.; Schaub, M.; Simeon, B. [Technische Univ. Muenchen, Garching (Germany). Zentrum Mathematik M2

    2005-12-15

    Mathematical models and numerical methods for the computation of both static equilibria and dynamic oscillations of railroad catenaries are derived and analyzed. These cable systems form a complex network of string and beam elements and lead to coupled partial differential equations in space and time where constraints and corresponding Lagrange multipliers express the interaction between carrier, contact wire, and pantograph head. For computing static equilibria, three different algorithms are presented and compared, while the dynamic case is treated by a finite element method in space, combined with stabilized time integration of the resulting differential algebraic system. Simulation examples based on reference data from industry illustrate the potential of such computational tools. (orig.)

  15. Actual interaction effects between policy measures for energy efficiency-A qualitative matrix method and quantitative simulation results for households

    International Nuclear Information System (INIS)

    Boonekamp, Piet G.M.

    2006-01-01

    Starting from the conditions for a successful implementation of saving options, a general framework was developed to investigate possible interaction effects in sets of energy policy measures. Interaction regards the influence of one measure on the energy saving effect of another measure. The method delivers a matrix for all combinations of measures, with each cell containing qualitative information on the strength and type of interaction: overlapping, reinforcing, or independent of each other. Results are presented for the set of policy measures on household energy efficiency in the Netherlands for 1990-2003. The second part regards a quantitative analysis of the interaction effects between three major measures: a regulatory energy tax, investment subsidies and regulation of gas use for space heating. Using a detailed bottom-up model, household energy use in the period 1990-2000 was simulated with and without these measures. The results indicate that combinations of two or three policy measures yield 13-30% less effect than the sum of the effects of the separate measures

  16. Assessing the impact of policy interventions on the adoption of plug-in electric vehicles: An agent-based model

    International Nuclear Information System (INIS)

    Silvia, Chris; Krause, Rachel M.

    2016-01-01

    Heightened concern regarding climate change and energy independence has increased interest in plug-in electric vehicles as one means to address these challenges and governments at all levels have considered policy interventions to encourage their adoption. This paper develops an agent-based model that simulates the introduction of four policy scenarios aimed at promoting electric vehicle adoption in an urban community and compares them against a baseline. These scenarios include reducing vehicle purchase price via subsidies, expanding the local public charging network, increasing the number and visibility of fully battery electric vehicles (BEVs) on the roadway through government fleet purchases, and a hybrid mix of these three approaches. The results point to the effectiveness of policy options that increased awareness of BEV technology. Specifically, the hybrid policy alternative was the most successful in encouraging BEV adoption. This policy increases the visibility and familiarity of BEV technology in the community and may help counter the idea that BEVs are not a viable alternative to gasoline-powered vehicles. - Highlights: •Various policy interventions to encourage electric vehicle adoption are examined. •An agent based model is used to simulate individual adoption decisions. •Policies that increase the familiarity of electric vehicles are most effective.

  17. Exploring policy options for a transition to sustainable heating system diffusion using an agent-based simulation

    International Nuclear Information System (INIS)

    Maya Sopha, Bertha; Kloeckner, Christian A.; Hertwich, Edgar G.

    2011-01-01

    Change in home heating to more efficient and renewable systems is important for a sound climate policy. The present paper aims to identify potential interventions for the uptake of wood-pellet heating in Norway using an agent-based model (ABM). The theoretically based, empirically founded, agent-based simulation demonstrates that financial support, i.e., a stable wood-pellet price, and technical development, i.e., functional reliability improvement, have to be established all at the same time for a successful wood-pellet market to start. Furthermore, a soft intervention through persuading households to use environmentally beneficial heating system is not a promising driver for wood-pellet diffusion. Limitations and suggestions for future work are also discussed. - Research highlights: → The theoretically based, empirically founded, agent-based simulation is applied to investigate potential policy options toward diffusion of wood-pellet heating in Norway. → Relative advantages are necessary for wood-pellet heating to be adopted, consistent with Diffusion of Innovation theory (). → Simultaneous development is also required for further uptake of wood-pellet heating, supporting the existing empirical hypothesis by . → Persuading households to use environmentally friendly heating system is not a promising driver, in line with empirical finding of , who investigated psychological factors underlying the adoption of wood-pellet heating.

  18. Exploring policy options for a transition to sustainable heating system diffusion using an agent-based simulation

    Energy Technology Data Exchange (ETDEWEB)

    Maya Sopha, Bertha, E-mail: bertha.sopha@ntnu.n [Industrial Ecology Programme and Department of Energy and Process Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Kloeckner, Christian A. [Department of Psychology, Section for Risk Psychology, Environment and Safety (RIPENSA), Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Hertwich, Edgar G. [Industrial Ecology Programme and Department of Energy and Process Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

    2011-05-15

    Change in home heating to more efficient and renewable systems is important for a sound climate policy. The present paper aims to identify potential interventions for the uptake of wood-pellet heating in Norway using an agent-based model (ABM). The theoretically based, empirically founded, agent-based simulation demonstrates that financial support, i.e., a stable wood-pellet price, and technical development, i.e., functional reliability improvement, have to be established all at the same time for a successful wood-pellet market to start. Furthermore, a soft intervention through persuading households to use environmentally beneficial heating system is not a promising driver for wood-pellet diffusion. Limitations and suggestions for future work are also discussed. - Research highlights: {yields} The theoretically based, empirically founded, agent-based simulation is applied to investigate potential policy options toward diffusion of wood-pellet heating in Norway. {yields} Relative advantages are necessary for wood-pellet heating to be adopted, consistent with Diffusion of Innovation theory (). {yields} Simultaneous development is also required for further uptake of wood-pellet heating, supporting the existing empirical hypothesis by . {yields} Persuading households to use environmentally friendly heating system is not a promising driver, in line with empirical finding of , who investigated psychological factors underlying the adoption of wood-pellet heating.

  19. An Agent-Based Monetary Production Simulation Model

    DEFF Research Database (Denmark)

    Bruun, Charlotte

    2006-01-01

    An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable......An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable...

  20. Simulation model for port shunting yards

    Science.gov (United States)

    Rusca, A.; Popa, M.; Rosca, E.; Rosca, M.; Dragu, V.; Rusca, F.

    2016-08-01

    Sea ports are important nodes in the supply chain, joining two high capacity transport modes: rail and maritime transport. The huge cargo flows transiting port requires high capacity construction and installation such as berths, large capacity cranes, respectively shunting yards. However, the port shunting yards specificity raises several problems such as: limited access since these are terminus stations for rail network, the in-output of large transit flows of cargo relatively to the scarcity of the departure/arrival of a ship, as well as limited land availability for implementing solutions to serve these flows. It is necessary to identify technological solutions that lead to an answer to these problems. The paper proposed a simulation model developed with ARENA computer simulation software suitable for shunting yards which serve sea ports with access to the rail network. Are investigates the principal aspects of shunting yards and adequate measures to increase their transit capacity. The operation capacity for shunting yards sub-system is assessed taking in consideration the required operating standards and the measure of performance (e.g. waiting time for freight wagons, number of railway line in station, storage area, etc.) of the railway station are computed. The conclusion and results, drawn from simulation, help transports and logistics specialists to test the proposals for improving the port management.

  1. Traffic simulation based ship collision probability modeling

    Energy Technology Data Exchange (ETDEWEB)

    Goerlandt, Floris, E-mail: floris.goerlandt@tkk.f [Aalto University, School of Science and Technology, Department of Applied Mechanics, Marine Technology, P.O. Box 15300, FI-00076 AALTO, Espoo (Finland); Kujala, Pentti [Aalto University, School of Science and Technology, Department of Applied Mechanics, Marine Technology, P.O. Box 15300, FI-00076 AALTO, Espoo (Finland)

    2011-01-15

    Maritime traffic poses various risks in terms of human, environmental and economic loss. In a risk analysis of ship collisions, it is important to get a reasonable estimate for the probability of such accidents and the consequences they lead to. In this paper, a method is proposed to assess the probability of vessels colliding with each other. The method is capable of determining the expected number of accidents, the locations where and the time when they are most likely to occur, while providing input for models concerned with the expected consequences. At the basis of the collision detection algorithm lays an extensive time domain micro-simulation of vessel traffic in the given area. The Monte Carlo simulation technique is applied to obtain a meaningful prediction of the relevant factors of the collision events. Data obtained through the Automatic Identification System is analyzed in detail to obtain realistic input data for the traffic simulation: traffic routes, the number of vessels on each route, the ship departure times, main dimensions and sailing speed. The results obtained by the proposed method for the studied case of the Gulf of Finland are presented, showing reasonable agreement with registered accident and near-miss data.

  2. Mission Assurance Modeling and Simulation: A Cyber Security Roadmap

    Science.gov (United States)

    Gendron, Gerald; Roberts, David; Poole, Donold; Aquino, Anna

    2012-01-01

    This paper proposes a cyber security modeling and simulation roadmap to enhance mission assurance governance and establish risk reduction processes within constrained budgets. The term mission assurance stems from risk management work by Carnegie Mellon's Software Engineering Institute in the late 19905. By 2010, the Defense Information Systems Agency revised its cyber strategy and established the Program Executive Officer-Mission Assurance. This highlights a shift from simply protecting data to balancing risk and begins a necessary dialogue to establish a cyber security roadmap. The Military Operations Research Society has recommended a cyber community of practice, recognizing there are too few professionals having both cyber and analytic experience. The authors characterize the limited body of knowledge in this symbiotic relationship. This paper identifies operational and research requirements for mission assurance M&S supporting defense and homeland security. M&S techniques are needed for enterprise oversight of cyber investments, test and evaluation, policy, training, and analysis.

  3. Modeling VOC transport in simulated waste drums

    International Nuclear Information System (INIS)

    Liekhus, K.J.; Gresham, G.L.; Peterson, E.S.; Rae, C.; Hotz, N.J.; Connolly, M.J.

    1993-06-01

    A volatile organic compound (VOC) transport model has been developed to describe unsteady-state VOC permeation and diffusion within a waste drum. Model equations account for three primary mechanisms for VOC transport from a void volume within the drum. These mechanisms are VOC permeation across a polymer boundary, VOC diffusion across an opening in a volume boundary, and VOC solubilization in a polymer boundary. A series of lab-scale experiments was performed in which the VOC concentration was measured in simulated waste drums under different conditions. A lab-scale simulated waste drum consisted of a sized-down 55-gal metal drum containing a modified rigid polyethylene drum liner. Four polyethylene bags were sealed inside a large polyethylene bag, supported by a wire cage, and placed inside the drum liner. The small bags were filled with VOC-air gas mixture and the VOC concentration was measured throughout the drum over a period of time. Test variables included the type of VOC-air gas mixtures introduced into the small bags, the small bag closure type, and the presence or absence of a variable external heat source. Model results were calculated for those trials where the VOC permeability had been measured. Permeabilities for five VOCs [methylene chloride, 1,1,2-trichloro-1,2,2-trifluoroethane (Freon-113), 1,1,1-trichloroethane, carbon tetrachloride, and trichloroethylene] were measured across a polyethylene bag. Comparison of model and experimental results of VOC concentration as a function of time indicate that model accurately accounts for significant VOC transport mechanisms in a lab-scale waste drum

  4. Risk assessment and remedial policy evaluation using predictive modeling

    International Nuclear Information System (INIS)

    Linkov, L.; Schell, W.R.

    1996-01-01

    As a result of nuclear industry operation and accidents, large areas of natural ecosystems have been contaminated by radionuclides and toxic metals. Extensive societal pressure has been exerted to decrease the radiation dose to the population and to the environment. Thus, in making abatement and remediation policy decisions, not only economic costs but also human and environmental risk assessments are desired. This paper introduces a general framework for risk assessment and remedial policy evaluation using predictive modeling. Ecological risk assessment requires evaluation of the radionuclide distribution in ecosystems. The FORESTPATH model is used for predicting the radionuclide fate in forest compartments after deposition as well as for evaluating the efficiency of remedial policies. Time of intervention and radionuclide deposition profile was predicted as being crucial for the remediation efficiency. Risk assessment conducted for a critical group of forest users in Belarus shows that consumption of forest products (berries and mushrooms) leads to about 0.004% risk of a fatal cancer annually. Cost-benefit analysis for forest cleanup suggests that complete removal of organic layer is too expensive for application in Belarus and a better methodology is required. In conclusion, FORESTPATH modeling framework could have wide applications in environmental remediation of radionuclides and toxic metals as well as in dose reconstruction and, risk-assessment

  5. 3D Core Model for simulation of nuclear power plants: Simulation requirements, model features, and validation

    International Nuclear Information System (INIS)

    Zerbino, H.

    1999-01-01

    In 1994-1996, Thomson Training and Simulation (TT and S) earned out the D50 Project, which involved the design and construction of optimized replica simulators for one Dutch and three German Nuclear Power Plants. It was recognized early on that the faithful reproduction of the Siemens reactor control and protection systems would impose extremely stringent demands on the simulation models, particularly the Core physics and the RCS thermohydraulics. The quality of the models, and their thorough validation, were thus essential. The present paper describes the main features of the fully 3D Core model implemented by TT and S, and its extensive validation campaign, which was defined in extremely positive collaboration with the Customer and the Core Data suppliers. (author)

  6. Modeling urban expansion policy scenarios using an agent-based approach for Guangzhou Metropolitan Region of China

    Directory of Open Access Journals (Sweden)

    Guangjin Tian

    2014-09-01

    Full Text Available Policy makers and the human decision processes of urban planning have an impact on urban expansion. The behaviors and decision modes of regional authority, real estate developer, resident, and farmer agents and their interactions can be simulated by the analytical hierarchy process (AHP method. The driving factors are regressed with urban dynamics instead of static land-use types. Agents' behaviors and decision modes have an impact on the urban dynamic pattern by adjusting parameter weights. We integrate an agent-based model (ABM with AHP to investigate a complex decision-making process and future urban dynamic processes. Three policy scenarios for baseline development, rapid development, and green land protection have been applied to predict the future development patterns of the Guangzhou metropolitan region. A future policy scenario analysis can help policy makers to understand the possible results. These individuals can adjust their policies and decisions according to their different objectives.

  7. Modeling and visual simulation of Microalgae photobioreactor

    Science.gov (United States)

    Zhao, Ming; Hou, Dapeng; Hu, Dawei

    Microalgae is a kind of nutritious and high photosynthetic efficiency autotrophic plant, which is widely distributed in the land and the sea. It can be extensively used in medicine, food, aerospace, biotechnology, environmental protection and other fields. Photobioreactor which is important equipment is mainly used to cultivate massive and high-density microalgae. In this paper, based on the mathematical model of microalgae which grew under different light intensity, three-dimensional visualization model was built and implemented in 3ds max, Virtools and some other three dimensional software. Microalgae is photosynthetic organism, it can efficiently produce oxygen and absorb carbon dioxide. The goal of the visual simulation is to display its change and impacting on oxygen and carbon dioxide intuitively. In this paper, different temperatures and light intensities were selected to control the photobioreactor, and dynamic change of microalgal biomass, Oxygen and carbon dioxide was observed with the aim of providing visualization support for microalgal and photobioreactor research.

  8. Efficient Turbulence Modeling for CFD Wake Simulations

    DEFF Research Database (Denmark)

    van der Laan, Paul

    Wind turbine wakes can cause 10-20% annual energy losses in wind farms, and wake turbulence can decrease the lifetime of wind turbine blades. One way of estimating these effects is the use of computational fluid dynamics (CFD) to simulate wind turbines wakes in the atmospheric boundary layer. Since...... this flow is in the high Reynolds number regime, it is mainly dictated by turbulence. As a result, the turbulence modeling in CFD dominates the wake characteristics, especially in Reynolds-averaged Navier-Stokes (RANS). The present work is dedicated to study and develop RANS-based turbulence models...... verified with a grid dependency study. With respect to the standard k-ε EVM, the k-ε- fp EVM compares better with measurements of the velocity deficit, especially in the near wake, which translates to improved power deficits of the first wind turbines in a row. When the CFD metholody is applied to a large...

  9. Molecular models and simulations of layered materials

    International Nuclear Information System (INIS)

    Kalinichev, Andrey G.; Cygan, Randall Timothy; Heinz, Hendrik; Greathouse, Jeffery A.

    2008-01-01

    The micro- to nano-sized nature of layered materials, particularly characteristic of naturally occurring clay minerals, limits our ability to fully interrogate their atomic dispositions and crystal structures. The low symmetry, multicomponent compositions, defects, and disorder phenomena of clays and related phases necessitate the use of molecular models and modern simulation methods. Computational chemistry tools based on classical force fields and quantum-chemical methods of electronic structure calculations provide a practical approach to evaluate structure and dynamics of the materials on an atomic scale. Combined with classical energy minimization, molecular dynamics, and Monte Carlo techniques, quantum methods provide accurate models of layered materials such as clay minerals, layered double hydroxides, and clay-polymer nanocomposites

  10. 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

  11. A Nuclear Waste Management Cost Model for Policy Analysis

    Science.gov (United States)

    Barron, R. W.; Hill, M. C.

    2017-12-01

    Although integrated assessments of climate change policy have frequently identified nuclear energy as a promising alternative to fossil fuels, these studies have often treated nuclear waste disposal very simply. Simple assumptions about nuclear waste are problematic because they may not be adequate to capture relevant costs and uncertainties, which could result in suboptimal policy choices. Modeling nuclear waste management costs is a cross-disciplinary, multi-scale problem that involves economic, geologic and environmental processes that operate at vastly different temporal scales. Similarly, the climate-related costs and benefits of nuclear energy are dependent on environmental sensitivity to CO2 emissions and radiation, nuclear energy's ability to offset carbon emissions, and the risk of nuclear accidents, factors which are all deeply uncertain. Alternative value systems further complicate the problem by suggesting different approaches to valuing intergenerational impacts. Effective policy assessment of nuclear energy requires an integrated approach to modeling nuclear waste management that (1) bridges disciplinary and temporal gaps, (2) supports an iterative, adaptive process that responds to evolving understandings of uncertainties, and (3) supports a broad range of value systems. This work develops the Nuclear Waste Management Cost Model (NWMCM). NWMCM provides a flexible framework for evaluating the cost of nuclear waste management across a range of technology pathways and value systems. We illustrate how NWMCM can support policy analysis by estimating how different nuclear waste disposal scenarios developed using the NWMCM framework affect the results of a recent integrated assessment study of alternative energy futures and their effects on the cost of achieving carbon abatement targets. Results suggest that the optimism reflected in previous works is fragile: Plausible nuclear waste management costs and discount rates appropriate for intergenerational cost

  12. At the biological modeling and simulation frontier.

    Science.gov (United States)

    Hunt, C Anthony; Ropella, Glen E P; Lam, Tai Ning; Tang, Jonathan; Kim, Sean H J; Engelberg, Jesse A; Sheikh-Bahaei, Shahab

    2009-11-01

    We provide a rationale for and describe examples of synthetic modeling and simulation (M&S) of biological systems. We explain how synthetic methods are distinct from familiar inductive methods. Synthetic M&S is a means to better understand the mechanisms that generate normal and disease-related phenomena observed in research, and how compounds of interest interact with them to alter phenomena. An objective is to build better, working hypotheses of plausible mechanisms. A synthetic model is an extant hypothesis: execution produces an observable mechanism and phenomena. Mobile objects representing compounds carry information enabling components to distinguish between them and react accordingly when different compounds are studied simultaneously. We argue that the familiar inductive approaches contribute to the general inefficiencies being experienced by pharmaceutical R&D, and that use of synthetic approaches accelerates and improves R&D decision-making and thus the drug development process. A reason is that synthetic models encourage and facilitate abductive scientific reasoning, a primary means of knowledge creation and creative cognition. When synthetic models are executed, we observe different aspects of knowledge in action from different perspectives. These models can be tuned to reflect differences in experimental conditions and individuals, making translational research more concrete while moving us closer to personalized medicine.

  13. Plasma simulation studies using multilevel physics models

    International Nuclear Information System (INIS)

    Park, W.; Belova, E.V.; Fu, G.Y.; Tang, X.Z.; Strauss, H.R.; Sugiyama, L.E.

    1999-01-01

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of δf particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future. copyright 1999 American Institute of Physics

  14. Plasma simulation studies using multilevel physics models

    International Nuclear Information System (INIS)

    Park, W.; Belova, E.V.; Fu, G.Y.

    2000-01-01

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future

  15. Modeling lift operations with SASmacr Simulation Studio

    Science.gov (United States)

    Kar, Leow Soo

    2016-10-01

    Lifts or elevators are an essential part of multistorey buildings which provide vertical transportation for its occupants. In large and high-rise apartment buildings, its occupants are permanent, while in buildings, like hospitals or office blocks, the occupants are temporary or users of the buildings. They come in to work or to visit, and thus, the population of such buildings are much higher than those in residential apartments. It is common these days that large office blocks or hospitals have at least 8 to 10 lifts serving its population. In order to optimize the level of service performance, different transportation schemes are devised to control the lift operations. For example, one lift may be assigned to solely service the even floors and another solely for the odd floors, etc. In this paper, a basic lift system is modelled using SAS Simulation Studio to study the effect of factors such as the number of floors, capacity of the lift car, arrival rate and exit rate of passengers at each floor, peak and off peak periods on the system performance. The simulation is applied to a real lift operation in Sunway College's North Building to validate the model.

  16. Discharge Fee Policy Analysis: A Computable General Equilibrium (CGE Model of Water Resources and Water Environments

    Directory of Open Access Journals (Sweden)

    Guohua Fang

    2016-09-01

    Full Text Available To alleviate increasingly serious water pollution and shortages in developing countries, various kinds of policies have been implemented by local governments. It is vital to quantify and evaluate the performance and potential economic impacts of these policies. This study develops a Computable General Equilibrium (CGE model to simulate the regional economic and environmental effects of discharge fees. Firstly, water resources and water environment factors are separated from the input and output sources of the National Economic Production Department. Secondly, an extended Social Accounting Matrix (SAM of Jiangsu province is developed to simulate various scenarios. By changing values of the discharge fees (increased by 50%, 100% and 150%, three scenarios are simulated to examine their influence on the overall economy and each industry. The simulation results show that an increased fee will have a negative impact on Gross Domestic Product (GDP. However, waste water may be effectively controlled. Also, this study demonstrates that along with the economic costs, the increase of the discharge fee will lead to the upgrading of industrial structures from a situation of heavy pollution to one of light pollution which is beneficial to the sustainable development of the economy and the protection of the environment.

  17. Simulation as a vehicle for enhancing collaborative practice models.

    Science.gov (United States)

    Jeffries, Pamela R; McNelis, Angela M; Wheeler, Corinne A

    2008-12-01

    Clinical simulation used in a collaborative practice approach is a powerful tool to prepare health care providers for shared responsibility for patient care. Clinical simulations are being used increasingly in professional curricula to prepare providers for quality practice. Little is known, however, about how these simulations can be used to foster collaborative practice across disciplines. This article provides an overview of what simulation is, what collaborative practice models are, and how to set up a model using simulations. An example of a collaborative practice model is presented, and nursing implications of using a collaborative practice model in simulations are discussed.

  18. Modeling and numerical simulations of the influenced Sznajd model

    Science.gov (United States)

    Karan, Farshad Salimi Naneh; Srinivasan, Aravinda Ramakrishnan; Chakraborty, Subhadeep

    2017-08-01

    This paper investigates the effects of independent nonconformists or influencers on the behavioral dynamic of a population of agents interacting with each other based on the Sznajd model. The system is modeled on a complete graph using the master equation. The acquired equation has been numerically solved. Accuracy of the mathematical model and its corresponding assumptions have been validated by numerical simulations. Regions of initial magnetization have been found from where the system converges to one of two unique steady-state PDFs, depending on the distribution of influencers. The scaling property and entropy of the stationary system in presence of varying level of influence have been presented and discussed.

  19. Model projections and policy reviews for energy saving in China's service sector

    International Nuclear Information System (INIS)

    Zhang, Lin

    2013-01-01

    Energy efficiency of buildings in the service sector is becoming increasingly important in China due to the structural shift of the economy from industry to services. This paper employs a bottom-up cohort model to simulate current energy saving policies and to make projections for future energy use and CO 2 emissions for the period 2000–2030 in the Chinese service sector. The analysis shows that energy demand in the service sector will approximately triple in 2030, far beyond the target of quadrupling GDP while only doubling energy use. However, it is feasible to achieve the target of emission reduction by 40% in 2020 even under the poor state of compliance rate of building standard. This paper also highlights four crucial aspects of designing optimal energy saving policies for China's service sector based on the model results. - Highlights: • Government energy saving target cannot realize with current policies in services. • Energy savings policies for new buildings are crucial than building retrofitting. • Cooling energy use increases significantly to reach equal weight as heating. • CO 2 tax can contribute to change in fuel mix, and thus emission reductions. • Low compliance rate limits further energy saving, hence green fund is required

  20. MODELING MONETARY POLICY RULES IN THE MENACOUNTRIES: ISSUES AND EVIDENCE

    Directory of Open Access Journals (Sweden)

    Mohamad Husam Helmi

    2011-07-01

    Full Text Available This paper estimates the monetary policy reaction function for two sets of MENAcountries: The inflation target countries, (Turkeyand Israel and the exchange ratetarget countries, (Jordan and Morocco. We motivateour empirical analysis byanalyzing a simple Taylor rule. This model looks atthe effects of inflation andoutput on setting the interest rate by the centralbank. Furthermore, we extendedour model by adding the exchange rate and the foreign interest rate using similarmodel used by Clarida et al (1998 with using GMM estimator.Findings of this study yield some interesting results,all the central banks in thesample uses interest rate smoothing in managing their monetary policy. Inaddition, The Central bank in Turkey, Israel and Morocco focuses on achievinglow level of inflation. On the other hand, the Monetary Authority in Jordan caresabout stabilizing the output gap. Estimating the extended Taylor rule suggests thehighly significant effect of foreign interest rateon setting the interest rate inTurkey. Taken all together, the results lend support to the importance of followinga rule rather than discretionary in reducing the inflation rate and crediblemonetary policy. In addition, the simple Taylor rule can be applied on MENAcountries but it requires some modification such asadding the exchange rate andthe foreign interest rate.

  1. On Regional Modeling to Support Air Quality Policies (book chapter)

    Science.gov (United States)

    We examine the use of the Community Multiscale Air Quality (CMAQ) model in simulating the changes in the extreme values of air quality that are of interest to the regulatory agencies. Year-to-year changes in ozone air quality are attributable to variations in the prevailing meteo...

  2. Dispersion modeling by kinematic simulation: Cloud dispersion model

    International Nuclear Information System (INIS)

    Fung, J C H; Perkins, R J

    2008-01-01

    A new technique has been developed to compute mean and fluctuating concentrations in complex turbulent flows (tidal current near a coast and deep ocean). An initial distribution of material is discretized into any small clouds which are advected by a combination of the mean flow and large scale turbulence. The turbulence can be simulated either by kinematic simulation (KS) or direct numerical simulation. The clouds also diffuse relative to their centroids; the statistics for this are obtained from a separate calculation of the growth of individual clouds in small scale turbulence, generated by KS. The ensemble of discrete clouds is periodically re-discretized, to limit the size of the small clouds and prevent overlapping. The model is illustrated with simulations of dispersion in uniform flow, and the results are compared with analytic, steady state solutions. The aim of this study is to understand how pollutants disperses in a turbulent flow through a numerical simulation of fluid particle motion in a random flow field generated by Fourier modes. Although this homogeneous turbulent is rather a 'simple' flow, it represents a building block toward understanding pollutant dispersion in more complex flow. The results presented here are preliminary in nature, but we expect that similar qualitative results should be observed in a genuine turbulent flow.

  3. National Environmental Policy Act guidance: A model process

    International Nuclear Information System (INIS)

    Angle, B.M.; Lockhart, V.A.T.; Sema, B.; Tuott, L.C.; Irving, J.S.

    1995-04-01

    The ''Model National Environmental Policy Act (NEPA) Process'' includes: References to regulations, guidance documents, and plans; training programs; procedures; and computer databases. Legislative Acts and reference documents from Congress, US Department of Energy, and Lockheed Idaho Technologies Company provide the bases for conducting NEPA at the Idaho National Engineering Laboratory (INEL). Lockheed Idaho Technologies Company (LITCO) NEPA / Permitting Department, the Contractor Environmental Organization (CEO) is responsible for developing and maintaining LITCO NEPA and permitting policies, guidance, and procedures. The CEO develops procedures to conduct environmental evaluations based on NEPA, Council on Environmental Quality (CEQ) regulations, and DOE guidance. This procedure includes preparation or support of environmental checklists, categorical exclusion determinations, environmental assessment determinations, environmental assessments, and environmental impact statements. In addition, the CEO uses this information to train personnel conducting environmental evaluations at the INEL. Streamlining these procedures fosters efficient use of resources, quality documents, and better decisions on proposed actions

  4. Optimization of maintenance policy using the proportional hazard model

    Energy Technology Data Exchange (ETDEWEB)

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  5. Comparison of performance of simulation models for floor heating

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    This paper describes the comparison of performance of simulation models for floor heating with different level of detail in the modelling process. The models are compared in an otherwise identical simulation model containing room model, walls, windows, ceiling and ventilation system. By exchanging...

  6. Spatial Planning and Policy Evaluation in an Urban Conurbation: a Regional Agent-Based Economic Model

    Directory of Open Access Journals (Sweden)

    Luzius Stricker

    2017-03-01

    Full Text Available This paper studies different functions and relations between 45 agglomerated municipalities in southern Switzerland (Ticino, using a territorial agent-based model. Our research adopts a bottom-up approach to urban systems, considering the agglomeration mechanism and effects of different regional and urban policies, and simulates the individual actions of diverse agents on a real city using an Agent-based model (ABM. Simulating the individual actions of diverse agents on a real city and measuring the resulting system behaviour and outcomes over time, they effectively provide a good test bed for evaluating the impact of different policies. The database is created merging the Swiss official secondary data for one reference year (2011 with Eurostat and OECD-Regpat. The results highlight that the understanding of municipalities’ functions on the territory appears to be essential for designing a solid institutional agglomeration (or city. From a methodological point of view, we contribute to improve the application of territorial ABM. Finally, our results provide a robust base to evaluate in a dynamic way various political interventions, in order to ensure a sustainable development of the agglomeration and the surrounding territories. Applying the analyses and the model on a larger scale, including further regions and conurbations, and including more indicators and variables, to obtain a more detailed and characteristic model, will constitute a further step of the research.

  7. Tecnomatix Plant Simulation modeling and programming by means of examples

    CERN Document Server

    Bangsow, Steffen

    2015-01-01

    This book systematically introduces the development of simulation models as well as the implementation and evaluation of simulation experiments with Tecnomatix Plant Simulation. It deals with all users of Plant Simulation, who have more complex tasks to handle. It also looks for an easy entry into the program. Particular attention has been paid to introduce the simulation flow language SimTalk and its use in various areas of the simulation. The author demonstrates with over 200 examples how to combine the blocks for simulation models and how to deal with SimTalk for complex control and analys

  8. Political economy models and agricultural policy formation : empirical applicability and relevance for the CAP

    OpenAIRE

    Zee, van der, F.A.

    1997-01-01

    This study explores the relevance and applicability of political economy models for the explanation of agricultural policies. Part I (chapters 4-7) takes a general perspective and evaluates the empirical applicability of voting models and interest group models to agricultural policy formation in industrialised market economics. Part II (chapters 8-11) focuses on the empirical applicability of political economy models to agricultural policy formation and agricultural policy developmen...

  9. Nonlinear distortion in wireless systems modeling and simulation with Matlab

    CERN Document Server

    Gharaibeh, Khaled M

    2011-01-01

    This book covers the principles of modeling and simulation of nonlinear distortion in wireless communication systems with MATLAB simulations and techniques In this book, the author describes the principles of modeling and simulation of nonlinear distortion in single and multichannel wireless communication systems using both deterministic and stochastic signals. Models and simulation methods of nonlinear amplifiers explain in detail how to analyze and evaluate the performance of data communication links under nonlinear amplification. The book addresses the analysis of nonlinear systems

  10. Multiple Time Series Ising Model for Financial Market Simulations

    International Nuclear Information System (INIS)

    Takaishi, Tetsuya

    2015-01-01

    In this paper we propose an Ising model which simulates multiple financial time series. Our model introduces the interaction which couples to spins of other systems. Simulations from our model show that time series exhibit the volatility clustering that is often observed in the real financial markets. Furthermore we also find non-zero cross correlations between the volatilities from our model. Thus our model can simulate stock markets where volatilities of stocks are mutually correlated

  11. Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

    Science.gov (United States)

    Hu, Xiaolin; Puddy, Richard

    This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

  12. Modeling and Simulation Techniques for Large-Scale Communications Modeling

    National Research Council Canada - National Science Library

    Webb, Steve

    1997-01-01

    .... Tests of random number generators were also developed and applied to CECOM models. It was found that synchronization of random number strings in simulations is easy to implement and can provide significant savings for making comparative studies. If synchronization is in place, then statistical experiment design can be used to provide information on the sensitivity of the output to input parameters. The report concludes with recommendations and an implementation plan.

  13. Evaluating the APEX model for simulating streamflow and water quality on ten agricultural watersheds in the U.S.

    Science.gov (United States)

    Simulation models are increasingly used to assess water quality constituent losses from agricultural systems. Mis-use often gives irrelevant or erroneous answers. The Agricultural Policy Environmental Extender (APEX) model is emerging as one of the premier modeling tools for fields, farms, and agr...

  14. Integrated simulation, evaluation of the climatic risks and safety policies. Synthesis report july 2002

    International Nuclear Information System (INIS)

    Hourcade, J.Ch.; LeTreut, H.

    2002-07-01

    The aim of this program is the improvement of the natural phenomena representation in the integrated models of the climate policies evaluation and to precise the methodological problems resulting from the damages treatment. It underlines the importance of the retroactions between the CO 2 emissions, the lands affectation and the carbon cycle, as the importance of the uncertainties on the climate sensitivity. (A.L.B.)

  15. Agricultural Policy Environmental eXtender Simulation of Three Adjacent Row-Crop Watersheds in the Claypan Region.

    Science.gov (United States)

    Anomaa Senaviratne, G M M M; Udawatta, Ranjith P; Baffaut, Claire; Anderson, Stephen H

    2013-01-01

    The Agricultural Policy Environmental Extender (APEX) model is used to evaluate best management practices on pollutant loading in whole farms or small watersheds. The objectives of this study were to conduct a sensitivity analysis to determine the effect of model parameters on APEX output and use the parameterized, calibrated, and validated model to evaluate long-term benefits of grass waterways. The APEX model was used to model three (East, Center, and West) adjacent field-size watersheds with claypan soils under a no-till corn ( L.)/soybean [ (L.) Merr.] rotation. Twenty-seven parameters were sensitive for crop yield, runoff, sediment, nitrogen (dissolved and total), and phosphorous (dissolved and total) simulations. The model was calibrated using measured event-based data from the Center watershed from 1993 to 1997 and validated with data from the West and East watersheds. Simulated crop yields were within ±13% of the measured yield. The model performance for event-based runoff was excellent, with calibration and validation > 0.9 and Nash-Sutcliffe coefficients (NSC) > 0.8, respectively. Sediment and total nitrogen calibration results were satisfactory for larger rainfall events (>50 mm), with > 0.5 and NSC > 0.4, but validation results remained poor, with NSC between 0.18 and 0.3. Total phosphorous was well calibrated and validated, with > 0.8 and NSC > 0.7, respectively. The presence of grass waterways reduced annual total phosphorus loadings by 13 to 25%. The replicated study indicates that APEX provides a convenient and efficient tool to evaluate long-term benefits of conservation practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Managing emergency department overcrowding via ambulance diversion: a discrete event simulation model.

    Science.gov (United States)

    Lin, Chih-Hao; Kao, Chung-Yao; Huang, Chong-Ye

    2015-01-01

    Ambulance diversion (AD) is considered one of the possible solutions to relieve emergency department (ED) overcrowding. Study of the effectiveness of various AD strategies is prerequisite for policy-making. Our aim is to develop a tool that quantitatively evaluates the effectiveness of various AD strategies. A simulation model and a computer simulation program were developed. Three sets of simulations were executed to evaluate AD initiating criteria, patient-blocking rules, and AD intervals, respectively. The crowdedness index, the patient waiting time for service, and the percentage of adverse patients were assessed to determine the effect of various AD policies. Simulation results suggest that, in a certain setting, the best timing for implementing AD is when the crowdedness index reaches the critical value, 1.0 - an indicator that ED is operating at its maximal capacity. The strategy to divert all patients transported by ambulance is more effective than to divert either high-acuity patients only or low-acuity patients only. Given a total allowable AD duration, implementing AD multiple times with short intervals generally has better effect than having a single AD with maximal allowable duration. An input-throughput-output simulation model is proposed for simulating ED operation. Effectiveness of several AD strategies on relieving ED overcrowding was assessed via computer simulations based on this model. By appropriate parameter settings, the model can represent medical resource providers of different scales. It is also feasible to expand the simulations to evaluate the effect of AD strategies on a community basis. The results may offer insights for making effective AD policies. Copyright © 2012. Published by Elsevier B.V.

  17. Monte Carlo simulation of Markov unreliability models

    International Nuclear Information System (INIS)

    Lewis, E.E.; Boehm, F.

    1984-01-01

    A Monte Carlo method is formulated for the evaluation of the unrealibility of complex systems with known component failure and repair rates. The formulation is in terms of a Markov process allowing dependences between components to be modeled and computational efficiencies to be achieved in the Monte Carlo simulation. Two variance reduction techniques, forced transition and failure biasing, are employed to increase computational efficiency of the random walk procedure. For an example problem these result in improved computational efficiency by more than three orders of magnitudes over analog Monte Carlo. The method is generalized to treat problems with distributed failure and repair rate data, and a batching technique is introduced and shown to result in substantial increases in computational efficiency for an example problem. A method for separating the variance due to the data uncertainty from that due to the finite number of random walks is presented. (orig.)

  18. Modeling and Recognizing Policy Conflicts with Resource Access Requests on Protected Health Information

    Directory of Open Access Journals (Sweden)

    Raik Kuhlisch

    2017-07-01

    Full Text Available This article discusses potential clashes between different types of security policies that regulate resource access requests on clinical patient data in hospitals by employees. Attribute-based Access Control (ABAC is proposed as a proper means for such regulation. A proper representation of ABAC policies must include a handling of policy attributes among different policy types. In this article, we propose a semantic policy model with predefined policy conflict categories. A conformance verification function detects erroneous, clashing or mutually susceptible rules early during the policy planning phase. The model and conflicts are used in a conceptual application environment and evaluated in a technical experiment during an interoperability test event.

  19. Effects of tobacco control policies on smoking prevalence and tobacco-attributable deaths in Mexico: the SimSmoke model

    Directory of Open Access Journals (Sweden)

    Luz Myriam Reynales-Shigematsu

    Full Text Available OBJECTIVE: To examine how policies adopted in Mexico in response to the Framework Convention on Tobacco Control affected smoking prevalence and smoking-attributable deaths. METHODS: The SimSmoke simulation model of tobacco control policy is applied to Mexico. This discrete time, first-order Markov model uses data on population size, smoking rates and tobacco control policy for Mexico. It assesses, individually and jointly, the effects of seven types of policies: cigarette taxes, smoke-free air laws, mass media campaigns, advertising bans, warning labels, cessation treatment, and youth tobacco access policies. RESULTS: The Mexico SimSmoke model estimates that smoking rates have been reduced by about 30% as a result of policies implemented since 2002, and that the number of smoking-attributable deaths will have been reduced by about 826 000 by 2053. Increases in cigarette prices are responsible for over 60% of the reductions, but health warnings, smoke-free air laws, marketing restrictions and cessation treatments also play important roles. CONCLUSIONS: Mexico has shown steady progress towards reducing smoking prevalence in a short period of time, as have other Latin American countries, such as Brazil, Panama and Uruguay. Tobacco control policies play an important role in continued efforts to reduce tobacco use and associated deaths in Mexico.

  20. Improving firm performance in out-of-equilibrium, deregulated markets using feedback simulation models

    International Nuclear Information System (INIS)

    Gary, S.; Larsen, E.R.

    2000-01-01

    Deregulation has reshaped the utility sector in many countries around the world. Organisations in these deregulated industries must adopt new polices which guide strategic decisions, in an uncertain and unfamiliar environment, that determine the short- and long-term fate of their companies. Traditional economic equilibrium models do not adequately address the issues facing these organisations in the shift towards deregulated market competition. Equilibrium assumptions break down in the out-of-equilibrium transition to competitive markets, and therefore different underpinning assumptions must be adopted in order to guide management in these periods. Simulation models incorporating information feedback through behavioural policies fill the void left by equilibrium models and support strategic policy analysis in out-of-equilibrium markets. As an example, we present a feedback simulation model developed to examine firm and industry level performance consequences of new generation capacity investment policies in the deregulated UK electricity sector. The model explicitly captures behavioural decision polices of boundedly rational managers and avoids equilibrium assumptions. Such models are essential to help managers evaluate the performance impact of various strategic policies in environments in which disequilibrum behaviour dominates. (Author)

  1. Generating WS-SecurityPolicy documents via security model transformation

    DEFF Research Database (Denmark)

    Jensen, Meiko

    2009-01-01

    When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriat...... security model definition and transformation approach, targeting the WS-SecurityPolicy and WS-BPEL specifications, in order to enable a Web-Service-based secure business process development.......When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriate...

  2. A systems approach to college drinking: development of a deterministic model for testing alcohol control policies.

    Science.gov (United States)

    Scribner, Richard; Ackleh, Azmy S; Fitzpatrick, Ben G; Jacquez, Geoffrey; Thibodeaux, Jeremy J; Rommel, Robert; Simonsen, Neal

    2009-09-01

    The misuse and abuse of alcohol among college students remain persistent problems. Using a systems approach to understand the dynamics of student drinking behavior and thus forecasting the impact of campus policy to address the problem represents a novel approach. Toward this end, the successful development of a predictive mathematical model of college drinking would represent a significant advance for prevention efforts. A deterministic, compartmental model of college drinking was developed, incorporating three processes: (1) individual factors, (2) social interactions, and (3) social norms. The model quantifies these processes in terms of the movement of students between drinking compartments characterized by five styles of college drinking: abstainers, light drinkers, moderate drinkers, problem drinkers, and heavy episodic drinkers. Predictions from the model were first compared with actual campus-level data and then used to predict the effects of several simulated interventions to address heavy episodic drinking. First, the model provides a reasonable fit of actual drinking styles of students attending Social Norms Marketing Research Project campuses varying by "wetness" and by drinking styles of matriculating students. Second, the model predicts that a combination of simulated interventions targeting heavy episodic drinkers at a moderately "dry" campus would extinguish heavy episodic drinkers, replacing them with light and moderate drinkers. Instituting the same combination of simulated interventions at a moderately "wet" campus would result in only a moderate reduction in heavy episodic drinkers (i.e., 50% to 35%). A simple, five-state compartmental model adequately predicted the actual drinking patterns of students from a variety of campuses surveyed in the Social Norms Marketing Research Project study. The model predicted the impact on drinking patterns of several simulated interventions to address heavy episodic drinking on various types of campuses.

  3. A Systems Approach to College Drinking: Development of a Deterministic Model for Testing Alcohol Control Policies*

    Science.gov (United States)

    Scribner, Richard; Ackleh, Azmy S.; Fitzpatrick, Ben G.; Jacquez, Geoffrey; Thibodeaux, Jeremy J.; Rommel, Robert; Simonsen, Neal

    2009-01-01

    Objective: The misuse and abuse of alcohol among college students remain persistent problems. Using a systems approach to understand the dynamics of student drinking behavior and thus forecasting the impact of campus policy to address the problem represents a novel approach. Toward this end, the successful development of a predictive mathematical model of college drinking would represent a significant advance for prevention efforts. Method: A deterministic, compartmental model of college drinking was developed, incorporating three processes: (1) individual factors, (2) social interactions, and (3) social norms. The model quantifies these processes in terms of the movement of students between drinking compartments characterized by five styles of college drinking: abstainers, light drinkers, moderate drinkers, problem drinkers, and heavy episodic drinkers. Predictions from the model were first compared with actual campus-level data and then used to predict the effects of several simulated interventions to address heavy episodic drinking. Results: First, the model provides a reasonable fit of actual drinking styles of students attending Social Norms Marketing Research Project campuses varying by “wetness” and by drinking styles of matriculating students. Second, the model predicts that a combination of simulated interventions targeting heavy episodic drinkers at a moderately “dry” campus would extinguish heavy episodic drinkers, replacing them with light and moderate drinkers. Instituting the same combination of simulated interventions at a moderately “wet” campus would result in only a moderate reduction in heavy episodic drinkers (i.e., 50% to 35%). Conclusions: A simple, five-state compartmental model adequately predicted the actual drinking patterns of students from a variety of campuses surveyed in the Social Norms Marketing Research Project study. The model predicted the impact on drinking patterns of several simulated interventions to address heavy

  4. Developing Cognitive Models for Social Simulation from Survey Data

    Science.gov (United States)

    Alt, Jonathan K.; Lieberman, Stephen

    The representation of human behavior and cognition continues to challenge the modeling and simulation community. The use of survey and polling instruments to inform belief states, issue stances and action choice models provides a compelling means of developing models and simulations with empirical data. Using these types of data to population social simulations can greatly enhance the feasibility of validation efforts, the reusability of social and behavioral modeling frameworks, and the testable reliability of simulations. We provide a case study demonstrating these effects, document the use of survey data to develop cognitive models, and suggest future paths forward for social and behavioral modeling.

  5. A Geostationary Earth Orbit Satellite Model Using Easy Java Simulation

    Science.gov (United States)

    Wee, Loo Kang; Goh, Giam Hwee

    2013-01-01

    We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modelled using a Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using a simple constant angular velocity equation. We discuss four computer model design ideas: (1) a simple and realistic…

  6. Optimal policies of non-cross-resistant chemotherapy on Goldie and Coldman's cancer model.

    Science.gov (United States)

    Chen, Jeng-Huei; Kuo, Ya-Hui; Luh, Hsing Paul

    2013-10-01

    Mathematical models can be used to study the chemotherapy on tumor cells. Especially, in 1979, Goldie and Coldman proposed the first mathematical model to relate the drug sensitivity of tumors to their mutation rates. Many scientists have since referred to this pioneering work because of its simplicity and elegance. Its original idea has also been extended and further investigated in massive follow-up studies of cancer modeling and optimal treatment. Goldie and Coldman, together with Guaduskas, later used their model to explain why an alternating non-cross-resistant chemotherapy is optimal with a simulation approach. Subsequently in 1983, Goldie and Coldman proposed an extended stochastic based model and provided a rigorous mathematical proof to their earlier simulation work when the extended model is approximated by its quasi-approximation. However, Goldie and Coldman's analytic study of optimal treatments majorly focused on a process with symmetrical parameter settings, and presented few theoretical results for asymmetrical settings. In this paper, we recast and restate Goldie, Coldman, and Guaduskas' model as a multi-stage optimization problem. Under an asymmetrical assumption, the conditions under which a treatment policy can be optimal are derived. The proposed framework enables us to consider some optimal policies on the model analytically. In addition, Goldie, Coldman and Guaduskas' work with symmetrical settings can be treated as a special case of our framework. Based on the derived conditions, this study provides an alternative proof to Goldie and Coldman's work. In addition to the theoretical derivation, numerical results are included to justify the correctness of our work. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Four Models of In Situ Simulation

    DEFF Research Database (Denmark)

    Musaeus, Peter; Krogh, Kristian; Paltved, Charlotte

    2014-01-01

    Introduction In situ simulation is characterized by being situated in the clinical environment as opposed to the simulation laboratory. But in situ simulation bears a family resemblance to other types of on the job training. We explore a typology of in situ simulation and suggest that there are f......Introduction In situ simulation is characterized by being situated in the clinical environment as opposed to the simulation laboratory. But in situ simulation bears a family resemblance to other types of on the job training. We explore a typology of in situ simulation and suggest...... that there are four fruitful approaches to in situ simulation: (1) In situ simulation informed by reported critical incidents and adverse events from emergency departments (ED) in which team training is about to be conducted to write scenarios. (2) In situ simulation through ethnographic studies at the ED. (3) Using...... the following processes: Transition processes, Action processes and Interpersonal processes. Design and purpose This abstract suggests four approaches to in situ simulation. A pilot study will evaluate the different approaches in two emergency departments in the Central Region of Denmark. Methods The typology...

  8. Modeling and simulation of the SDC data collection chip

    International Nuclear Information System (INIS)

    Hughes, E.; Haney, M.; Golin, E.; Jones, L.; Knapp, D.; Tharakan, G.; Downing, R.

    1992-01-01

    This paper describes modeling and simulation of the Data Collection Chip (DCC) design for the Solenoidal Detector Collaboration (SDC). Models of the DCC written in Verilog and VHDL are described, and results are presented. The models have been simulated to study queue depth requirements and to compare control feedback alternatives. Insight into the management of models and simulation tools is given. Finally, techniques useful in the design process for data acquisition systems are discussed

  9. How much monetary policy rules do we need to estimate DSGE model for Russia?

    OpenAIRE

    Shulgin, Andrei

    2014-01-01

    This paper presents a three-sector DSGE model for a small open economy under the intermediate exchange rate regime. The central bank balance sheet equations are added to allow introducing two different monetary policy rules in the model. The principal question is how many independent monetary policy rules we need to describe Russian monetary policy in 2001–2012. To get an answer we perform Bayesian estimation of the DSGE model for four different combinations of monetary policy rules. The main...

  10. Molecular Simulation towards Efficient and Representative Subsurface Reservoirs Modeling

    KAUST Repository

    Kadoura, Ahmad Salim

    2016-01-01

    This dissertation focuses on the application of Monte Carlo (MC) molecular simulation and Molecular Dynamics (MD) in modeling thermodynamics and flow of subsurface reservoir fluids. At first, MC molecular simulation is proposed as a promising method

  11. Modelling toolkit for simulation of maglev devices

    Science.gov (United States)

    Peña-Roche, J.; Badía-Majós, A.

    2017-01-01

    A stand-alone App1 has been developed, focused on obtaining information about relevant engineering properties of magnetic levitation systems. Our modelling toolkit provides real time simulations of 2D magneto-mechanical quantities for superconductor (SC)/permanent magnet structures. The source code is open and may be customised for a variety of configurations. Ultimately, it relies on the variational statement of the critical state model for the superconducting component and has been verified against experimental data for YBaCuO/NdFeB assemblies. On a quantitative basis, the values of the arising forces, induced superconducting currents, as well as a plot of the magnetic field lines are displayed upon selection of an arbitrary trajectory of the magnet in the vicinity of the SC. The stability issues related to the cooling process, as well as the maximum attainable forces for a given material and geometry are immediately observed. Due to the complexity of the problem, a strategy based on cluster computing, database compression, and real-time post-processing on the device has been implemented.

  12. Simulation and Modeling Application in Agricultural Mechanization

    Directory of Open Access Journals (Sweden)

    R. M. Hudzari

    2012-01-01

    Full Text Available This experiment was conducted to determine the equations relating the Hue digital values of the fruits surface of the oil palm with maturity stage of the fruit in plantation. The FFB images were zoomed and captured using Nikon digital camera, and the calculation of Hue was determined using the highest frequency of the value for R, G, and B color components from histogram analysis software. New procedure in monitoring the image pixel value for oil palm fruit color surface in real-time growth maturity was developed. The estimation of day harvesting prediction was calculated based on developed model of relationships for Hue values with mesocarp oil content. The simulation model is regressed and predicts the day of harvesting or a number of days before harvest of FFB. The result from experimenting on mesocarp oil content can be used for real-time oil content determination of MPOB color meter. The graph to determine the day of harvesting the FFB was presented in this research. The oil was found to start developing in mesocarp fruit at 65 days before fruit at ripe maturity stage of 75% oil to dry mesocarp.

  13. Disability Policy Evaluation: Combining Logic Models and Systems Thinking

    Science.gov (United States)

    Claes, Claudia; Ferket, Neelke; Vandevelde, Stijn; Verlet, Dries; De Maeyer, Jessica

    2017-01-01

    Policy evaluation focuses on the assessment of policy-related personal, family, and societal changes or benefits that follow as a result of the interventions, services, and supports provided to those persons to whom the policy is directed. This article describes a systematic approach to policy evaluation based on an evaluation framework and an…

  14. Impact of policies regulating foreign physician migration to Switzerland: a modelling case study in anaesthesia.

    Science.gov (United States)

    Haller, Guy; Combescure, Christophe; Mamie, Chantal; Zoccatelli, Davide; Clergue, François

    2015-05-22

    Several countries have developed policies that restrict or limit duration of stay, clinical privileges or the number of residency permits allocated to migrating physicians. Switzerland is currently preparing a new law limiting overall foreign immigration. The impact of such restrictive policies is currently unknown. In a case study of anaesthesia care in Switzerland we modelled, trends in the size of physicians' workforce until 2024, following the implementation of a strict quota policy for foreign medical trainees. We developed a computer-based Markov model with Monte-Carlo simulations to project, in the context of a strict quota policy for foreign trainees, supply and demand for anaesthesia positions until 2024. We used data from a cross-sectional study performed in the French- and Italian-speaking cantons of Switzerland and the Health dataset from the OECD. With 8 to 12 (95% CI 4-20) anaesthetists retiring per year, the implementation of strict quotas of foreign graduates would result in a 38% decrease in the number of anaesthetists in intermediary (senior registrars) positions by 2024. This decrease would be particularly important in district hospitals where nearly half (49%) of the non-Swiss anaesthetists are practising. Swiss graduates are unlikely to balance the shortage. Despite efforts by Swiss universities to increase the number of medical graduates, their number has dropped from 10.5 to 9.7/100 000 inhabitants between 2000 and 2012, due to the growth of the population. This case study in Latin Switzerland shows that a restrictive policy limiting foreign immigration of trainees would result in a major deficit in the number of anaesthetists available to meet population needs. These aspects should be carefully considered when countries develop restrictions and limitations of foreign immigration.

  15. Modelization and simulation of capillary barriers

    International Nuclear Information System (INIS)

    Lisbona Cortes, F.; Aguilar Villa, G.; Clavero Gracia, C.; Gracia Lozano, J.L.

    1998-01-01

    Among the different underground transport phenomena, that due to water flows is of great relevance. Water flows in infiltration and percolation processes are responsible of the transport of hazardous wastes towards phreatic layers. From the industrial and geological standpoints, there is a great interest in the design of natural devices to avoid the flows transporting polluting substances. This interest is increased when devices are used to isolate radioactive waste repositories, whose life is to be longer than several hundred years. The so-called natural devices are those based on the superimposition of material with different hydraulic properties. In particular, the flow retention in this kind stratified media, in unsaturated conditions, is basically due to the capillary barrier effect, resulting from placing a low conductivity material over another with a high hydraulic conductivity. Covers designed from the effect above have also to allow a drainage of the upper layer. The lower cost of these covers, with respect to other kinds of protection systems, and the stability in time of their components make them very attractive. However, a previous investigation to determine their effectivity is required. In this report we present the computer code BCSIM, useful for easy simulations of unsaturated flows in a capillary barrier configuration with drainage, and which is intended to serve as a tool for designing efficient covers. The model, the numerical algorithm and several implementation aspects are described. Results obtained in several simulations, confirming the effectivity of capillary barriers as a technique to build safety covers for hazardous waste repositories, are presented. (Author)

  16. An electrical circuit model for simulation of indoor radon concentration.

    Science.gov (United States)

    Musavi Nasab, S M; Negarestani, A

    2013-01-01

    In this study, a new model based on electric circuit theory was introduced to simulate the behaviour of indoor radon concentration. In this model, a voltage source simulates radon generation in walls, conductivity simulates migration through walls and voltage across a capacitor simulates radon concentration in a room. This simulation considers migration of radon through walls by diffusion mechanism in one-dimensional geometry. Data reported in a typical Greek house were employed to examine the application of this technique of simulation to the behaviour of radon.

  17. Aircraft vulnerability analysis by modeling and simulation

    Science.gov (United States)

    Willers, Cornelius J.; Willers, Maria S.; de Waal, Alta

    2014-10-01

    guidance acceleration and seeker sensitivity. For the purpose of this investigation the aircraft is equipped with conventional pyrotechnic decoy flares and the missile has no counter-countermeasure means (security restrictions on open publication). This complete simulation is used to calculate the missile miss distance, when the missile is launched from different locations around the aircraft. The miss distance data is then graphically presented showing miss distance (aircraft vulnerability) as a function of launch direction and range. The aircraft vulnerability graph accounts for aircraft and missile characteristics, but does not account for missile deployment doctrine. A Bayesian network is constructed to fuse the doctrinal rules with the aircraft vulnerability data. The Bayesian network now provides the capability to evaluate the combined risk of missile launch and aircraft vulnerability. It is shown in this paper that it is indeed possible to predict the aircraft vulnerability to missile attack in a comprehensive modelling and a holistic process. By using the appropriate real-world models, this approach is used to evaluate the effectiveness of specific countermeasure techniques against specific missile threats. The use of a Bayesian network provides the means to fuse simulated performance data with more abstract doctrinal rules to provide a realistic assessment of the aircraft vulnerability.

  18. Design and application of a technologically explicit hybrid energy-economy policy model with micro and macro economic dynamics

    Science.gov (United States)

    Bataille, Christopher G. F.

    2005-11-01

    Are further energy efficiency gains, or more recently greenhouse gas reductions, expensive or cheap? Analysts provide conflicting advice to policy makers based on divergent modelling perspectives, a 'top-down/bottom-up debate' in which economists use equation based models that equilibrate markets by maximizing consumer welfare, and technologists use technology simulation models that minimize the financial cost of providing energy services. This thesis summarizes a long term research project to find a middle ground between these two positions that is more useful to policy makers. Starting with the individual components of a behaviourally realistic and technologically explicit simulation model (ISTUM---Inter Sectoral Technology Use Model), or "hybrid", the individual sectors of the economy are linked using a framework of micro and macro economic feedbacks. These feedbacks are taken from the economic theory that informs the computable general equilibrium (CGE) family of models. Speaking in the languages of both economists and engineers, the resulting "physical" equilibrium model of Canada (CIMS---Canadian Integrated Modeling System), equilibrates energy and end-product markets, including imports and exports, for seven regions and 15 economic sectors, including primary industry, manufacturing, transportation, commerce, residences, governmental infrastructure and the energy supply sectors. Several different policy experiments demonstrate the value-added of the model and how its results compare to top-down and bottom-up practice. In general, the results show that technical adjustments make up about half the response to simulated energy policy, and macroeconomic demand adjustments the other half. Induced technical adjustments predominate with minor policies, while the importance of macroeconomic demand adjustment increases with the strength of the policy. Results are also shown for an experiment to derive estimates of future elasticity of substitution (ESUB) and

  19. Model calibration for building energy efficiency simulation

    International Nuclear Information System (INIS)

    Mustafaraj, Giorgio; Marini, Dashamir; Costa, Andrea; Keane, Marcus

    2014-01-01

    Highlights: • Developing a 3D model relating to building architecture, occupancy and HVAC operation. • Two calibration stages developed, final model providing accurate results. • Using an onsite weather station for generating the weather data file in EnergyPlus. • Predicting thermal behaviour of underfloor heating, heat pump and natural ventilation. • Monthly energy saving opportunities related to heat pump of 20–27% was identified. - Abstract: This research work deals with an Environmental Research Institute (ERI) building where an underfloor heating system and natural ventilation are the main systems used to maintain comfort condition throughout 80% of the building areas. Firstly, this work involved developing a 3D model relating to building architecture, occupancy and HVAC operation. Secondly, the calibration methodology, which consists of two levels, was then applied in order to insure accuracy and reduce the likelihood of errors. To further improve the accuracy of calibration a historical weather data file related to year 2011, was created from the on-site local weather station of ERI building. After applying the second level of calibration process, the values of Mean bias Error (MBE) and Cumulative Variation of Root Mean Squared Error (CV(RMSE)) on hourly based analysis for heat pump electricity consumption varied within the following ranges: (MBE) hourly from −5.6% to 7.5% and CV(RMSE) hourly from 7.3% to 25.1%. Finally, the building was simulated with EnergyPlus to identify further possibilities of energy savings supplied by a water to water heat pump to underfloor heating system. It found that electricity consumption savings from the heat pump can vary between 20% and 27% on monthly bases

  20. Econometric Model of Rice Policy Based On Presidential Instruction

    Science.gov (United States)

    Abadi Sembiring, Surya; Hutauruk, Julia

    2018-01-01

    The objective of research is to build an econometric model based on Presidential Instruction rice policy. The data was monthly time series from March 2005 to September 2009. Rice policy model specification using simultaneous equation, consisting of 14 structural equations and four identity equation, which was estimated using Two Stages Least Squares (2SLS) method. The results show that: (1) an increase of government purchasing price of dried harvest paddy has a positive impact on to increase in total rice production and community rice stock, (2) an increase community rice stock lead to decrease the rice imports, (3) an increase of the realization of the distribution of subsidized ZA fertilizers and the realization of the distribution of subsidized NPK fertilizers has a positive impact on to increase in total rice production and community rice stock and to reduce rice imports, (4) the price of the dried harvest paddy is highly responsive to the water content of dried harvest paddy both the short run and long run, (5) the quantity of rice imported is highly responsive to the imported rice price, both short run and long run.

  1. Predictive Capability Maturity Model for computational modeling and simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy; Pilch, Martin M.

    2007-10-01

    The Predictive Capability Maturity Model (PCMM) is a new model that can be used to assess the level of maturity of computational modeling and simulation (M&S) efforts. The development of the model is based on both the authors experience and their analysis of similar investigations in the past. The perspective taken in this report is one of judging the usefulness of a predictive capability that relies on the numerical solution to partial differential equations to better inform and improve decision making. The review of past investigations, such as the Software Engineering Institute's Capability Maturity Model Integration and the National Aeronautics and Space Administration and Department of Defense Technology Readiness Levels, indicates that a more restricted, more interpretable method is needed to assess the maturity of an M&S effort. The PCMM addresses six contributing elements to M&S: (1) representation and geometric fidelity, (2) physics and material model fidelity, (3) code verification, (4) solution verification, (5) model validation, and (6) uncertainty quantification and sensitivity analysis. For each of these elements, attributes are identified that characterize four increasing levels of maturity. Importantly, the PCMM is a structured method for assessing the maturity of an M&S effort that is directed toward an engineering application of interest. The PCMM does not assess whether the M&S effort, the accuracy of the predictions, or the performance of the engineering system satisfies or does not satisfy specified application requirements.

  2. Sunspot Modeling: From Simplified Models to Radiative MHD Simulations

    Directory of Open Access Journals (Sweden)

    Rolf Schlichenmaier

    2011-09-01

    Full Text Available We review our current understanding of sunspots from the scales of their fine structure to their large scale (global structure including the processes of their formation and decay. Recently, sunspot models have undergone a dramatic change. In the past, several aspects of sunspot structure have been addressed by static MHD models with parametrized energy transport. Models of sunspot fine structure have been relying heavily on strong assumptions about flow and field geometry (e.g., flux-tubes, "gaps", convective rolls, which were motivated in part by the observed filamentary structure of penumbrae or the necessity of explaining the substantial energy transport required to maintain the penumbral brightness. However, none of these models could self-consistently explain all aspects of penumbral structure (energy transport, filamentation, Evershed flow. In recent years, 3D radiative MHD simulations have been advanced dramatically to the point at which models of complete sunspots with sufficient resolution to capture sunspot fine structure are feasible. Here overturning convection is the central element responsible for energy transport, filamentation leading to fine-structure and the driving of strong outflows. On the larger scale these models are also in the progress of addressing the subsurface structure of sunspots as well as sunspot formation. With this shift in modeling capabilities and the recent advances in high resolution observations, the future research will be guided by comparing observation and theory.

  3. Incorporating teleconnection information into reservoir operating policies using Stochastic Dynamic Programming and a Hidden Markov Model

    Science.gov (United States)

    Turner, Sean; Galelli, Stefano; Wilcox, Karen

    2015-04-01

    Water reservoir systems are often affected by recurring large-scale ocean-atmospheric anomalies, known as teleconnections, that cause prolonged periods of climatological drought. Accurate forecasts of these events -- at lead times in the order of weeks and months -- may enable reservoir operators to take more effective release decisions to improve the performance of their systems. In practice this might mean a more reliable water supply system, a more profitable hydropower plant or a more sustainable environmental release policy. To this end, climate indices, which represent the oscillation of the ocean-atmospheric system, might be gainfully employed within reservoir operating models that adapt the reservoir operation as a function of the climate condition. This study develops a Stochastic Dynamic Programming (SDP) approach that can incorporate climate indices using a Hidden Markov Model. The model simulates the climatic regime as a hidden state following a Markov chain, with the state transitions driven by variation in climatic indices, such as the Southern Oscillation Index. Time series analysis of recorded streamflow data reveals the parameters of separate autoregressive models that describe the inflow to the reservoir under three representative climate states ("normal", "wet", "dry"). These models then define inflow transition probabilities for use in a classic SDP approach. The key advantage of the Hidden Markov Model is that it allows conditioning the operating policy not only on the reservoir storage and the antecedent inflow, but also on the climate condition, thus potentially allowing adaptability to a broader range of climate conditions. In practice, the reservoir operator would effect a water release tailored to a specific climate state based on available teleconnection data and forecasts. The approach is demonstrated on the operation of a realistic, stylised water reservoir with carry-over capacity in South-East Australia. Here teleconnections relating

  4. Guidelines for Reproducibly Building and Simulating Systems Biology Models.

    Science.gov (United States)

    Medley, J Kyle; Goldberg, Arthur P; Karr, Jonathan R

    2016-10-01

    Reproducibility is the cornerstone of the scientific method. However, currently, many systems biology models cannot easily be reproduced. This paper presents methods that address this problem. We analyzed the recent Mycoplasma genitalium whole-cell (WC) model to determine the requirements for reproducible modeling. We determined that reproducible modeling requires both repeatable model building and repeatable simulation. New standards and simulation software tools are needed to enhance and verify the reproducibility of modeling. New standards are needed to explicitly document every data source and assumption, and new deterministic parallel simulation tools are needed to quickly simulate large, complex models. We anticipate that these new standards and software will enable researchers to reproducibly build and simulate more complex models, including WC models.

  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. Hybrid modeling to support energy-climate policy: Effects of feed-in tariffs to promote renewable energy in Portugal

    International Nuclear Information System (INIS)

    Proença, Sara; St Aubyn, Miguel

    2013-01-01

    Feed-in tariffs have been the main policy instrument applied in Portugal for the promotion of electricity produced from renewable energy sources under the EU Directives on energy and climate regulation. In this paper, we provide an empirical impact assessment of the economic and environmental effects of Portugal's FITs policy to promote RES-E generation. Impact assessment of policy instruments plays a crucial role on decision-making process. For numerical simulations, we make use of a hybrid top-down/bottom-up general equilibrium modeling approach, which represents a reliable tool to analyze the complex interactions between economic, energy, and environmental issues related to energy policies. Numerical simulations confirm the empirical evidence that the FITs policy implemented by Portugal was both an effective and a cost-efficient way to increase the generation of electricity from renewable energy sources and thus to achieve the national RES-E target of 45% in 2010. Results show relatively modest macroeconomic impacts indicating potentially low economic adjustment costs. From an environmental perspective, the deployment of renewable energy source results in significant carbon emissions reductions. - Highlights: ► We provide an impact assessment of Portugal's FITs policy to promote RES-E generation. ► For numerical simulations, we make use of a hybrid top-down/bottom-up general equilibrium model. ► Portugal's FITs policy proved to be a cost-efficient way to increase generation of renewable electricity. ► Results show relatively modest macroeconomic effects indicating potentially low economic adjustment costs. ► The deployment of renewable energy sources results in significant carbon emission reductions

  7. Beyond Modeling: All-Atom Olfactory Receptor Model Simulations

    Directory of Open Access Journals (Sweden)

    Peter C Lai

    2012-05-01

    Full Text Available Olfactory receptors (ORs are a type of GTP-binding protein-coupled receptor (GPCR. These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can validate experimental functional studies as well as generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level. Here we have shown the specific advantages of simulating the dynamic environment that is associated with OR-odorant interactions. We present a rigorous methodology that ranges from the creation of a computationally-derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.

  8. Modelling issues on climate change policies. A discussion of the GTAP-E model

    International Nuclear Information System (INIS)

    Kremers, H.; Nijkamp, P.; Wang, Shunli

    2000-01-01

    Ater the Kyoto agreements the need has arisen to trace the implications of various international environmental strategies. In this paper, we discuss relevant modelling issues of incorporating important environmental policy measures in one of the popular applied general equilibrium models for international trade, the so-called GTAP model. Special attention is paid to an extended version, the GTAP-E (Global Trade Analysis Project - Energy) by addressing the question how to include the widely discussed instruments of International Emission Trading, Joint Implementation, and Clean Development Mechanisms. The paper will be concluded with some policy issues. 10 refs

  9. Modelling issues on climate change policies. A discussion of the GTAP-E model

    Energy Technology Data Exchange (ETDEWEB)

    Kremers, H.; Nijkamp, P.; Wang, Shunli [Department of Spatial Economics, Free University, Amsterdam (Netherlands)

    2000-11-01

    Ater the Kyoto agreements the need has arisen to trace the implications of various international environmental strategies. In this paper, we discuss relevant modelling issues of incorporating important environmental policy measures in one of the popular applied general equilibrium models for international trade, the so-called GTAP model. Special attention is paid to an extended version, the GTAP-E (Global Trade Analysis Project - Energy) by addressing the question how to include the widely discussed instruments of International Emission Trading, Joint Implementation, and Clean Development Mechanisms. The paper will be concluded with some policy issues. 10 refs.

  10. Learning by Doing vs Learning by Researching in a Model of Climate Change Policy Analysis

    International Nuclear Information System (INIS)

    Castelnuovo, E.; Galeotti, M.; Vergalli, S.; Gambarelli, G.

    2004-01-01

    Many predictions and conclusions in the climate change literature have been made and drawn on the basis of theoretical analyses and quantitative models that assume exogenous technological change. One is naturally led to wonder whether those conclusions and policy prescriptions hold in the more realistic case of endogenously evolving technologies. In previous work we took a popular integrated assessment model and modified it so as to allow for an explicit role of the stock of knowledge which accumulates through R and D investment. In our formulation knowledge affects both the output production technology and the emission-output ratio. In this paper we make further progress in our efforts aimed to model the process of technological change. In keeping with recent theories of endogenous growth, we specify two ways in which knowledge accumulates: via a deliberate, optimally selected R and D decision or via experience, giving rise to Learning by Doing. As an illustration, we simulate the model under the two versions of endogenous technical change and look at the dynamics of a selected number of relevant variables, including growth rates of GDP and physical capital, as well as total emissions and rate of domestic abatement. Keywords: Climate Policy, Environmental Modeling, Integrated Assessment, Technical Change

  11. Tax policy can change the production path: A model of optimal oil extraction in Alaska

    International Nuclear Information System (INIS)

    Leighty, Wayne; Lin, C.-Y. Cynthia

    2012-01-01

    We model the economically optimal dynamic oil production decisions for seven production units (fields) on Alaska's North Slope. We use adjustment cost and discount rate to calibrate the model against historical production data, and use the calibrated model to simulate the impact of tax policy on production rate. We construct field-specific cost functions from average cost data and an estimated inverse production function, which incorporates engineering aspects of oil production into our economic modeling. Producers appear to have approximated dynamic optimality. Consistent with prior research, we find that changing the tax rate alone does not change the economically optimal oil production path, except for marginal fields that may cease production. Contrary to prior research, we find that the structure of tax policy can be designed to affect the economically optimal production path, but at a cost in net social benefit. - Highlights: ► We model economically optimal dynamic oil production decisions for 7 Alaska fields. ► Changing tax rate alone does not alter the economically optimal oil production path. ► But change in tax structure can affect the economically optimal oil production path. ► Tax structures that modify the optimal production path reduce net social benefit. ► Field-specific cost functions and inverse production functions are estimated

  12. Smoker-free workplace policies: developing a model of public health consequences of workplace policies barring employment to smokers.

    Science.gov (United States)

    Houle, B; Siegel, M

    2009-02-01

    A marked shift in tobacco-related workplace health promotion intervention involves the adoption of policies barring employment to smokers. We discuss the potential public health consequences of these policies on those affected-smokers, their families, the surrounding community and society at large. We find a lack of published evidence evaluating the effectiveness and consequences of these policies. By developing a model of policy effects, we outline possible unintended consequences. With such large gaps in the evidence base and the potential for deleterious consequences, we argue for increased discussion about the use of smoker-free employment policies as a public health intervention and for increased engagement of employers by the public health community in worksite health promotion.

  13. An integrated model to simulate sown area changes for major crops at a global scale

    Institute of Scientific and Technical Information of China (English)

    WU WenBin; YANG Peng; MENG ChaoYing; SHIBASAKI Ryosuke; ZHOU QingBo; TANG HuaJun; SHI Yun

    2008-01-01

    Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is presented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users' decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions,while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS)global land cover product in 2001. Both validation approaches indicated reliability of the model for addressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally,the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline.The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

  14. The COD Model: Simulating Workgroup Performance

    Science.gov (United States)

    Biggiero, Lucio; Sevi, Enrico

    Though the question of the determinants of workgroup performance is one of the most central in organization science, precise theoretical frameworks and formal demonstrations are still missing. In order to fill in this gap the COD agent-based simulation model is here presented and used to study the effects of task interdependence and bounded rationality on workgroup performance. The first relevant finding is an algorithmic demonstration of the ordering of interdependencies in terms of complexity, showing that the parallel mode is the most simplex, followed by the sequential and then by the reciprocal. This result is far from being new in organization science, but what is remarkable is that now it has the strength of an algorithmic demonstration instead of being based on the authoritativeness of some scholar or on some episodic empirical finding. The second important result is that the progressive introduction of realistic limits to agents' rationality dramatically reduces workgroup performance and addresses to a rather interesting result: when agents' rationality is severely bounded simple norms work better than complex norms. The third main finding is that when the complexity of interdependence is high, then the appropriate coordination mechanism is agents' direct and active collaboration, which means teamwork.

  15. Optical Imaging and Radiometric Modeling and Simulation

    Science.gov (United States)

    Ha, Kong Q.; Fitzmaurice, Michael W.; Moiser, Gary E.; Howard, Joseph M.; Le, Chi M.

    2010-01-01

    OPTOOL software is a general-purpose optical systems analysis tool that was developed to offer a solution to problems associated with computational programs written for the James Webb Space Telescope optical system. It integrates existing routines into coherent processes, and provides a structure with reusable capabilities that allow additional processes to be quickly developed and integrated. It has an extensive graphical user interface, which makes the tool more intuitive and friendly. OPTOOL is implemented using MATLAB with a Fourier optics-based approach for point spread function (PSF) calculations. It features parametric and Monte Carlo simulation capabilities, and uses a direct integration calculation to permit high spatial sampling of the PSF. Exit pupil optical path difference (OPD) maps can be generated using combinations of Zernike polynomials or shaped power spectral densities. The graphical user interface allows rapid creation of arbitrary pupil geometries, and entry of all other modeling parameters to support basic imaging and radiometric analyses. OPTOOL provides the capability to generate wavefront-error (WFE) maps for arbitrary grid sizes. These maps are 2D arrays containing digital sampled versions of functions ranging from Zernike polynomials to combination of sinusoidal wave functions in 2D, to functions generated from a spatial frequency power spectral distribution (PSD). It also can generate optical transfer functions (OTFs), which are incorporated into the PSF calculation. The user can specify radiometrics for the target and sky background, and key performance parameters for the instrument s focal plane array (FPA). This radiometric and detector model setup is fairly extensive, and includes parameters such as zodiacal background, thermal emission noise, read noise, and dark current. The setup also includes target spectral energy distribution as a function of wavelength for polychromatic sources, detector pixel size, and the FPA s charge

  16. Modeling ground-based timber harvesting systems using computer simulation

    Science.gov (United States)

    Jingxin Wang; Chris B. LeDoux

    2001-01-01

    Modeling ground-based timber harvesting systems with an object-oriented methodology was investigated. Object-oriented modeling and design promote a better understanding of requirements, cleaner designs, and better maintainability of the harvesting simulation system. The model developed simulates chainsaw felling, drive-to-tree feller-buncher, swing-to-tree single-grip...

  17. Simulation Modeling of a Facility Layout in Operations Management Classes

    Science.gov (United States)

    Yazici, Hulya Julie

    2006-01-01

    Teaching quantitative courses can be challenging. Similarly, layout modeling and lean production concepts can be difficult to grasp in an introductory OM (operations management) class. This article describes a simulation model developed in PROMODEL to facilitate the learning of layout modeling and lean manufacturing. Simulation allows for the…

  18. Dynamic wind turbine models in power system simulation tool

    DEFF Research Database (Denmark)

    Hansen, A.; Jauch, Clemens; Soerensen, P.

    The present report describes the dynamic wind turbine models implemented in the power system simulation tool DIgSILENT. The developed models are a part of the results of a national research project, whose overall objective is to create a model database in different simulation tools. The report...

  19. A conceptual modeling framework for discrete event simulation using hierarchical control structures.

    Science.gov (United States)

    Furian, N; O'Sullivan, M; Walker, C; Vössner, S; Neubacher, D

    2015-08-01

    Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM's applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models' system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example.

  20. A New Model for Simulating TSS Washoff in Urban Areas

    Directory of Open Access Journals (Sweden)

    E. Crobeddu

    2011-01-01

    Full Text Available This paper presents the formulation and validation of the conceptual Runoff Quality Simulation Model (RQSM that was developed to simulate the erosion and transport of solid particles in urban areas. The RQSM assumes that solid particle accumulation on pervious and impervious areas is infinite. The RQSM simulates soil erosion using rainfall kinetic energy and solid particle transport with linear system theory. A sensitivity analysis was conducted on the RQSM to show the influence of each parameter on the simulated load. Total suspended solid (TSS loads monitored at the outlet of the borough of Verdun in Canada and at three catchment outlets of the City of Champaign in the United States were used to validate the RQSM. TSS loads simulated by the RQSM were compared to measured loads and to loads simulated by the Rating Curve model and the Exponential model of the SWMM software. The simulation performance of the RQSM was comparable to the Exponential and Rating Curve models.

  1. Digital Aquifer - Integrating modeling, technical, software and policy aspects to develop a groundwater management tool

    Science.gov (United States)

    Tirupathi, S.; McKenna, S. A.; Fleming, K.; Wambua, M.; Waweru, P.; Ondula, E.

    2016-12-01

    Groundwater management has traditionally been observed as a study for long term policy measures to ensure that the water resource is sustainable. IBM Research, in association with the World Bank, extended this traditional analysis to include realtime groundwater management by building a context-aware, water rights management and permitting system. As part of this effort, one of the primary objectives was to develop a groundwater flow model that can help the policy makers with a visual overview of the current groundwater distribution. In addition, the system helps the policy makers simulate a range of scenarios and check the sustainability of the groundwater resource in a given region. The system also enables a license provider to check the effect of the introduction of a new well on the existing wells in the domain as well as the groundwater resource in general. This process simplifies how an engineer will determine if a new well should be approved. Distance to the nearest well neighbors and the maximum decreases in water levels of nearby wells are continually assessed and presented as evidence for an engineer to make the final judgment on approving the permit. The system also facilitates updated insights on the amount of groundwater left in an area and provides advice on how water fees should be structured to balance conservation and economic development goals. In this talk, we will discuss the concept of Digital Aquifer, the challenges in integrating modeling, technical and software aspects to develop a management system that helps policy makers and license providers with a robust decision making tool. We will concentrate on the groundwater model developed using the analytic element method that plays a very important role in the decision making aspects. Finally, the efficiency of this system and methodology is shown through a case study in Laguna Province, Philippines, which was done in collaboration with the National Water Resource Board, Philippines and World

  2. Business Process Simulation: Requirements for Business and Resource Models

    Directory of Open Access Journals (Sweden)

    Audrius Rima

    2015-07-01

    Full Text Available The purpose of Business Process Model and Notation (BPMN is to provide easily understandable graphical representation of business process. Thus BPMN is widely used and applied in various areas one of them being a business process simulation. This paper addresses some BPMN model based business process simulation problems. The paper formulate requirements for business process and resource models in enabling their use for business process simulation.

  3. Policy options and their potential effects on Moroccan small farmers and the poor facing increased world food prices: A general equilibrium model analysis

    OpenAIRE

    Diao, Xinshen; Doukkali, Rachid; Yu, Bingxin

    2008-01-01

    "This study evaluates the potential impact of the recent rise in world food prices on the Moroccan economy and possible policy options to respond to it. The study focuses mainly on the poverty effects of such an external shock and the possible policy responses to it. A new social accounting matrix (SAM) and a computable general equilibrium (CGE) model have been developed for this study based on micro-level data in combination with sectoral and economywide data. The CGE model simulations show ...

  4. Coupled energy economic model framework for analyzing Swiss electricity markets in changing policy environments

    OpenAIRE

    Maire, Sophie

    2016-01-01

    Energy policy needs to rely on the proper understanding of the interactions between policy instruments, consumer preferences, investment behavior, market structure, electricity supply, and the wider policy environment. This asks for appropriate modeling tools, able to represent precisely electricity supply options, model all types of energy and climate policies, as well as the reactions of the rest of the economy. Chapter 2 describes the ELECTRA-CH framework, developed to analyze electrici...

  5. Development and Application of Econometric Models for Forecasting and Analysis of Monetary Policy Scenarios

    OpenAIRE

    Malugin, Vladimir; Demidenko , Mikhail; Kalechits, Dmitry; Miksjuk , Alexei; Tsukarev , Taras

    2009-01-01

    A system of econometric models designed for forecasting target monetary indicators as well as conducting monetary policy scenarios analysis is presented. The econometric models integrated in the system are represented in the error correction form and are interlinked by means of monetary policy instruments variables, common exogenous variables characterizing external shocks, and monetary policy target endogenous variables. Forecast accuracy estimates and monetary policy analysis results are pr...

  6. Mathematical model and simulations of radiation fluxes from buried radionuclides

    International Nuclear Information System (INIS)

    Ahmad Saat

    1999-01-01

    A mathematical model and a simple Monte Carlo simulations were developed to predict radiation fluxes from buried radionuclides. The model and simulations were applied to measured (experimental) data. The results of the mathematical model showed good acceptable order of magnitude agreement. A good agreement was also obtained between the simple simulations and the experimental results. Thus, knowing the radionuclide distribution profiles in soil from a core sample, it can be applied to the model or simulations to estimate the radiation fluxes emerging from the soil surface. (author)

  7. Quantum Link Models and Quantum Simulation of Gauge Theories

    International Nuclear Information System (INIS)

    Wiese, U.J.

    2015-01-01

    This lecture is about Quantum Link Models and Quantum Simulation of Gauge Theories. The lecture consists out of 4 parts. The first part gives a brief history of Computing and Pioneers of Quantum Computing and Quantum Simulations of Quantum Spin Systems are introduced. The 2nd lecture is about High-Temperature Superconductors versus QCD, Wilson’s Lattice QCD and Abelian Quantum Link Models. The 3rd lecture deals with Quantum Simulators for Abelian Lattice Gauge Theories and Non-Abelian Quantum Link Models. The last part of the lecture discusses Quantum Simulators mimicking ‘Nuclear’ physics and the continuum limit of D-Theorie models. (nowak)

  8. Modeling and Simulation of U-tube Steam Generator

    Science.gov (United States)

    Zhang, Mingming; Fu, Zhongguang; Li, Jinyao; Wang, Mingfei

    2018-03-01

    The U-tube natural circulation steam generator was mainly researched with modeling and simulation in this article. The research is based on simuworks system simulation software platform. By analyzing the structural characteristics and the operating principle of U-tube steam generator, there are 14 control volumes in the model, including primary side, secondary side, down channel and steam plenum, etc. The model depends completely on conservation laws, and it is applied to make some simulation tests. The results show that the model is capable of simulating properly the dynamic response of U-tube steam generator.

  9. Functional Decomposition of Modeling and Simulation Terrain Database Generation Process

    National Research Council Canada - National Science Library

    Yakich, Valerie R; Lashlee, J. D

    2008-01-01

    .... This report documents the conceptual procedure as implemented by Lockheed Martin Simulation, Training, and Support and decomposes terrain database construction using the Integration Definition for Function Modeling (IDEF...

  10. Global Information Enterprise (GIE) Modeling and Simulation (GIESIM)

    National Research Council Canada - National Science Library

    Bell, Paul

    2005-01-01

    ... AND S) toolkits into the Global Information Enterprise (GIE) Modeling and Simulation (GIESim) framework to create effective user analysis of candidate communications architectures and technologies...

  11. Modeling, Simulation and Position Control of 3DOF Articulated Manipulator

    Directory of Open Access Journals (Sweden)

    Hossein Sadegh Lafmejani

    2014-08-01

    Full Text Available In this paper, the modeling, simulation and control of 3 degrees of freedom articulated robotic manipulator have been studied. First, we extracted kinematics and dynamics equations of the mentioned manipulator by using the Lagrange method. In order to validate the analytical model of the manipulator we compared the model simulated in the simulation environment of Matlab with the model was simulated with the SimMechanics toolbox. A sample path has been designed for analyzing the tracking subject. The system has been linearized with feedback linearization and then a PID controller was applied to track a reference trajectory. Finally, the control results have been compared with a nonlinear PID controller.

  12. Lysimetric evaluation of the APEX Model to simulate daily ET for irrigated crops in the Texas High Plains

    Science.gov (United States)

    The NTT (Nutrient Tracking Tool) was designed to provide an opportunity for all users, including producers, to simulate the complex models, such as APEX (Agricultural Policy Environmental eXtender) and associated required databases. The APEX model currently nested within NTT provides estimates of th...

  13. SD simulation study on degraded farmland policy on farming-pastoral area under the constrains of water resources-Taking Tongliao City of Inner Mongolia as example

    Science.gov (United States)

    Xu, D. P.; Zhao, B.; Li, T. S.; Zhu, J. W.; Yu, M. M.

    2017-08-01

    Water resources are the primary factor in restricting the sustainable development of farming-pastoral regions. To support the sustainable development of water resources, whether or not the land uses patterns of farming-pastoral areas is a reasonably important issue. This paper takes Tongliao city as example for the purpose of sustainably developing the farming-pastoral area in the north. Several scientific preductions and evaluations were conducted to study the farming-pastoral landuse pattern, which is the key problem that effects sustainable development of farming-pastoral areas. The paper then proposes that 1:7 landuse pattern is suitable for the sustainable development of farming-pastotal area. Based on the analysis of the research findings on sustainable development of farming-pastoral area, the paper established a suitability evaluation indicators system of degraded farmland policies in Tongliao city, and used an Analytical Hierarchy Process (AHP) method to determine the weight to run system dynamic (SD) model. The simulation results were then obtained on social economic ecological development in Tongliao city under different degraded farmland policies, and used the comprehensive evaluation model to optimize the results. It is concluded that stabilizing the policy of degraded farmland policy is the preferential policy in Tongliao, which provides useful theoretical research for the sustainable development of farming-pastoral area.

  14. A model for policy analysis of the greenhouse effect

    International Nuclear Information System (INIS)

    Hope, C.

    1992-01-01

    This paper describes the PAGE model (for Policy Analysis of the Greenhouse Effect), developed by Cambridge Decision Analysts for the Directorate general for Environment, Nuclear Safety and Civil Protection of the Commission of the European Communities. The rest of this section describes the motivation for developing PAGE; it is followed by sections outlining the features of PAGE, explaining its structure in more detail, and reporting some of the uses to which it is being put. The current consensus is that unchecked emissions of greenhouse gases will lead to a rise in global mean temperature. The causal chain from emissions to temperature is complex, and current estimates give a range of 2 - 5 deg C for the temperature rise by the year 2100 if no specific actions are taken to control emissions. The damage that a global temperature rise of a few degrees over a century would cause is also not well known. Some influential groups are sufficiently alarmed to have called for global agreements to stabilize or reduce the emissions of greenhouse gases. Others claim that the costs of doing so would not be justified, and that adapting to a changed climate would be the best policy. Negotiations are further complicated by the global nature of the problem; if a country, or even a major trading block such as the European Community, decided to control emissions of a greenhouse gas, some of the benefit would be gained in other parts of the world that have not shared in the cost of control. 12 refs., 6 figs

  15. Application of system dynamics on nuclear policy model

    International Nuclear Information System (INIS)

    An, N. S.; Kim, J. C.; Kim, D. W.; Kang, S. C.

    2000-01-01

    A system dynamics model for a nuclear energy policy in Korea (SIMNEP) was developed to analyze the Korea nuclear system and to predict the influence of the nuclear energy policy in the future. Two cases were analyzed using SIMNEP. The first case is to see the effect of the occurrence of severe nuclear accident in foreign country on the Korean government support. In the beginning, the Korean government support drops but jump up to the higher value than normal support due to the intelligentsia support influenced by the delay time of perception. Then, the national government support converges to the normal support. This turns out that the intelligentsia support plays a major role in increasing the government support. The second case is to see the effect of prior efforts on the foreign factors and/or on domestic factors on the U.S. government support. In the short term, effort on the U.S. government is more effective to increase U.S. government support but in the long term (about after 5 years), efforts on the domestic factors influence on the U.S. government support more than efforts on the foreign factors. The Korean government counter reaction among the influencing factors on the U.S. government support plays a major role to explain this result

  16. JERM model of care: an in-principle model for dental health policy.

    Science.gov (United States)

    Lam, Raymond; Kruger, Estie; Tennant, Marc

    2014-01-01

    Oral diseases are the most prevalent conditions in the community. Their economic burden is high and their impact on quality of life is profound. There is an increasing body of evidence indicating that oral diseases have wider implications beyond the confines of the mouth. The importance of oral health has not been unnoticed by the government. The Commonwealth (Federal) government under the Howard-led Coalition in 2004 had broken tradition by placing dentistry in its universal health insurance scheme, Medicare. Known as the Chronic Disease Dental Scheme (CDDS), the program aimed to manage patients with chronic conditions as part of the Enhanced Primary Care initiative. This scheme was a landmark policy for several reasons. Besides being the first major dental policy under Medicare, the program proved to be the most expensive and controversial. Unfortunately, cost containment and problems with service provision led to its cessation in 2012 by the Gillard Labor Government. Despite being seen as a failure, the CDDS provided a unique opportunity to assess national policy in practice. By analysing the policy-relevant effects of the CDDS, important lessons can be learnt for policy development. This paper discusses these lessons and has formulated a set of principles recommended for effective oral health policy. The JERM model represents the principles of a justified, economical and research-based model of care.

  17. A pedagogical walkthrough of computational modeling and simulation of Wnt signaling pathway using static causal models in MATLAB

    OpenAIRE

    Sinha, Shriprakash

    2016-01-01

    Simulation study in systems biology involving computational experiments dealing with Wnt signaling pathways abound in literature but often lack a pedagogical perspective that might ease the understanding of beginner students and researchers in transition, who intend to work on the modeling of the pathway. This paucity might happen due to restrictive business policies which enforce an unwanted embargo on the sharing of important scientific knowledge. A tutorial introduction to computational mo...

  18. MODEL OF HEAT SIMULATOR FOR DATA CENTERS

    Directory of Open Access Journals (Sweden)

    Jan Novotný

    2016-08-01

    Full Text Available The aim of this paper is to present a design and a development of a heat simulator, which will be used for a flow research in data centers. The designed heat simulator is based on an ideological basis of four-processor 1U Supermicro server. The designed heat simulator enables to control the flow and heat output within the range of 10–100 %. The paper covers also the results of testing measurements of mass flow rates and heat flow rates in the simulator. The flow field at the outlet of the server was measured by the stereo PIV method. The heat flow rate was determined, based on measuring the temperature field at the inlet and outlet of the simulator and known mass flow rate.

  19. Six challenges in modelling for public health policy.

    Science.gov (United States)

    Metcalf, C J E; Edmunds, W J; Lessler, J

    2015-03-01

    The World Health Organisation's definition of public health refers to all organized measures to prevent disease, promote health, and prolong life among the population as a whole (World Health Organization, 2014). Mathematical modelling plays an increasingly important role in helping to guide the most high impact and cost-effective means of achieving these goals. Public health programmes are usually implemented over a long period of time with broad benefits to many in the community. Clinical trials are seldom large enough to capture these effects. Observational data may be used to evaluate a programme after it is underway, but have limited value in helping to predict the future impact of a proposed policy. Furthermore, public health practitioners are often required to respond to new threats, for which there is little or no previous data on which to assess the threat. Computational and mathematical models can help to assess potential threats and impacts early in the process, and later aid in interpreting data from complex and multifactorial systems. As such, these models can be critical tools in guiding public health action. However, there are a number of challenges in achieving a successful interface between modelling and public health. Here, we discuss some of these challenges. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Six challenges in modelling for public health policy

    Directory of Open Access Journals (Sweden)

    C.J.E. Metcalf

    2015-03-01

    Full Text Available The World Health Organisation's definition of public health refers to all organized measures to prevent disease, promote health, and prolong life among the population as a whole (World Health Organization, 2014. Mathematical modelling plays an increasingly important role in helping to guide the most high impact and cost-effective means of achieving these goals. Public health programmes are usually implemented over a long period of time with broad benefits to many in the community. Clinical trials are seldom large enough to capture these effects. Observational data may be used to evaluate a programme after it is underway, but have limited value in helping to predict the future impact of a proposed policy. Furthermore, public health practitioners are often required to respond to new threats, for which there is little or no previous data on which to assess the threat. Computational and mathematical models can help to assess potential threats and impacts early in the process, and later aid in interpreting data from complex and multifactorial systems. As such, these models can be critical tools in guiding public health action. However, there are a number of challenges in achieving a successful interface between modelling and public health. Here, we discuss some of these challenges.