Sublethal toxicant effects with dynamic energy budget theory: model formulation.
Muller, Erik B; Nisbet, Roger M; Berkley, Heather A
2010-01-01
We develop and test a general modeling framework to describe the sublethal effects of pollutants by adding toxicity modules to an established dynamic energy budget (DEB) model. The DEB model describes the rates of energy acquisition and expenditure by individual organisms; the toxicity modules describe how toxicants affect these rates by changing the value of one or more DEB parameters, notably the parameters quantifying the rates of feeding and maintenance. We investigate four toxicity modules that assume: (1) effects on feeding only; (2) effects on maintenance only; (3) effects on feeding and maintenance with similar values for the toxicity parameters; and (4) effects on feeding and maintenance with different values for the toxicity parameters. We test the toxicity modules by fitting each to published data on feeding, respiration, growth and reproduction. Among the pollutants tested are metals (mercury and copper) and various organic compounds (chlorophenols, toluene, polycyclic aromatic hydrocarbons, tetradifon and pyridine); organisms include mussels, oysters, earthworms, water fleas and zebrafish. In most cases, the data sets could be adequately described with any of the toxicity modules, and no single module gave superior fits to all data sets. We therefore propose that for many applications, it is reasonable to use the most general and parameter sparse module, i.e. module 3 that assumes similar effects on feeding and maintenance, as a default. For one example (water fleas), we use parameter estimates to calculate the impact of food availability and toxicant levels on the long term population growth rate. PMID:19633955
Martin, Benjamin
2013-01-01
In the context of ecological risk assessment of chemicals, individual-based population models hold great potential to increase the ecological realism of current regulatory risk assessment procedures. However, developing and parameterizing such models is time-consuming and often ad hoc. Using standardized, tested submodels of individual organisms would make individual-based modelling more efficient and coherent. In this thesis, I explored whether Dynamic Energy Budget (DEB) theory is suitable ...
Augustine, Starrlight; Rosa, Sara; Kooijman, Sebastiaan A. L. M.; Carlotti, François; Poggiale, Jean-Christophe
2014-11-01
Parameters for the standard Dynamic Energy Budget (DEB) model were estimated for the purple mauve stinger, Pelagia noctiluca, using literature data. Overall, the model predictions are in good agreement with data covering the full life-cycle. The parameter set we obtain suggests that P. noctiluca is well adapted to survive long periods of starvation since the predicted maximum reserve capacity is extremely high. Moreover we predict that the reproductive output of larger individuals is relatively insensitive to changes in food level while wet mass and length are. Furthermore, the parameters imply that even if food were scarce (ingestion levels only 14% of the maximum for a given size) an individual would still mature and be able to reproduce. We present detailed model predictions for embryo development and discuss the developmental energetics of the species such as the fact that the metabolism of ephyrae accelerates for several days after birth. Finally we explore a number of concrete testable model predictions which will help to guide future research. The application of DEB theory to the collected data allowed us to conclude that P. noctiluca combines maximizing allocation to reproduction with rather extreme capabilities to survive starvation. The combination of these properties might explain why P. noctiluca is a rapidly growing concern to fisheries and tourism.
A Theory of the Perturbed Consumer with General Budgets
DEFF Research Database (Denmark)
McFadden, Daniel L; Fosgerau, Mogens
We consider demand systems for utility-maximizing consumers facing general budget constraints whose utilities are perturbed by additive linear shifts in marginal utilities. Budgets are required to be compact but are not required to be convex. We define demand generating functions (DGF) whose......-valued and smooth in their arguments. We also give sufficient conditions for integrability of perturbed demand. Our analysis provides a foundation for applications of consumer theory to problems with nonlinear budget constraints....
Hodges, Wilfrid
1993-01-01
An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.
Nambe Pueblo Water Budget and Forecasting model.
Energy Technology Data Exchange (ETDEWEB)
Brainard, James Robert
2009-10-01
This report documents The Nambe Pueblo Water Budget and Water Forecasting model. The model has been constructed using Powersim Studio (PS), a software package designed to investigate complex systems where flows and accumulations are central to the system. Here PS has been used as a platform for modeling various aspects of Nambe Pueblo's current and future water use. The model contains three major components, the Water Forecast Component, Irrigation Scheduling Component, and the Reservoir Model Component. In each of the components, the user can change variables to investigate the impacts of water management scenarios on future water use. The Water Forecast Component includes forecasting for industrial, commercial, and livestock use. Domestic demand is also forecasted based on user specified current population, population growth rates, and per capita water consumption. Irrigation efficiencies are quantified in the Irrigated Agriculture component using critical information concerning diversion rates, acreages, ditch dimensions and seepage rates. Results from this section are used in the Water Demand Forecast, Irrigation Scheduling, and the Reservoir Model components. The Reservoir Component contains two sections, (1) Storage and Inflow Accumulations by Categories and (2) Release, Diversion and Shortages. Results from both sections are derived from the calibrated Nambe Reservoir model where historic, pre-dam or above dam USGS stream flow data is fed into the model and releases are calculated.
Decentralized Budgeting in Education: Model Variations and Practitioner Perspectives.
Hall, George; Metsinger, Jackie; McGinnis, Patricia
In educational settings, decentralized budgeting refers to various fiscal practices that disperse budgeting responsibility away from central administration to the line education units. This distributed decision-making is common to several financial management models. Among the many financial management models that employ decentralized budgeting…
Stochastic Models for Budget Optimization in Search-Based Advertising
Muthukrishnan, S.; Pal, Martin; Svitkina, Zoya
2006-01-01
Internet search companies sell advertisement slots based on users' search queries via an auction. Advertisers have to determine how to place bids on the keywords of their interest in order to maximize their return for a given budget: this is the budget optimization problem. The solution depends on the distribution of future queries. In this paper, we formulate stochastic versions of the budget optimization problem based on natural probabilistic models of distribution over future queries, and ...
JOLIEN DE BAERDEMAEKER; WERNER BRUGGEMAN
2014-01-01
This paper seeks to examine the impact of budget participation on managers’ budgetary motivation from a self-determination theory perspective. Using data from 18 in-depth interviews with a cross-section of managers from three different Western-European companies, we document two types of budget motivation. In particular, the findings suggest that budget participation can relate to both autonomous and controlled budget motivation. That is, budget participation’s effect on autonomous motivation...
A model for analysis of TDA budget allocation
Remer, D. S.; Buchanan, H. R.
1994-01-01
There is an ever-increasing need to achieve greater efficiency in the operation of the Deep Space Network (DSN), i.e., increased productivity at reduced cost. One of the tools used in the course of a planning workshop on this subject was a methodology for budget allocation applicable to long-range planning. This article presents a model for analysis of the TDA budget allocation. For the 1994 through 1999 period, the percentage of the total TDA budget allocated to capacity and capability is being cut in half, whereas the percentage spent on efficiency of delivery will be increasing.
Challenging the Principles of the Beyond Budgeting Model : Can you really go beyond?
Mejzini, Nalan; Seidel, Hendrik
2015-01-01
This thesis examines whether the principles of the beyond budgeting model are entirely separated from any budgeting approach. Research has shown that managers express their concern that budgets are indispensible in their nature. However, the beyond budgeting advocates stress that improving existing budget approaches is not sufficient. Companies should rather abandon budgets and operate according to the beyond budget principles. This contrast between the views triggered the authors of this the...
Combustion theory and modeling
Buckmaster, J; Clavin, Paul; Liñán Martínez, Amable; Matalon, M.; Peters, N; Sivashinsky, G.; Williams, F. A.
2005-01-01
In honor of the fiftieth anniversary of the Combustion Institute, we are asked to assess accomplishments of theory in combustion over the past fifty years and prospects for the future. The title of our article is chosen to emphasize that development of theory necessarily goes hand-in-hand with specification of a model. Good conceptual models underlie successful mathematical theories. Models and theories are discussed here for deflagrations, detonations, diffusion flames, ignition, propellant ...
Barkstrom, Bruce R.; Direskeneli, Haldun; Halyo, Nesim
1992-01-01
An information theory approach to examine the temporal nonuniform sampling characteristics of shortwave (SW) flux for earth radiation budget (ERB) measurements is suggested. The information gain is computed by computing the information content before and after the measurements. A stochastic diurnal model for the SW flux is developed, and measurements for different orbital parameters are examined. The methodology is applied to specific NASA Polar platform and Tropical Rainfall Measuring Mission (TRMM) orbital parameters. The information theory approach, coupled with the developed SW diurnal model, is found to be promising for measurements involving nonuniform orbital sampling characteristics.
3D modeling of satellite spectral images, radiation budget and energy budget of urban landscapes
Gastellu-Etchegorry, J. P.
2008-12-01
DART EB is a model that is being developed for simulating the 3D (3 dimensional) energy budget of urban and natural scenes, possibly with topography and atmosphere. It simulates all non radiative energy mechanisms (heat conduction, turbulent momentum and heat fluxes, water reservoir evolution, etc.). It uses DART model (Discrete Anisotropic Radiative Transfer) for simulating radiative mechanisms: 3D radiative budget of 3D scenes and their remote sensing images expressed in terms of reflectance or brightness temperature values, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (ray tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. This paper presents two major and recent improvements of DART for adapting it to urban canopies. (1) Simulation of the geometry and optical characteristics of urban elements (houses, etc.). (2) Modeling of thermal infrared emission by vegetation and urban elements. The new DART version was used in the context of the CAPITOUL project. For that, districts of the Toulouse urban data base (Autocad format) were translated into DART scenes. This allowed us to simulate visible, near infrared and thermal infrared satellite images of Toulouse districts. Moreover, the 3D radiation budget was used by DARTEB for simulating the time evolution of a number of geophysical quantities of various surface elements (roads, walls, roofs). Results were successfully compared with ground measurements of the CAPITOUL project.
Prest, M
1988-01-01
In recent years the interplay between model theory and other branches of mathematics has led to many deep and intriguing results. In this, the first book on the topic, the theme is the interplay between model theory and the theory of modules. The book is intended to be a self-contained introduction to the subject and introduces the requisite model theory and module theory as it is needed. Dr Prest develops the basic ideas concerning what can be said about modules using the information which may be expressed in a first-order language. Later chapters discuss stability-theoretic aspects of module
Transparency and numeric rules in the budgeting process: Theory and evidence
Amoroso, Nicolás
2008-01-01
In this paper I develop a simple dynamic agency model postulating that, among budgetary institutions, transparency of the budgeting process is the main driving force in explaining differences in fiscal outcomes and that budgetary numeric rules can be an active long-run constraint only if the budgeting process is transparent enough. The model does not only account for long-run differences where countries with better budgetary institutions will have more disciplined fiscal outcomes, but can rat...
Theory Modeling and Simulation
Energy Technology Data Exchange (ETDEWEB)
Shlachter, Jack [Los Alamos National Laboratory
2012-08-23
Los Alamos has a long history in theory, modeling and simulation. We focus on multidisciplinary teams that tackle complex problems. Theory, modeling and simulation are tools to solve problems just like an NMR spectrometer, a gas chromatograph or an electron microscope. Problems should be used to define the theoretical tools needed and not the other way around. Best results occur when theory and experiments are working together in a team.
Kamali, Mikael; Chen, Xiaohang
2014-01-01
The budget is used in many organizations to estimate and control costs. The budgeting process requires extensive knowledge and information exchange between the budget setters in the organization. It is therefore critical for budget setters, often finance and line managers, to communicate and exchange knowledge to reach a budget for the upcoming period. The aim of this thesis is to highlight both budgeting and internal communication findings from past research, and develop a model for how in...
Electric solar wind sail mass budget model
Directory of Open Access Journals (Sweden)
P. Janhunen
2013-02-01
Full Text Available The electric solar wind sail (E-sail is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.
Model of Stochastic Automation Asymptotically Optimal Behavior for Inter-budget Regulation
Directory of Open Access Journals (Sweden)
Elena D. Streltsova
2013-01-01
Full Text Available This paper is focused on the topical issue of inter-budget control in the structure ↔ by applying econometric models. To create the decision-making model, mathematical tool of the theory of stochastic automation, operating in random environments was used. On the basis of the application of this mathematical tool, the adaptive training economic and mathematical model, able to adapt to the environment, maintained by the income from the payment of federal and regional taxes and fees, payable to the budget of the constituent entity of the RF and paid to the budget of a lower level in the form of budget regulation was developed. The authors have developed the structure of the machine, described its behavior in a random environment and introduced the expression for the final probabilities of machine in each of its states. The behavioral aspect of the machine by means of a mathematically rigorous proof of the theorem on the feasibility of behavior and the asymptotic optimality of the proposed design of the machine were presented.
Prospects of Use of Modern Models of Budgeting in Domestic Banks
Zaytseva Iryna P.
2013-01-01
The goal of the article is to identify prospects of use of modern models of budgeting in domestic banking institutions. Having analysed, systemised and generalised scientific and practical developments on this issue, the article considers evolution of models of budgeting and their strong and weak points. As a result, it identifies an aggregate of factors that influence selection of a specific model of budgeting. It justifies that a correctly selected model increases efficiency of the budget p...
Picoche, Coralie; Le Gendre, Romain; Flye-Sainte-Marie, Jonathan; Françoise, Sylvaine; Maheux, Frank; Simon, Benjamin; Gangnery, Aline
2014-01-01
The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB) models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a ...
Bakken, T.H.; Bjørkenes, A.; Dagestad, K
2003-01-01
This is the functional specification of a complete pollution budget model for water. A crucial improvement of this model is implementation of new pollution sources and modification of existing sources. The specification of a water quality model, based on the results from the pollution budget model is also included. The document is intended to give a cost and time estimate of the programming of the functionality it describes, and will be the guideline for implementation of the specified functi...
DEFF Research Database (Denmark)
Andersen, Asger Lau; Lassen, David Dreyer; Nielsen, Lasse Holbøll Westh
The budget forms the legal basis of government spending. If a budget is not in place at the beginning of the fiscal year, planning as well as current spending are jeopardized and government shutdown may result. This paper develops a continuous-time war-of-attrition model of budgeting in a...... presidential style-democracy to explain the duration of budget negotiations. We build our model around budget baselines as reference points for loss averse negotiators. We derive three testable hypotheses: there are more late budgets, and they are more late, when fiscal circumstances change; when such changes...... are negative rather than positive; and when there is divided government. We test the hypotheses of the model using a unique data set of late budgets for US state governments, based on dates of budget approval collected from news reports and a survey of state budget o¢ cers for the period 1988...
How processing digital elevation models can affect simulated water budgets
Kuniansky, E.L.; Lowery, M.A.; Campbell, B.G.
2009-01-01
For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation of the water table used in model cells is estimated via a two-step process. First, a regression equation is developed using existing land and water table elevations from wells in the area. This equation is then used to predict the water table surface for each model cell using land surface elevation available from digital elevation models (DEM). Two methods of processing DEM for estimating the land surface for each cell are commonly used (value nearest the cell centroid or mean value in the cell). This article demonstrates how these two methods of DEM processing can affect the simulated water budget. For the example presented, approximately 20% more total flow through the aquifer system is simulated if the centroid value rather than the mean value is used. This is due to the one-third greater average ground water gradients associated with the centroid value than the mean value. The results will vary depending on the particular model area topography and cell size. The use of the mean DEM value in each model cell will result in a more conservative water budget and is more appropriate because the model cell water table value should be representative of the entire cell area, not the centroid of the model cell.
Corruption, Public Procurement, and the Budget Composition : Theory and Evidence from OECD Countries
Zohal Hessami
2013-01-01
This paper examines the relationship between corruption and the composition of public expenditures. First, I derive a theoretical model that links the degree of corruption in a country - to be understood as the prevailing culture of corruption - to distortions in the budget composition. The transmission channel is a rent-seeking contest where firms from different sectors pay bribes to politicians and bureaucrats to influence public procurement decisions, which give rise to endogenous rents. I...
Holman, Gordon D.
The primary purpose of the Theory and Modeling Group meeting was to identify scientists engaged or interested in theoretical work pertinent to the Max '91 program, and to encourage theorists to pursue modeling which is directly relevant to data which can be expected to result from the program. A list of participants and their institutions is presented. Two solar flare paradigms were discussed during the meeting -- the importance of magnetic reconnection in flares and the applicability of numerical simulation results to solar flare studies.
Kühn, Michael
In order to deal with the complexity of natural systems simplified models are employed to illustrate the principal and regulatory factors controlling a chemical system. Following the aphorism of Albert Einstein: Everything should be made as simple as possible, but not simpler, models need not to be completely realistic to be useful (Stumm and Morgan 1996), but need to meet a successful balance between realism and practicality. Properly constructed, a model is neither too simplified that it is unrealistic nor too detailed that it cannot be readily evaluated and applied to the problem of interest (Bethke 1996). The results of a model have to be at least partially observable or experimentally verifiable (Zhu and Anderson 2002). Geochemical modeling theories are presented here in a sequence of increasing complexity from geochemical equilibrium models to kinetic, reaction path, and finally coupled transport and reaction models. The description is far from complete but provides the needs for the set up of reactive transport models of hydrothermal systems as done within subsequent chapters. Extensive reviews of geochemical models in general can be found in the literature (Appelo and Postma 1999, Bethke 1996, Melchior and Bassett 1990, Nordstrom and Ball 1984, Paschke and van der Heijde 1996).
Duarte, P.; Fernández-Reiriz, M. J.; Labarta, U.
2012-01-01
The environmental and the economic importance of shellfish stimulated a great deal of studies on their physiology over the last decades, with many attempts to model their growth. The first models developed to simulate bivalve growth were predominantly based on the Scope For Growth ( SFG) paradigm. In the last years there has been a shift towards the Dynamic Energy Budget ( DEB) paradigm. The general objective of this work is contributing to the evaluation of different approaches to simulate bivalve growth in low seston waters by: (i) implementing a model to simulate mussel growth in low suspended matter ecosystems based on the DEB theory (Kooijman, S.A.L.M., 2000. Dynamic and energy mass budgets in biological systems, Cambridge University Press); (ii) comparing and discussing different approaches to simulate feeding processes, in the light of recently published works both on experimental physiology and physiology modeling; (iii) comparing and discussing results obtained with a model based on EMMY ( Scholten and Smaal, 1998). The model implemented allowed to successfully simulate mussel feeding and shell length growth in two different Galician Rias. Obtained results together with literature data suggest that modeling of bivalve feeding should incorporate physiologic feed-backs related with food digestibility. In spite of considerable advances in bivalve modeling a number of issues is yet to be resolved, with emphasis on the way food sources are represented and feeding processes formulated.
Information System Model of A Work-Plan Budget
Bens Pardamean; Hutanti Setyodewi
2014-01-01
As a form of accountability in carrying out its duties, functions, and authority, a government agency must prepare a budget and work plan. The budgeting process in many government agencies utilizes manual processes with various documents, resulting in long processing time, numerous errors, and difficulty in data searching. Furthermore, the lack of data integration interferes with the need to meet requirements, standards, and budget-planning deadlines. The research methods were conducted throu...
Exploring the Beta Model Using Proportional Budget Information in a Contingent Valuation Study
Hui Li; Robert P. Berrens; Bohara, Alok K.; Hank C. Jenkins-Smith; Silva, Carol L.; Weimer, David L
2005-01-01
Using a set of random telephone and Internet (web-based) survey samples for a national advisory referendum, we implement Beta models to handle proportional budget information, and allow for consistency in modeling assumptions and the calculation of estimated willingness to pay (WTP). Results indicate significant budget constraint effects and demonstrate the potential for Beta models in handling mental-accounting type information.
Evaluation of a Water Budget Model for Use in Wetland Design
Neuhaus, Eric
2013-01-01
Wetland ecological function greatly depends on the wetland hydrology. As a result, correctly estimating the wetland water budget, is essential to the success of created wetlands. A wetland water budget model, Wetbud, was developed by collaborators from Virginia Tech, Old Dominion University, and the Technical University of Crete for estimating wetland water budgets to assist wetland design in the Virginia Piedmont. The Wetbud model has basic and advanced modules. The basic module uses level p...
Breunig, Christian; Mortensen, Peter B.
2012-01-01
Budget dynamics may sound as a contradiction in terms to scholars familiar with Wildavsky and colleagues' seminal work on public budgeting (Wildavsky 1964). As stated by Davis, Dempster, and Wildavsky (1966, 529): “This year’s budget is based on last year’s budget, with special attention given to a narrow range of increases or decreases.” For some years this simple model was considered something of an empirical law of public budgets. However, already in the 1970s several scholars started to q...
TAn Activity Based Budgeting Model Suggestion For Hotel Enterprises
Şen, Lütfi Mustafa; PAZARÇEVİREN, Selim Yüksel; ZENGİN, Burhanettin
2013-01-01
The main purpose of the study is to reveal that Activity Based Budgeting (ABB) is implementable for tourism enterprises just as hotel enterprises and its importance as a budgeting system by developing an ABB that is special to hotel enterprises and presenting a sample for researchers and implementers. Interview, trip and observation methods were used in the research. Thus, some observations and interviews had been made at an international five star hotel in İstanbul with managers in different...
Probability theory and its models
Humphreys, Paul
2008-01-01
This paper argues for the status of formal probability theory as a mathematical, rather than a scientific, theory. David Freedman and Philip Stark's concept of model based probabilities is examined and is used as a bridge between the formal theory and applications.
Schwaninger, Markus; Grösser, Stefan N.
2008-01-01
The purpose of this contribution is to make the idea of modeling as theory-building operational. We conceive the modeling process as a theory-building process, thereby opening up a new perspective on the methodology of modeling in the social sciences. By reconceptualizing the notion of modeling, we hope to convey the advantages of more conceptual thinking in management. Practitioners could gain effectiveness in dealing with external complexity if they would espouse the modeling task as a disc...
Mkasiwa, Tausi
2011-01-01
This research investigates the phenomenon of budgeting practices in the Tanzanian Central Government. It seeks to understand how budgeting systems under the New Public Management (NPM), World Bank- and IMF-exhorted systems were adopted and implemented. There were several motives for this research: the significance of budgeting in financial management, the sparsity of empirical studies on NPM in developing countries, and a call for an understanding of the local contexts of the country and an e...
International Nuclear Information System (INIS)
We show how to represent a class of expressions involving discrete sums over partitions as matrix models. We apply this technique to the partition functions of 2* theories, i.e. Seiberg-Witten theories with the massive hypermultiplet in the adjoint representation. We consider theories in four, five, and six dimensions, and obtain new matrix models, respectively, of rational, trigonometric, and elliptic type. The matrix models for five- and six-dimensional U(1) theories are derived from the topological vertex construction related to curves of genus one and two.
Sigma models and string theory
International Nuclear Information System (INIS)
The authors present a pedagogical discussion of conformally invariant two-dimensional nonlinear sigma models and their relation to string theory. They show how to calculate the Weyl anomaly coefficients in the bosonic, supersymmetric and heterotic sigma models and explain their interpretation as string theory equations of motion for spacetime background fields
Modelling the global tropospheric ozone budget: exploring the variability in current models
Directory of Open Access Journals (Sweden)
O. Wild
2007-02-01
Full Text Available What are the largest uncertainties in modelling ozone in the troposphere, and how do they affect the calculated ozone budget? Published chemistry-transport model studies of tropospheric ozone differ significantly in their conclusions regarding the importance of the key processes controlling the ozone budget: influx from the stratosphere, chemical processing and surface deposition. This study surveys ozone budgets from previous studies and demonstrates that about two thirds of the increase in ozone production seen between early assessments and more recent model intercomparisons can be accounted for by increased precursor emissions. Model studies using recent estimates of emissions compare better with ozonesonde measurements than studies using older data, and the tropospheric burden of ozone is closer to that derived here from measurement climatologies, 335±10 Tg. However, differences between individual model studies remain large and cannot be explained by surface precursor emissions alone; cross-tropopause transport, wet and dry deposition, humidity, and lightning make large contributions to the differences seen between models. The importance of these processes is examined here using a chemistry-transport model to investigate the sensitivity of the calculated ozone budget to different assumptions about emissions, physical processes, meteorology and model resolution. The budget is particularly sensitive to the magnitude and location of lightning NO_{x} emissions, which remain poorly constrained; the 3–8 TgN/yr range in recent model studies may account for a 10% difference in tropospheric ozone burden and a 1.4 year difference in CH_{4} lifetime. Differences in humidity and dry deposition account for some of the variability in ozone abundance and loss seen in previous studies, with smaller contributions from wet deposition and stratospheric influx. At coarse model resolutions stratospheric influx is systematically overestimated
Dependent-Chance Programming Models for Capital Budgeting in Fuzzy Environments
Institute of Scientific and Technical Information of China (English)
LIANG Rui; GAO Jinwu
2008-01-01
Capital budgeting is concerned with maximizing the total net profit subject to budget constraints by selecting an appropriate combination of projects. This paper presents chance maximizing models for capital budgeting with fuzzy input data and multiple conflicting objectives. When the decision maker sets a prospec-tive profit level and wants to maximize the chances of the total profit achieving the prospective profit level, a fuzzy dependent-chance programming model, a fuzzy multi-objective dependent-chance programming model, and a fuzzy goal dependent-chance programming model are used to formulate the fuzzy capital budgeting problem. A fuzzy simulation based genetic algorithm is used to solve these models. Numerical examples are provided to illustrate the effectiveness of the simulation-based genetic algorithm and the po-tential applications of these models.
DART : a 3D model for remote sensing images and radiative budget of earth surfaces
Gastellu-Etchegorry, J.P.; Grau, E.; Lauret, N.
2012-01-01
Modeling the radiative behavior and the energy budget of land surfaces is relevant for many scientific domains such as the study of vegetation functioning with remotely acquired information. DART model (Discrete Anisotropic Radiative Transfer) is developed since 1992. It is one of the most complete 3D models in this domain. It simulates radiative transfer (R.T.) in the optical domain: 3D radiative budget and remote sensing images (i.e., radiance, reflectance, brightness temperature) of vegeta...
Mashika, Ruth
2016-01-01
This Bachelors’ thesis deals with financial budget development and analysis for a commissioning entity. The main objective was to identify and evaluate the financial viability of alternative modes of operation, analyse the most preferred operating mode, and provide the commissioning entity with a toolkit to facilitate independent budgeting and analysis. The thesis consists of a theory section and an empirical section. The theory section describes business model canvas, master budget, cost...
Budgeting and Budgetary Institutions
Shah, Anwar
2007-01-01
Budgetary institutions have historically played a critical role in a gradual movement toward responsive, responsible, and accountable public governance in industrial countries. This paper includes the following headings: overview; a primer on budgeting and budgetary institutions; the budget and its coverage; capital budgets -- theory and practice; budget methods and practices; a primer on ...
Directory of Open Access Journals (Sweden)
Hlіnska Olha M.
2014-01-01
Full Text Available The article considers issues of efficient budgeting and use of labour resources at coal mining enterprises. It proves expediency of use of modern neuronet, namely, multilayer perceptron, for solution of tasks of modelling the process of budgeting and use of labour resources at coal mining enterprises. It shows that Statistika is the best software package for creation of neuronets of the multilayer perceptron architecture. On the basis of analysis and comparative characteristic the article selects the topology and builds a neuronet model of budgeting and use of labour resources at coal mining enterprises.
Water budget and its variation in Hutuo River basin predicted with the VIP ecohydrological model
Huang, F; Mo, X.
2015-01-01
Accurate assessment of water budgets is important to water resources management and sustainable development in catchments. Here the VIP (Vegetation Interface Processes) ecohydrological model is used to estimate the water budget and its influence factors in Hutuo River basin, China. The model runs from 1956 to 2010 with a spatial resolution of 1 km, utilizing remotely sensed LAI data of MODIS. During the study period the canopy transpiration takes up 58% of evapotranspiration over the whole ca...
Directory of Open Access Journals (Sweden)
Coralie Picoche
Full Text Available The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel-environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy. Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to
Picoche, Coralie; Le Gendre, Romain; Flye-Sainte-Marie, Jonathan; Françoise, Sylvaine; Maheux, Frank; Simon, Benjamin; Gangnery, Aline
2014-01-01
The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB) models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel-environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy). Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration) completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to different
Indonesian local governments’ budgeting practice: a theory of managing the harmonising of interests
Utomo, Dwi
2015-01-01
This study investigates practices of Indonesian local government budgeting during the reform implementation of a performance based budgeting system as the result of the adoption of New Public Management (NPM) in government entities. Despite there being few successful stories about the reform, the study aims to provide an empirical understanding of particular forms of budgetary practices in the context of a developing country that might be different from experiences in developed nations. Addit...
Warped models in string theory
International Nuclear Information System (INIS)
Warped models, originating with the ideas of Randall and Sundrum, provide a fascinating extension of the standard model with interesting consequences for the LHC. We investigate in detail how string theory realises such models, with emphasis on fermion localisation and the computation of Yukawa couplings. We find, in contrast to the 5d models, that fermions can be localised anywhere in the extra dimension, and that there are new mechanisms to generate exponential hierarchies amongst the Yukawa couplings. We also suggest a way to distinguish these string theory models with data from the LHC. (author)
Hollik, W.
2015-01-01
In this conference report a summary is given on the theoretical work that has contributed to provide accurate theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the vector boson masses, for the Z resonance, W pair production, and for the g-2 of the muon are reviewed and the theoretical situation for the Higgs sector is summarized. The status of the standard model is discussed in the light of the recent high and low energy data....
Lika, Konstadia; Kearney, Michael R.; Freitas, Vânia; van der Veer, Henk W.; van der Meer, Jaap; Wijsman, Johannes W. M.; Pecquerie, Laure; Kooijman, Sebastiaan A. L. M.
2011-11-01
The Dynamic Energy Budget (DEB) theory for metabolic organisation captures the processes of development, growth, maintenance, reproduction and ageing for any kind of organism throughout its life-cycle. However, the application of DEB theory is challenging because the state variables and parameters are abstract quantities that are not directly observable. We here present a new approach of parameter estimation, the covariation method, that permits all parameters of the standard Dynamic Energy Budget (DEB) model to be estimated from standard empirical datasets. Parameter estimates are based on the simultaneous minimization of a weighted sum of squared deviations between a number of data sets and model predictions or the minimisation of the negative log likelihood function, both in a single-step procedure. The structure of DEB theory permits the unusual situation of using single data-points (such as the maximum reproduction rate), which we call "zero-variate" data, for estimating parameters. We also introduce the concept of "pseudo-data", exploiting the rules for the covariation of parameter values among species that are implied by the standard DEB model. This allows us to introduce the concept of a generalised animal, which has specified parameter values. We here outline the philosophy behind the approach and its technical implementation. In a companion paper, we assess the behaviour of the estimation procedure and present preliminary findings of emerging patterns in parameter values across diverse taxa.
Window-Dressing and Lobbying in Performance-Budgeting: a Model for the Public Sector
Bischoff, Ivo; Blaeschke, Frédéric
2012-01-01
Performance budgeting schemes in the public sector have to operate with imperfect performance measures. We argue that these imperfections lead to wasteful fund-seeking (window dressing and lobbying) by the administrative units that produce public services. We develop a game-theoretical model to analyse the trade-off between the productivity-enhancing effect of performance budgeting and the social waste it induces. The optimal performancebudgeting scheme crucially depends on the objective func...
Hlіnska Olha M.; Parkhomenko Sergіy O.; Khmelyova Anhelina V.
2014-01-01
The article considers issues of efficient budgeting and use of labour resources at coal mining enterprises. It proves expediency of use of modern neuronet, namely, multilayer perceptron, for solution of tasks of modelling the process of budgeting and use of labour resources at coal mining enterprises. It shows that Statistika is the best software package for creation of neuronets of the multilayer perceptron architecture. On the basis of analysis and comparative characteristic the article sel...
Surface heat budget over the Weddell Sea: Buoy results and model comparisons
Vihma, Timo; Uotila, Juha; Cheng, Bin; Launiainen, Jouko
2002-02-01
The surface heat budget over the Weddell Sea ice cover in 1996 was studied on the basis of data from Argos buoys equipped with meteorological sensors. In addition, a thermodynamic sea ice model, satellite-based data on the sea ice concentration, sonar results on ice thickness distribution, and output from large-scale meteorological models were all utilized. Applying the buoy data, the sensible heat flux over sea ice was calculated by Monin-Obukhov theory using the gradient method, and the latent heat flux was obtained by the bulk method. A second estimate for the surface fluxes was obtained from the thermodynamic sea ice model, which was forced by the buoy observations. The results showed a reasonable agreement. The dominating component in the heat budget over ice was the net longwave radiation, which had a mean annual cooling effect of -28 W m-2. This was balanced by the net shortwave radiation (annual mean 13 W m-2), the sensible (13 W m-2) and latent (-3 W m-2) heat fluxes, and the conductive heat flux through the ice (5 W m-2). The regional surface fluxes over the fractured ice cover were estimated using the buoy data and Special Sensor Microwave Imager (SSMI)-derived ice concentrations. In winter the regional surface sensible heat flux was sensitive to the ice concentration and thickness distribution. The estimate for the area-averaged formation rate of new ice in leads in winter varies from 0.05 to 0.21 m per month depending on the SSMI processing algorithm applied. Countergradient fluxes occurred 8-10% of the time. The buoy observations were compared with the operational analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the reanalyses of the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR). The 2 m air temperature and surface temperature were 3.5° and 4.4°C too high, respectively, in the ECMWF and 3.2° and 3.0°C too low in the NCEP/NCAR fields, but the models reproduced the
Advances in CBL Budgetting and Inverse Modelling by Applying an Off-the-shelf Mesoscale Model
van der Molen, M. K.; Dolman, H.; Ronda, R. J.
2005-12-01
Eddy flux towers measure carbon sinks/sources at a local scale (~0.1 km), with the CBL budget method fluxes may be determined at a landscape scale (~1 km), and inverse models may determine the source/sink distribution at a global/continental scale (~1000-10000 km). Although currently efforts are made to increase the resolution of inverse models to the regional scale (~100 km), the meso-scale (100-1000 km) is rather badly represented in this spectrum of approaches. Boundary layer profiles contain signatures of mesoscale processes, such as the effect of wind divergence, topography and forest breezes on the boundary layer height and the subsidence velocity. 3-D advection of resulting concentration gradients is one of the main reasons of failure of the CBL budget approach and the representation error in inverse models and may be addressed in mesoscale atmospheric models. This study shows that considerable improvement may be obtained in the interpretation of boundary layer profiles by running an off-the-shelf mesoscale model without detailed prior knowlegde of the surface flux distribution. The simulations were carried out in the region around Zotino, Central Siberia to aid the interpretation of profile observations collected as part of TCOS-Siberia.
Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we conducted growth and bioaccumulation studies that contribute t...
Memmesheimer, M.; Ebel, A.; Roemer, M.
1997-01-01
Results from two air quality models (LOTOS, EURAD) have been used to analyse the contribution of the different terms in the continuity equation to the budget of ozone, NO(x) and PAN. Both models cover large parts of Europe and describe the processes relevant for tropospheric chemistry and dynamics.
Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.
2012-01-01
We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.
Stochastic Climate Theory and Modelling
Franzke, Christian L E; Berner, Judith; Williams, Paul D; Lucarini, Valerio
2014-01-01
Stochastic methods are a crucial area in contemporary climate research and are increasingly being used in comprehensive weather and climate prediction models as well as reduced order climate models. Stochastic methods are used as subgrid-scale parameterizations as well as for model error representation, uncertainty quantification, data assimilation and ensemble prediction. The need to use stochastic approaches in weather and climate models arises because we still cannot resolve all necessary processes and scales in comprehensive numerical weather and climate prediction models. In many practical applications one is mainly interested in the largest and potentially predictable scales and not necessarily in the small and fast scales. For instance, reduced order models can simulate and predict large scale modes. Statistical mechanics and dynamical systems theory suggest that in reduced order models the impact of unresolved degrees of freedom can be represented by suitable combinations of deterministic and stochast...
Directory of Open Access Journals (Sweden)
Edo Cvrkalj
2015-12-01
Full Text Available Traditional budgeting principles, with strictly defined business goals, have been, since 1998, slowly growing into more sophisticated and organization-adjusted alternative budgeting concepts. One of those alternative concepts is the “Beyond budgeting” model with an implemented performance effects measuring process. In order for the model to be practicable, budget planning and control has to be reoriented to the “bottom up” planning and control approach. In today’s modern business surroundings one has to take both present and future opportunities and threats into consideration, by valorizing them in a budget which would allow a company to realize a whole pallet of advantages over the traditional budgeting principles which are presented later in the article. It is essential to emphasize the importance of successfully implementing the new budgeting principles within an organization. If the implementation has been lacking and done without a higher goal in mind, it is easily possible that the process has been implemented without coordination, planning and control framework within the organization itself. Further in the article we present an overview of managerial techniques and instruments within the “Beyond budgeting” model such as balanced scorecard, rolling forecast, dashboard, KPI and other supporting instruments. Lastly we define seven steps for implementing the “Beyond budgeting” model and offer a comparison of “Beyond budgeting” model against traditional budgeting principles which lists twelve reasons why “Beyond budgeting” is better suited to modern and market-oriented organizations. Each company faces those challenges in their own characteristic way but implementing new dynamic planning models will soon become essential for surviving in the market.
Pouvreau, Stephane; Bourles, Yves; LEFEBVRE, Sebastien; Gangnery, Aline; ALUNNO-BRUSCIA, Marianne
2006-01-01
The Dynamic Energy Budget (DEB) model (Kooijman, S.A.L.M., 1986. Energy budgets can explain body size relations. J. Theor. Biol. 121, 269¿282; Kooijman, S.A.L.M., 2000. Dynamic Energy and Mass Budgets in Biological Systems. Cambridge University Press, Cambridge, 424 pp.) has been adapted to describe the dynamics of growth and reproduction of the Pacific oyster (Crassostrea gigas) reared in different areas under conditions ranging from controlled to natural. The values of the model parameters ...
State Univ. of New York, Buffalo. Western New York School Study Council.
Although the public is best served by governmental agencies which have integrated the major functions of planning, managing, and budgeting, it can be asserted that the planning function is paramount. A review of the evolution of public agency administration in the U.S. reveals that until recent years the planning function has been largely…
Jones, L R; McCaffery, Jerry L.
2005-01-01
Resource decision making for the Department of Defense (DOD) is one of the most challenging tasks in all of public financial management. DOD coordinates national security threat assessment, long- and intermediate-range planning and programming with annual budget formulation and execution. Between 2001 and 2004, Defense Secretary Donald Rumsfeld changed the system significantly, simplifying, and synchronizing it with presidential terms of office. We assess Planning, Programming, Budgeting S...
The Becker Fertility Model: Theory and Critique
Joseph Burke
2012-01-01
This paper is an exploration of the theoretical properties of the Becker fertility model. I demonstrate that the comparative statics of the Becker fertility model with a general budget constraint and its corresponding expenditure model can be expressed in terms of the ordinary consumer expenditure function with a change of variable. When there are no fixed-costs of quality per child, the Becker fertility model is equivalent to the ordinary consumer model with restrictions on the form of the u...
Ryder, J.; Polcher, J.; Peylin, P.; Ottlé, C.; Chen, Y.; van Gorsel, E.; Haverd, V.; McGrath, M. J.; Naudts, K.; Otto, J.; Valade, A.; Luyssaert, S.
2016-01-01
In Earth system modelling, a description of the energy budget of the vegetated surface layer is fundamental as it determines the meteorological conditions in the planetary boundary layer and as such contributes to the atmospheric conditions and its circulation. The energy budget in most Earth system models has been based on a big-leaf approach, with averaging schemes that represent in-canopy processes. Furthermore, to be stable, that is to say, over large time steps and without large iterations, a surface layer model should be capable of implicit coupling to the atmospheric model. Surface models with large time steps, however, have difficulties in reproducing consistently the energy balance in field observations. Here we outline a newly developed numerical model for energy budget simulation, as a component of the land surface model ORCHIDEE-CAN (Organising Carbon and Hydrology In Dynamic Ecosystems - CANopy). This new model implements techniques from single-site canopy models in a practical way. It includes representation of in-canopy transport, a multi-layer long-wave radiation budget, height-specific calculation of aerodynamic and stomatal conductance, and interaction with the bare-soil flux within the canopy space. Significantly, it avoids iterations over the height of the canopy and so maintains implicit coupling to the atmospheric model LMDz (Laboratoire de Météorologie Dynamique Zoomed model). As a first test, the model is evaluated against data from both an intensive measurement campaign and longer-term eddy-covariance measurements for the intensively studied Eucalyptus stand at Tumbarumba, Australia. The model performs well in replicating both diurnal and annual cycles of energy and water fluxes, as well as the vertical gradients of temperature and of sensible heat fluxes.
Foundations of compositional model theory
Czech Academy of Sciences Publication Activity Database
Jiroušek, Radim
2011-01-01
Roč. 40, č. 6 (2011), s. 623-678. ISSN 0308-1079 R&D Projects: GA MŠk 1M0572; GA ČR GA201/09/1891; GA ČR GEICC/08/E010 Institutional research plan: CEZ:AV0Z10750506 Keywords : multidimensional probability distribution * conditional independence * graphical Markov model * composition of distributions Subject RIV: IN - Informatics, Computer Science Impact factor: 0.667, year: 2011 http://library.utia.cas.cz/separaty/2011/MTR/jirousek-foundations of compositional model theory.pdf
Using a unit cost model to predict the impact of budget cuts on logistics products and services
Van Haasteren, Cleve J.
1992-01-01
Approved for Public Release; Distribution is Unlimited The Director of the Trident Integrated Logistics Support Division at the Naval Sea Systems Command manages a complex and dynamic budget that supports the provision of logistics products and services to the Trident submarine fleet. This thesis focuses on analyzing the Logistics Division budget and developing a model where the impact of a budget cut can be predicted by employing marginal cost. The thesis also explores ...
Logic in the 1930s: type theory and model theory
Schiemer, Georg; Reck, Erich H.
2013-01-01
In historical discussions of twentieth-century logic, it is typically assumed that model theory emerged within the tradition that adopted first-order logic as the standard framework. Work within the type-theoretic tradition, in the style of Principia Mathematica, tends to be downplayed or ignored in this connection. Indeed, the shift from type theory to first-order logic is sometimes seen as involving a radical break that first made possible the rise of modern model theory. ...
Models in theory building: the case of early string theory
International Nuclear Information System (INIS)
The history of the origins and first steps of string theory, from Veneziano's formulation of his famous scattering amplitude in 1968 to the 'first string revolution' in 1984, provides rich material for discussing traditional issues in the philosophy of science. This paper focusses on the initial phase of this history, that is the making of early string theory out of the 'dual theory of strong interactions' motivated by the aim of finding a viable theory of hadrons in the framework of the so-called S-matrix theory of the Sixties: from the first two models proposed (the Dual Resonance Model and the Shapiro-Virasoro Model) to all the subsequent endeavours to extend and complete the theory, including its string interpretation. As is the aim of this paper to show, by representing an exemplary illustration of the building of a scientific theory out of tentative and partial models this is a particularly fruitful case study for the current philosophical discussion on how to characterize a scientific model, a scientific theory, and the relation between models and theories.
Standard Model Double Field Theory
Choi, Kang-Sin
2015-01-01
We show that, without any extra physical degree introduced, the Standard Model can be readily reformulated as a Double Field Theory. Consequently, the Standard Model can couple to an arbitrary stringy gravitational background in an $\\mathbf{O}(4,4)$ T-duality covariant manner and manifests two independent local Lorentz symmetries, $\\mathbf{Spin}(1,3)\\times\\mathbf{Spin}(3,1)$. While the diagonal gauge fixing of the twofold spin groups leads to the conventional formulation on the flat Minkowskian background, the enhanced symmetry makes the Standard Model more rigid, and also stringy, than it appeared. The CP violating $\\theta$-term is no longer allowed by the symmetry, and hence the strong CP problem is solved. There are now stronger constraints imposed on the possible higher order corrections. We urge experimentalists to test if the quarks and the leptons belong to the same spin class or not.
Budgeting rockfall and modeling sedimentary delivery in torrent systems
Loye A.
2014-01-01
This thesis is a compilation of projects to study sediment processes recharging debris flow channels. These works, conducted during my stay at the University of Lausanne, focus in the geological and morphological implications of torrent catchments to characterize debris supply, a fundamental element to predict debris flows. Other aspects of sediment dynamics are considered, e.g. the coupling headwaters - torrent, as well as the development of a modeling software that simulates sediment transf...
Budget study of a mesoscale convective system - Model simulation
Tao, Wei-Kuo; Simpson, Joanne; Mccumber, Michael
1988-01-01
A tropical squall-type cloud cluster is examined as an example of a mesoscale convective complex. The precipitation growth processes and air circulations that develop in the convective and stratiform regions are studied using a data set generated from a time-dependent numerical cloud model. The relationship of the stratiform region of the mesoscale convective complex is discussed. The vertical profiles of heating and drying are calculated. Comparisons are made between simulations with and without ice-phase microphysical processes and a simulation with forcing by weaker lifting at middle and upper levels.
Schulz C; Schulte-Bisping H; Raspe S; Meiwes K-J; Meesenburg H; Konopatzky A; Kallweit R; Einert P; Berthold D; Beese F; Puhlmann M; Jochheim H
2008-01-01
It is shown that by calibrating the simulation model BIOME-BGC with mandatory and optional Level II data, within the ICP Forest programme, a well-founded calculation of the carbon budget of forest stands is achievable and, based on succeeded calibration, the modified BIOME-BGC model is a useful tool to assess the effect of climate change on forest ecosystems.
The global energy budget with a regional climate model over Europe
Chiacchio, Marc; Solmon, Fabien; Giorgi, Filippo; Stackhouse, Paul, Jr.
2013-04-01
With a greater focus recently placed on regional climate modeling for a better understanding of regional climate processes, knowledge of the earth's radiation balance is crucial in these models as it plays a key role as driver of the climate system. Thus, this study evaluates both the longwave and shortwave components of the radiation budget at the surface and top of the atmosphere (TOA) for the present day period over Europe using simulations from the regional climate model RegCM4. The simulations will be assessed by comparing them to radiative fluxes from satellite derived and ground based observations. These data include those from reanalysis products such as ERA40 and the NASA/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget (SRB) Project, which provides global TOA, atmospheric and surface shortwave and longwave radiative fluxes for various uses including detecting climate trends with high precision. Additional radiative fluxes for comparison to the simulated ones, particularly at the TOA, will include the Clouds and Earth's Radiant Energy System (CERES) directly measured fluxes that are still ongoing on three separate satellite missions. Highly accurate ground based measurements, such as the Baseline Surface Radiation Network (BSRN), will also be used for assessing the surface modeled fluxes. The evaluation of the regional model will be further discussed with sensitivity experiments to determine the dependence and impact of climate parameters such as cloud fraction, planetary and surface albedo and surface temperature on the radiation budget taking into account their errors. This analysis will contribute to the usefulness of the regional model for not only evaluating the radiation budget but its determination to simulate the climate as well and its importance within the research community.
Evaluating the global energy budget with a regional climate model over Europe
Chiacchio, M.; Solmon, F.; Giorgi, F.; Stackhouse, P.
2012-04-01
With a greater focus recently placed on regional climate modeling for a better understanding of regional climate processes, knowledge of the earth's radiation balance is crucial in these models as it plays a key role as driver of the climate system. Thus, this study evaluates both the longwave and shortwave components of the radiation budget at the surface and top of the atmosphere (TOA) for the present day period over Europe using simulations from the regional climate model RegCM4. The simulations will be assessed by comparing them to radiative fluxes from satellite derived and ground based observations. These data include those from reanalysis products such as ERA40 and the NASA/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget (SRB) Project, which provides global TOA, atmospheric and surface shortwave and longwave radiative fluxes for various uses including detecting climate trends with high precision. Additional radiative fluxes for comparison to the simulated ones, particularly at the TOA, will include the Clouds and Earth's Radiant Energy System (CERES) directly measured fluxes that are still ongoing on three separate satellite missions. Highly accurate ground based measurements, such as the Baseline Surface Radiation Network (BSRN), will also be used for assessing the surface modeled fluxes. The evaluation of the regional model will be further discussed with sensitivity experiments to determine the dependence and impact of climate parameters such as cloud fraction, planetary and surface albedo and surface temperature on the radiation budget taking into account their errors. This analysis will contribute to the usefulness of the regional model for not only evaluating the radiation budget but its determination to simulate the climate as well and its importance within the research community.
Field theory and the Standard Model
Dudas, E
2014-01-01
This brief introduction to Quantum Field Theory and the Standard Model con- tains the basic building blocks of perturbation theory in quantum field theory, an elementary introduction to gauge theories and the basic classical and quan- tum features of the electroweak sector of the Standard Model. Some details are given for the theoretical bias concerning the Higgs mass limits, as well as on obscure features of the Standard Model which motivate new physics con- structions
Lattice models and conformal field theories
International Nuclear Information System (INIS)
Theoretical studies concerning the connection between critical physical systems and the conformal theories are reviewed. The conformal theory associated to a critical (integrable) lattice model is derived. The obtention of the central charge, critical exponents and torus partition function, using renormalization group arguments, is shown. The quantum group structure, in the integrable lattice models, and the theory of Visaro algebra representations are discussed. The relations between off-critical integrable models and conformal theories, in finite geometries, are studied
Halo modelling in chameleon theories
International Nuclear Information System (INIS)
We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations
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.
Analysis of regional budgets of sulfur species modeled for the COSAM exercise
International Nuclear Information System (INIS)
The COSAM intercomparison exercise (comparison of large-scale sulfur models) was organized to compare and evaluate the performance of global sulfur cycle models. Eleven models participated, and from these models the simulated surface concentrations, vertical profiles and budget terms were submitted. This study focuses on simulated budget terms for the sources and sinks of SO2 and sulfate in three polluted regions in the Northern Hemisphere, i.e., eastern North America, Europe, and Southeast Asia. Qualitatively, features of the sulfur cycle are modelled quite consistently between models, such as the relative importance of dry deposition as a removal mechanism for SO2, the importance of aqueous phase oxidation over gas phase oxidation for SO2, and the importance of wet over dry deposition for removal of sulfate aerosol. Quantitatively, however, models may show large differences, especially for cloud-related processes, i.e., aqueous phase oxidation of SO2 and sulfate wet deposition. In some cases a specific behavior can be related to the treatment of oxidants for aqueous phase SO2 oxidation, or the vertical resolution applied in models. Generally, however, the differences between models appear to be related to simulated cloud (micro-)physics and distributions, whereas differences in vertical transport efficiencies related to convection play an additional role. The estimated sulfur column burdens, lifetimes and export budgets vary between models by about a factor of 2 or 3. It can be expected that uncertainties in related effects which are derived from global sulfur model calculations, such as direct and indirect climate forcing estimates by sulfate aerosol, are at least of similar magnitude
Turbulence kinetic energy budget during the afternoon transition - Part 2: A simple TKE model
Nilsson, Erik; Lothon, Marie; Lohou, Fabienne; Pardyjak, Eric; Hartogensis, Oscar; Darbieu, Clara
2016-07-01
A simple model for turbulence kinetic energy (TKE) and the TKE budget is presented for sheared convective atmospheric conditions based on observations from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign. It is based on an idealized mixed-layer approximation and a simplified near-surface TKE budget. In this model, the TKE is dependent on four budget terms (turbulent dissipation rate, buoyancy production, shear production and vertical transport of TKE) and only requires measurements of three available inputs (near-surface buoyancy flux, boundary layer depth and wind speed at one height in the surface layer) to predict vertical profiles of TKE and TKE budget terms.This simple model is shown to reproduce some of the observed variations between the different studied days in terms of near-surface TKE and its decay during the afternoon transition reasonably well. It is subsequently used to systematically study the effects of buoyancy and shear on TKE evolution using idealized constant and time-varying winds during the afternoon transition. From this, we conclude that many different TKE decay rates are possible under time-varying winds and that generalizing the decay with simple scaling laws for near-surface TKE of the form tα may be questionable.The model's errors result from the exclusion of processes such as elevated shear production and horizontal advection. The model also produces an overly rapid decay of shear production with height. However, the most influential budget terms governing near-surface TKE in the observed sheared convective boundary layers are included, while only second-order factors are neglected. Comparison between modeled and averaged observed estimates of dissipation rate illustrates that the overall behavior of the model is often quite reasonable. Therefore, we use the model to discuss the low-turbulence conditions that form first in the upper parts of the boundary layer during the afternoon transition and are only
Ajami, Hoori; Meixner, Thomas; Maddock, Thomas; Hogan, James F.; Guertin, D. Phillip
2011-09-01
Riparian groundwater evapotranspiration (ETg) constitutes a major component of the water balance especially in many arid and semi-arid environments. Although spatial and temporal variability of riparian ETg are controlled by climate, vegetation and subsurface characteristics, depth to water table (DTWT) is often considered the major controlling factor. Relationships between ETg rates and DTWT, referred to as ETg curves, are implemented in MODFLOW ETg packages (EVT, ETS1 and RIP-ET) with different functional forms. Here, the sensitivity of the groundwater budget in MODFLOW groundwater models to ETg parameters (including ETg curves, land-surface elevation and ETg seasonality) are investigated. A MODFLOW model of the hypothetical Dry Alkaline Valley in the Southwestern USA is used to show how spatial representation of riparian vegetation and digital elevation model (DEM) processing methods impact the water budget when RIPGIS-NET (a GIS-based ETg program) is used with MODFLOW's RIP-ET package, and results are compared with the EVT and ETS1 packages. Results show considerable impact on ETg and other groundwater budget components caused by spatial representation of riparian vegetation, vegetation type, fractional coverage areas and land-surface elevation. RIPGIS-NET enhances ETg estimation in MODFLOW by incorporating vegetation and land-surface parameters, providing a tool for ecohydrology studies, riparian ecosystem management and stream restoration.
Theory, Models and Implementation in Financial Management
J. Morris McInnes; Willard J. Carleton
1982-01-01
A theory of corporate financial management is summarized from the broad flow of finance literature. Within this, contributions to a normative theory, amenable to corporate financial modeling, are reviewed in some detail. The central propositions of a normative theory are isolated to provide a basis of comparison for the practice of financial modeling, as observed through a field research study. Differences between theory and practice are identified and discussed. Compared with the experience ...
Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria
Directory of Open Access Journals (Sweden)
E. Artinyan
2008-01-01
Full Text Available A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997, at an eight km resolution. The impact of the human activities on the rivers (especially hydropower or irrigation was taken into account. An improvement of the hydrometeorological model was made: for better simulation of summer riverflow, two additional reservoirs were added to simulate the slow component of the runoff. Those reservoirs were calibrated using the observed data of the 1st year, while the 2nd year was used for validation. 56 hydrologic stations and 12 dams were used for the model calibration while 41 river gauges were used for the validation of the model. The results compare well with the daily-observed discharges, with good results obtained over more than 25% of the river gauges. The simulated snow depth was compared to daily measurements at 174 stations and the evolution of the snow water equivalent was validated at 5 sites. The process of melting and refreezing of snow was found to be important in this region. The comparison of the normalized values of simulated versus measured soil moisture showed good correlation. The surface water budget shows large spatial variations due to the elevation influence on the precipitation, soil properties and vegetation variability. An inter-annual difference was observed in the water cycle as the first year was more influenced by Mediterranean climate, while the second year was characterised by continental influence. The energy budget shows a dominating sensible heat component in summer, due to the fact that the water stress limits the evaporation. This study is a first step for the implementation of an operational hydrometeorological model that could be used for real time monitoring and forecasting of water budget
International Nuclear Information System (INIS)
An air pollution model (Skewed Puff Model, SPM) based on the Monin-Obukhov similarity theory was applied to investigate the atmospheric dispersion of radionuclides at Ipero' in Brazil, the location of a nuclear industrial installation. The SPM numerical simulation were carried out using an input 5-minute averaged wind speed and direction observed at 11. m, friction velocity and the Monin-Obukhov length supplied by the surface energy-budget model, along with PBL height, estimated for the daytime. The agreement between the observed and simulated sensible and latent heat fluxes, friction velocity and the Monin-Obukhov length, within a level of confidence of 99.9% indicates that the internal parameters chosen for the surface energy-budget model are representative of the interface soil-vegetation conditions at Ipero'. The mean concentration field at the surface was estimated assuming that a hypothetical accident at Ipero' produced a continuous emission from a 10 m high point source for 18 hours during the summer of 1993 and of 36 hours during the winter of 1992. The results indicated that, in the case of an accident, the highest concentration values are located near to the source and most of the contaminated area is within a 5 km range, in both seasons. The shape of the contaminated area is defined by the wind and speed pattern
Apreda, Rodolfo
2002-01-01
This paper introduces a cash flow model to budget and monitor distinctive matters usually arising in corporate governance. By enlarging the standard cash flow model widely used in Finance, and avoiding some of its downsides, it sets up a composite of cash flows called governance slack, which amounts to a comprehensive budget for the most usual governance issues. This slack has a dual structure whose dynamics keeps track of uses and sources of its components, preventing likely agency problems ...
The Friction Theory for Viscosity Modeling
DEFF Research Database (Denmark)
Cisneros, Sergio; Zeberg-Mikkelsen, Claus Kjær; Stenby, Erling Halfdan
2001-01-01
In this work the one-parameter friction theory (f-theory) general models have been extended to the viscosity prediction and modeling of characterized oils. It is demonstrated that these simple models, which take advantage of the repulsive and attractive pressure terms of cubic equations of state...... such as the SRK, PR and PRSV, can provide accurate viscosity prediction and modeling of characterized oils. In the case of light reservoir oils, whose properties are close to those of normal alkanes, the one-parameter f-theory general models can predict the viscosity of these fluids with good accuracy. Yet...... below the saturation pressure. In addition, a tuned f-theory general model delivers accurate modeling of different kinds of light and heavy oils. Thus, the simplicity and stability of the f-theory general models make them a powerful tool for applications such as reservoir simulations, between others. (C...
Turbulence Kinetic Energy budget during the afternoon transition - Part 2: A simple TKE model
Nilsson, E.; Lothon, M.; Lohou, F.; Pardyjak, E.; Hartogensis, O.; Darbieu, C.
2015-11-01
A simple model for turbulence kinetic energy (TKE) and the TKE budget is presented for sheared convective atmospheric conditions based on observations from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign. It is based on an idealized mixed-layer approximation and a simplified near-surface TKE budget. In this model, the TKE is dependent on four budget terms (turbulent dissipation rate, buoyancy production, shear production and vertical transport of TKE) and only requires measurements of three input available (near-surface buoyancy flux, boundary layer depth and wind speed at one height in the surface layer). This simple model is shown to reproduce some of the observed variations between the different studied days in terms of near-surface TKE and its decay during the afternoon transition reasonably well. It is subsequently used to systematically study the effects of buoyancy and shear on TKE evolution using idealized constant and time-varying winds during the afternoon transition. From this, we conclude that many different TKE decay rates are possible under time-varying winds and that generalizing the decay with simple scaling laws for near-surface TKE of the form tα may be questionable. The model's errors result from the exclusion of processes such as elevated shear production and horizontal advection. The model also produces an overly rapid decay of shear production with height. However, the most influential budget terms governing near-surface TKE in the observed sheared convective boundary layers are included, while only second order factors are neglected. Comparison between modeled and averaged observed estimates of dissipation rate illustrate that the overall behavior of the model is often quite reasonable. Therefore, we use the model to discuss the low turbulence conditions that form first in the upper parts of the boundary layer during the afternoon transition and are only apparent later near the surface. This occurs as a
Green, Sophie M.; Baird, Andy J.
2016-04-01
There is growing interest in estimating annual budgets of peatland-atmosphere carbon dioxide (CO2) and methane (CH4) exchanges. Such budgeting is required for calculating peatland carbon balance and the radiative forcing impact of peatlands on climate. There have been multiple approaches used to estimate CO2 budgets; however, there is a limited literature regarding the modelling of annual CH4 budgets. Using data collected from flux chamber tests in an area of blanket peatland in North Wales, we compared annual estimates of peatland-atmosphere CH4 emissions using an interpolation approach and an additive and multiplicative modelling approach. Flux-chamber measurements represent a snapshot of the conditions on a particular site. In contrast to CO2, most studies that have estimated the time-integrated flux of CH4 have not used models. Typically, linear interpolation is used to estimate CH4 fluxes during the time periods between flux-chamber measurements. It is unclear how much error is involved with such a simple integration method. CH4 fluxes generally show a rise followed by a fall through the growing season that may be captured reasonably well by interpolation, provided there are sufficiently frequent measurements. However, day-to-day and week-to-week variability is also often evident in CH4 flux data, and will not necessarily be properly represented by interpolation. Our fits of the CH4 flux models yielded r2 > 0.5 in 38 of the 48 models constructed, with 55% of these having a weighted rw2 > 0.4. Comparison of annualised CH4 fluxes estimated by interpolation and modelling reveals no correlation between the two data sets; indeed, in some cases even the sign of the flux differs. The difference between the methods seems also to be related to the size of the flux - for modest annual fluxes there is a fairly even scatter of points around the 1:1 line, whereas when the modelled fluxes are high, the corresponding interpolated fluxes tend to be low. We consider the
Applications of model theory to functional analysis
Iovino, Jose
2014-01-01
During the last two decades, methods that originated within mathematical logic have exhibited powerful applications to Banach space theory, particularly set theory and model theory. This volume constitutes the first self-contained introduction to techniques of model theory in Banach space theory. The area of research has grown rapidly since this monograph's first appearance, but much of this material is still not readily available elsewhere. For instance, this volume offers a unified presentation of Krivine's theorem and the Krivine-Maurey theorem on stable Banach spaces, with emphasis on the
Quantum field theory competitive models
Tolksdorf, Jürgen; Zeidler, Eberhard
2009-01-01
For more than 70 years, quantum field theory (QFT) can be seen as a driving force in the development of theoretical physics. Equally fascinating is the fruitful impact which QFT had in rather remote areas of mathematics. The present book features some of the different approaches, different physically viewpoints and techniques used to make the notion of quantum field theory more precise. For example, the present book contains a discussion including general considerations, stochastic methods, deformation theory and the holographic AdS/CFT correspondence. It also contains a discussion of more recent developments like the use of category theory and topos theoretic methods to describe QFT. The present volume emerged from the 3rd 'Blaubeuren Workshop: Recent Developments in Quantum Field Theory', held in July 2007 at the Max Planck Institute of Mathematics in the Sciences in Leipzig/Germany. All of the contributions are committed to the idea of this workshop series: 'To bring together outstanding experts working in...
Directory of Open Access Journals (Sweden)
Schulz C
2009-01-01
Full Text Available It is shown that by calibrating the simulation model BIOME-BGC with mandatory and optional Level II data, within the ICP Forest programme, a well-founded calculation of the carbon budget of forest stands is achievable and, based on succeeded calibration, the modified BIOME-BGC model is a useful tool to assess the effect of climate change on forest ecosystems.
Troost, T. A.; Wijsman, J.W.M.; Saraiva, S.; de Freitas, V.
2010-01-01
Dynamic energy budget models for growth of individual cockles (Cerastoderma edule) and mussels (Mytilus edulis) are adjusted and calibrated to the Oosterschelde by formulating and parametrizing their functional responses using an extensive set of field observations. The resulting model predictions fit the observations satisfactorily. Results indicate that food quality and the importance of detritus as a food source are site-specific as well as species-specific. Despite these differences in th...
Domain Theory, Its Models and Concepts
DEFF Research Database (Denmark)
Andreasen, Mogens Myrup; Howard, Thomas J.; Bruun, Hans Peter Lomholt
2014-01-01
Domain Theory is a systems approach for the analysis and synthesis of products. Its basic idea is to view a product as systems of activities, organs and parts and to define structure, elements, behaviour and function in these domains. The theory is a basis for a long line of research contributions...... and industrial applications especially for the DFX areas (not reported here) and for product modelling. The theory therefore contains a rich ontology of interrelated concepts. The Domain Theory is not aiming to create normative methods but the creation of a collection of concepts related to design phenomena......, which can support design work and to form elements of designers’ mindsets and thereby their practice. The theory is a model-based theory, which means it is composed of concepts and models, which explains certain design phenomena. Many similar theories are described in the literature with differences...
Theory and Experience in Deliberative Democracy and Budget Review%协商民主与预算审议的理论与经验
Institute of Scientific and Technical Information of China (English)
顾维萌
2012-01-01
The theory of deliberative democracy emphasizes that through the way of rational dialogue in freedom and equality, debate, citizens should participate in public affairs consultation, deliberation, giving legitimacy to legislation and decision, which will be of great significance to the budget review. The practices of participatory budgeting in Brazil Porto Alegre and China Wenling are typical cases of deliberative democracy. Referring to the theory of deliberative democracy and participatory budgeting practice, China＇s regime improvement about budget review should start from consummating legal system; Structuring procedure mechanism and promoting citizens＇ autonomous ability in participation.%协商民主理论强调公民通过自由、平等的理性对话、辩论、协商、审议等方式来参与公共事务，赋予立法和决策以合法性，对预算审议有着重要意义。巴西阿雷格里港市和中国温岭的参与式预算实践是协商民主的典型体现。要想通过借鉴协商民主理论和参与式预算实践完善我国预算审议制度，就必须完善法律体系，构建程序机制，提升民众参与自治的能力。
Theories, Models and Methodology in Writing Research
Rijlaarsdam, Gert; Bergh, van den Huub; Couzijn, Michel
1996-01-01
Theories, Models and Methodology in Writing Research describes the current state of the art in research on written text production. The chapters in the first part offer contributions to the creation of new theories and models for writing processes. The second part examines specific elements of the w
The Friction Theory for Viscosity Modeling
DEFF Research Database (Denmark)
Cisneros, Sergio; Zeberg-Mikkelsen, Claus Kjær; Stenby, Erling Halfdan
2001-01-01
In this work the one-parameter friction theory (f-theory) general models have been extended to the viscosity prediction and modeling of characterized oils. It is demonstrated that these simple models, which take advantage of the repulsive and attractive pressure terms of cubic equations of state...... such as the SRK, PR and PRSV, can provide accurate viscosity prediction and modeling of characterized oils. In the case of light reservoir oils, whose properties are close to those of normal alkanes, the one-parameter f-theory general models can predict the viscosity of these fluids with good accuracy....... Yet, in the case when experimental information is available a more accurate modeling can be obtained by means of a simple tuning procedure. A tuned f-theory general model can deliver highly accurate viscosity modeling above the saturation pressure and good prediction of the liquid-phase viscosity at...
Cockey, Caroline
This report examines New York State's experience with multi-element formulas in budgeting for the State University of New York, and considers some of the obstacles confronting scientific budgeting in a political environment. A specific budgeting formula (the Academic Discipline Model) is examined, its evolution and application discussed, and the…
Barkstrom, B. R.
1983-01-01
The measurement of the earth's radiation budget has been chosen to illustrate the technique of objective system design. The measurement process is an approximately linear transformation of the original field of radiant exitances, so that linear statistical techniques may be employed. The combination of variability, measurement strategy, and error propagation is presently made with the help of information theory, as suggested by Kondratyev et al. (1975) and Peckham (1974). Covariance matrices furnish the quantitative statement of field variability.
Energy- and flux-budget (EFB) turbulence closure model for stably stratified flows
Zilitinkevich, S S; Kleeorin, N; Rogachevskii, I
2006-01-01
We propose a new turbulence closure model based on the budget equations for the basic second moments: turbulent kinetic and potential energies: TKE and TPE, which comprise the turbulent total energy: TTE = TKE + TPE; and vertical turbulent fluxes of momentum and buoyancy (potential temperature). Besides the new concept of the TTE, other key points are: non-gradient correction to the traditional formulation for the flux of buoyancy (potential temperature), and advanced analysis of the stability dependence of anisotropy of turbulence. The proposed model affords the existence of turbulence at any gradient Richardson number, Ri. Instead of the critical value of Ri separating the turbulent and the laminar regimes, the model includes its threshold value, between 0.2 and 0.3, which separates two turbulent regimes of essentially different nature: fully developed, chaotic turbulence at low Ri and weak, strongly anisotropic turbulence at large Ri. Predictions from the proposed model are consistent with available data f...
A Budget Impact Model for Paclitaxel-eluting Stent in Femoropopliteal Disease in France
International Nuclear Information System (INIS)
The Zilver PTX drug-eluting stent (Cook Ireland Ltd., Limerick, Ireland) represents an advance in endovascular treatments for atherosclerotic superficial femoral artery (SFA) disease. Clinical data demonstrate improved clinical outcomes compared to bare-metal stents (BMS). This analysis assessed the likely impact on the French public health care budget of introducing reimbursement for the Zilver PTX stent. A model was developed in Microsoft Excel to estimate the impact of a progressive transition from BMS to Zilver PTX over a 5-year horizon. The number of patients undergoing SFA stenting was estimated on the basis of hospital episode data. The analysis from the payer perspective used French reimbursement tariffs. Target lesion revascularization (TLR) after primary stent placement was the primary outcome. TLR rates were based on 2-year data from the Zilver PTX single-arm study (6 and 9 %) and BMS rates reported in the literature (average 16 and 22 %) and extrapolated to 5 years. Net budget impact was expressed as the difference in total costs (primary stenting and reinterventions) for a scenario where BMS is progressively replaced by Zilver PTX compared to a scenario of BMS only. The model estimated a net cumulative 5-year budget reduction of €6,807,202 for a projected population of 82,316 patients (21,361 receiving Zilver PTX). Base case results were confirmed in sensitivity analyses. Adoption of Zilver PTX could lead to important savings for the French public health care payer. Despite higher initial reimbursement for the Zilver PTX stent, fewer expected SFA reinterventions after the primary stenting procedure result in net savings.
A Budget Impact Model for Paclitaxel-eluting Stent in Femoropopliteal Disease in France
Energy Technology Data Exchange (ETDEWEB)
De Cock, Erwin, E-mail: erwin.decock@unitedbiosource.com [United BioSource Corporation, Peri- and Post-Approval Services (Spain); Sapoval, Marc, E-mail: Marc.sapoval2@egp.aphp.fr [Hopital Europeen Georges Pompidou, Universite Rene Descartes, Department of Cardiovascular and Interventional Radiology (France); Julia, Pierre, E-mail: pierre.julia@egp.aphp.fr [Hopital Europeen Georges Pompidou, Universite Rene Descartes, Cardiovascular Surgery Department (France); Lissovoy, Greg de, E-mail: gdelisso@jhsph.edu [Johns Hopkins Bloomberg School of Public Health, Department of Health Policy and Management (United States); Lopes, Sandra, E-mail: Sandra.Lopes@CookMedical.com [Cook Medical, Health Economics and Reimbursement (Denmark)
2013-04-15
The Zilver PTX drug-eluting stent (Cook Ireland Ltd., Limerick, Ireland) represents an advance in endovascular treatments for atherosclerotic superficial femoral artery (SFA) disease. Clinical data demonstrate improved clinical outcomes compared to bare-metal stents (BMS). This analysis assessed the likely impact on the French public health care budget of introducing reimbursement for the Zilver PTX stent. A model was developed in Microsoft Excel to estimate the impact of a progressive transition from BMS to Zilver PTX over a 5-year horizon. The number of patients undergoing SFA stenting was estimated on the basis of hospital episode data. The analysis from the payer perspective used French reimbursement tariffs. Target lesion revascularization (TLR) after primary stent placement was the primary outcome. TLR rates were based on 2-year data from the Zilver PTX single-arm study (6 and 9 %) and BMS rates reported in the literature (average 16 and 22 %) and extrapolated to 5 years. Net budget impact was expressed as the difference in total costs (primary stenting and reinterventions) for a scenario where BMS is progressively replaced by Zilver PTX compared to a scenario of BMS only. The model estimated a net cumulative 5-year budget reduction of Euro-Sign 6,807,202 for a projected population of 82,316 patients (21,361 receiving Zilver PTX). Base case results were confirmed in sensitivity analyses. Adoption of Zilver PTX could lead to important savings for the French public health care payer. Despite higher initial reimbursement for the Zilver PTX stent, fewer expected SFA reinterventions after the primary stenting procedure result in net savings.
Bromley, J. M.; Somerville, R. S.; Fabian, A. C.
2004-05-01
We investigate the constraints on models of supermassive black hole (SMBH) and quasar formation obtainable from two recent observational developments: the discovery of luminous quasars at z~ 6, and estimates of the local mass density of SMBHs. If ~90 per cent of this mass was accreted at redshifts zjoint constraints pose a challenge for models, which must account for the observed luminous quasar population at z~ 6 within a very limited `mass budget'. We investigate a class of models based within the hierarchical structure formation scenario, in which major mergers lead to black hole formation and fuelling, and the resulting quasars shine at their Eddington-limited rate until their fuel is exhausted. We show that the simplest such model, in which a constant fraction of the gas within the halo is accreted in each major merger, cannot satisfy both constraints simultaneously. When this model is normalized to reproduce the number density of luminous quasars at z~ 6, the mass budget is grossly exceeded owing to an overabundance of lower-mass SMBHs. We explore a range of modifications to the simple model designed to overcome this problem. We show that both constraints can be satisfied if the gas accretion fraction scales as a function of the halo virial velocity. Similar scalings have been proposed in order to reproduce the local M•-σ relation. Successful models can also be constructed by restricting the formation of seed black holes to redshifts above zcrit~ 11.5 or to haloes above a velocity threshold vcrit~ 55 km s-1, or assuming that only a fraction of major mergers result in formation of a seed SMBH. We also briefly discuss the issue of trying to assume a `universal M•-σ relation' within the framework of simple Press-Schechter models, and further show that a fixed universal relation between SMBH mass and host halo mass is unlikely.
Energy Technology Data Exchange (ETDEWEB)
Zhang, Xuesong; Izaurralde, Roberto C.; Manowitz, David H.; Sahajpal, Ritvik; West, Tristram O.; Thomson, Allison M.; Xu, Min; Zhao, Kaiguang; LeDuc, Stephen D.; Williams, Jimmy R.
2015-01-01
Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO2 concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatially-explicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems to each of them by geo-referencing surveyed crop management information at the county or state level. A parallel computing algorithm was also developed to facilitate the computationally intensive model runs and output post-processing and visualization. We evaluated GAMS against National Agricultural Statistics Service (NASS) reported crop yields and inventory estimated county-scale cropland C budgets averaged over 2000–2008. We observed good overall agreement, with spatial correlation of 0.89, 0.90, 0.41, and 0.87, for crop yields, Net Primary Production (NPP), Soil Organic C (SOC) change, and Net Ecosystem Exchange (NEE), respectively. However, we also detected notable differences in the magnitude of NPP and NEE, as well as in the spatial pattern of SOC change. By performing crop-specific annual comparisons, we discuss possible explanations for the discrepancies between GAMS and the inventory method, such as data requirements, representation of agroecosystem processes, completeness and accuracy of crop management data, and accuracy of crop area representation. Based on these analyses, we further discuss strategies to improve GAMS by updating input
Hentschke, Guilbert C.; Shaughnessy, John
1973-01-01
Attempts to describe the budgeting process in school districts. Discusses general budget calendars and explains the process of constructing a Program Evaluation and Review Technique (PERT) chart of the budgeting process. Presents a detailed list of activities to be included in the budgeting process and a PERT chart indicating how these activities…
Energy Technology Data Exchange (ETDEWEB)
Sanchez-Gomez, E. [CERFACS/CNRS, SUC URA1875, Toulouse Cedex (France); Somot, S.; Dubois, C.; Deque, M. [CNRM/GAME, Meteo-France/CNRS, Toulouse (France); Josey, S.A. [National Oceanography Centre, Southampton (United Kingdom); Elguindi, N. [LA, CNRS, Toulouse (France)
2011-11-15
Air-sea heat and freshwater water fluxes in the Mediterranean Sea play a crucial role in dense water formation. Here, we compare estimates of Mediterranean Sea heat and water budgets from a range of observational datasets and discuss the main differences between them. Taking into account the closure hypothesis at the Gibraltar Strait, we have built several observational estimates of water and heat budgets by combination of their different observational components. We provide then three estimates for water budget and one for heat budget that satisfy the closure hypothesis. We then use these observational estimates to assess the ability of an ensemble of ERA40-driven high resolution (25 km) Regional Climate Models (RCMs) from the FP6-EU ENSEMBLES database, to simulate the various components, and net values, of the water and heat budgets. Most of the RCM Mediterranean basin means are within the range spanned by the observational estimates of the different budget components, though in some cases the RCMs have a tendency to overestimate the latent heat flux (or evaporation) with respect to observations. The RCMs do not show significant improvements of the total water budget estimates comparing to ERA40. Moreover, given the large spread found in observational estimates of precipitation over the sea, it is difficult to draw conclusions on the performance of RCM for the freshwater budget and this underlines the need for better precipitation observations. The original ERA40 value for the basin mean net heat flux is -15 W/m{sup 2} which is 10 W/m{sup 2} less than the value of -5 W/m{sup 2} inferred from the transport measurements at Gibraltar Strait. The ensemble of heat budget values estimated from the models show that most of RCMs do not achieve heat budget closure. However, the ensemble mean value for the net heat flux is -7 {+-} 21 W/m{sup 2}, which is close to the Gibraltar value, although the spread between the RCMs is large. Since the RCMs are forced by the same
Mean kinetic energy budget of wakes within an array of model wind turbines and porous discs
Cal, Raúl Bayoán; Camp, Elizabeth
2015-11-01
Wind turbines are often modeled as porous actuator discs within computational studies. In this wind tunnel study, stereo particle image velocimetry (SPIV) is used to characterize the wakes within a 4 ×3 model wind turbine array and an analogous array of porous disks. The SPIV measurements are performed upstream between - 2 . 9 <= x / D <= - 0 . 3 and downstream between 0 . 7 <= x / D <= 5 . 6 of the center turbine in the fourth row. To provide context, the similarities and differences in the flow fields as well as the mean and turbulent stresses are found. The primary analysis revolves around the mean kinetic energy budget in the wakes for both cases, model turbines and discs, obtained by the computation of mean kinetic energy, production of turbulence and flux of kinetic energy as these are equivalent to a measure of extracted power.
Particle hopping models and traffic flow theory
Nagel, Kai
1995-01-01
This paper shows how particle hopping models fit into the context of traffic flow theory. Connections between fluid-dynamical traffic flow models, which derive from the Navier-Stokes-equations, and particle hopping models are shown. In some cases, these connections are exact and have long been established, but have never been viewed in the context of traffic theory. In other cases, critical behavior of traffic jam clusters can be compared to instabilities in the partial differential equations...
Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria
Directory of Open Access Journals (Sweden)
E. Artinyan
2007-03-01
Full Text Available A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used in order to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997, at an eight km resolution. It was based on the data available at the National Institute of Meteorology and Hydrology (NIMH of Bulgaria. Atmospheric parameters were carefully checked and interpolated with a high level of detail in space and time (3-h step. Comparing computed Penman evapotranspiration versus observed pan evaporation validated the quality of the implemented forcing. The impact of the human activities on the rivers (especially hydropower or irrigation was taken into account. Some improvements of the hydrometeorological model were made: for better simulation of summer riverflow, two additional reservoirs were added to simulate the slow component of the runoff. Those reservoirs were calibrated using the observed data of the 1st year, while the 2nd year was used for validation. 56 hydrologic stations and 12 dams were used for the model calibration while 41 rivergages were used for the validation of the model. The results compare well with the daily-observed discharges, with good results obtained over more than 25% of the rivergages. The simulated snow depth was compared to daily measurements at 174 stations and the evolution of the snow water equivalent was validated at 5 sites. The process of melting and refreezing of snow was found to be important on this region. The comparison of the normalized values of simulated versus measured soil moisture showed good correlation. The surface water budget shows large spatial variations due to the elevation influence on the precipitations, soil properties and vegetation variability. An inter annual difference was observed in the water cycle as the first year was more influenced by Mediterranean climate, while the
Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria
Artinyan, E.; Habets, F.; Noilhan, J.; Ledoux, E.; Dimitrov, D.; Martin, E.; Le Moigne, P.
2007-03-01
A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used in order to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997), at an eight km resolution. It was based on the data available at the National Institute of Meteorology and Hydrology (NIMH) of Bulgaria. Atmospheric parameters were carefully checked and interpolated with a high level of detail in space and time (3-h step). Comparing computed Penman evapotranspiration versus observed pan evaporation validated the quality of the implemented forcing. The impact of the human activities on the rivers (especially hydropower or irrigation) was taken into account. Some improvements of the hydrometeorological model were made: for better simulation of summer riverflow, two additional reservoirs were added to simulate the slow component of the runoff. Those reservoirs were calibrated using the observed data of the 1st year, while the 2nd year was used for validation. 56 hydrologic stations and 12 dams were used for the model calibration while 41 rivergages were used for the validation of the model. The results compare well with the daily-observed discharges, with good results obtained over more than 25% of the rivergages. The simulated snow depth was compared to daily measurements at 174 stations and the evolution of the snow water equivalent was validated at 5 sites. The process of melting and refreezing of snow was found to be important on this region. The comparison of the normalized values of simulated versus measured soil moisture showed good correlation. The surface water budget shows large spatial variations due to the elevation influence on the precipitations, soil properties and vegetation variability. An inter annual difference was observed in the water cycle as the first year was more influenced by Mediterranean climate, while the second year was
Dimer models and quiver gauge theories
Pichai, Ramadevi
2013-12-01
= 1 quiver gauge theories on coincident D3 branes placed at a tip of a Calabi-Yau singularity C are dual to string theories on AdS5×X5 where X5 are Sasaki-Einstein spaces. We present a neat combinatorial approach called dimer model to understand interrelations between toric quiver gauge theories and toric data representing the Calabi-Yau singularities.
Scientific Theories, Models and the Semantic Approach
Directory of Open Access Journals (Sweden)
Décio Krause
2007-12-01
Full Text Available According to the semantic view, a theory is characterized by a class of models. In this paper, we examine critically some of the assumptions that underlie this approach. First, we recall that models are models of something. Thus we cannot leave completely aside the axiomatization of the theories under consideration, nor can we ignore the metamathematics used to elaborate these models, for changes in the metamathematics often impose restrictions on the resulting models. Second, based on a parallel between van Fraassen’s modal interpretation of quantum mechanics and Skolem’s relativism regarding set-theoretic concepts, we introduce a distinction between relative and absolute concepts in the context of the models of a scientific theory. And we discuss the significance of that distinction. Finally, by focusing on contemporary particle physics, we raise the question: since there is no general accepted unification of the parts of the standard model (namely, QED and QCD, we have no theory, in the usual sense of the term. This poses a difficulty: if there is no theory, how can we speak of its models? What are the latter models of? We conclude by noting that it is unclear that the semantic view can be applied to contemporary physical theories.
A water-budget model and estimates of groundwater recharge for Guam
Johnson, Adam G.
2012-01-01
On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation of groundwater recharge on Guam using the most current data and accepted methods. For this investigation, a daily water-budget model was developed and used to estimate mean recharge for various land-cover and rainfall conditions. Recharge was also estimated for part of the island using the chloride mass-balance method. Using the daily water-budget model, estimated mean annual recharge on Guam is 394.1 million gallons per day, which is 39 percent of mean annual rainfall (999.0 million gallons per day). Although minor in comparison to rainfall on the island, water inflows from water-main leakage, septic-system leachate, and stormwater runoff may be several times greater than rainfall at areas that receive these inflows. Recharge is highest in areas that are underlain by limestone, where recharge is typically between 40 and 60 percent of total water inflow. Recharge is relatively high in areas that receive stormwater runoff from storm-drain systems, but is relatively low in urbanized areas where stormwater runoff is routed to the ocean or to other areas. In most of the volcanic uplands in southern Guam where runoff is substantial, recharge is less than 30 percent of total water inflow. The water-budget model in this study differs from all previous water-budget investigations on Guam by directly accounting for canopy evaporation in forested areas, quantifying the evapotranspiration rate of each land-cover type, and accounting for evaporation from impervious areas. For the northern groundwater subbasins defined in Camp, Dresser & McKee Inc. (1982), mean annual baseline recharge computed in this study is 159.1 million gallons
Gravitational Model of the Three Elements Theory
Directory of Open Access Journals (Sweden)
Frederic Lassiaille
2012-05-01
Full Text Available The gravitational model of the three elements theory is an alternative theory to dark matter. It uses a modification of Newton’s law in order to explain gravitational mysteries. The results of this model are explanations for the dark matter mysteries, and the Pioneer anomaly. The disparity of the gravitational constant measurements might also be explained. Concerning the Earth flyby anomalies, the theoretical order of magnitude is the same as the experimental one. A very small change of the perihelion advance of the planet orbits is calculated by this model. Meanwhile, this gravitational model is perfectly compatible with restricted relativity and general relativity, and is part of the three element theory, a unifying theory.
Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are developing growth and bioaccumulation studies that contrib...
Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are conducting growth and bioaccumulation studies that contrib...
Staircase models from affine Toda field theory
International Nuclear Information System (INIS)
The authors propose a class of purely elastic scattering theories generalizing the staircase model of Al. B. Zamolodchikov, based on the affine Toda field theories for simply-laced Lie algebras g = A,D,E at suitable complex values of their coupling constants. Considering their Thermodynamic Bethe Ansatz equations, they give analytic arguments in support of a conjectured renormalization group flow visiting the neighborhood of each Wg minimal model in turn
Gravitational Model of the Three Elements Theory
Frederic Lassiaille
2012-01-01
The gravitational model of the three elements theory is an alternative theory to dark matter. It uses a modification of Newton’s law in order to explain gravitational mysteries. The results of this model are explanations for the dark matter mysteries, and the Pioneer anomaly. The disparity of the gravitational constant measurements might also be explained. Concerning the Earth flyby anomalies, the theoretical order of magnitude is the same as the experimental one. A very small change of the p...
Motivation in Beyond Budgeting: A Motivational Paradox?
DEFF Research Database (Denmark)
Sandalgaard, Niels; Bukh, Per Nikolaj
In this paper we discuss the role of motivation in relation to budgeting and we analyse how the Beyond Budgeting model functions compared with traditional budgeting. In the paper we focus on budget related motivation (and motivation in general) and conclude that the Beyond Budgeting model is a...... motivational paradox....
Integrable Models, SUSY Gauge Theories, and String Theory
Nam, S
1996-01-01
We consider the close relation between duality in N=2 SUSY gauge theories and integrable models. Vario us integrable models ranging from Toda lattices, Calogero models, spinning tops, and spin chains are re lated to the quantum moduli space of vacua of N=2 SUSY gauge theories. In particular, SU(3) gauge t heories with two flavors of massless quarks in the fundamental representation can be related to the spec tral curve of the Goryachev-Chaplygin top, which is a Nahm's equation in disguise. This can be generaliz ed to the cases with massive quarks, and N_f = 0,1,2, where a system with seven dimensional phas e space has the relevant hyperelliptic curve appear in the Painlevé test. To understand the stringy o rigin of the integrability of these theories we obtain exact nonperturbative point particle limit of ty pe II string compactified on a Calabi-Yau manifold, which gives the hyperelliptic curve of SU(2) QCD w ith N_f =1 hypermultiplet.
Water budget comparison of global climate models and experimental data in Onça Creek basin, Brazil
Melo, D. C. D.; Marin, I. S. P.; Wendland, E.
2014-09-01
Groundwater is an important part of the hydrological cycle, accounting for more than 25% of human needs on the global scale. As a result of aquifer overexploitation associated with climate change, even in the most conservative future climate scenarios, mean water-table levels can experience drastic drops. Although there are efforts to include groundwater dynamics in global climate models (GCMs), its influence is still not taken into full account in GCM water budgets, although it is as important as the other water sources considered. To assess the role of percolation in the water balance, we compared the water budget from climate forcing scenarios using 10 GCMs with the water budget from experimental data of a basin in São Paulo state, Brazil. We used the delta factor approach to correct the bias of the model's temperature and precipitation for a control period from 1970 to 1999, and calculated evapotranspiration using the Thornthwaite method. Experimental data for runoff and interception were derived for the basin's representative crops (sugar cane and pasture) for both water budgets. As the GCMs ignore subsurface flow and the only input considered is precipitation and snow melt, the excess surface water is assumed to be redistributed among the other water budget components. The experimental data shows that there is enough available water for infiltration, indicating that recharge cannot be ignored in the water balance. This leads to the possibility of the models' overestimating the other components to compensate for the ignored recharge.
Francisco Barbosa Filho; Cláudio Parisi
2007-01-01
This article has resulted from research developed by the Beyond Budgeting Round Table (BBRT) on a management model and budget practices and it presents a case study carried out in 2003 at Sadia S.A., a large Brazilian food company. The BBRT has as its basic proposal a series of principles aiming at management flexibilization and decentralization, which should be absorbed by the companies’ management models to allow them adapt better to entrepreneurial environment. To reach that, the BBRT iden...
ALUNNO-BRUSCIA, Marianne; Van Der Veer, Henk; Kooijman, S. A. L. M.
2011-01-01
This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007–2011). In this introductory paper we summarise the progress made during the running time of this 5 years’ project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs ...
Lattice Gauge Theories and Spin Models
Mathur, Manu
2016-01-01
The Wegner $Z_2$ gauge theory-$Z_2$ Ising spin model duality in $(2+1)$ dimensions is revisited and derived through a series of canonical transformations. These $Z_2$ results are directly generalized to SU(N) lattice gauge theory in $(2+1)$ dimensions to obtain a dual SU(N) spin model in terms of the SU(N) magnetic fields and electric scalar potentials. The gauge-spin duality naturally leads to a new gauge invariant disorder operator for SU(N) lattice gauge theory. A variational ground state of the dual SU(2) spin model with only nearest neighbour interactions is constructed to analyze SU(2) lattice gauge theory.
Autotrophic carbon budget in coral tissue: a new 13C-based model of photosynthate translocation.
Tremblay, Pascale; Grover, Renaud; Maguer, Jean François; Legendre, Louis; Ferrier-Pagès, Christine
2012-04-15
Corals live in symbiosis with dinoflagellates of the genus Symbiodinum. These dinoflagellates translocate a large part of the photosynthetically fixed carbon to the host, which in turn uses it for its own needs. Assessing the carbon budget in coral tissue is a central question in reef studies that still vexes ecophysiologists. The amount of carbon fixed by the symbiotic association can be determined by measuring the rate of photosynthesis, but the amount of carbon translocated by the symbionts to the host and the fate of this carbon are more difficult to assess. In the present study, we propose a novel approach to calculate the budget of autotrophic carbon in the tissue of scleractinian corals, based on a new model and measurements made with the stable isotope (13)C. Colonies of the scleractinian coral Stylophora pistillata were incubated in H(13)CO (-)(3)-enriched seawater, after which the fate of (13)C was followed in the symbionts, the coral tissue and the released particulate organic carbon (i.e. mucus). Results obtained showed that after 15 min, ca. 60% of the carbon fixed was already translocated to the host, and after 48 h, this value reached 78%. However, ca. 48% of the photosynthetically fixed carbon was respired by the symbiotic association, and 28% was released as dissolved organic carbon. This is different from other coral species, where coral tissue after 48 h. Results show that our (13)C-based model could successfully trace the carbon flow from the symbionts to the host, and the photosynthetically acquired carbon lost from the symbiotic association. PMID:22442377
Robert D. Behn
1984-01-01
The process of cutback budgeting that occurs in an era of retrenchment differs significantly from budgeting in circumstances of revenue growth. Negotiating an agreement on a set of decrements is far more complicated than allocating increments: No one wants to be the first to propose a cut in another constituency's budget, and any coalition formed in support of a given package of cuts is inherently unstable. Still, several conditions appear to facilitate cutback budgeting: an overarching issue...
Dorsey, Myrtle E. B.
2008-01-01
The integrated online planning and budget development system at Baton Rouge Community College is an innovative approach to systematically link college strategic priorities and unit plan objectives with financial resources. Using two industry standards (Microsoft Access and Sungard Banner), a user-friendly program was developed that has facilitated…
Dorel BERCEANU; Costel IONAŞCU
2009-01-01
This paper has like objective to present some aspects concerning capital budgeting. So, after a short introduction where we specify necessary conditions for a decision situation and we define investment decision and capital budgeting we made a large presentation of stages of capital budgeting process.
Pouvreau, Stéphane; Bourles, Yves; Lefebvre, Sébastien; Gangnery, Aline; Alunno-Bruscia, Marianne
2006-08-01
The Dynamic Energy Budget (DEB) model (Kooijman, S.A.L.M., 1986. Energy budgets can explain body size relations. J. Theor. Biol. 121, 269-282; Kooijman, S.A.L.M., 2000. Dynamic Energy and Mass Budgets in Biological Systems. Cambridge University Press, Cambridge, 424 pp.) has been adapted to describe the dynamics of growth and reproduction of the Pacific oyster ( Crassostrea gigas) reared in different areas under conditions ranging from controlled to natural. The values of the model parameters were estimated from available physiological data and from published information. The sets of data used to validate the model came from three long-term growth experiments (> 5 months) performed on Pacific oysters reared under different conditions of food and environment. The forcing variables were temperature and phytoplankton densities, the latter being assessed from in vivo fluorescence and chlorophyll-a concentration measurement. The successful validation of the model on the three data sets demonstrated its ability to capture the dynamics of the energy budget in the Pacific oyster in various environments with the same set of parameters. The only parameter that varied between simulations was the half-saturation coefficient (X K), because of a different diet composition between the three environments under test. The model successfully reproduced quantitatively the growth and reproduction and the timing of spawning. These first simulation data led us to propose several promising perspectives of application for this model in shellfish ecosystems.
ENSO-driven energy budget perturbations in observations and CMIP models
Mayer, Michael; Fasullo, John T.; Trenberth, Kevin E.; Haimberger, Leopold
2016-03-01
Various observation-based datasets are employed to robustly quantify changes in ocean heat content (OHC), anomalous ocean-atmosphere energy exchanges and atmospheric energy transports during El Niño-Southern Oscillation (ENSO). These results are used as a benchmark to evaluate the energy pathways during ENSO as simulated by coupled climate model runs from the CMIP3 and CMIP5 archives. The models are able to qualitatively reproduce observed patterns of ENSO-related energy budget variability to some degree, but key aspects are seriously biased. Area-averaged tropical Pacific OHC variability associated with ENSO is greatly underestimated by all models because of strongly biased responses of net radiation at top-of-the-atmosphere to ENSO. The latter are related to biases of mean convective activity in the models and project on surface energy fluxes in the eastern Pacific Intertropical Convergence Zone region. Moreover, models underestimate horizontal and vertical OHC redistribution in association with the generally too weak Bjerknes feedback, leading to a modeled ENSO affecting a too shallow layer of the Pacific. Vertical links between SST and OHC variability are too weak even in models driven with observed winds, indicating shortcomings of the ocean models. Furthermore, modeled teleconnections as measured by tropical Atlantic OHC variability are too weak and the tropical zonal mean ENSO signal is strongly underestimated or even completely missing in most of the considered models. Results suggest that attempts to infer insight about climate sensitivity from ENSO-related variability are likely to be hampered by biases in ENSO in CMIP simulations that do not bear a clear link to future changes.
Arnault, Joel; Kunstmann, Harald; Knoche, Hans-Richard
2015-04-01
Many numerical studies have shown that the West African monsoon is highly sensitive to the state of the land surface. It is however questionable to which extend a local change of land surface properties would affect the local climate, especially with respect to precipitation. This issue is traditionally addressed with the concept of precipitation recycling, defined as the contribution of local surface evaporation to local precipitation. For this study the West African monsoon has been simulated with the Weather Research and Forecasting (WRF) model using explicit convection, for the domain (1°S-21°N, 18°W-14°E) at a spatial resolution of 10 km, for the period January-October 2013, and using ERA-Interim reanalyses as driving data. This WRF configuration has been selected for its ability to simulate monthly precipitation amounts and daily histograms close to TRMM (Tropical Rainfall Measuring Mission) data. In order to investigate precipitation recycling in this WRF simulation, surface evaporation tagging has been implemented in the WRF source code as well as the budget of total and tagged atmospheric water. Surface evaporation tagging consists in duplicating all water species and the respective prognostic equations in the source code. Then, tagged water species are set to zero at the lateral boundaries of the simulated domain (no inflow of tagged water vapor), and tagged surface evaporation is considered only in a specified region. All the source terms of the prognostic equations of total and tagged water species are finally saved in the outputs for the budget analysis. This allows quantifying the respective contribution of total and tagged atmospheric water to atmospheric precipitation processes. The WRF simulation with surface evaporation tagging and budgets has been conducted two times, first with a 100 km2 tagged region (11-12°N, 1-2°W), and second with a 1000 km2 tagged region (7-16°N, 6°W -3°E). In this presentation we will investigate hydro
Graphical Model Theory for Wireless Sensor Networks
International Nuclear Information System (INIS)
Information processing in sensor networks, with many small processors, demands a theory of computation that allows the minimization of processing effort, and the distribution of this effort throughout the network. Graphical model theory provides a probabilistic theory of computation that explicitly addresses complexity and decentralization for optimizing network computation. The junction tree algorithm, for decentralized inference on graphical probability models, can be instantiated in a variety of applications useful for wireless sensor networks, including: sensor validation and fusion; data compression and channel coding; expert systems, with decentralized data structures, and efficient local queries; pattern classification, and machine learning. Graphical models for these applications are sketched, and a model of dynamic sensor validation and fusion is presented in more depth, to illustrate the junction tree algorithm
Graphical Model Theory for Wireless Sensor Networks
Energy Technology Data Exchange (ETDEWEB)
Davis, William B.
2002-12-08
Information processing in sensor networks, with many small processors, demands a theory of computation that allows the minimization of processing effort, and the distribution of this effort throughout the network. Graphical model theory provides a probabilistic theory of computation that explicitly addresses complexity and decentralization for optimizing network computation. The junction tree algorithm, for decentralized inference on graphical probability models, can be instantiated in a variety of applications useful for wireless sensor networks, including: sensor validation and fusion; data compression and channel coding; expert systems, with decentralized data structures, and efficient local queries; pattern classification, and machine learning. Graphical models for these applications are sketched, and a model of dynamic sensor validation and fusion is presented in more depth, to illustrate the junction tree algorithm.
Internal variability of Earth’s energy budget simulated by CMIP5 climate models
International Nuclear Information System (INIS)
We analyse a large number of multi-century pre-industrial control simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) to investigate relationships between: net top-of-atmosphere radiation (TOA), globally averaged surface temperature (GST), and globally integrated ocean heat content (OHC) on decadal timescales. Consistent with previous studies, we find that large trends (∼0.3 K dec−1) in GST can arise from internal climate variability and that these trends are generally an unreliable indicator of TOA over the same period. In contrast, trends in total OHC explain 95% or more of the variance in TOA for two-thirds of the models analysed; emphasizing the oceans’ role as Earth’s primary energy store. Correlation of trends in total system energy (TE ≡ time integrated TOA) against trends in OHC suggests that for most models the ocean becomes the dominant term in the planetary energy budget on a timescale of about 12 months. In the context of the recent pause in global surface temperature rise, we investigate the potential importance of internal climate variability in both TOA and ocean heat rearrangement. The model simulations suggest that both factors can account for O (0.1 W m−2) on decadal timescales and may play an important role in the recently observed trends in GST and 0–700 m (and 0–1800 m) ocean heat uptake. (paper)
Self Modeling: Expanding the Theories of Learning
Dowrick, Peter W.
2012-01-01
Self modeling (SM) offers a unique expansion of learning theory. For several decades, a steady trickle of empirical studies has reported consistent evidence for the efficacy of SM as a procedure for positive behavior change across physical, social, educational, and diagnostic variations. SM became accepted as an extreme case of model similarity;…
F-theory and linear sigma models
Bershadsky, M; Greene, Brian R; Johansen, A; Lazaroiu, C I
1998-01-01
We present an explicit method for translating between the linear sigma model and the spectral cover description of SU(r) stable bundles over an elliptically fibered Calabi-Yau manifold. We use this to investigate the 4-dimensional duality between (0,2) heterotic and F-theory compactifications. We indirectly find that much interesting heterotic information must be contained in the `spectral bundle' and in its dual description as a gauge theory on multiple F-theory 7-branes. A by-product of these efforts is a method for analyzing semistability and the splitting type of vector bundles over an elliptic curve given as the sheaf cohomology of a monad.
Modeling long-term, large-scale sediment storage using a simple sediment budget approach
Naipal, Victoria; Reick, Christian; Van Oost, Kristof; Hoffmann, Thomas; Pongratz, Julia
2016-05-01
Currently, the anthropogenic perturbation of the biogeochemical cycles remains unquantified due to the poor representation of lateral fluxes of carbon and nutrients in Earth system models (ESMs). This lateral transport of carbon and nutrients between terrestrial ecosystems is strongly affected by accelerated soil erosion rates. However, the quantification of global soil erosion by rainfall and runoff, and the resulting redistribution is missing. This study aims at developing new tools and methods to estimate global soil erosion and redistribution by presenting and evaluating a new large-scale coarse-resolution sediment budget model that is compatible with ESMs. This model can simulate spatial patterns and long-term trends of soil redistribution in floodplains and on hillslopes, resulting from external forces such as climate and land use change. We applied the model to the Rhine catchment using climate and land cover data from the Max Planck Institute Earth System Model (MPI-ESM) for the last millennium (here AD 850-2005). Validation is done using observed Holocene sediment storage data and observed scaling between sediment storage and catchment area. We find that the model reproduces the spatial distribution of floodplain sediment storage and the scaling behavior for floodplains and hillslopes as found in observations. After analyzing the dependence of the scaling behavior on the main parameters of the model, we argue that the scaling is an emergent feature of the model and mainly dependent on the underlying topography. Furthermore, we find that land use change is the main contributor to the change in sediment storage in the Rhine catchment during the last millennium. Land use change also explains most of the temporal variability in sediment storage in floodplains and on hillslopes.
Security Theorems via Model Theory
Directory of Open Access Journals (Sweden)
Joshua Guttman
2009-11-01
Full Text Available A model-theoretic approach can establish security theorems for cryptographic protocols. Formulas expressing authentication and non-disclosure properties of protocols have a special form. They are quantified implications for all xs . (phi implies for some ys . psi. Models (interpretations for these formulas are *skeletons*, partially ordered structures consisting of a number of local protocol behaviors. *Realized* skeletons contain enough local sessions to explain all the behavior, when combined with some possible adversary behaviors. We show two results. (1 If phi is the antecedent of a security goal, then there is a skeleton A_phi such that, for every skeleton B, phi is satisfied in B iff there is a homomorphism from A_phi to B. (2 A protocol enforces for all xs . (phi implies for some ys . psi iff every realized homomorphic image of A_phi satisfies psi. Hence, to verify a security goal, one can use the Cryptographic Protocol Shapes Analyzer CPSA (TACAS, 2007 to identify minimal realized skeletons, or "shapes," that are homomorphic images of A_phi. If psi holds in each of these shapes, then the goal holds.
Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.
2011-11-01
This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007-2011). In this introductory paper we summarise the progress made during the running time of this 5 years' project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability within the context of DEB theory for metabolic organisation, and (ii) to evaluate the inter-relationships between different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). AquaDEB phase I focussed on quantifying bio-energetic processes of various aquatic species ( e.g. molluscs, fish, crustaceans, algae) and phase II on: (i) comparing of energetic and physiological strategies among species through the DEB parameter values and identifying the factors responsible for any differences in bioenergetics and physiology; (ii) considering different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) scaling up the models for a few species from the individual level up to the level of evolutionary processes. Apart from the three special issues in the Journal of Sea Research — including the DEBIB collaboration (see vol. 65 issue 2), a theme issue on DEB theory appeared in the Philosophical Transactions of the Royal Society B (vol 365, 2010); a large number of publications were produced; the third edition of the DEB book appeared (2010); open-source software was substantially expanded (over 1000 functions); a large open-source systematic collection of ecophysiological data and DEB parameters has been set up; and a series of DEB
Budgeting tool for Restaurant X
Nguyen, Uyen
2014-01-01
In order to improve profitability and advance a company’s commitment to organ-ize growth, details plans which are called budgets are required. A budgeting tool is a beneficial asset for a company because it helps the budgeting preparation process become easier and faster. Thus, the aim of this thesis is to create a budgeting tool for Restaurant X. This thesis is product-orientated. There are three tasks conducted in this thesis. First one is to cover all relevant theories about a budget. T...
Parasitic castration: a perspective from a model of dynamic energy budgets.
Hall, Spencer R; Becker, Claes; Cáceres, Carla E
2007-08-01
Models of the evolution of virulence have typically focused on increased mortality, one of two negative effects that parasites can inflict on their host. Those that consider the other effect, fecundity reduction, can predict that parasites should completely sterilize their hosts. Although this prediction seems extreme, sterilization features prominently in a fascinating strategy, parasitic castration. Such castration can be accompanied by gigantism (unusually large growth of infected hosts), long infectious periods, and fecundity compensation (where, before heavy parasite burdens ensue, newly infected hosts reproduce earlier/more than they would if not infected). Using a model of dynamic energy budgets (DEB), we show how these results readily emerge, assuming that parasites consume energy reserves of the host. The simple, but mechanistic, DEB model follows energy flow though hosts and parasites, starting with ingestion, and continuing with storage of assimilated energy, and use of those reserves for growth and reproduction, as allocated by the host according to the "κ-rule". Using this model, we compare and contrast two strategies for parasites. "Consumers" only steal energy from their hosts, thereby indirectly altering allocation of energy to growth and reproduction, reducing fecundity, and enhancing mortality. "Castrators" steal energy but also directly modify the scheme by which hosts allocate reserve energy, shunting resources from reproduction to growth. Not surprisingly, the model predicts that this strategy should promote gigantism, but it also forecasts longer infectious periods and fecundity compensation. Thus, commonly observed characteristics of parasitic castration readily emerge from a mechanistic model of energy flow using a minimal number of assumptions. Finally, the DEB model for both "consumers" and "castrators" highlight that variation in resources supplied to hosts promotes variation in virulence in a given host-parasite system, holding all else
A numerical modelling study on regional mercury budget for eastern North America
Directory of Open Access Journals (Sweden)
X. Lin
2003-01-01
Full Text Available In this study, we have integrated an up-to-date physio-chemical transformation mechanism of Hg into the framework of US EPA's CMAQ model system. In addition, the model adapted detailed calculations of the air-surface exchange for Hg to properly describe Hg re-emissions and dry deposition from and to natural surfaces. The mechanism covers Hg in three categories, elemental Hg (Hg0, reactive gaseous Hg (RGM and particulate Hg (HgP. With interfacing to MM5 (meteorology processor and SMOKE (emission processor, we applied the model to a 4-week period in June/July 1995 on a domain covering most of eastern North America. Results indicate that the model simulates reasonably well the levels of total gaseous Hg (TGM and the specific Hg wet deposition measurements made by the Hg deposition network (MDN. Moreover, results from various scenario runs reveal that the Hg system behaves in a closely linear way in terms of contributions from different source categories, i.e. anthropogenic emissions, natural re-emissions and background. Analyses of the scenario results suggest that 37% of anthropogenically emitted Hg was deposited back in the model domain with 5155 kg of anthropogenic Hg moving out of the domain during the simulation period. Overall, the domain served as a net source, which supplied ~a half ton of Hg to the global background pool over the period. Our model validation and a sensitivity test further rationalized the rate constant for gaseous oxidation of Hg0 by hydroxyl radical OH used in the global scale modelling study by Bergan and Rodhe (2001. A further laboratory determination of the reaction rate constant, including its temperature dependence, stands as one of the important issues critical to improving our knowledge on the budget and cycling of Hg.
Vacation queueing models theory and applications
Tian, Naishuo
2006-01-01
A classical queueing model consists of three parts - arrival process, service process, and queue discipline. However, a vacation queueing model has an additional part - the vacation process which is governed by a vacation policy - that can be characterized by three aspects: 1) vacation start-up rule; 2) vacation termination rule, and 3) vacation duration distribution. Hence, vacation queueing models are an extension of classical queueing theory. Vacation Queueing Models: Theory and Applications discusses systematically and in detail the many variations of vacation policy. By allowing servers to take vacations makes the queueing models more realistic and flexible in studying real-world waiting line systems. Integrated in the book's discussion are a variety of typical vacation model applications that include call centers with multi-task employees, customized manufacturing, telecommunication networks, maintenance activities, etc. Finally, contents are presented in a "theorem and proof" format and it is invaluabl...
Reconstructing bidimensional scalar field theory models
Energy Technology Data Exchange (ETDEWEB)
Flores, Gabriel H.; Svaiter, N.F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: gflores@cbpf.br; nfuxsvai@cbpf.br
2001-07-01
In this paper we review how to reconstruct scalar field theories in two dimensional spacetime starting from solvable Scrodinger equations. Theree different Schrodinger potentials are analyzed. We obtained two new models starting from the Morse and Scarf II hyperbolic potencials, the U ({theta}) {theta}{sup 2} In{sup 2} ({theta}{sup 2}) model and U ({theta}) = {theta}{sup 2} cos{sup 2} (In({theta}{sup 2})) model respectively. (author)
Halyo, Nesim; Direskeneli, Haldun; Barkstrom, Bruce R.
1991-01-01
Satellite measurements are subject to a wide range of uncertainties due to their temporal, spatial, and directional sampling characteristics. An information-theory approach is suggested to examine the nonuniform temporal sampling of ERB measurements. The information (i.e., its entropy or uncertainty) before and after the measurements is determined, and information gain (IG) is defined as a reduction in the uncertainties involved. A stochastic model for the diurnal outgoing flux variations that affect the ERB is developed. Using Gaussian distributions for the a priori and measured radiant exitance fields, the IG is obtained by computing the a posteriori covariance. The IG for the monthly outgoing flux measurements is examined for different orbital parameters and orbital tracks, using the Earth Observing System orbital parameters as specific examples. Variations in IG due to changes in the orbit's inclination angle and the initial ascending node local time are investigated.
Algebraic model theory for languages without equality
Elgueta Montó, Raimon
1994-01-01
In our opinion, it is fair to distinguish two separate branches in the origins of model theory. The first one, the model theory of first-order logic, can be traced back to the pioneering work of L. Lowenheim, T. Skolem, K. Gödel, A. Tarski and A.I. MaI 'cev, published before the mid 30's. This branch was put forward during the 40s' and 50s’ by several authors, including A. Tarski, L. Henkin, A. Robinson, J. Los. Their contribution, however, was rather influenced by modern algebra, a disciplin...
Quantum field theory and the standard model
Schwartz, Matthew D
2014-01-01
Providing a comprehensive introduction to quantum field theory, this textbook covers the development of particle physics from its foundations to the discovery of the Higgs boson. Its combination of clear physical explanations, with direct connections to experimental data, and mathematical rigor make the subject accessible to students with a wide variety of backgrounds and interests. Assuming only an undergraduate-level understanding of quantum mechanics, the book steadily develops the Standard Model and state-of-the-art calculation techniques. It includes multiple derivations of many important results, with modern methods such as effective field theory and the renormalization group playing a prominent role. Numerous worked examples and end-of-chapter problems enable students to reproduce classic results and to master quantum field theory as it is used today. Based on a course taught by the author over many years, this book is ideal for an introductory to advanced quantum field theory sequence or for independe...
International Nuclear Information System (INIS)
Several two dimensional quantum field theory models have more than one vacuum state. An investigation of super selection sectors in two dimensions from an axiomatic point of view suggests that there should be also states, called soliton or kink states, which interpolate different vacua. Familiar quantum field theory models, for which the existence of kink states have been proven, are the Sine-Gordon and the φ42-model. In order to establish the existence of kink states for a larger class of models, we investigate the following question: Which are sufficient conditions a pair of vacuum states has to fulfill, such that an interpolating kink state can be constructed? We discuss the problem in the framework of algebraic quantum field theory which includes, for example, the P(φ)2-models. We identify a large class of vacuum states, including the vacua of the P(φ)2-models, the Yukawa2-like models and special types of Wess-Zumino models, for which there is a natural way to construct an interpolating kink state. In two space-time dimensions, massive particle states are kink states. We apply the Haag-Ruelle collision theory to kink sectors in order to analyze the asymptotic scattering states. We show that for special configurations of n kinks the scattering states describe n freely moving non interacting particles. (orig.)
Institute of Scientific and Technical Information of China (English)
LI Xiang; WANG Hui; ZHANG Zhanhai; WU Huiding
2008-01-01
The surface heat budget of the Arctic Ocean (SHEBA) project has shown that the study of the surface heat budget characteristics is crucial to understanding the interface process and environmental change in the polar region.An arctic single-column model (ARCSCM) of Colorado University is used to simulate the arctic surface radiation and energy budget during the summertime.The simulation results are analyzed and compared with the SHEBA measurements.Sensitivity analyses are performed to test microphys- ical and radiative parameterizations in this model.The results show that the ARCSCM model is able to simulate the surface radia- tion and energy budget in the arctic during the summertime,and the different parameterizations have a significant influence on the results.The combination of cloud microphysics and RRTM parameterizations can fairly derive the surface solar shortwave radiation and downwelling Iongwave radiation flux.But this cloud microphysics parameterization scheme deviates notably from the simula- tion of surface sensible and latent heat flux.Further improvement for the parameterization scheme applied to the Arctic Regions is necessary.
Operational budgeting using fuzzy goal programming
Directory of Open Access Journals (Sweden)
Saeed Mohammadi
2013-10-01
Full Text Available Having an efficient budget normally has different advantages such as measuring the performance of various organizations, setting appropriate targets and promoting managers based on their achievements. However, any budgeting planning requires prediction of different cost components. There are various methods for budgeting planning such as incremental budgeting, program budgeting, zero based budgeting and performance budgeting. In this paper, we present a fuzzy goal programming to estimate operational budget. The proposed model uses fuzzy triangular as well as interval number to estimate budgeting expenses. The proposed study of this paper is implemented for a real-world case study in province of Qom, Iran and the results are analyzed.
International Nuclear Information System (INIS)
The aim of this dissertation is to characterize the toxicity of uranium on the metabolism of zebra fish, nio rerio. The first three chapters of this manuscript are dedicated to characterizing the blank metabolism of zebra fish. I used the Dynamic Energy Budget (deb) theory for this characterisation; it is presently the only theory that covers the full life cycle of the organism and quantifies feeding, assimilation, growth, reproduction, maturation, maintenance and ageing. Any metabolic effect of uranium should appear as effects on one or more of these fundamental processes. Since the life span of zebra fish is some four and a half years, and larger individuals respond slower to chemical stress, the focus was on the early life stages. Considerable breakthroughs in the quantification of zebra fish development, growth and reproduction have been made. It turned out the zebra fish accelerates its metabolism after birth till metamorphosis, when acceleration ceases. This process is seen in some, but not all, species of fish. Another striking conclusion was that somatic maintenance was much higher than is typical for fish. We don't yet have an explanation for this funding. Further it turned out that the details of reproduction matter: allocation to reproduction (in adults) accumulates in a reproduction buffer and this buffer is used to prepare batches of eggs. We needed to detail this preparation process to understand how zebra fish can eliminate uranium via eggs. Deb theory specifies that a particular developmental stage (birth, metamorphosis, puberty) is reached at specified levels of maturity. For different temperatures and food levels, that can occur at different ages and body sizes. We extended this idea to include all the described morphologically defined developmental stages of the zebra fish in the literature; the observed variations in ages and body sizes can now be explained by deb theory. To test if deb theory can also explain perturbations of maturation, we
Effects of water and ice clouds on cloud microphysical budget: An equilibrium modeling study
International Nuclear Information System (INIS)
The effects of water and ice clouds on the cloud microphysical budget associated with rainfall are investigated through the analysis of grid-scale data from a series of two-dimensional cloud-resolving model equilibrium sensitivity simulations. The model is imposed without large-scale vertical velocity. In the control experiment, the contribution from rainfall (cM) associated with net evaporation and hydrometeor loss/convergence is about 29% of that from the rainfall (Cm) associated with net condensation and hydrometeor gain/divergence and about 39% of that from the rainfall (CM) associated with net condensation and hydrometeor loss/convergence. The exclusion of ice clouds enhances rainfall contribution of CM, whereas it reduces rainfall contributions of Cm and cM. The removal of radiative effects of water clouds increases rainfall contribution of CM, barely changes rainfall contribution of Cm and reduces the rainfall contribution of cM in the presence of the radiative effects of ice clouds. Elimination of the radiative effects of water clouds reduces the rainfall contributions of CM and Cm, whereas it increases the rainfall contribution of cM in the absence of the radiative effects of ice clouds. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Forecasting Rainfall Induced Landslide using High Resolution DEM and Simple Water Budget Model
Luzon, P. K. D.; Lagmay, A. M. F. A.
2014-12-01
Philippines is hit by an average of 20 typhoons per year bringing large amount of rainfall. Monsoon carrying rain coming from the southwest of the country also contributes to the annual total rainfall that causes different hazards. Such is shallow landslide mainly triggered by high saturation of soil due to continuous downpour which could take up from hours to days. Recent event like this happened in Zambales province September of 2013 where torrential rain occurred for 24 hours amounting to half a month of rain. Rainfall intensity measured by the nearest weather station averaged to 21 mm/hr from 10 pm of 22 until 10 am the following day. The monsoon rains was intensified by the presence of Typhoon Usagi positioned north and heading northwest of the country. A number of landslides due to this happened in 3 different municipalities; Subic, San Marcelino and Castillejos. The disaster have taken 30 lives from the province. Monitoring these areas for the entire country is but a big challenge in all aspect of disaster preparedness and management. The approach of this paper is utilizing the available forecast of rainfall amount to monitor highly hazardous area during the rainy seasons and forecasting possible landslide that could happen. A simple water budget model following the equation Perct=Pt-R/Ot-∆STt-AETt (where as the terms are Percolation, Runoff, Change in Storage, and Actual Evapotraspiration) was implemented in quantifying all the water budget component. Computations are in Python scripted grid system utilizing the widely used GIS forms for easy transfer of data and faster calculation. Results of successive runs will let percolation and change in water storage as indicators of possible landslide.. This approach needs three primary sets of data; weather data, topographic data, and soil parameters. This research uses 5 m resolution DEM (IfSAR) to define the topography. Soil parameters are from fieldworks conducted. Weather data are from the Philippine
Troost, T A; Wijsman, J W M; Saraiva, S; Freitas, V
2010-11-12
Dynamic energy budget models for growth of individual cockles (Cerastoderma edule) and mussels (Mytilus edulis) are adjusted and calibrated to the Oosterschelde by formulating and parametrizing their functional responses using an extensive set of field observations. The resulting model predictions fit the observations satisfactorily. Results indicate that food quality and the importance of detritus as a food source are site-specific as well as species-specific. Despite these differences in their calibrated parameter values, both species show a very similar functional response. Compared with other systems, however, the functional responses of mussels in the present study are clearly higher than those of mussels in other systems. This may be explained by the absence of intra-specific competition in the measurement set-up that was used, and therefore supports the idea that the generally small functional response of M. edulis is caused by intra-specific competition. PMID:20921054
Allen Schick
2009-01-01
Budgeting is fundamentally altered, if only temporarily, by pressures that overwhelm established policies and practices. This article discusses conventional and non-conventional responses to crisis, and how crisis impacts on the budget process. Just as crisis has mobilised governments to take global actions that spill beyond national boundaries, the aftermath of crisis will spur them to harmonise and integrate budget policies that affect the international financial system.
Using chemical organization theory for model checking
Kaleta, Christoph; Richter, Stephan; Dittrich, Peter
2009-01-01
Motivation: The increasing number and complexity of biomodels makes automatic procedures for checking the models' properties and quality necessary. Approaches like elementary mode analysis, flux balance analysis, deficiency analysis and chemical organization theory (OT) require only the stoichiometric structure of the reaction network for derivation of valuable information. In formalisms like Systems Biology Markup Language (SBML), however, information about the stoichiometric coefficients re...
Griffith, S. M.; Hansen, R. F.; Dusanter, S.; Michoud, V.; Gilman, J. B.; Kuster, W. C.; Veres, P. R.; Graus, M.; Gouw, J. A.; Roberts, J.; Young, C.; Washenfelder, R.; Brown, S. S.; Thalman, R.; Waxman, E.; Volkamer, R.; Tsai, C.; Stutz, J.; Flynn, J. H.; Grossberg, N.; Lefer, B.; Alvarez, S. L.; Rappenglueck, B.; Mielke, L. H.; Osthoff, H. D.; Stevens, P. S.
2016-04-01
Measurements of hydroxyl (OH) and hydroperoxy (HO2*) radical concentrations were made at the Pasadena ground site during the CalNex-LA 2010 campaign using the laser-induced fluorescence-fluorescence assay by gas expansion technique. The measured concentrations of OH and HO2* exhibited a distinct weekend effect, with higher radical concentrations observed on the weekends corresponding to lower levels of nitrogen oxides (NOx). The radical measurements were compared to results from a zero-dimensional model using the Regional Atmospheric Chemical Mechanism-2 constrained by NOx and other measured trace gases. The chemical model overpredicted measured OH concentrations during the weekends by a factor of approximately 1.4 ± 0.3 (1σ), but the agreement was better during the weekdays (ratio of 1.0 ± 0.2). Model predicted HO2* concentrations underpredicted by a factor of 1.3 ± 0.2 on the weekends, while measured weekday concentrations were underpredicted by a factor of 3.0 ± 0.5. However, increasing the modeled OH reactivity to match the measured total OH reactivity improved the overall agreement for both OH and HO2* on all days. A radical budget analysis suggests that photolysis of carbonyls and formaldehyde together accounted for approximately 40% of radical initiation with photolysis of nitrous acid accounting for 30% at the measurement height and ozone photolysis contributing less than 20%. An analysis of the ozone production sensitivity reveals that during the week, ozone production was limited by volatile organic compounds throughout the day during the campaign but NOx limited during the afternoon on the weekends.
International Nuclear Information System (INIS)
This paper reports that all businesses, including individuals, should have a budget - that is, an estimation of income and expense over an annual cycle. For companies, the budget is generally prepared and approved about one quarter before the start of the company's fiscal year and is updated and revised each quarter during the year. Although budgeting is a task dreaded by most exploration managers, it is usually the vehicle by which drilling prospects, the heart of any exploration program, are sold to the final decision makers. The budgeting process should be viewed as an opportunity rather than as a chore to be completed as quickly as possible
Theory and Model for Martensitic Transformations
DEFF Research Database (Denmark)
Lindgård, Per-Anker; Mouritsen, Ole G.
1986-01-01
Martensitic transformations are shown to be driven by the interplay between two fluctuating strain components. No soft mode is needed, but a central peak occurs representing the dynamics of strain clusters. A two-dimensional magnetic-analog model with the martensitic-transition symmetry is constr...... constructed and analyzed by computer simulation and by a theory which accounts for correlation effects. Dramatic precursor effects at the first-order transition are demonstrated. The model is also of relevance for surface reconstruction transitions....
Information theory models for clinical decision support
Czech Academy of Sciences Publication Activity Database
Vajda, Igor
Praha : Ústav informatiky AV ČR, v.v.i, 2009 - (Z. Valenta). s. 117-117 [Výroční konference Mezinárodní společnosti pro klinickou biostatistiku /30./. 23.08.2009-27.08.2009, Praha] R&D Projects: GA MŠk 1M06014; GA MŠk(CZ) 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Information * decision error * decision risk * ROC curve * information bounds Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2010/SI/vajda-information theory models for clinical decision support.doc
Directory of Open Access Journals (Sweden)
Tânia Regina Sordi Relvas
2011-09-01
Full Text Available Diante da constatação de que os estudos sobre o orçamento exploram o fenômeno de forma reducionista, este artigo tem por objetivo propor uma teoria substantiva abrangente e fundamentada em dados empíricos para a análise do orçamento. Essa abordagem considera seus elementos constituintes e suas interdependências. Isso foi feito por meio da aplicação da abordagem indutiva fundamentada nos dados empíricos (grounded theory, sob o paradigma qualitativo. O foco de análise foi uma instituição financeira de grande porte e o trabalho de campo foi desenvolvido ao longo de dois anos, envolvendo vários níveis gerenciais. A contribuição do trabalho advém da disponibilização de framework para o tratamento do tema em um contexto amplo, o que permitiu entender aspectos que deixariam de ser considerados com uma abordagem de análise mais restrita e menos abrangente. Como produto da teoria substantiva, cinco proposições foram desenvolvidas com a perspectiva de serem aplicadas nas organizações. --- Budgeting: substantive analysis using grounded theory --- Abstract --- Considering the fact that studies into budgeting basically use a reductionist approach, this paper proposes a comprehensive substantive theory based on empirical data to be used in budget analysis. This approach takes into consideration its elements and interdependence by applying the inductive approach based on empirical data (grounded theory on a qualitative paradigm. The focus was an in-depth two-year study of a large Brazilian financial institution involving several management levels. The main contribution of the study is as a framework that treats all elements of the budget process in a comprehensive and coherent fashion, otherwise impossible using a reductionist approach. As products of the substantive theory, five propositions were developed to be applied in organizations.
Continental scale atmospheric and terrestrial water budget modeling and comparison to GRACE
Fersch, B.; Kunstmann, H.; Sneeuw, N.; Devaraju, B.
2009-04-01
2008, correlations between monthly GRACE derived and regionally modeled water storage changes are shown for the mentioned areas. Also, the uncertainty bounds of the atmospheric moisture flux computations that arise from different atmospheric driving data (NCEP Reanalysis, ECMWF Operational Analysis, ECMWF ERA-INTERIM) are estimated. Also, the effects of different sea surface temperature data and nudging towards global datasets will be depicted. Furthermore, the estimated water budgets are compared to weekly GRACE solutions that have become available in late 2008 by GFZ Potsdam.
A dynamical theory for the Rishon model
International Nuclear Information System (INIS)
We propose a composite model for quarks and leptons based on an exact SU(3)sub(C)xSU(3)sub(H) gauge theory and two fundamental J=1/2 fermions: a charged T-rishon and a neutral V-rishon. Quarks, leptons and W-bosons are SU(3)sub(H)-singlet composites of rishons. A dynamically broken effective SU(3)sub(C)xSU(2)sub(L)xSU(2)sub(R)xU(1)sub(B-L) gauge theory emerges at the composite level. The theory is ''natural'', anomaly-free, has no fundamental scalar particles, and describes at least three generations of quarks and leptons. Several ''technicolor'' mechanisms are automatically present. (Author)
A comprehensive theory-based transport model
International Nuclear Information System (INIS)
A new theory based transport model with comprehensive physics (trapping, general toroidal geometry, finite beta, collisions) has been developed. The core of the model is the new trapped-gyro-Landau-fluid (TGLF) equations which provide a fast and accurate approximation to the linear eigenmodes for gyrokinetic drift-wave instabilities (trapped ion and electron modes, ion and electron temperature gradient modes and kinetic ballooning modes). This new TGLF transport model removes the limitation of its predecessor GLF23 and is valid for the same conditions as the gyrokinetic equations. A theory-based philosophy is used in the model construction. The closure coefficients of the TGLF equations are fit to local kinetic theory to give accurate linear eigenmodes. The saturation model is fit to non-linear turbulence simulations. No fitting to experiment is done so applying the model to experiments is a true test of the theory it is approximating. The TGLF model unifies trapped and passing particles in a single set of gyrofluid equations. A model for the averaging of the Landau resonance by the trapped particles makes the equations work seamlessly over the whole drift-wave wavenumber range from trapped ion modes to electron temperature gradient modes. A fast eigenmode solution method enables unrestricted magnetic geometry. Electron-ion collisions and full electromagnetic fluctuations round out the physics. The linear eigenmodes have been benchmarked against comprehensive physics gyrokinetic calculations over a large range of plasma parameters. The deviation between the gyrokinetic and TGLF linear growth rates averages 11.4% in shifted circle geometry. The transport model uses the TGLF eigenmodes to compute quasilinear fluxes of energy and particles. A model for the saturated amplitude of the turbulence completes the calculation. The saturation model is constructed to fit a large set of nonlinear gyrokinetic turbulence simulations. The TGLF model is valid in new physical
A comprehensive theory-based transport model
International Nuclear Information System (INIS)
Full text: A new theory based transport model with comprehensive physics (trapping, general toroidal geometry, finite beta, collisions) has been developed. The core of the model is the new trapped-gyro- Landau-fluid (TGLF) equations which provide a fast and accurate approximation to the linear eigenmodes for gyrokinetic drift-wave instabilities (trapped ion and electron modes, ion and electron temperature gradient modes and kinetic ballooning modes). This new TGLF transport model removes the limitation of its predecessor GLF23 and is valid for the same conditions as the gyrokinetic equations. A theory-based philosophy is used in the model construction. The closure coefficients of the TGLF equations are fit to local kinetic theory to give accurate linear eigenmodes. The saturation model is fit to non-linear turbulence simulations. No fitting to experiment is done so applying the model to experiments is a true test of the theory it is approximating. The TGLF model unifies trapped and passing particles in a single set of gyrofluid equations. A model for the averaging of the Landau resonance by the trapped particles makes the equations work seamlessly over the whole drift-wave wavenumber range from trapped ion modes to electron temperature gradient modes. A fast eigenmode solution method enables unrestricted magnetic geometry. Electron-ion collisions and full electromagnetic fluctuations round out the physics. The linear eigenmodes have been benchmarked against comprehensive physics gyrokinetic calculations over a large range of plasma parameters. The deviation between the gyrokinetic and TGLF linear growth rates averages 11.4% in shifted circle geometry. The transport model uses the TGLF eigenmodes to compute quasilinear fluxes of energy and particles. A model for the saturated amplitude of the turbulence completes the calculation. The saturation model is constructed to fit a large set of nonlinear gyrokinetic turbulence simulations. The TGLF model is valid in new
Crack propagation modeling using Peridynamic theory
Hafezi, M. H.; Alebrahim, R.; Kundu, T.
2016-04-01
Crack propagation and branching are modeled using nonlocal peridynamic theory. One major advantage of this nonlocal theory based analysis tool is the unifying approach towards material behavior modeling - irrespective of whether the crack is formed in the material or not. No separate damage law is needed for crack initiation and propagation. This theory overcomes the weaknesses of existing continuum mechanics based numerical tools (e.g. FEM, XFEM etc.) for identifying fracture modes and does not require any simplifying assumptions. Cracks grow autonomously and not necessarily along a prescribed path. However, in some special situations such as in case of ductile fracture, the damage evolution and failure depend on parameters characterizing the local stress state instead of peridynamic damage modeling technique developed for brittle fracture. For brittle fracture modeling the bond is simply broken when the failure criterion is satisfied. This simulation helps us to design more reliable modeling tool for crack propagation and branching in both brittle and ductile materials. Peridynamic analysis has been found to be very demanding computationally, particularly for real-world structures (e.g. vehicles, aircrafts, etc.). It also requires a very expensive visualization process. The goal of this paper is to bring awareness to researchers the impact of this cutting-edge simulation tool for a better understanding of the cracked material response. A computer code has been developed to implement the peridynamic theory based modeling tool for two-dimensional analysis. A good agreement between our predictions and previously published results is observed. Some interesting new results that have not been reported earlier by others are also obtained and presented in this paper. The final objective of this investigation is to increase the mechanics knowledge of self-similar and self-affine cracks.
Zhou, Lian-Tong; Du, Zhencai
2016-04-01
The present study provides an evaluation of the regional differences over China in surface energy budget components as simulated by a selection of models from phase five of the Coupled Model Intercomparison Project (CMIP5), covering the period 1960-2005. Similarities and differences exist among the models in terms of both spatial and magnitude patterns. For climatology, the CMIP5 models show quite different spatial distributions of shortwave radiation and sensible heat flux. In terms of seasonal variation, the surface energy budgets are remarkably different between western and eastern China. The discrepancies in the seasonal variation of sensible heat flux are mainly attributable to temperature differences and wind speed, while those of shortwave radiation are caused by the seasonal variation in total cloud cover. Cloudiness is one of the most crucial parameters in estimating the surface energy budget. In addition, the study also reveals that the magnitudes of the various components show larger (more than two-fold) differences between western and eastern parts of China, especially in net longwave and upward shortwave radiation, as well as latent and sensible heat fluxes. The results for surface soil heat flux show that there is more incoming energy during spring and summer and more outgoing energy during fall and winter in both western and eastern China. Furthermore, compared to NCEP2 data, the ERA-40 reanalysis product produces results more similar to the multi-model ensemble mean for most components.
DEFF Research Database (Denmark)
Jeppesen, Palle
1996-01-01
The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers.......The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers....
Innovation for Development and South-South Cooperation, IDEASS
2007-01-01
This book provides an overview of the principles underlying participatory budgeting. It analyzes the merits and demerits of participatory budgeting practices around the world with a view to guiding policy makers and practitioners on improving such practices in the interest of inclusive governance. This publication includes five regional surveys, and seven country case studies can be found ...
CO2 budgeting at the regional scale using a Lagrangian experimental strategy and meso-scale modeling
Directory of Open Access Journals (Sweden)
C. Gerbig
2008-07-01
Full Text Available An atmospheric Lagrangian experiment for regional CO2 budgeting with aircraft measurements took place during the CarboEurope Regional Experiment campaign (CERES in south-western France, in June, 2005. The atmospheric CO2 aircraft measurements taken upstream and downstream of an active and homogeneous pine forest revealed a CO2 depletion in the same air mass. This field experiment is analyzed with a meteorological meso-scale model interactively coupled with a surface scheme, allowing plant assimilation, ecosystem respiration, CO2 anthropogenic emissions and sea fluxes. First, the model is carefully validated against observations close to the surface and in the atmospheric boundary layer. Then, the carbon budget is evaluated using the numerous CERES observations and as well as the modeling results in order to estimate the relative contribution of each physical process. A good agreement is shown in terms of the estimation of the regional CO2 surface flux by the Eulerian meso-scale model budget and by the observations at the surface flux sites. A Lagrangian estimation of regional CO2 surface flux from aircraft observations is more difficult due to several sources of uncertainty. In our case, probable errors are due to the determination of CO2 vertical profile measurements and owing to the difficulties in monitoring the meteorological condition evolution during several hours.
Quantum mechanical model in gravity theory
Losyakov, V. V.
2016-05-01
We consider a model of a real massive scalar field defined as homogeneous on a d-dimensional sphere such that the sphere radius, time scale, and scalar field are related by the equations of the general theory of relativity. We quantize this system with three degrees of freedom, define the observables, and find dynamical mean values of observables in the regime where the scalar field mass is much less than the Planck mass.
Computational modeling of appraisal theory of emotion
Meuleman, Ben
2015-01-01
Appraisal theories of emotion have proposed detailed—and causal—hypotheses about the connection between situations and emotional responding, and between the components that constitute emotional responding. Many of these hypotheses present computational challenges to scientific research, in that they require the analysis of numerous mental and bodily changes simultaneously over time. In this thesis, I applied statistical models of machine learning to address these challenges, and to investigat...
Incentive theory: II. Models for choice
Killeen, Peter R.
1982-01-01
Incentive theory is extended to account for concurrent chained schedules of reinforcement. The basic model consists of additive contributions from the primary and secondary effects of reinforcers, which serve to direct the behavior activated by reinforcement. The activation is proportional to the rate of reinforcement and interacts multiplicatively with the directive effects. The two free parameters are q, the slope of the delay of reinforcement gradient, whose value is constant across many e...
Directory of Open Access Journals (Sweden)
A. Ito
2012-02-01
Full Text Available We assessed the global terrestrial budget of methane (CH_{4} by using a process-based biogeochemical model (VISIT and inventory data for components of the budget that were not included in the model. Emissions from wetlands, paddy fields, biomass burning, and plants, as well as oxidative consumption by upland soils, were simulated by the model. Emissions from ruminant livestock and termites were evaluated by using an inventory approach. These CH_{4} flows were estimated for each of the model's 0.5° × 0.5° grid cells from 1901 to 2009, while accounting for atmospheric composition, meteorological factors, and land-use changes. Estimation uncertainties were examined through ensemble simulations using different parameterization schemes and input data (e.g., different wetland maps and emission factors. From 1996 to 2005, the average global terrestrial CH_{4} budget was estimated on the basis of 1152 simulations, and terrestrial ecosystems were found to be a net source of 308.3 ± 20.7 Tg CH_{4} yr^{−1}. Wetland and livestock ruminant emissions were the primary sources. The results of our simulations indicate that sources and sinks are distributed highly heterogeneously over the Earth's land surface. Seasonal and interannual variability in the terrestrial budget was also assessed. The trend of increasing net emission from terrestrial sources and its relationship with temperature variability imply that terrestrial CH_{4} feedbacks will play an increasingly important role as a result of future climatic change.
C. H. Song; Kim, H. S.; von Glasow, R.; Brimblecombe, P.; Kim, J; R. J. Park; Woo, J. H.
2010-01-01
Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget) of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume pho...
Development and application of a GIS-based sediment budget model.
Ramos-Scharrón, Carlos E; Macdonald, Lee H
2007-07-01
Accelerated erosion and increased sediment yields resulting from changes in land use are a critical environmental problem. Resource managers and decision makers need spatially explicit tools to help them predict the changes in sediment production and delivery due to unpaved roads and other types of land disturbance. This is a particularly important issue in much of the Caribbean because of the rapid pace of development and potential damage to nearshore coral reef communities. The specific objectives of this study were to: (1) develop a GIS-based sediment budget model; (2) use the model to evaluate the effects of unpaved roads on sediment delivery rates in three watersheds on St. John in the US Virgin Islands; and (3) compare the predicted sediment yields to pre-existing data. The St. John Erosion Model (STJ-EROS) is an ArcInfo-based program that uses empirical sediment production functions and delivery ratios to quantify watershed-scale sediment yields. The program consists of six input routines and five routines to calculate sediment production and delivery. The input routines have interfaces that allow the user to adjust the key variables that control sediment production and delivery. The other five routines use pre-set erosion rate constants, user-defined variables, and values from nine data layers to calculate watershed-scale sediment yields from unpaved road travelways, road cutslopes, streambanks, treethrow, and undisturbed hillslopes. STJ-EROS was applied to three basins on St. John with varying levels of development. Predicted sediment yields under natural conditions ranged from 2 to 7Mgkm(-2)yr(-1), while yield rates for current conditions ranged from 8 to 46Mgkm(-2)yr(-1). Unpaved roads are estimated to be increasing sediment delivery rates by 3-6 times for Lameshur Bay, 5-9 times for Fish Bay, and 4-8 times for Cinnamon Bay. Predicted basin-scale sediment yields for both undisturbed and current conditions are within the range of measured sediment yields
Kadantsev, Evgeny; Fortelius, Carl; Druzhinin, Oleg; Mortikov, Evgeny; Glazunov, Andrey; Zilitinkevich, Sergej
2016-04-01
We examine and validate the EFB turbulence closure model (Zilitinkevich et al., 2013), which is based on the budget equations for basic second moments, namely, two energies: turbulent kinetic energy EK and turbulent potential energy EP, and vertical turbulent fluxes of momentum and potential temperature, τi (i = 1, 2) and Fz. Instead of traditional postulation of down-gradient turbulent transport, the EFB closure determines the eddy viscosity and eddy conductivity from the steady-state version of the budget equations for τi and Fz. Furthermore, the EFB closure involves new prognostic equation for turbulent dissipation time scale tT, and extends the theory to non-steady turbulence regimes accounting for non-gradient and non-local turbulent transports (when the traditional concepts of eddy viscosity and eddy conductivity become generally inconsistent). Our special interest is in asymptotic behavior of the EFB closure in strongly stable stratification. For this purpose, we consider plane Couette flow, namely, the flow between two infinite parallel plates, one of which is moving relative to another. We use a set of Direct Numerical Simulation (DNS) experiments at the highest possible Reynolds numbers for different bulk Richardson numbers (Druzhinin et al., 2015). To demonstrate potential improvements in Numerical Weather Prediction models, we test the new closure model in various idealized cases, varying stratification from the neutral and conventionally neutral to stable (GABLS1) running a test RANS model and HARMONIE/AROME model in single-column mode. Results are compared with DNS and LES (Large Eddy Simulation) runs and different numerical weather prediction models.
International Nuclear Information System (INIS)
A global carbon cycle model is used to reconstruct the carbon budget, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial biosphere. We apply Bayesian statistics to estimate uncertainty of carbon uptake by the oceans and the terrestrial biosphere based on carbon dioxide and carbon isotope records, and prior information on model parameter probability distributions. This results in a quantitative reconstruction of past carbon budget and its uncertainty derived from an explicit choice of model, data-based constraints, and prior distribution of parameters. Our estimated ocean sink for the 1980s is 17±7 Gt C (90% confidence interval) and is comparable to the estimate of 20±8 Gt C given in the recent Intergovernmental Panel on Climate Change assessment [Schimel et al., 1996]. Constraint choice is tested to determine which records have the most influence over estimates of the past carbon budget; records individually (e.g., bomb-radiocarbon inventory) have little effect since there are other records which form similar constraints. (c) 1999 American Geophysical Union
Standard Model as a Double Field Theory
Choi, Kang-Sin; Park, Jeong-Hyuck
2015-01-01
We show that, without any extra physical degree introduced, the Standard Model can be readily reformulated as a Double Field Theory. Consequently, the Standard Model can couple to an arbitrary stringy gravitational background in an $\\mathbf{O}(4,4)$ T-duality covariant manner and manifest two independent local Lorentz symmetries, $\\mathbf{Spin}(1,3)\\times\\mathbf{Spin}(3,1)$. While the diagonal gauge fixing of the twofold spin groups leads to the conventional formulation on the flat Minkowskia...
Sparse modeling theory, algorithms, and applications
Rish, Irina
2014-01-01
""A comprehensive, clear, and well-articulated book on sparse modeling. This book will stand as a prime reference to the research community for many years to come.""-Ricardo Vilalta, Department of Computer Science, University of Houston""This book provides a modern introduction to sparse methods for machine learning and signal processing, with a comprehensive treatment of both theory and algorithms. Sparse Modeling is an ideal book for a first-year graduate course.""-Francis Bach, INRIA - École Normale Supřieure, Paris
Veloso, A.; Ceschia, E.
2014-12-01
Croplands occupy more than one third of Earth's terrestrial surface contributing to climate change and also being impacted by those changes, since their production is conditioned by climatic conditions and water resources. It is thus essential to quantify and analyze the production and the main components of the carbon and water cycles for crop ecosystems. We propose here a regional modeling approach that combines: high spatial and temporal resolutions (HSTR) optical remote sensing data, a simple crop model and an extensive set of in-situ measurements for model's calibration and validation. The model, named SAFYE-CO2 (Simple Algorithm for Fluxes and Yield Estimates), is a daily time step model based on Monteith's light-use efficiency theory and coupled with a water budget module (FAO-56 method). SAFYE-CO2 estimates components of the carbon budget (gross primary production (GPP), ecosystem respiration (Reco), net ecosystem exchange (NEE), …) and of the crop water cycle (evaporation, transpiration, evapotranspiration (ETR) and soil water content) and also time courses of dry aboveground biomass and yield by assimilating Green Area Index (GAI) data obtained from HSTR satellite observations. For this work, we used a unique set of Formosat-2 and SPOT images acquired from 2006 to 2011 in southwest France. Crop and soil model parameters were set using both in-situ measurements and values found in the literature. Phenological parameters were calibrated by the GAI assimilation. The results indicate that the model correctly reproduces winter wheat biomass and yield production (relative error about 25%) for years with contrasted climatic conditions. The estimated net carbon flux components were overall in agreement with the flux measurements, presenting good correlations (R² about 0.9 for GPP, 0.77 for Reco and 0.84 for NEE). Regarding the ETR, a good correlation (R2 about 0.73) and satisfactory errors (RMSE about 0.47 mm.d-1) were found. Carbon and water budgets as well
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.
Theory, modeling and simulation: Annual report 1993
International Nuclear Information System (INIS)
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
DEFF Research Database (Denmark)
Maar, Marie; Saurel, Camille; Landes, Anja; Dolmer, Per; Petersen, Jens Kjerulf
2015-01-01
to incorporate the effects of low salinity into an eco-physiological model of blue mussels and to identify areas suitable for mussel production. A Dynamic Energy Budget (DEB) model was modified with respect to i) the morphological parameters (DW/WW-ratio, shape factor), ii) change in ingestion rate...... fromhigh eutrophication symptoms or as part of integrated multi-trophic aquaculture production. The model can also be used to predict the effects of salinity changes on mussel populations e.g. in climate change studies...
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
Government initiatives to publicize budgetary information allow for greater public supervision In an unprecedented move,four ministries under the Central Government recently posted their 2010 budgets on their official websites.
Directory of Open Access Journals (Sweden)
Mahlich J
2015-05-01
Full Text Available Jörg Mahlich,1,2 Masamichi Nishi,3 Yoshimichi Saito11Health Economics, Janssen Pharmaceutical KK, Tokyo, Japan; 2Düsseldorf Institute for Competition Economics, University of Düsseldorf, Düsseldorf, Germany; 3Pricing, Janssen Pharmaceutical KK, Tokyo, JapanBackground: The cost of schizophrenia in Japan is high and new long-acting injectable (LAI antipsychotics might be able to reduce costs by causing a reduction of hospital stays. We aim to estimate budget effects of the introduction of a new 1-month LAI, paliperidone palmitate, in Japan.Methods: A budget impact analysis was conducted from a payer perspective. The model took direct costs of illness into account (ie, costs for inpatient and outpatient services, as well as drug costs. The robustness of the model was checked using a sensitivity analysis.Results: According to our calculations, direct total costs of schizophrenia reach 710,500 million yen a year (US$6 billion. These costs decrease to 691,000 million yen (US$5.9 billion 3 years after the introduction of paliperidone palmitate.Conclusion: From a payer point of view, the introduction of a new treatment for schizophrenia in Japan helps to save resources and is not associated with a higher financial burden.Keywords: budget impact, schizophrenia, long-acting injectables, paliperidone, Japan
String field theory inspired phantom model
International Nuclear Information System (INIS)
An exact solution to the Friedmann equations with a stringy inspired phantom field is constructed. The Universe is considered as a slowly decaying D3-brane, which is described in the string field theory framework. The notable features of the concerned exactly solvable stringy dark energy (DE) model are a ghost sign of the kinetic term and a special polynomial form of the effective tachyon potential. Cosmological consequences of adding the cold dark matter (CDM) to this model are investigated as well. Solutions with large initial value of the CDM energy density attracted by the exact solution without the CDM are constructed numerically. In contrast to the ACDM model the Hubble parameter in our model is not a monotonic function of time. For specific initial data the DE state parameter UJDE is also not monotonic function of time. For these cases there are two separate domains of time where U'DE being less than - 1 is close to - 1. Stability conditions, under which the constructed solution is stable with respect to small fluctuations of the initial conditions, including the CDM energy density, are found. Keywords: string field theory, cosmology, tachyon, phantom, dark energy, cold dark matter, Big Rip (authors)
An Optimization Model Based on Game Theory
Directory of Open Access Journals (Sweden)
Yang Shi
2014-04-01
Full Text Available Game Theory has a wide range of applications in department of economics, but in the field of computer science, especially in the optimization algorithm is seldom used. In this paper, we integrate thinking of game theory into optimization algorithm, and then propose a new optimization model which can be widely used in optimization processing. This optimization model is divided into two types, which are called “the complete consistency” and “the partial consistency”. In these two types, the partial consistency is added disturbance strategy on the basis of the complete consistency. When model’s consistency is satisfied, the Nash equilibrium of the optimization model is global optimal and when the model’s consistency is not met, the presence of perturbation strategy can improve the application of the algorithm. The basic experiments suggest that this optimization model has broad applicability and better performance, and gives a new idea for some intractable problems in the field of artificial intelligence
The Jackiw-Pi model: Classical theory
International Nuclear Information System (INIS)
Full text: One of the central problems in the framework of gauge field theories is the issue of gauge field mass. Gauge symmetry is not, in principle, conflicting with the presence of a massive gauge boson. In two space-time dimensions, the well-known Schwinger model puts in evidence the presence of a massive photon without the breaking of gauge symmetry. Another evidence for the compatibility between gauge symmetry and massive vector fields comes from the study of three-dimensional gauge theories. A topological mass term referred to as the Chern-Simons Lagrangian, once added to the Yang-Mills term, shifts the photon mass to a non-vanishing value without breaking gauge invariance, however parity symmetry is lost. In 1997, a massive even-parity non- Abelian gauge model in three space-time dimensions has been proposed by Jackiw and Pi, which is studied, at the tree-level, in this work. The propagators are computed and the spectrum consistency is analyzed, besides, the symmetries of the model are collected and established through BRS invariance and Slavnov-Taylor identity. In the Landau gauge, thanks to the antighost equations and the Slavnov-Taylor identity, two rigid symmetries are identified by means of Ward identities. It is presented here a promising path for perturbatively quantization of the Jackiw-Pi model and a hint concerning its possible quantum scale invariance is also pointed out. (author)
Directory of Open Access Journals (Sweden)
Francisco Barbosa Filho
2007-07-01
Full Text Available This article has resulted from research developed by the Beyond Budgeting Round Table (BBRT on a management model and budget practices and it presents a case study carried out in 2003 at Sadia S.A., a large Brazilian food company. The BBRT has as its basic proposal a series of principles aiming at management flexibilization and decentralization, which should be absorbed by the companies’ management models to allow them adapt better to entrepreneurial environment. To reach that, the BBRT identified as the right way the exclusion of budget from managerial instruments, intending to eliminate corporate games and management centralization. This study presupposed that Sadia S.A. has a tendency to adopt the BBRT principles and, for the empirical verification, the same BBRT procedures were used in the research. The investigation consisted of applying a questionnaire, answered by 18 executives of the company and, after analyzing their answers, it has been established that the presupposition was corroborated partially. Keywords: Management model. Budget practices. Beyond Budgeting Round Table. O presente artigo foi elaborado a partir de pesquisas desenvolvidas pelo Beyond Budgeting Round Table (BBRT sobre modelo de gestão e práticas de orçamento e apresenta um estudo de caso realizado em 2003, na Sadia S.A., empresa brasileira do ramo de alimentos. O BBRT tem como proposta básica um conjunto de princípios orientado à flexibilização da gestão e descentralização, que deve ser absorvido pelos modelos de gestão das empresas para torná-los mais adaptados ao ambiente empresarial. Para que isso ocorra, o BBRT identificou como caminho o abandono do orçamento como instrumento de gestão, buscando com isso eliminar os jogos corporativos e a centralização da gestão. O trabalho assumiu como pressuposto que a Sadia S.A. tem tendência em adotar os princípios do Beyond Budgeting e, para a verificação empírica, utilizaram-se os mesmos
Rustomji, Paul; Caitcheon, Gary; Hairsine, Peter
2008-01-01
Information about diffuse pollutant sources in river catchments and the processes responsible for their generation is often obtained using geochemical tracing, in-stream monitoring, or process based modeling. Yet these methods are rarely combined. In this study, we combine these three methods to produce a catchment sediment budget for the Lake Burragorang catchment in Australia. The physically based process model SedNet was modified using local catchment data to constrain predicted hillslope erosion rates in forested areas, the rate and texture of sediment supply from gully erosion, and the predicted floodplain deposition rates. The model's capacity to match the geochemical tracer (both spatial source and erosion process) data and gauging station load data improved markedly. Hillslope erosion, primarily in the steeper, mainly forested areas near the reservoir, is identified by the model as the main source of sediment delivered to Lake Burragorang. The contribution from gully and river bank erosion is comparatively small, though gully erosion can be locally dominant. This result is consistent with the tracer data. Utilizing multiple independent data sets allows for a more rigorous evaluation of model performance and, it is argued, increases the likelihood that the model is correctly representing the main components of the catchment's sediment budget. The identification of diffuse sediment sources in other catchments can clearly benefit from combining a range of observational data with a structured model evaluation process.
Standard Model as a Double Field Theory
Choi, Kang-Sin; Park, Jeong-Hyuck
2015-10-01
We show that, without any extra physical degree introduced, the standard model can be readily reformulated as a double field theory. Consequently, the standard model can couple to an arbitrary stringy gravitational background in an O (4 ,4 ) T -duality covariant manner and manifest two independent local Lorentz symmetries, Spin(1 ,3 )×Spin(3 ,1 ) . While the diagonal gauge fixing of the twofold spin groups leads to the conventional formulation on the flat Minkowskian background, the enhanced symmetry makes the standard model more rigid, and also stringy, than it appeared. The C P violating θ term may no longer be allowed by the symmetry, and hence the strong C P problem can be solved. There are now stronger constraints imposed on the possible higher order corrections. We speculate that the quarks and the leptons may belong to the two different spin classes.
Standard Model as a Double Field Theory.
Choi, Kang-Sin; Park, Jeong-Hyuck
2015-10-23
We show that, without any extra physical degree introduced, the standard model can be readily reformulated as a double field theory. Consequently, the standard model can couple to an arbitrary stringy gravitational background in an O(4,4) T-duality covariant manner and manifest two independent local Lorentz symmetries, Spin(1,3)×Spin(3,1). While the diagonal gauge fixing of the twofold spin groups leads to the conventional formulation on the flat Minkowskian background, the enhanced symmetry makes the standard model more rigid, and also stringy, than it appeared. The CP violating θ term may no longer be allowed by the symmetry, and hence the strong CP problem can be solved. There are now stronger constraints imposed on the possible higher order corrections. We speculate that the quarks and the leptons may belong to the two different spin classes. PMID:26551099
A lattice gauge theory model for graphene
Porta, Marcello
2011-01-01
In this Ph.D. thesis a model for graphene in presence of quantized electromagnetic interactions is introduced. The zero and low temperature properties of the model are studied using rigorous renormalization group methods and lattice Ward identities. In particular, it is shown that, at all orders in renormalized perturbation theory, the Schwinger functions and the response functions decay with interaction dependent anomalous exponents. Regarding the 2-point Schwinger function, the wave function renormalization diverges in the infrared limit, while the effective Fermi velocity flows to the speed of light. Concerning the response functions, those associated to a Kekul\\'e distortion of the honeycomb lattice and to a charge density wave instability are enhanced by the electromagnetic electron-electron interactions (their scaling in real space is depressed), while the lowest order correction to the scaling exponent of the density-density response function is vanishing. Then, the model in presence of a fixed Kekul\\'...
PT-symmetric Rabi Model: Perturbation Theory
Lee, Tony E
2015-01-01
We study a non-Hermitian version of the Rabi model, where a two-level system is periodically driven with an imaginary-valued drive strength, leading to alternating gain and loss. In the Floquet picture, the model exhibits PT symmetry, which can be broken when the drive is sufficiently strong. We derive the boundaries of the PT phase diagram for the different resonances by doing perturbation theory beyond the rotating-wave approximation. For the main resonance, we show that the non-Hermitian analog of the Bloch-Siegert shift corresponds to maximal PT-breaking. For the higher-order resonances, we capture the boundaries to lowest order. We also solve the regime of high frequency by mapping to the Wannier-Stark ladder. Our model can be experimentally realized in waveguides with spatially-modulated loss or in atoms with time-modulated spontaneous decay.
Queuing theory models for computer networks
Galant, David C.
1989-01-01
A set of simple queuing theory models which can model the average response of a network of computers to a given traffic load has been implemented using a spreadsheet. The impact of variations in traffic patterns and intensities, channel capacities, and message protocols can be assessed using them because of the lack of fine detail in the network traffic rates, traffic patterns, and the hardware used to implement the networks. A sample use of the models applied to a realistic problem is included in appendix A. Appendix B provides a glossary of terms used in this paper. This Ames Research Center computer communication network is an evolving network of local area networks (LANs) connected via gateways and high-speed backbone communication channels. Intelligent planning of expansion and improvement requires understanding the behavior of the individual LANs as well as the collection of networks as a whole.
Budget Management Model Based on Zero-based Budget%基于零基预算的预算管理模式研究
Institute of Scientific and Technical Information of China (English)
王海玲
2013-01-01
本文从我国国家预算管理体制大环境入手，从高职院校预算管理角度对目前我国高职院校预算管理中存在的问题进行研究和分析，并提出了适应新的公共财政预算制度的对策和建议。本文的研究对加强高职院校的预算管理，提高财务管理水平具有重要的现实意义。%Starting with our national budget management system, the paper studies and researches the problems in current budget management of national vocational colleges, and puts forward the strategies and suggestions on adapting the new public finance budget system. This study is significant to strengthen budgeting management in higher vocational colleges and improve financial management level.
Directory of Open Access Journals (Sweden)
X. M. Liu
2010-09-01
Full Text Available The aim of this paper is to study the impacts of overshooting convection at a local scale on the water distribution in the tropical UTLS. Overshooting convection is assumed to be one of the processes controlling the entry of water vapour mixing ratio in the stratosphere by injecting ice crystals above the tropopause which later sublimate and hydrate the lower stratosphere. For this purpose, we quantify the individual impact of two cases of overshooting convection in Africa observed during SCOUT-AMMA: the case of 4 August 2006 over Southern Chad which is likely to have influenced the water vapour measurements by micro-SDLA and FLASH-B from Niamey on 5 August, and the case of a mesoscale convective system over Aïr on 5 August 2006. We make use of high resolution (down to 1 km horizontally nested grid simulations with the three-dimensional regional atmospheric model BRAMS (Brazilian Regional Atmospheric Modelling System. In both cases, BRAMS succeeds in simulating the main features of the convective activity, as well as overshooting convection, though the exact position and time of the overshoots indicated by MSG brightness temperature difference is not fully reproduced (typically 1° displacement in latitude compared with the overshoots indicated by brightness temperature difference from satellite observations for both cases, and several hours shift for the Aïr case on 5 August 2006. Total water budgets associated with these two events show a significant injection of ice particles above the tropopause with maximum values of about 3.7 ton s^{−1} for the Chad case (4 August and 1.4 ton s^{−1} for the Aïr case (5 August, and a total upward cross tropopause transport of about 3300 ton h^{−1} for the Chad case and 2400 ton h^{−1} for the Aïr case in the third domain of simulation. The order of magnitude of these modelled fluxes is lower but comparable with similar studies in other tropical areas based on
Sigma-model representation of gauge theories
International Nuclear Information System (INIS)
A new formulation of gauge theories in terms of the eight-dimensional nonlinear sigma-model is presented. The basic quantity is the principal chiral field b(x,y) with values in the relevant group algebra, xsub(μ) being identified as the usual Minkowski 4-coordinate. The Yang-Mills field is defined as bsub(μ)(x). The higher components in the y-expansion of b(x,y) are shown to be removable at the expense of bsub(μ)(x) by imposing on b(x,Y) certain covariant constraints. This procedure results in the ''string'' representation for b(x,y) in terms of the path-ordered integral of bsub(μ)(x) along a fixed path between points (x+y),x. The standard source-free Yang-Mills equations are found to be equivalent to the continuity equation (with respect to y-differentiation) for the Cartan form associated with some particular b(x, y). The striking analogy with ordinary sigma-models suggests that the symmetric, gauge-invariant phase of the Yang-Mills theory may be described most adequately within the corresponding eight-dimensional linear sigma-model
Quantum Link Models: A Discrete Approach to Gauge Theories
Chandrasekharan, S; Wiese, U.-J.
1996-01-01
We construct lattice gauge theories in which the elements of the link matrices are represented by non-commuting operators acting in a Hilbert space. These quantum link models are related to ordinary lattice gauge theories in the same way as quantum spin models are related to ordinary classical spin systems. Here U(1) and SU(2) quantum link models are constructed explicitly. As Hamiltonian theories quantum link models are nonrelativistic gauge theories with potential applications in condensed ...
Michot, Béatrice; Meselhe, Ehab A.; Rivera-Monroy, Victor H.; Coronado-Molina, Carlos; Twilley, Robert R.
2011-07-01
Taylor Slough is one of the natural freshwater contributors to Florida Bay through a network of microtidal creeks crossing the Everglades Mangrove Ecotone Region (EMER). The EMER ecological function is critical since it mediates freshwater and nutrient inputs and controls the water quality in Eastern Florida Bay. Furthermore, this region is vulnerable to changing hydrodynamics and nutrient loadings as a result of upstream freshwater management practices proposed by the Comprehensive Everglades Restoration Program (CERP), currently the largest wetland restoration project in the USA. Despite the hydrological importance of Taylor Slough in the water budget of Florida Bay, there are no fine scale (˜1 km 2) hydrodynamic models of this system that can be utilized as a tool to evaluate potential changes in water flow, salinity, and water quality. Taylor River is one of the major creeks draining Taylor Slough freshwater into Florida Bay. We performed a water budget analysis for the Taylor River area, based on long-term hydrologic data (1999-2007) and supplemented by hydrodynamic modeling using a MIKE FLOOD (DHI, http://dhigroup.com/) model to evaluate groundwater and overland water discharges. The seasonal hydrologic characteristics are very distinctive (average Taylor River wet vs. dry season outflow was 6 to 1 during 1999-2006) with a pronounced interannual variability of flow. The water budget shows a net dominance of through flow in the tidal mixing zone, while local precipitation and evapotranspiration play only a secondary role, at least in the wet season. During the dry season, the tidal flood reaches the upstream boundary of the study area during approximately 80 days per year on average. The groundwater field measurements indicate a mostly upwards-oriented leakage, which possibly equals the evapotranspiration term. The model results suggest a high importance of groundwater contribution to the water salinity in the EMER. The model performance is satisfactory
Theory and Modelling of Electrolytes and Chain Molecules
Li, Ming
2011-01-01
An aqueous solution of electrolytes can be modelled simplistically as charged hard spheresdispersed in a dielectric continuum. We review various classical theories for hard sphere systems including the Percus-Yevick theory, the mean spherical approximation, the Debye-Hückel theory and the hyper-netted chain theory, and we compare the predictions of the theories with simulation results. The statistical associating fluid theory (SAFT) has proved to be accurate for neutral polymers. It is mo...
Nature, theory and modelling of geophysical convective planetary boundary layers
Zilitinkevich, Sergej
2015-04-01
horizontal branches of organised structures. This mechanism (Zilitinkevich et al., 2006), was overlooked in conventional local theories, such as the Monin-Obukhov similarity theory, and convective heat/mass transfer law: Nu~Ra1/3, where Nu and Ra are the Nusselt number and Raleigh numbers. References Hellsten A., Zilitinkevich S., 2013: Role of convective structures and background turbulence in the dry convective boundary layer. Boundary-Layer Meteorol. 149, 323-353. Zilitinkevich, S.S., 1973: Shear convection. Boundary-Layer Meteorol. 3, 416-423. Zilitinkevich, S.S., 1991: Turbulent Penetrative Convection, Avebury Technical, Aldershot, 180 pp. Zilitinkevich S.S., 2012: The Height of the Atmospheric Planetary Boundary layer: State of the Art and New Development - Chapter 13 in 'National Security and Human Health Implications of Climate Change', edited by H.J.S. Fernando, Z. Klaić, J.L. McKulley, NATO Science for Peace and Security Series - C: Environmental Security (ISBN 978-94-007-2429-7), Springer, 147-161. Zilitinkevich S.S., 2013: Atmospheric Turbulence and Planetary Boundary Layers. Fizmatlit, Moscow, 248 pp. Zilitinkevich, S.S., Hunt, J.C.R., Grachev, A.A., Esau, I.N., Lalas, D.P., Akylas, E., Tombrou, M., Fairall, C.W., Fernando, H.J.S., Baklanov, and A., Joffre, S.M., 2006: The influence of large convective eddies on the surface layer turbulence. Quart. J. Roy. Met. Soc. 132, 1423-1456. Zilitinkevich S.S., Tyuryakov S.A., Troitskaya Yu. I., Mareev E., 2012: Theoretical models of the height of the atmospheric planetary boundary layer and turbulent entrainment at its upper boundary. Izvestija RAN, FAO, 48, No.1, 150-160 Zilitinkevich, S.S., Elperin, T., Kleeorin, N., Rogachevskii, I., Esau, I.N., 2013: A hierarchy of energy- and flux-budget (EFB) turbulence closure models for stably stratified geophysical flows. Boundary-Layer Meteorol. 146, 341-373.
Performance based budgeting a model for the Indonesian DoD
Syukri, Hendri.
2005-01-01
A dramatic increase in the past three years in the Indonesian defense budget, from approximately US $800 million (FY2002$) in 2002 to approximately US $2.4 billion (FY2005$) in 2005, has created the need for the Indonesian Department of Defense (DOD) and National Armed Forces (TNI) to enhance performance and accountability for effective and efficient use of state funding. It is imperative that DOD and TNI move to better inform the public and high level government officials by increasing trans...
Site Water Budget: Influences of Measurement Uncertainties on Measurement Results and Model Results
Spank, Uwe
2010-01-01
The exact quantification of site water budget is a necessary precondition for successful and sustainable management of forests, agriculture and water resources. In this study the water balance was investigated at the spatial scale of canopies and at different temporal scales with focus on the monthly time scale. The estimation of the individual water balance components was primarily based on micrometeorological measurement methods. Evapotranspiration was assessed by the eddy-covariance (EC) m...
Application of Chaos Theory to Psychological Models
Blackerby, Rae Fortunato
This dissertation shows that an alternative theoretical approach from physics--chaos theory--offers a viable basis for improved understanding of human beings and their behavior. Chaos theory provides achievable frameworks for potential identification, assessment, and adjustment of human behavior patterns. Most current psychological models fail to address the metaphysical conditions inherent in the human system, thus bringing deep errors to psychological practice and empirical research. Freudian, Jungian and behavioristic perspectives are inadequate psychological models because they assume, either implicitly or explicitly, that the human psychological system is a closed, linear system. On the other hand, Adlerian models that require open systems are likely to be empirically tenable. Logically, models will hold only if the model's assumptions hold. The innovative application of chaotic dynamics to psychological behavior is a promising theoretical development because the application asserts that human systems are open, nonlinear and self-organizing. Chaotic dynamics use nonlinear mathematical relationships among factors that influence human systems. This dissertation explores these mathematical relationships in the context of a sample model of moral behavior using simulated data. Mathematical equations with nonlinear feedback loops describe chaotic systems. Feedback loops govern the equations' value in subsequent calculation iterations. For example, changes in moral behavior are affected by an individual's own self-centeredness, family and community influences, and previous moral behavior choices that feed back to influence future choices. When applying these factors to the chaos equations, the model behaves like other chaotic systems. For example, changes in moral behavior fluctuate in regular patterns, as determined by the values of the individual, family and community factors. In some cases, these fluctuations converge to one value; in other cases, they diverge in
Modified perturbation theory for the Yukawa model
Poluektov, Yu M
2016-01-01
A new formulation of perturbation theory for a description of the Dirac and scalar fields (the Yukawa model) is suggested. As the main approximation the self-consistent field model is chosen, which allows in a certain degree to account for the effects caused by the interaction of fields. Such choice of the main approximation leads to a normally ordered form of the interaction Hamiltonian. Generation of the fermion mass due to the interaction with exchange of the scalar boson is investigated. It is demonstrated that, for zero bare mass, the fermion can acquire mass only if the coupling constant exceeds the critical value determined by the boson mass. In this connection, the problem of the neutrino mass is discussed.
Model theory and the Tannakian formalism
Kamensky, Moshe
2009-01-01
We draw the connection between the model theoretic notions of internality and the binding group on one hand, and the Tannakian formalism on the other. More precisely, we deduce the fundamental results of the Tannakian formalism by associating to a Tannakian category a first order theory, and applying the results on internality there. In the other direction, we formulate prove a general categorical statement that can be viewed as a ``non-linear'' version of the Tannakian formalism, and deduce the model theoretic result from it. For dessert, we formulate a version of the Tannakian formalism for differential linear groups, and show how the same techniques can be used to deduce the analogous results in that context.
Verkhoglyadova, Olga; Meng, Xing; Mannucci, Anthony J.; Tsurutani, Bruce T.; Hunt, Linda A.; Mlynczak, Martin G.; Hajra, Rajkumar; Emery, Barbara A.
2016-04-01
We analyze the energy budget of the ionosphere-thermosphere (IT) system during two High-Speed Streams (HSSs) on 22-31 January, 2007 (in the descending phase of solar cycle 23) and 25 April-2 May, 2011 (in the ascending phase of solar cycle 24) to understand typical features, similarities, and differences in magnetosphere-ionosphere-thermosphere (IT) coupling during HSS geomagnetic activity. We focus on the solar wind energy input into the magnetosphere (by using coupling functions) and energy partitioning within the IT system during these intervals. The Joule heating is estimated empirically. Hemispheric power is estimated based on satellite measurements. We utilize observations from TIMED/SABER (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry) to estimate nitric oxide (NO) and carbon dioxide (CO2) cooling emission fluxes. We perform a detailed modeling study of these two similar HSS events with the Global Ionosphere-Thermosphere Model (GITM) and different external driving inputs to understand the IT response and to address how well the model reproduces the energy transport. GITM is run in a mode with forecastable inputs. It is shown that the model captures the main features of the energy coupling, but underestimates NO cooling and auroral heating in high latitudes. Lower thermospheric forcing at 100 km altitude is important for correct energy balance of the IT system. We discuss challenges for a physics-based general forecasting approach in modeling the energy budget of moderate IT storms caused by HSSs.
PARFUME Theory and Model basis Report
Energy Technology Data Exchange (ETDEWEB)
Darrell L. Knudson; Gregory K Miller; G.K. Miller; D.A. Petti; J.T. Maki; D.L. Knudson
2009-09-01
The success of gas reactors depends upon the safety and quality of the coated particle fuel. The fuel performance modeling code PARFUME simulates the mechanical, thermal and physico-chemical behavior of fuel particles during irradiation. This report documents the theory and material properties behind vari¬ous capabilities of the code, which include: 1) various options for calculating CO production and fission product gas release, 2) an analytical solution for stresses in the coating layers that accounts for irradiation-induced creep and swelling of the pyrocarbon layers, 3) a thermal model that calculates a time-dependent temperature profile through a pebble bed sphere or a prismatic block core, as well as through the layers of each analyzed particle, 4) simulation of multi-dimensional particle behavior associated with cracking in the IPyC layer, partial debonding of the IPyC from the SiC, particle asphericity, and kernel migration (or amoeba effect), 5) two independent methods for determining particle failure probabilities, 6) a model for calculating release-to-birth (R/B) ratios of gaseous fission products that accounts for particle failures and uranium contamination in the fuel matrix, and 7) the evaluation of an accident condition, where a particle experiences a sudden change in temperature following a period of normal irradiation. The accident condi¬tion entails diffusion of fission products through the particle coating layers and through the fuel matrix to the coolant boundary. This document represents the initial version of the PARFUME Theory and Model Basis Report. More detailed descriptions will be provided in future revisions.
Stochastic linear programming models, theory, and computation
Kall, Peter
2011-01-01
This new edition of Stochastic Linear Programming: Models, Theory and Computation has been brought completely up to date, either dealing with or at least referring to new material on models and methods, including DEA with stochastic outputs modeled via constraints on special risk functions (generalizing chance constraints, ICC’s and CVaR constraints), material on Sharpe-ratio, and Asset Liability Management models involving CVaR in a multi-stage setup. To facilitate use as a text, exercises are included throughout the book, and web access is provided to a student version of the authors’ SLP-IOR software. Additionally, the authors have updated the Guide to Available Software, and they have included newer algorithms and modeling systems for SLP. The book is thus suitable as a text for advanced courses in stochastic optimization, and as a reference to the field. From Reviews of the First Edition: "The book presents a comprehensive study of stochastic linear optimization problems and their applications. … T...
Performance budgeting: Its rise and fall
Nguyen, Hoang-Phuong
2007-01-01
Among various budgeting theories and practices at the federal level, performance budgeting has played an important role with its long developmental history. Performance budgeting was short-lived as it was replaced by program budgeting in the early 1960s. Looking at the period between the first decade of the twentieth century and the mid-1960s, the present paper seeks to investigate two major questions to which budgetary literature has given short shrift: 1) What forces led to the emergence of...
TRADITIONAL BUDGETING VERSUS BEYOND BUDGETING: A LITERATURE REVIEW
Directory of Open Access Journals (Sweden)
CARDOS ILDIKO REKA
2014-07-01
Full Text Available Budgets are an important part of the business environment since 1920 and are considered to be the key drivers and evaluators of managerial performance; and the key elements for planning and control. Budgets are the most powerful tool for management control; they can play an essential role in the organization’s power politics because it can increase the power and authority of top management and limit the autonomy of lower-level managers. Besides its advantages traditional budgeting presents disadvantages also. In recent years criticism towards traditional budgeting has increased. The basis of this criticism is that traditional budgeting is a relic of the past; it prevents reactions to changes in the market, it cannot keep up with the changes and requirements of today’s business world and it isn’t useful for business management. In order to eliminate criticism researchers and practitioners have developed more systematic and alternative concepts of budgeting that suits better for the needs of the modern business environment. Beyond budgeting, better budgeting, rolling forecasts, activity-based budgeting are the main alternatives developed in the last years. From the mentioned alternatives this article examines only beyond budgeting. Our paper discusses how budgeting has evolved into its current state, before examining why this universal technique has come under such heavy criticism of late. The paper is a literature analysis, it contributes to the existing managerial accounting literature and it is structured as follows. In the first part the background and evolution of budgeting is presented, followed by the analysis of related theories in traditional budgeting, emphasizing both the advantages and disadvantages of traditional budgeting. The second part of the paper continues with the discussion about alternative budgeting methods highlighting pros and cons of alternative methods, especially beyond budgeting. In the third part conducted
Silván-Cárdenas, Jose L.; Corona-Romero, Nirani
2015-10-01
In this paper, we describe some results from a study on hyperspectral analysis of coniferous canopy scattering for the purpose of estimating forest biophysical and structural parameters. Georeferenced airborne hyperspectral measurements were taken from a flying helicopter over a coniferous forest dominated by Pinus hartweguii and Abies religiosa within the Federal District Conservation Land in Mexico City. Hyperspectral data was recorded in the optical range from 350 to 2500 nm at 1nm spectral resolution using the FieldSpec 4 (ASD Inc.). Spectral measurements were also carried out in the ground for vegetation and understory components, including leaf, bark, soil and grass. Measurements were then analyzed through a previously developed multiple scattering approximation (MSA) model, which represents above-canopy spectral reflectance through a non-linear combination of pure spectral components (endmembers), as well as through a set of photon recollision probabilities and interceptance fractions. In this paper we provide an expression for the canopy absorptance as the basis for estimating the components of canopy radiation budget using the MSA model. Furthermore, since MSA does not prescribe a priori the endmembers to incorporate in the model, a multiple endmember selection method (MESMSA) was developed and tested. Photon recollision probabilities and interceptance fractions were estimated by fitting the model to airborne spectral reflectance and selected endmembers where then used to estimate the canopy radiation budget at each measured location.
Educational Program Evaluation Model, From the Perspective of the New Theories
Directory of Open Access Journals (Sweden)
Soleiman Ahmady
2014-05-01
Full Text Available Introduction: This study is focused on common theories that influenced the history of program evaluation and introduce the educational program evaluation proposal format based on the updated theory. Methods: Literature searches were carried out in March-December 2010 with a combination of key words, MeSH terms and other free text terms as suitable for the purpose. A comprehensive search strategy was developed to search Medline by the PubMed interface, ERIC (Education Resources Information Center and the main journal of medical education regarding current evaluation models and theories. We included all study designs in our study. We found 810 articles related to our topic, and finally 63 with the full text article included. We compared documents and used expert consensus for selection the best model. Results: We found that the complexity theory using logic model suggests compatible evaluation proposal formats, especially with new medical education programs. Common components of a logic model are: situation, inputs, outputs, and outcomes that our proposal format is based on. Its contents are: title page, cover letter, situation and background, introduction and rationale, project description, evaluation design, evaluation methodology, reporting, program evaluation management, timeline, evaluation budget based on the best evidences, and supporting documents. Conclusion: We found that the logic model is used for evaluation program planning in many places, but more research is needed to see if it is suitable for our context.
Nonsingular models of universes in teleparallel theories.
de Haro, Jaume; Amoros, Jaume
2013-02-15
Different models of universes are considered in the context of teleparallel theories. Assuming that the universe is filled by a fluid with an equation of state P=-ρ-f(ρ), for different teleparallel theories and different equation of state we study its dynamics. Two particular cases are studied in detail: in the first one we consider a function f with two zeros (two de Sitter solutions) that mimics a huge cosmological constant at early times and a pressureless fluid at late times; in the second one, in the context of loop quantum cosmology with a small cosmological constant, we consider a pressureless fluid (P=0⇔f(ρ)=-ρ) which means there are de Sitter and anti-de Sitter solutions. In both cases one obtains a nonsingular universe that at early times is in an inflationary phase; after leaving this phase, it passes trough a matter dominated phase and finally at late times it expands in an accelerated way. PMID:25166366
Shah, Anwar
2007-01-01
This publication, Local Budgeting, provides a comprehensive guide for local administrators who are involved in designing and implementing budgetary institutions and who wish to improve efficiency and equity in service delivery and to strengthen internal and external accountability. It details principles and practices to improve fiscal management. It reviews techniques available in developi...
Smith, J. McCree
Three methods for the preparation of maintenance budgets are discussed--(1) a traditional method, inconclusive and obsolete, based on gross square footage, (2) the formula approach method based on building classification (wood-frame, masonry-wood, masonry-concrete) with maintenance cost factors for each type plus custodial service rates by type of…
Ian Hawkesworth; Richard Emery; Joachim Wehner; Kristin Saenger
2009-01-01
Bulgaria’s budget management has seen a series of structural and procedural reforms, including in budget execution, treasury functions, internal audit, and programme and medium-term budgeting. This article discusses the use of modern budgeting techniques in Bulgaria such as top-down budgeting, multi-year budgeting perspectives and the use of performance information in the budget process, and makes recommendations for budget formulation, the role of Parliament, budget execution and management ...
Idealized numerical modeling of polar mesocyclones dynamics diagnosed by energy budget
Sergeev, Dennis; Stepanenko, Victor
2014-05-01
can be interpreted as the growth rate of the vortex) and energy conversion in the diagnostic equations for kinetic and available potential energy (APE). The energy budget equations are implemented in two forms. The first approach follows the scheme developed by Lorenz (1955) in which KE and APE are broken into a mean component and an eddy component forming a well-known energy cycle. The second method is based on the energy equations that are strictly derived from the governing equations of the numerical mesoscale model used. The latter approach, hence, takes into account all the approximations and numerical features used in the model. Some conclusions based on the comparison of the described methods are presented in the study. A series of high-resolution experiments is carried out using three-dimensional non-hydrostatic limited-area sigma-coordinate numerical model ReMeDy (Research Mesoscale Dynamics), being developed at Lomonosov Moscow State University [3]. An idealized basic state condition is used for all simulations. It is composed of the zonally oriented baroclinic zone over the sea surface partly covered with ice. To realize a baroclinic channel environment zero-gradient boundary conditions at the meridional lateral oundaries are imposed, while the zonal boundary conditions are periodic. The initialization of the mesocyclone is achieved by creating a small axis-symmetric vortex in the center of the model domain. The baroclinicity and stratification of the basic state, as well as the surface parameters, are varied in the typically observed range. References 1. Heinemann G, Øyvind S. 2013. Workshop On Polar Lows. Bull. Amer. Meteor. Soc. 94: ES123-ES126. 2. Yanase W, Niino H. 2006. Dependence of Polar Low Development on Baroclinicity and Physical Processes: An Idealized High-Resolution Experiment, J. Atmos. Sci. 64: 3044-3067. 3. Chechin DG et al. 2013. Idealized dry quasi 2-D mesoscale simulations of cold-air outbreaks over the marginal sea ice zone with fine
Abe, Tomoyuki; Tachiki, Yuuya; Kon, Hirokazu; Nagasaka, Akiko; Onodera, Kensuke; Minamino, Kazuhiro; Han, Qingmin; Satake, Akiko
2016-09-01
Synchronised and fluctuating reproduction by plant populations, called masting, is widespread in diverse taxonomic groups. Here, we propose a new method to explore the proximate mechanism of masting by combining spatiotemporal flowering data, biochemical analysis of resource allocation and mathematical modelling. Flowering data of 170 trees over 13 years showed the emergence of clustering with trees in a given cluster mutually synchronised in reproduction, which was successfully explained by resource budget models. Analysis of resources invested in the development of reproductive organs showed that parametric values used in the model are significantly different between nitrogen and carbon. Using a fully parameterised model, we showed that the observed flowering pattern is explained only when the interplay between nitrogen dynamics and climatic cues was considered. This result indicates that our approach successfully identified resource type-specific roles on masting and that the method is suitable for a wide range of plant species. PMID:27449602
Modeling and Optimization : Theory and Applications Conference
Terlaky, Tamás
2015-01-01
This volume contains a selection of contributions that were presented at the Modeling and Optimization: Theory and Applications Conference (MOPTA) held at Lehigh University in Bethlehem, Pennsylvania, USA on August 13-15, 2014. The conference brought together a diverse group of researchers and practitioners, working on both theoretical and practical aspects of continuous or discrete optimization. Topics presented included algorithms for solving convex, network, mixed-integer, nonlinear, and global optimization problems, and addressed the application of deterministic and stochastic optimization techniques in energy, finance, logistics, analytics, healthcare, and other important fields. The contributions contained in this volume represent a sample of these topics and applications and illustrate the broad diversity of ideas discussed at the meeting.
A modelling study of the impact of cirrus clouds on the moisture budget of the upper troposphere
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S. Fueglistaler
2006-01-01
Full Text Available We present a modelling study of the effect of cirrus clouds on the moisture budget of the layer wherein the cloud formed. Our framework simplifies many aspects of cloud microphysics and collapses the problem of sedimentation onto a 0-dimensional box model, but retains essential feedbacks between saturation mixing ratio, particle growth, and water removal through particle sedimentation. The water budget is described by two coupled first-order differential equations for dimensionless particle number density and saturation point temperature, where the parameters defining the system (layer depth, reference temperature, amplitude and time scale of temperature perturbation and inital particle number density, which may or may not be a function of reference temperature and cooling rate are encapsulated in a single coefficient. This allows us to scale the results to a broad range of atmospheric conditions, and to test sensitivities. Results of the moisture budget calculations are presented for a range of atmospheric conditions (T: 238–205 K; p: 325–180 hPa and a range of time scales τT of the temperature perturbation that induces the cloud formation. The cirrus clouds are found to efficiently remove water for τT longer than a few hours, with longer perturbations (τT≳10 h required at lower temperatures (T≲210 K. Conversely, we find that temperature perturbations of duration order 1 h and less (a typical timescale for e.g., gravity waves do not efficiently dehydrate over most of the upper troposphere. A consequence is that (for particle densities typical of current cirrus clouds the assumption of complete dehydration to the saturation mixing ratio may yield valid predictions for upper tropospheric moisture distributions if it is based on the large scale temperature field, but this assumption is not necessarily valid if it is based on smaller scale temperature fields.
Modeling missing data in knowledge space theory.
de Chiusole, Debora; Stefanutti, Luca; Anselmi, Pasquale; Robusto, Egidio
2015-12-01
Missing data are a well known issue in statistical inference, because some responses may be missing, even when data are collected carefully. The problem that arises in these cases is how to deal with missing data. In this article, the missingness is analyzed in knowledge space theory, and in particular when the basic local independence model (BLIM) is applied to the data. Two extensions of the BLIM to missing data are proposed: The former, called ignorable missing BLIM (IMBLIM), assumes that missing data are missing completely at random; the latter, called missing BLIM (MissBLIM), introduces specific dependencies of the missing data on the knowledge states, thus assuming that the missing data are missing not at random. The IMBLIM and the MissBLIM modeled the missingness in a satisfactory way, in both a simulation study and an empirical application, depending on the process that generates the missingness: If the missing data-generating process is of type missing completely at random, then either IMBLIM or MissBLIM provide adequate fit to the data. However, if the pattern of missingness is functionally dependent upon unobservable features of the data (e.g., missing answers are more likely to be wrong), then only a correctly specified model of the missingness distribution provides an adequate fit to the data. PMID:26651988
Modeling active memory: Experiment, theory and simulation
Amit, Daniel J.
2001-06-01
Neuro-physiological experiments on cognitively performing primates are described to argue that strong evidence exists for localized, non-ergodic (stimulus specific) attractor dynamics in the cortex. The specific phenomena are delay activity distributions-enhanced spike-rate distributions resulting from training, which we associate with working memory. The anatomy of the relevant cortex region and the physiological characteristics of the participating elements (neural cells) are reviewed to provide a substrate for modeling the observed phenomena. Modeling is based on the properties of the integrate-and-fire neural element in presence of an input current of Gaussian distribution. Theory of stochastic processes provides an expression for the spike emission rate as a function of the mean and the variance of the current distribution. Mean-field theory is then based on the assumption that spike emission processes in different neurons in the network are independent, and hence the input current to a neuron is Gaussian. Consequently, the dynamics of the interacting network is reduced to the computation of the mean and the variance of the current received by a cell of a given population in terms of the constitutive parameters of the network and the emission rates of the neurons in the different populations. Within this logic we analyze the stationary states of an unstructured network, corresponding to spontaneous activity, and show that it can be stable only if locally the net input current of a neuron is inhibitory. This is then tested against simulations and it is found that agreement is excellent down to great detail. A confirmation of the independence hypothesis. On top of stable spontaneous activity, keeping all parameters fixed, training is described by (Hebbian) modification of synapses between neurons responsive to a stimulus and other neurons in the module-synapses are potentiated between two excited neurons and depressed between an excited and a quiescent neuron
Gravothermal Star Clusters - Theory and Computer Modelling
Spurzem, Rainer
2010-11-01
In the George Darwin lecture, delivered to the British Royal Astronomical Society in 1960 by Viktor A. Ambartsumian he wrote on the evolution of stellar systems that it can be described by the "dynamic evolution of a gravitating gas" complemented by "a statistical description of the changes in the physical states of stars". This talk will show how this physical concept has inspired theoretical modeling of star clusters in the following decades up to the present day. The application of principles of thermodynamics shows, as Ambartsumian argued in his 1960 lecture, that there is no stable state of equilibrium of a gravitating star cluster. The trend to local thermodynamic equilibrium is always disturbed by escaping stars (Ambartsumian), as well as by gravothermal and gravogyro instabilities, as it was detected later. Here the state-of-the-art of modeling the evolution of dense stellar systems based on principles of thermodynamics and statistical mechanics (Fokker-Planck approximation) will be reviewed. Recent progress including rotation and internal correlations (primordial binaries) is presented. The models have also very successfully been used to study dense star clusters around massive black holes in galactic nuclei and even (in a few cases) relativistic supermassive dense objects in centres of galaxies (here again briefly touching one of the many research fields of V.A. Ambartsumian). For the modern present time of high-speed supercomputing, where we are tackling direct N-body simulations of star clusters, we will show that such direct modeling supports and proves the concept of the statistical models based on the Fokker-Planck theory, and that both theoretical concepts and direct computer simulations are necessary to support each other and make scientific progress in the study of star cluster evolution.
A Mathematical Theory of the Gauged Linear Sigma Model
Fan, Huijun; Ruan, Yongbin
2015-01-01
We construct a rigorous mathematical theory of Witten's Gauged Linear Sigma Model (GLSM). Our theory applies to a wide range of examples, including many cases with non-Abelian gauge group. Both the Gromov-Witten theory of a Calabi-Yau complete intersection X and the Landau-Ginzburg dual (FJRW-theory) of X can be expressed as gauged linear sigma models. Furthermore, the Landau-Ginzburg/Calabi-Yau correspondence can be interpreted as a variation of the moment map or a deformation of GIT in the GLSM. This paper focuses primarily on the algebraic theory, while a companion article will treat the analytic theory.
Nagura, Motoki; McPhaden, Michael J.
2014-07-01
This study examines the zonal momentum budget along the equator in the Indian Ocean in a high-resolution ocean general circulation model. Wyrtki Jets, wind-driven eastward flows in the upper 100 m that appear typically twice per year in boreal spring and fall, are a prominent feature of the ocean circulation in this region. Our results indicate that nonlinearity associated with these jets is an important element of the zonal momentum budget, with wind driven eastward momentum advected downward into the thermocline. This advection results in annually averaged zonal currents that flow against the zonal pressure gradient in the upper 200 m, such that there is no mean subsurface undercurrent in the Indian Ocean as there is in the Pacific and Atlantic Oceans. Zonal momentum is further distributed along the equator by zonal advection, with eastward flow substantially enhanced in the eastern basin relative to the western basin. Meridional advection, though generally weak, tends to decelerate surface eastward flow along the equator. These results contrast with those from previous idealized wind-forced model experiments that primarily emphasized the importance of vertical momentum advection. Also, beyond semiannual period fluctuations, significant momentum advection results from a broad range of interacting processes, spanning intraseasonal to interannual time scales. We conclude that proper simulation of zonal flows along the equator in the Indian Ocean, including their climatically relevant impacts on the mass and heat balance, requires accurate representation of nonlinearities that derive from a broad range of time and space scales.
McColl, Kaighin A.; Katul, Gabriel G.; Gentine, Pierre; Entekhabi, Dara
2016-03-01
A series of recent studies has shown that a model of the turbulent vertical velocity variance spectrum (Fvv) combined with a simplified cospectral budget can reproduce many macroscopic flow properties of turbulent wall-bounded flows, including various features of the mean-velocity profile (MVP), i.e., the "law of the wall". While the approach reasonably models the MVP's logarithmic layer, the buffer layer displays insufficient curvature compared to measurements. The assumptions are re-examined here using a direct numerical simulation (DNS) dataset at moderate Reynolds number that includes all the requisite spectral and co-spectral information. Starting with several hypotheses for the cause of the "missing" curvature in the buffer layer, it is shown that the curvature deficit is mainly due to mismatches between (i) the modelled and DNS-observed pressure-strain terms in the cospectral budget and (ii) the DNS-observed Fvv and the idealized form used in previous models. By replacing the current parameterization for the pressure-strain term with an expansive version that directly accounts for wall-blocking effects, the modelled and DNS reported pressure-strain profiles match each other in the buffer and logarithmic layers. Forcing the new model with DNS-reported Fvv rather than the idealized form previously used reproduces the missing buffer layer curvature to high fidelity thereby confirming the "spectral link" between Fvv and the MVP across the full profile. A broad implication of this work is that much of the macroscopic properties of the flow (such as the MVP) may be derived from the energy distribution in turbulent eddies (i.e., Fvv) representing the microstate of the flow, provided the link between them accounts for wall-blocking.
Oaida, C. M.; Xue, Y.; Chin, M.; Flanner, M.; De Sales, F.; Painter, T. H.
2014-12-01
Snow albedo is known to have a significant impact on energy and water budgets by modulating land-atmosphere flux exchanges. In recent decades, anthropogenic activities that cause dust and soot emission and deposition on snow-covered areas have lead to the alteration of snow albedo. Our study aims to investigate and quantitatively assess the impact of aerosols-in-snow on surface energy and water budgets at a local and regional scale using a recently enhanced regional climate model that has physically based snow processes, including aerosols in snow. We employ NCAR's WRF-ARW model, which we have previously coupled with a land surface model, Simplified Simple Biosphere version 3 (SSiB-3). We improve the original WRF/SSiB-3 framework to include a snow-radiative transfer model, Snow, Ice, and Aerosol Radiative (SNICAR) model, which considers the effects of snow grain size and aerosols-in-snow on snow albedo evolution. Furthermore, the modified WRF/SSiB-3 can now account for the deposition and tracking of aerosols in snow. The model is run for 10 continuous years (2000-2009) over North America under two scenarios: (1) no aerosol deposition in snow, and (2) with GOCART dust, black carbon, and organic carbon surface deposition in snow. By comparing the two cases, we can investigate the impact of aerosols-in-snow. We examine the changes in surface energy balance, such as albedo, surface net solar radiation (radiative forcing), and surface air and skin temperature, and how these might interact with, and lead to, changes in the hydrologic cycle, including SWE, runoff, evapotranspiration and soil moisture. We investigate the mechanisms and feedbacks that might contribute to the changes seen across select regions of North America, which are potentially a result of both local and remote effects.
International Nuclear Information System (INIS)
We review the assumptions and domain of applicability of Landau's Hydrodynamical Model. By considering two models of particle production, pair production from strong electric fields and particle production in the linear σ model, we demonstrate that many of Landau's ideas are verified in explicit field theory calculations
Drafting Multiannual Local Budgets by Economic-Mathematical Modelling of the Evolution of Revenues
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Ioan Radu
2009-01-01
Full Text Available Although seen as a sector with a high degree of inertia and conservatism the public administration system determines the public institutions to record a set of influences both from the internal and external environment. The public administration system is influenced by the frequent legislative changes and recently by the requirements claimed by the European Union. Given the complexity and dynamics of the competitive environment the approach of strategic management tools at the level of public administration becomes more and more important and necessary. One of the main types of exercise of strategic management is represented by financial planning moulded into policies, strategies, plans and programmes whose generation is based on multiannual budgets.
Density functional theory and multiscale materials modeling
Indian Academy of Sciences (India)
Swapan K Ghosh
2003-01-01
One of the vital ingredients in the theoretical tools useful in materials modeling at all the length scales of interest is the concept of density. In the microscopic length scale, it is the electron density that has played a major role in providing a deeper understanding of chemical binding in atoms, molecules and solids. In the intermediate mesoscopic length scale, an appropriate picture of the equilibrium and dynamical processes has been obtained through the single particle number density of the constituent atoms or molecules. A wide class of problems involving nanomaterials, interfacial science and soft condensed matter has been addressed using the density based theoretical formalism as well as atomistic simulation in this regime. In the macroscopic length scale, however, matter is usually treated as a continuous medium and a description using local mass density, energy density and other related density functions has been found to be quite appropriate. A unique single unified theoretical framework that emerges through the density concept at these diverse length scales and is applicable to both quantum and classical systems is the so called density functional theory (DFT) which essentially provides a vehicle to project the many-particle picture to a single particle one. Thus, the central equation for quantum DFT is a one-particle Schrödinger-like Kohn–Sham equation, while the same for classical DFT consists of Boltzmann type distributions, both corresponding to a system of noninteracting particles in the field of a density-dependent effective potential. Selected illustrative applications of quantum DFT to microscopic modeling of intermolecular interaction and that of classical DFT to a mesoscopic modeling of soft condensed matter systems are presented.
Directory of Open Access Journals (Sweden)
C. R. Flechard
2009-10-01
Full Text Available The net annual NH_{3} exchange budget of a fertilised, cut grassland in Central Switzerland is presented. The observation-based budget was computed from semi-continuous micrometeorological fluxes over a time period of 16 months and using a process-based gap-filling procedure. The data for emission peak events following the application of cattle slurry and for background exchange were analysed separately to distinguish short-term perturbations from longer-term ecosystem functioning. A canopy compensation point model of background exchange is parameterised on the basis of measured data and applied for the purposes of gap-filling. The data show that, outside fertilisation events, grassland behaves as a net sink for atmospheric NH_{3} with an annual dry deposition flux of −3.0 kg N ha^{−1} yr^{−1}, although small NH_{3} emissions by the canopy were measured in dry daytime conditions. The median Γ_{s} ratio in the apoplast (=[NH_{4}^{+}]/[H^{+}] estimated from micrometeorological measurements was 620, equivalent to a stomatal compensation point of 1.3 μg NH_{3} m^{−3} at 15°C. Non-stomatal resistance to deposition R_{w} was shown to increase with temperature and decrease with surface relative humidity, and R_{w} values were among the highest published for European grasslands, consistent with a relatively high ratio of NH_{3} to acid gases in the boundary layer at this site. Since the gross annual NH_{3} emission by slurry spreading was of the order of +20 kg N ha^{−1} yr^{−1}, the fertilised grassland was a net NH_{3} source of +17 kg N ha^{−1} yr^{−1}. A comparison with the few other measurement-based budget values from the literature reveals considerable variability, demonstrating both the influence of soil, climate, management and grassland type on the NH
Directory of Open Access Journals (Sweden)
Verkhoglyadova Olga
2016-01-01
Full Text Available We analyze the energy budget of the ionosphere-thermosphere (IT system during two High-Speed Streams (HSSs on 22–31 January, 2007 (in the descending phase of solar cycle 23 and 25 April–2 May, 2011 (in the ascending phase of solar cycle 24 to understand typical features, similarities, and differences in magnetosphere-ionosphere-thermosphere (IT coupling during HSS geomagnetic activity. We focus on the solar wind energy input into the magnetosphere (by using coupling functions and energy partitioning within the IT system during these intervals. The Joule heating is estimated empirically. Hemispheric power is estimated based on satellite measurements. We utilize observations from TIMED/SABER (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry to estimate nitric oxide (NO and carbon dioxide (CO2 cooling emission fluxes. We perform a detailed modeling study of these two similar HSS events with the Global Ionosphere-Thermosphere Model (GITM and different external driving inputs to understand the IT response and to address how well the model reproduces the energy transport. GITM is run in a mode with forecastable inputs. It is shown that the model captures the main features of the energy coupling, but underestimates NO cooling and auroral heating in high latitudes. Lower thermospheric forcing at 100 km altitude is important for correct energy balance of the IT system. We discuss challenges for a physics-based general forecasting approach in modeling the energy budget of moderate IT storms caused by HSSs.
Big Bang Models in String Theory
Craps, Ben
2006-01-01
These proceedings are based on lectures delivered at the "RTN Winter School on Strings, Supergravity and Gauge Theories", CERN, January 16 - January 20, 2006. The school was mainly aimed at Ph.D. students and young postdocs. The lectures start with a brief introduction to spacetime singularities and the string theory resolution of certain static singularities. Then they discuss attempts to resolve cosmological singularities in string theory, mainly focusing on two specific examples: the Milne...
Big bang models in string theory
International Nuclear Information System (INIS)
These proceedings are based on lectures delivered at the 'RTN Winter School on Strings, Supergravity and Gauge Theories', CERN, 16-20 January 2006. The school was mainly aimed at PhD students and young postdocs. The lectures start with a brief introduction to spacetime singularities and the string theory resolution of certain static singularities. Then they discuss attempts to resolve cosmological singularities in string theory, mainly focusing on two specific examples: the Milne orbifold and the matrix big bang
Local Models in F-Theory and M-Theory with Three Generations
Bourjaily, Jacob L.
2009-01-01
We describe a general framework that can be used to geometrically engineer local, phenomenological models in F-theory and M-theory based on ALE-fibrations, and we present several concrete examples of such models that feature three generations of matter with semi-realistic phenomenology. We show that the geometric structures required for generating interactions--triple-intersections of matter-curves in F-theory and supersymmetric three-cycles supporting multiple conical singularities in M-theo...
Miller, James R.; Russell, Gary L.
1996-01-01
The annual flux of freshwater into the Arctic Ocean by the atmosphere and rivers is balanced by the export of sea ice and oceanic freshwater. Two 150-year simulations of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. Relative to the control, the last 50-year period of the GHG experiment indicates that the total inflow of water from the atmosphere and rivers increases by 10% primarily due to an increase in river discharge, the annual sea-ice export decreases by about half, the oceanic liquid water export increases, salinity decreases, sea-ice cover decreases, and the total mass and sea-surface height of the Arctic Ocean increase. The closed, compact, and multi-phased nature of the hydrologic cycle in the Arctic Ocean makes it an ideal test of water budgets that could be included in model intercomparisons.
Lazeroms, W. M.; Bazile, E.; Brethouwer, G.; Wallin, S.; Johansson, A. V.; Svensson, G.
2014-12-01
Turbulent flows with buoyancy effects occur in many situations, both in industry and in the atmosphere. It is challenging to correctly model such flows, especially in the case of stably stratified turbulence, where vertical motions are damped by buoyancy forces. For this purpose, we have derived a so-called explicit algebraic model for the Reynolds stresses and turbulent heat flux that gives accurate predictions in flows with buoyancy effects. Although inspired by turbulence models from engineering, the main aim of our work is to improve the parametrization of turbulence in the atmospheric boundary layer (ABL). Explicit algebraic turbulence models are a class of parametrizations that, on the one hand, are more advanced than standard eddy-diffusivity relations. On the other hand, they are signficantly easier to handle numerically than models that require the solution of the full flux-budget equations. To derive the algebraic model, we apply the assumption that transport terms of dimensionless fluxes can be neglected. Careful considerations of the algebra lead to a consistent formulation of the Reynolds stresses and turbulent heat flux, which is more general and robust than previous models of a similar kind. The model is shown to give good results compared to direct numerical simulations of engineering test cases, such as turbulent channel flow. Recent work has been aimed at testing the model in an atmospheric context. The first of these tests makes use of the GABLS1 case, in which a stable atmospheric boundary layer develops through a constant surface cooling rate. The model is able to give good predictions of this case compared to LES (see attached figure). Interestingly, the results are very close to the outcome of the recently developed Energy-Flux-Budget (EFB) closure by Zilitinkevich et al. (2013). A detailed discussion of the similarities and differences between these models will be given, which can give insight in the more general gap between engineering and
THE BIG BANG THEORY AND UNIVERSE MODELING. MISTAKES IN THE RELATIVITY THEORY
Javadov, Khaladdin; Javadli, Elmaddin
2014-01-01
This article is about Theory of Big Bang and it describes some details of Universe Modelling. It is Physical and Mathematical modeling of Universe formation. Application of mathematical and physical formulas for Universe Calculations.
Theory and modeling of active brazing.
Energy Technology Data Exchange (ETDEWEB)
van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.
2013-09-01
Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.
Filgueira, Ramón; Rosland, Rune; Grant, Jon
2011-11-01
Growth of Mytilus edulis was simulated using individual based models following both Scope For Growth (SFG) and Dynamic Energy Budget (DEB) approaches. These models were parameterized using independent studies and calibrated for each dataset by adjusting the half-saturation coefficient of the food ingestion function term, XK, a common parameter in both approaches related to feeding behavior. Auto-calibration was carried out using an optimization tool, which provides an objective way of tuning the model. Both approaches yielded similar performance, suggesting that although the basis for constructing the models is different, both can successfully reproduce M. edulis growth. The good performance of both models in different environments achieved by adjusting a single parameter, XK, highlights the potential of these models for (1) producing prospective analysis of mussel growth and (2) investigating mussel feeding response in different ecosystems. Finally, we emphasize that the convergence of two different modeling approaches via calibration of XK, indicates the importance of the feeding behavior and local trophic conditions for bivalve growth performance. Consequently, further investigations should be conducted to explore the relationship of XK to environmental variables and/or to the sophistication of the functional response to food availability with the final objective of creating a general model that can be applied to different ecosystems without the need for calibration.
Spectral and scattering theory for translation invariant models in quantum field theory
DEFF Research Database (Denmark)
Rasmussen, Morten Grud
This thesis is concerned with a large class of massive translation invariant models in quantum field theory, including the Nelson model and the Fröhlich polaron. The models in the class describe a matter particle, e.g. a nucleon or an electron, linearly coupled to a second quantised massive scalar...... spectrum is proven to hold globally and scattering theory of the model is studied using time-dependent methods, of which the main result is asymptotic completeness....
QUANTUM THEORY FOR THE BINOMIAL MODEL IN FINANCE THEORY
Institute of Scientific and Technical Information of China (English)
CHEN Zeqian
2004-01-01
In this paper, a quantum model for the binomial market in finance is proposed. We show that its risk-neutral world exhibits an intriguing structure as a disk in the unit ball of R3, whose radius is a function of the risk-free interest rate with two thresholds which prevent arbitrage opportunities from this quantum market. Furthermore, from the quantum mechanical point of view we re-deduce the Cox-Ross-Rubinstein binomial option pricing formula by considering Maxwell-Boltzmann statistics of the system of N distinguishable particles.
Santoni, G. W.; Xiang, B.; Kort, E. A.; Daube, B.; Andrews, A. E.; Sweeney, C.; Wecht, K.; Peischl, J.; Ryerson, T. B.; Angevine, W. M.; Trainer, M.; Nehrkorn, T.; Eluszkiewicz, J.; Wofsy, S. C.
2012-12-01
We present constraints on California emission inventories of methane (CH4) using atmospheric observations from nine NOAA P-3 flights during the California Nexus (CalNex) campaign in May and June of 2010. Measurements were made using a quantum cascade laser spectrometer (QCLS) and a cavity ring-down spectrometer (CRDS) and calibrated to NOAA standards in-flight. Five flights sampled above the northern and southern central valley and an additional four flights probed the south coast air basin, quantifying emissions from the Los Angeles basin. The data show large (>100 ppb) CH4 enhancements associated with point and area sources such as cattle and manure management, landfills, wastewater treatment, gas production and distribution infrastructure, and rice agriculture. We compare aircraft observations to modeled CH4 distributions by accounting for a) transport using the Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by Weather Research and Forecasting (WRF) meteorology, b) emissions from inventories such as EDGAR and ones constructed from California-specific state and county databases, each gridded to 0.1° x 0.1° resolution, and c) spatially and temporally evolving boundary conditions such as GEOS-Chem and a NOAA aircraft profile measurement derived curtain imposed at the edge of the WRF domain. After accounting for errors associated with transport, planetary boundary layer height, lateral boundary conditions, seasonality of emissions, and the spatial resolution of surface emission prior estimates, we find that the California Air Resources Board (CARB) CH4 budget is a factor of 1.64 too low. Using a Bayesian inversion to the flight data, we estimate California's CH4 budget to be 2.5 TgCH4/yr, with emissions from cattle and manure management, landfills, rice, and natural gas infrastructure, representing roughly 82%, 26%, 9% and 32% (sum = 149% with other sources accounting for the additional 15%) of the current CARB CH4 budget estimate of 1.52 TgCH4
The Standard Model is Natural as Magnetic Gauge Theory
DEFF Research Database (Denmark)
Sannino, Francesco
2011-01-01
We suggest that the Standard Model can be viewed as the magnetic dual of a gauge theory featuring only fermionic matter content. We show this by first introducing a Pati-Salam like extension of the Standard Model and then relating it to a possible dual electric theory featuring only fermionic...... matter. The absence of scalars in the electric theory indicates that the associated magnetic theory is free from quadratic divergences. Our novel solution to the Standard Model hierarchy problem leads also to a new insight on the mystery of the observed number of fundamental fermion generations by...
Maar, Marie; Saurel, Camille; Landes, Anja; Dolmer, Per; Petersen, Jens Kjerulf
2015-08-01
For blue mussels, Mytilus edulis, one major constrain in the Baltic Sea is the low salinities that reduce the efficiency of mussel production. However, the effects of living in low and variable salinity regimes are rarely considered in models describing mussel growth. The aim of the present study was to incorporate the effects of low salinity into an eco-physiological model of blue mussels and to identify areas suitable for mussel production. A Dynamic Energy Budget (DEB) model was modified with respect to i) the morphological parameters (DW/WW-ratio, shape factor), ii) change in ingestion rate and iii) metabolic costs due to osmoregulation in different salinity environments. The modified DEB model was validated with experimental data from different locations in the Western Baltic Sea (including the Limfjorden) with salinities varying from 8.5 to 29.9 psu. The identified areas suitable for mussel production in the Baltic Sea are located in the Little Belt area, the Great Belt, the southern Kattegat and the Limfjorden according to the prevailing salinity regimes. The new model can be used for supporting site selection of new mussel nutrient extraction cultures in the Baltic Sea that suffers from high eutrophication symptoms or as part of integrated multi-trophic aquaculture production. The model can also be used to predict the effects of salinity changes on mussel populations e.g. in climate change studies.
Glass Durability Modeling, Activated Complex Theory (ACT)
International Nuclear Information System (INIS)
ratios is shown to represent the structural effects of the glass on the dissolution and the formation of activated complexes in the glass leached layer. This provides two different methods by which a linear glass durability model can be formulated. One based on the quasi- crystalline mineral species in a glass and one based on cation ratios in the glass: both are related to the activated complexes on the surface by the law of mass action. The former would allow a new Thermodynamic Hydration Energy Model to be developed based on the hydration of the quasi-crystalline mineral species if all the pertinent thermodynamic data were available. Since the pertinent thermodynamic data is not available, the quasi-crystalline mineral species and the activated complexes can be related to cation ratios in the glass by the law of mass action. The cation ratio model can, thus, be used by waste form producers to formulate durable glasses based on fundamental structural and activated complex theories. Moreover, glass durability model based on atomic ratios simplifies HLW glass process control in that the measured ratios of only a few waste components and glass formers can be used to predict complex HLW glass performance with a high degree of accuracy, e.g. an R2 approximately 0.97
Wentz, D.A.; Rose, W.J.
1989-01-01
Components of the hydrologic budget for a northern Wisconsin seepage lake were analyzed by applying correlation and regression techniques to monthly data. Analyses for the 1981-83 water years revealed a statistically significant, direct relationship between storage change and precipitation-evaporation balance. Ground-water outflow was negatively correlated with ground-water inflow, and this relationship was influenced by similar relationships for both hydraulic gradients and cross-sectional areas in outflow versus inflow regions of the lake. Neither ground-water outflow nor inflow was significantly related to precipitation, evaporation, storage change, or lake stage; this may reflect a lag in response time of the ground-water system compared to the lake. The results (1) emphasize the complexity of factors that influence ground-water interactions with seepage lakes and (2) suggest the importance of completing detailed hydrologic studies of these systems before mechanistic models, such as those developed to predict effects of acid deposition, are applied.
Harazono, Y.; Ueyama, M.; Miyata, A.
2006-12-01
Net ecosystem CO2 exchange (NEE) at a sub-arctic black spruce forest in interior Alaska has been measured as eddy fluxes since 2003. Based on the observed dataset, the empirical relationship and parameters controlling NEE were examined. BIOME-BGC model was modified for cold regions and was tuned for the forest, and then the model output was examined. Modified and tuned BIOME-BGC reproduced 3-yr trends of C-budget well at the forest, while that with general parameter sets showed overestimate in C-sink. To evaluate forest productivity over Alaska black spruce forest, the observed 3-yr dataset and MODIS standard products (NDVI, LST) were linked using an empirical model. Satellite images were coupled into a model, and the model outputs were examined by comparing the observed results and BIOME BGC outputs. The MODIS linked model provided good agreements in 3-yr C-budget, while MOD17 standard outputs showed overestimation in C-sink in mid-summer. The applications of observed dataset to remote sensing and modeling provided reasonable 3-yr trends of C-budget, thus the spatial distribution of C-budget might be better than original products.
Linking Complexity and Sustainability Theories: Implications for Modeling Sustainability Transitions
Camaren Peter; Mark Swilling
2014-01-01
In this paper, we deploy a complexity theory as the foundation for integration of different theoretical approaches to sustainability and develop a rationale for a complexity-based framework for modeling transitions to sustainability . We propose a framework based on a comparison of complex systemsâ€™ properties that characterize the different theories that deal with transitions to sustainability. We argue that adopting a complexity theory based approach for modeling transitions requires going...
Speaking of Theories and Models in the Accounting Sciences
Gilberto de Andrade Martins
2005-01-01
Just as happens with the concept of theory, the meaning of model is also very diffuse. This paper intends to contribute to a better understanding of the distinct concepts of theory and model as used in accounting science by clarifying the sense of the two dimensions, following an epistemological path of logical ordering. Theories, understood as gathered knowledge with diverse levels of systematization and credibility whose purpose is to explain, elucidate, interpret and unify given domains of...
Alternative Production Models in Economic Theory
Martin Dlouhý
2011-01-01
In the paper, marginal analysis and linear programming are described and then compared as two independent theoretical approaches to production theory. Although marginal analysis dominates economic literature, we argue that linear programming is an equivalent theory with some advantages and, of course, some disadvantages in comparison to marginal analysis. Marginal analysis will be a more suitable choice if we assume continuous changes and perfect substitution in production and unlimited capac...
Huang, M.; Asner, G. P.; Keller, M.; Knapp, D.
2005-12-01
Selective logging has been identified as an important form of land use in the Brazilian Amazon region based on studies in Large-scale Biosphere Atmosphere Experiment (LBA) Phase II (Nepstad et al., 1999; Asner et al., 2004). The ground and canopy damage caused by selective logging could have significant ecological, biogeochemical and micrometeorological consequences. Logging creates canopy gaps that affect photosynthetically active radiation (PAR) interception, latent and sensible heat fluxes, water stress and plant productivity. Also, it creates an increased amount of coarse woody debris (CWD), dead leaves and roots, which enlarge the carbon pools for respiration and fire. Furthermore, the biogeochemical processes in the tropical forest including the nutrient cycles and wildlife would also be altered. Unfortunately, previous studies on impacts of selective logging in that region are generally limited in space and/or time. In this study, a high-resolution (30 m by 30 m) version of the Carnegie-Ames-Stanford Approach (CASA) model is applied to quantify the impact of selective logging on the regional carbon budget at the Tapajos National Forest. A unique aspect of this study is to take advantage of recent progress in characterizing explicitly the spatial and temporal dynamics of forest canopy gaps and CWD generation based upon field and remote sensing measurements (Asner et al., 2005; Keller et al., 2004). An undisturbed forest scenario and a logging scenario will be considered. The undisturbed forest scenario corresponds to the condition prior to logging and will serve as a baseline simulation for comparison. By assimilating satellite-derived vegetation indices, gap fractions, and CWD estimates before and after logging, we expect to simulate the spatial changes of carbon storage and carbon release caused by logging over time. Measurements from the km 83 flux tower located at the Tapajos National Forest will be used to constrain the model. This study constitutes our
The logical foundations of scientific theories languages, structures, and models
Krause, Decio
2016-01-01
This book addresses the logical aspects of the foundations of scientific theories. Even though the relevance of formal methods in the study of scientific theories is now widely recognized and regaining prominence, the issues covered here are still not generally discussed in philosophy of science. The authors focus mainly on the role played by the underlying formal apparatuses employed in the construction of the models of scientific theories, relating the discussion with the so-called semantic approach to scientific theories. The book describes the role played by this metamathematical framework in three main aspects: considerations of formal languages employed to axiomatize scientific theories, the role of the axiomatic method itself, and the way set-theoretical structures, which play the role of the models of theories, are developed. The authors also discuss the differences and philosophical relevance of the two basic ways of aximoatizing a scientific theory, namely Patrick Suppes’ set theoretical predicate...
Solid modeling and applications rapid prototyping, CAD and CAE theory
Um, Dugan
2016-01-01
The lessons in this fundamental text equip students with the theory of Computer Assisted Design (CAD), Computer Assisted Engineering (CAE), the essentials of Rapid Prototyping, as well as practical skills needed to apply this understanding in real world design and manufacturing settings. The book includes three main areas: CAD, CAE, and Rapid Prototyping, each enriched with numerous examples and exercises. In the CAD section, Professor Um outlines the basic concept of geometric modeling, Hermite and Bezier Spline curves theory, and 3-dimensional surface theories as well as rendering theory. The CAE section explores mesh generation theory, matrix notion for FEM, the stiffness method, and truss Equations. And in Rapid Prototyping, the author illustrates stereo lithographic theory and introduces popular modern RP technologies. Solid Modeling and Applications: Rapid Prototyping, CAD and CAE Theory is ideal for university students in various engineering disciplines as well as design engineers involved in product...
Evolutionary Economics, Endogenous Growth Models, and Resource-Advantage Theory
Shelby D. Hunt
1997-01-01
The gap between evolutionary and neoclassical economics remains large. This article proposed that the gap can be narrowed by evolutionary economies developing process theories that can provide evolutionary theoretical foundations for formal models in the neoclassical equilibrium tradition. This article argues that a process of competitions labeled "resource-advantage theory," can provide an evolutionary, theoretical foundation for formal models of endogenous economic growth.
Energy Technology Data Exchange (ETDEWEB)
Hollmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik
2000-07-01
Since forty years instruments onboard satellites have been demonstrated their usefulness for many applications in the field of meteorology and oceanography. Several experiments, like ERBE, are dedicated to establish a climatology of the global Earth radiation budget at the top of the atmosphere. Now the focus has been changed to the regional scale, e.g. GEWEX with its regional sub-experiments like BALTEX. To obtain a regional radiation budget for Europe in the first part of the work the well calibrated measurements from ScaRaB (scanner for radiation budget) are used to derive a narrow-to-broadband conversion, which is applicable to the AVHRR (advanced very high resolution radiometer). It is shown, that the accuracy of the method is in the order of that from SCaRaB itself. In the second part of the work, results of REMO have been compared with measurements of ScaRaB and AVHRR for March 1994. The model reproduces the measurements overall well, but it is overestimating the cold areas and underestimating the warm areas in the longwave spectral domain. Similarly it is overestimating the dark areas and underestimating the bright areas in the solar spectral domain. (orig.)
"Biennial Budgeting for the Federal Government: Lessons from the States"
Whalen, Charles J.
1995-01-01
Proposals that would establish a two-year budget and appropriations cycle for the U.S. government have been offered by both Democrats and Republicans in recent years. This article analyzes the potential impact on such budgeting. The first section examines the budget period in theory and practice. The second section introduces federal biennial- budgeting proposals and the core arguments offered in support of this reform. The next three sections draw heavily on studies of state budgeting -- inc...
Theory of stellar convection - II. First stellar models
Pasetto, S.; Chiosi, C.; Chiosi, E.; Cropper, M.; Weiss, A.
2016-07-01
We present here the first stellar models on the Hertzsprung-Russell diagram, in which convection is treated according to the new scale-free convection theory (SFC theory) by Pasetto et al. The aim is to compare the results of the new theory with those from the classical, calibrated mixing-length (ML) theory to examine differences and similarities. We integrate the equations describing the structure of the atmosphere from the stellar surface down to a few per cent of the stellar mass using both ML theory and SFC theory. The key temperature over pressure gradients, the energy fluxes, and the extension of the convective zones are compared in both theories. The analysis is first made for the Sun and then extended to other stars of different mass and evolutionary stage. The results are adequate: the SFC theory yields convective zones, temperature gradients ∇ and ∇e, and energy fluxes that are very similar to those derived from the `calibrated' MT theory for main-sequence stars. We conclude that the old scale dependent ML theory can now be replaced with a self-consistent scale-free theory able to predict correct results, as it is more physically grounded than the ML theory. Fundamentally, the SFC theory offers a deeper insight of the underlying physics than numerical simulations.
Large field inflation models from higher-dimensional gauge theories
Energy Technology Data Exchange (ETDEWEB)
Furuuchi, Kazuyuki [Manipal Centre for Natural Sciences, Manipal University, Manipal, Karnataka 576104 (India); Koyama, Yoji [Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan R.O.C. (China)
2015-02-23
Motivated by the recent detection of B-mode polarization of CMB by BICEP2 which is possibly of primordial origin, we study large field inflation models which can be obtained from higher-dimensional gauge theories. The constraints from CMB observations on the gauge theory parameters are given, and their naturalness are discussed. Among the models analyzed, Dante’s Inferno model turns out to be the most preferred model in this framework.
The Birth of Model Theory Lowenheim's Theorem in the Frame of the Theory of Relatives
Badesa, Calixto
2008-01-01
Löwenheim's theorem reflects a critical point in the history of mathematical logic, for it marks the birth of model theory--that is, the part of logic that concerns the relationship between formal theories and their models. However, while the original proofs of other, comparably significant theorems are well understood, this is not the case with Löwenheim's theorem. For example, the very result that scholars attribute to Löwenheim today is not the one that Skolem--a logician raised in the algebraic tradition, like Löwenheim--appears to have attributed to him. In The Birth of Model Theory, Cali
Plasma and fluid turbulence: Theory and modelling
International Nuclear Information System (INIS)
The area of turbulence has been covered by many books over the years. This has, of course, mainly been fluid turbulence, while the area of plasma turbulence has been treated much less. This book by Yoshizawa et al covers both plasma and fluid turbulence, in a way that does justice to both areas at the same time as cross-disciplinary aspects are illuminated. The book should be useful to physicists working in both areas partly because it examines fundamental aspects in a pedagogical way, partly because it is up to date and partly because of the cross-disciplinary aspects which enrich both areas. It is written as an advanced textbook. The reader should have previous knowledge of at least one of the areas and also some background in statistical physics. The book starts with the very important and highly up to date area of structure formation which is relevant both to fluids and plasmas. Here, pipe flow of fluids is treated as an introduction to the area, then follows discussion of the generation of magnetic fields by turbulent motion in stellar objects and structure formation in plasmas confined by a magnetic field. Also the concept of bifurcation is introduced. This part builds up knowledge from the simple fluid case to the problems of magnetic confinement of plasmas in a very pedagogical way. It continues by introducing the fundamentals of fluid turbulence. This is done very systematically and concepts useful for industrial applications like the K-e method and several ways of heuristic modelling are introduced. Also the two dimensional vortex equation, which is also relevant to magnetized plasmas is introduced. In chapter 5 the statistical theory of turbulence is treated. It starts with a very nice and easy to understand example of renormalization of a simple nonlinear equation where the exact solution is known. It introduces the method of partial renormalization, Greens functions and the direct interaction approximation (DIA). The book then continues with an
General autocatalytic theory and simple model of financial markets
Thuy Anh, Chu; Lan, Nguyen Tri; Viet, Nguyen Ai
2015-06-01
The concept of autocatalytic theory has become a powerful tool in understanding evolutionary processes in complex systems. A generalization of autocatalytic theory was assumed by considering that the initial element now is being some distribution instead of a constant value as in traditional theory. This initial condition leads to that the final element might have some distribution too. A simple physics model for financial markets is proposed, using this general autocatalytic theory. Some general behaviours of evolution process and risk moment of a financial market also are investigated in framework of this simple model.
Non-linear σ-models and string theories
International Nuclear Information System (INIS)
The connection between σ-models and string theories is discussed, as well as how the σ-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs
Non-linear sigma-models and string theories
Energy Technology Data Exchange (ETDEWEB)
Sen, A.
1986-10-01
The connection between sigma-models and string theories is discussed, as well as how the sigma-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs. (LEW)
Quantum Link Models and Quantum Simulation of Gauge Theories
International Nuclear Information System (INIS)
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)
Fractional Order Modelling Using State Space Theory
Directory of Open Access Journals (Sweden)
Pritesh Shah
2013-06-01
Full Text Available There are various fractional order systems existing. This paper deals with the modelling of fractional order systems using an old and unique model structure i.e. state space model. The fractional order process system can be mathematically modelled by state space model. Simulation results validated that the fractional order model using state space is better as compared to other models such as first order with delay.
A Punctuated Equilibrium in French Budgeting Processes
B. Baumgartner, Frank; Foucault, Martial; François, Abel
2006-01-01
We use data on French budgeting to test models of friction, incrementalism and punctuated equilibrium. Data include the overall state budget since 1820; ministerial budgets for seven ministries since 1868; and a more complete ministerial series covering ten ministries since 1947. Our results in every case are remarkably similar to the highly leptokurtic distributions that Jones and Baumgartner (2005) demonstrated in US budgeting processes. This suggests that general characteristics of adminis...
A model for gauge theories with Higgs fields
International Nuclear Information System (INIS)
We discuss in details a simple, purely bosonic, quantum field theory belonging to larger class of models with the following properties: a) They are asymptotically free, with a dynamically generated mass scale. b) They have a space of parameters which gets quantum corrections drastically modifying the classical singularity structure. The quantum theory can have massless solitons, Argyres-Douglas-like CFTs, exhibit confinement, etc... c) The physics can, to a large extent, be worked out in models with a large number of supersymmetries as well as in purely bosonic ones. In the former case, exact BPS mass formulas can be derived, brane constructions and embedding in M theory do exist. d) The models have an interesting 1/N expansion, and it is possible to define a double scaling limit in the sense of the 'old' matrix models when approaching the singularities in parameter space. These properties make these theories very good toy models for four dimensional gauge theories with Higgs fields, and provide a framework where the effects of breaking supersymmetry can be explicitly studied. In our model, we work out in details the quantum space of parameters. We obtain the non-local lagrangian description of the Argyres-Douglas-like CFT, and show that it admits a strongly coupled fixed point. We also explicitly demonstrate property d). The possibility of defining such double scaling limits was not anticipated on the gauge theory side, and could be of interest to understand the gauge theory/string theory correspondence. (author)
Houcine, A.; Bargaoui, Z.
2012-04-01
Modelling soil water budget is a key issue for assessing drought awareness indices based on soil moisture estimation. The aim of the study is to compare drought indices based on rainfall time series to those based on soil water content time series and evapotranspiration time series. To this end, a vertically averaged water budget over the root zone is implemented to assist the estimation of evapotranspiration flux. A daily time step is adopted to run the water budget model for a lumped watershed of 250 km2 under arid climate where recorded meteorological and hydrological data are available for a ten year period. The water balance including 7 parameters is computed including evapotranspiration, runoff and leakage. Soil properties related parameters are derived according to pedo transfer functions while two remaining parameters are considered as data driven and are subject to calibration. The model is calibrated using daily hydro meteorological data (solar radiation, air temperature, air humidity, mean areal rainfall) as well as daily runoff records and also average annual (or regional) evapotranspiration. The latter is estimated using an empirical sub-model. A set of acceptable solutions is identified according to the values of the Nash coefficients for annual and decadal runoffs as well as the relative bias for average annual evapotranspiration. Using these acceptable solutions several drought indices are computed: SPI (standard precipitation index), SMDI (soil moisture deficit index) and ETDI (evapotranspiration deficit index). While SPI indicators are based only on monthly precipitation time series, SMDI are based on weekly mean soil water content as computed by the hydrological model. On the other hand ETDI indices are based on weekly mean potential and actual evapotranspirations as estimated by the meteorological and hydrological models. For SPI evaluation various time scales are considered from one to twelve months (SPI1, SPI3, SPI6, SPI9 and SPI12). For all
Jón R. Blöndal; Sang-In Kim
2005-01-01
Thailand has a sophisticated budget formulation process which has delivered solid fiscal results over time. This article discusses aspects of the budget process, including strategic performance budgeting, central development planning, the steps in the budget preparation timetable, and the roles of the spending ministries, the Bureau of the Budget and the Central Fund.
KAOS: A Kinetic Theory Tool for Modeling Complex Social Systems
Directory of Open Access Journals (Sweden)
Bruneo Dario
2016-01-01
Full Text Available The kinetic theory approach is successfully used to model complex phenomena related to social systems, allowing to predict the dynamics and emergent behavior of large populations of agents. In particular, kinetic theory for active particles (KTAP models are usually analyzed by numerically solving the underlying Boltzmann-type differential equations through ad-hoc implementations. In this paper, we present KAOS: a kinetic theory of active particles modeling and analysis software tool. To the best of our knowledge, KAOS represents the first attempt to design and implement a comprehensive tool that assists the user in all the steps of the modeling process in the framework of the kinetic theories, from the model definition to the representation of transient solutions. To show the KAOS features, we present a new model capturing the competition/cooperation dynamics of a socio-economic system with welfare dynamics, in different socio-political conditions
生态预算:一种城市环境管理模型%Eco-budget - A Model of Urban Environmental Management
Institute of Scientific and Technical Information of China (English)
郝韦霞
2005-01-01
In this paper, a new model of urban environmental resource management is introduced. The article analyzes the gap between urban environmental management and the management of economy and human resources. The significance, the key points, the implementation procedures, and steps of eco-budget cycle are discussed.
Silva, Walter A.
1993-01-01
The presentation begins with a brief description of the motivation and approach that has been taken for this research. This will be followed by a description of the Volterra Theory of Nonlinear Systems and the CAP-TSD code which is an aeroelastic, transonic CFD (Computational Fluid Dynamics) code. The application of the Volterra theory to a CFD model and, more specifically, to a CAP-TSD model of a rectangular wing with a NACA 0012 airfoil section will be presented.
Adachi, M.; Ito, A.; Takeuchi, W.; Yamagata, Y.
2011-12-01
Reducing emissions from deforestation and forest degradation in developing countries (REDD) is one of the most important carbon emission reduction efforts in the tropical region. Deforestation and land use changes are human activities with major impact on the regional carbon budged and the other greenhouse gases (CH4 and N2O) emissions. Forest carbon biomass in Southeast Asia is largest in Asia region; however, the area of primary forest had continuously decreased due to land-use conversion. The objective of the present study was to evaluate carbon budged and greenhouse gases induced by deforestation from Borneo Island. We used time-series satellite remote-sensing data to track deforestation history in Borneo Island, Southeast Asia, and estimated the resulting forest carbon budget using a process-based model (VISIT: Vegetation Integrative SImulator for Trace gases). The forest/non-forest area was mapped by applying the ALOS/PALSAR-calibrated threshold value to MODIS, SPOT-VEGETATION, and NOAA-AVHRR images. The model allowed us to estimate changes in carbon budged and greenhouse gases by human disturbances, including land-use conversion from primary forest to cropland (e.g., oil-palm plantation). The estimated carbon stocks, budged, and greenhouse gases were verified using field observation of previous studies at some point of Borneo Island. Our results suggested that the southern part of Borneo Island was a large carbon source due to deforestation, although the VISIT model need be revised to account for tropical peatland.
Semiparametric theory based MIMO model and performance analysis
Institute of Scientific and Technical Information of China (English)
XU Fang-min; XU Xiao-dong; ZHANG Ping
2007-01-01
In this article, a new approach for modeling multi- input multi-output (MIMO) systems with unknown nonlinear interference is introduced. The semiparametric theory based MIMO model is established, and Kernel estimation is applied to combat the nonlinear interference. Furthermore, we derive MIMO capacity for these systems and explore the asymptotic properties of the new channel matrix via theoretical analysis. The simulation results show that the semiparametric theory based modeling and kernel estimation are valid to combat this kind of interference.
Directory of Open Access Journals (Sweden)
M. Adachi
2011-09-01
Full Text Available More reliable estimates of the carbon (C stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia and one agro-forest (an oil palm plantation in Malaysia to estimate the C budget of tropical ecosystems in Southeast Asia, including the impacts of land-use conversion. The observed aboveground biomass in the seasonal dry tropical forest in Thailand (226.3 t C ha^{−1} and the rainforest in Malaysia (201.5 t C ha^{−1} indicate that tropical forests of Southeast Asia are among the most C-abundant ecosystems in the world. The model simulation results in rainforests were consistent with field data, except for the NEP, however, the VISIT model tended to underestimate C budget and stock in the seasonal dry tropical forest. The gross primary production (GPP based on field observations ranged from 32.0 to 39.6 t C ha^{−1} yr^{−1} in the two primary forests, whereas the model slightly underestimated GPP (26.5–34.5 t C ha^{−1} yr^{−1}. The VISIT model appropriately captured the impacts of disturbances such as deforestation and land-use conversions on the C budget. Results of sensitivity analysis showed that the proportion of remaining residual debris was a key parameter determining the soil C budget after the deforestation event. According to the model simulation, the total C stock (total biomass and soil C of the oil palm plantation was about 35% of the rainforest's C stock at 30 yr following initiation of the plantation. However, there were few field data of C budget and stock, especially in oil palm plantation. The C budget of each ecosystem must be evaluated over the long term using both the model simulations and observations to
Adachi, M.; Ito, A.; Ishida, A.; Kadir, W. R.; Ladpala, P.; Yamagata, Y.
2011-09-01
More reliable estimates of the carbon (C) stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT) was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia) and one agro-forest (an oil palm plantation in Malaysia) to estimate the C budget of tropical ecosystems in Southeast Asia, including the impacts of land-use conversion. The observed aboveground biomass in the seasonal dry tropical forest in Thailand (226.3 t C ha-1) and the rainforest in Malaysia (201.5 t C ha-1) indicate that tropical forests of Southeast Asia are among the most C-abundant ecosystems in the world. The model simulation results in rainforests were consistent with field data, except for the NEP, however, the VISIT model tended to underestimate C budget and stock in the seasonal dry tropical forest. The gross primary production (GPP) based on field observations ranged from 32.0 to 39.6 t C ha-1 yr-1 in the two primary forests, whereas the model slightly underestimated GPP (26.5-34.5 t C ha-1 yr-1). The VISIT model appropriately captured the impacts of disturbances such as deforestation and land-use conversions on the C budget. Results of sensitivity analysis showed that the proportion of remaining residual debris was a key parameter determining the soil C budget after the deforestation event. According to the model simulation, the total C stock (total biomass and soil C) of the oil palm plantation was about 35% of the rainforest's C stock at 30 yr following initiation of the plantation. However, there were few field data of C budget and stock, especially in oil palm plantation. The C budget of each ecosystem must be evaluated over the long term using both the model simulations and observations to understand the effects of climate and land-use conversion on C budgets in tropical forest
Iterated perturbation theory for the attractive Holstein and Hubbard models
Freericks, J. K.; Jarrell, Mark (Eds. )
1994-01-01
A strictly truncated (weak-coupling) perturbation theory is applied to the attractive Holstein and Hubbard models in infinite dimensions. These results are qualified by comparison with essentially exact Monte Carlo results. The second order iterated perturbation theory is shown to be quite accurate in calculating transition temperatures for retarded interactions, but is not as accurate for the self energy or the irreducible vertex functions themselves. Iterated perturbation theory is carried ...
The Self-Perception Theory vs. a Dynamic Learning Model
Swank, Otto
2006-01-01
Several economists have directed our attention to a finding in the social psychological literature that extrinsic motivation may undermine intrinsic motivation. The self-perception (SP) theory developed by Bem (1972) explains this finding. The crux of this theory is that people remember their past decisions and the extrinsic rewards they received, but they do not recall their intrinsic motives. In this paper I show that the SP theory can be modeled as a variant of a conventional dynamic learn...
Gromov-Witten theory, Hurwitz numbers, and Matrix models, I
Okounkov, Andrei; Pandharipande, Rahul
2001-01-01
The main goal of the paper is to present a new approach via Hurwitz numbers to Kontsevich's combinatorial/matrix model for the intersection theory of the moduli space of curves. A secondary goal is to present an exposition of the circle of ideas involved: Hurwitz numbers, Gromov-Witten theory of the projective line, matrix integrals, and the theory of random trees. Further topics will be treated in a sequel.
Conditional spatial policy dependence: theory and model specification
Neumayer, Eric; Plümper, Thomas
2012-01-01
The authors discuss how scholars can bring theories of spatial policy dependence and empirical model specifications closer in line so that the empirical analysis actually tests the theoretical predictions. Comprehensive theories of spatial policy dependence typically suggest that the jurisdictions receiving spatial stimuli systematically differ in their exposure to such signals as a function of the intensity of their interaction with other jurisdictions. Similarly, theories often predict that...
Budgeting for School Media Centers.
Drott, M. Carl
1978-01-01
Describes various forms of budgets and discusses concepts in budgeting useful to supervisors of school media centers: line item budgets, capital budgets, creating budgets, the budget calendar, innovations, PPBS (Planning, Programing, Budgeting System), zero-based budgeting, cost-benefit analysis, benefits, benefit guidelines, and budgeting for the…
G. Formetta; R. Mantilla; Franceschi, S; A. Antonello; R. Rigon
2011-01-01
This paper presents a discussion of the predictive capacity of the implementation of the semi-distributed hydrological modeling system JGrass-NewAge. This model focuses on the hydrological budgets of medium scale to large scale basins as the product of the processes at the hillslope scale with the interplay of the river network. The part of the modeling system presented here deals with the: (i) estimation of the space-time structure of precipitation, (ii) estimation of runoff production; (iii...
Theories and models of globalization ethicizing
Directory of Open Access Journals (Sweden)
Dritan Abazović
2016-05-01
Full Text Available Globalization as a phenomenon is under the magnifying glass of many philosophical discussions and theoretical deliberations. While most theorists deal with issues that are predominantly of economic or political character, this article has a different logic. The article presents six theories which in their own way explain the need for movement by ethicizing globalization. Globalization is a process that affects all and as such it has become inevitable, but it is up the people to determine its course and make it either functional or uncontrolled. The survival and development of any society is measured primarily by the quality of its moral and ethical foundation. Therefore, it is clear that global society can survive and be functional only if it finds a minimum consensus on ethical norms or, as said in theory, if it establishes its ethical system based on which it would be built and developed.
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.
Theory and model use in social marketing health interventions.
Luca, Nadina Raluca; Suggs, L Suzanne
2013-01-01
The existing literature suggests that theories and models can serve as valuable frameworks for the design and evaluation of health interventions. However, evidence on the use of theories and models in social marketing interventions is sparse. The purpose of this systematic review is to identify to what extent papers about social marketing health interventions report using theory, which theories are most commonly used, and how theory was used. A systematic search was conducted for articles that reported social marketing interventions for the prevention or management of cancer, diabetes, heart disease, HIV, STDs, and tobacco use, and behaviors related to reproductive health, physical activity, nutrition, and smoking cessation. Articles were published in English, after 1990, reported an evaluation, and met the 6 social marketing benchmarks criteria (behavior change, consumer research, segmentation and targeting, exchange, competition and marketing mix). Twenty-four articles, describing 17 interventions, met the inclusion criteria. Of these 17 interventions, 8 reported using theory and 7 stated how it was used. The transtheoretical model/stages of change was used more often than other theories. Findings highlight an ongoing lack of use or underreporting of the use of theory in social marketing campaigns and reinforce the call to action for applying and reporting theory to guide and evaluate interventions. PMID:22934539
Measurement Models for Reasoned Action Theory
Hennessy, Michael; Bleakley, Amy; Fishbein, Martin
2012-01-01
Quantitative researchers distinguish between causal and effect indicators. What are the analytic problems when both types of measures are present in a quantitative reasoned action analysis? To answer this question, we use data from a longitudinal study to estimate the association between two constructs central to reasoned action theory: behavioral beliefs and attitudes toward the behavior. The belief items are causal indicators that define a latent variable index while the attitude items are ...
Theories and models of globalization ethicizing
Dritan Abazović
2016-01-01
Globalization as a phenomenon is under the magnifying glass of many philosophical discussions and theoretical deliberations. While most theorists deal with issues that are predominantly of economic or political character, this article has a different logic. The article presents six theories which in their own way explain the need for movement by ethicizing globalization. Globalization is a process that affects all and as such it has become inevitable, but it is up the people to determine its ...
The model equation of soliton theory
Adler, V. E.; Shabat, A. B.
2007-01-01
We consider an hierarchy of integrable 1+2-dimensional equations related to Lie algebra of the vector fields on the line. The solutions in quadratures are constructed depending on $n$ arbitrary functions of one argument. The most interesting result is the simple equation for the generating function of the hierarchy which defines the dynamics for the negative times and also has applications to the second order spectral problems. A rather general theory of integrable 1+1-dimensional equations c...
An Application of Rough Set Theory to Modelling and Utilising Data Warehouses
Institute of Scientific and Technical Information of China (English)
DENG Ming-rong; YANG Jian-bo; PAN Yun-he
2001-01-01
A data warehouse often accommodates enormous summary information in various granularities and is mainly used to support on-line analytical processing. Ideally all detailed data should be accessible by residing in some legacy systems or on-line transaction processing systems. In many cases, however, data sources in computers are also kinds of summary data due to technological problems or budget limits and also because different aggregation hierarchies may need to be used among various transaction systems. In such circumstances, it is necessary to investigate how to design dimensions, which play a major role in dimensional model for a data warehouse, and how to estimate summary information, which is not stored in the data warehouse. In this paper, the rough set theory is applied to support the dimension design and information estimation.
Modeling Routinization in Games: An Information Theory Approach
DEFF Research Database (Denmark)
Wallner, Simon; Pichlmair, Martin; Hecher, Michael;
2015-01-01
Routinization is the result of practicing until an action stops being a goal-directed process. This paper formulates a definition of routinization in games based on prior research in the fields of activity theory and practice theory. Routinization is analyzed using the formal model of discrete......-time, discrete-space Markov chains and information theory to measure the actual error between the dynamically trained models and the player interaction. Preliminary research supports the hypothesis that Markov chains can be effectively used to model routinization in games. A full study design is presented...
Directory of Open Access Journals (Sweden)
P. Martinerie
2009-01-01
Full Text Available The budgets of seven halogenated gases (CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl_{4} and SF_{6} are studied by comparing measurements in polar firn air from two Arctic and three Antarctic sites, and simulation results of two numerical models: a 2-D atmospheric chemistry model and a 1-D firn diffusion model. The first one is used to calculate atmospheric concentrations from emission trends based on industrial inventories; the calculated concentration trends are used by the second one to produce depth concentration profiles in the firn. The 2-D atmospheric model is validated in the boundary layer by comparison with atmospheric station measurements, and vertically for CFC-12 by comparison with balloon and FTIR measurements. Firn air measurements provide constraints on historical atmospheric concentrations over the last century. Age distributions in the firn are discussed using a Green function approach. Finally, our results are used as input to a radiative model in order to evaluate the radiative forcing of our target gases. Multi-species and multi-site firn air studies allow to better constrain atmospheric trends. The low concentrations of all studied gases at the bottom of the firn, and their consistency with our model results confirm that their natural sources are insignificant. Our results indicate that the emissions, sinks and trends of CFC-11, CFC-12, CFC-113, CFC-115 and SF_{6} are well constrained, whereas it is not the case for CFC-114 and CCl_{4}. Significant emission-dependent changes in the lifetimes of halocarbons destroyed in the stratosphere were obtained. Those result from the time needed for their transport from the surface where they are emitted to the stratosphere where they are destroyed. Efforts should be made to update and reduce the large uncertainties on CFC lifetimes.
Pessacg, Natalia L.; Solman, Silvina A.; Samuelsson, Patrick; Sanchez, Enrique; Marengo, José; Li, Laurent; Remedio, Armelle Reca C.; da Rocha, Rosmeri P.; Mourão, Caroline; Jacob, Daniela
2014-09-01
The performance of seven regional climate models in simulating the radiation and heat fluxes at the surface over South America (SA) is evaluated. Sources of uncertainty and errors are identified. All simulations have been performed in the context of the CLARIS-LPB Project for the period 1990-2008 and are compared with the GEWEX-SRB, CRU, and GLDAS2 dataset and NCEP-NOAA reanalysis. Results showed that most of the models overestimate the net surface short-wave radiation over tropical SA and La Plata Basin and underestimate it over oceanic regions. Errors in the short-wave radiation are mainly associated with uncertainties in the representation of surface albedo and cloud fraction. For the net surface long-wave radiation, model biases are diverse. However, the ensemble mean showed a good agreement with the GEWEX-SRB dataset due to the compensation of individual model biases. Errors in the net surface long-wave radiation can be explained, in a large proportion, by errors in cloud fraction. For some particular models, errors in temperature also contribute to errors in the net long-wave radiation. Analysis of the annual cycle of each component of the energy budget indicates that the RCMs reproduce generally well the main characteristics of the short- and long-wave radiations in terms of timing and amplitude. However, a large spread among models over tropical SA is apparent. The annual cycle of the sensible heat flux showed a strong overestimation in comparison with the reanalysis and GLDAS2 dataset. For the latent heat flux, strong differences between the reanalysis and GLDAS2 are calculated particularly over tropical SA.
Camp, E.; Cal, R. B.
2015-12-01
To optimize the power production of large wind farms, it is important to understand the flow within the wind turbine array as well as its interaction with the surrounding atmosphere. Computational simulations are often employed to study both the velocity field within and immediately above wind farms. In many computational studies, wind turbines are modeled as stationary, porous actuator discs. A wind tunnel study is done in order to compare the wakes within an array of porous discs and an equivalent array of model wind turbines. To characterize the wakes within a 4×3 model wind farm, stereoscopic particle image velocimetry (SPIV) is employed. SPIV measurements focus on the region along the centerline of the array upstream and downstream of the center turbine in the fourth row. The computed mean flow fields and turbulent stresses provide a basis to compare the near and far wakes of the turbines with those of the porous discs. The detailed analysis of the wakes for each case focus on the mean kinetic energy budget within the wakes. Examining the mean kinetic energy budget is done via computing the mean kinetic energy, flux of kinetic energy, and production of turbulence which are analogous to a measure of extracted power.
N=2 minimal model from 4d supersymmetric theory
Honda, Masazumi
2015-01-01
Previous studies have shown that supersymmetric partition function on $T^2 \\times S^2$ is related to elliptic genus of two dimensional supersymmetric theory. In this short note we find a four dimensional supersymmetric theory, whose partition function on $T^2 \\times S^2$ is the same as elliptic genera of $\\mathcal{N}=2$ minimal models in two dimensions.
Jia, Y.; Ding, X.; C. Qin; Wang, H.
2009-01-01
A distributed model for simulating the land surface hydrological processes in the Heihe river basin was developed and validated on the basis of considering the physical mechanism of hydrological cycle and the artificial system of water utilization in the basin. Modeling approach of every component process was introduced from 2 aspects, i.e., water cycle and energy cycle. The hydrological processes include evapotranspiration, infiltration, runoff, groundwater flow, interaction between groundwa...
Jia, Y.; Ding, X.; C. Qin; Wang, H.
2009-01-01
A distributed model for simulating the land surface hydrological processes in the Heihe river basin was developed and validated on the basis of considering the physical mechanism of hydrological cycle and the artificial system of water utilization in the basin. Modeling approach of every component process was introduced from 2 aspects, i.e., water cycle and energy cycle. The hydrological processes include evapotranspiration, infiltration, runoff, groundwater flow, interactio...
Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria
E. Artinyan; F. Habets; Noilhan, J.; Ledoux, Emmanuel; Dimitrov, D; Martin, E.; Le Moigne, P.
2007-01-01
A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used in order to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997), at an eight km resolution. It was based on the data available at the National Institute of Meteorology and Hydrology (NIMH) of Bulgaria. Atmospheric parameters were carefully checked and interpolated with a hi...
Klok, Chris
2008-12-01
Laboratory tests are typically conducted under optimal conditions testing the single effect of a toxicant In the field, due to suboptimal conditions, density dependence can both diminish and enhance effects of toxicants on populations. A review of the literature indicated that general insight on interaction of density and toxicants is lacking, and therefore no predictions on their combined action can be made. In this paper the influence of zinc was tested at different population densities on the demographic rates: growth, reproduction, and survival in the earthworm Lumbricus rubellus. Changes in these rates were extrapolated with a combined Dynamic energy budget (DEB) and a population model to assess consequences at the population level. Inference from the DEB model indicated that density decreased the assimilation of food whereas zinc increased the maintenance costs. The combined effects of density and zinc resulted in a decrease in the intrinsic rate of population increase which suddenly dropped to zero at combinations of zinc and density where development is so strongly retarded that individuals do not mature. This already happened at zinc levels where zinc induced mortality is low and therefore density enhances zinc effects and density dependent compensation is not expected. PMID:19192801
Directory of Open Access Journals (Sweden)
P. Nabat
2012-07-01
Full Text Available The present study investigates the dust emission and load over the Mediterranean basin using the coupled-chemistry-aerosol regional climate model RegCM-4. The first step of this work focuses on dust particle emission size distribution modeling. We compare a parameterization in which the emission is based on the individual kinetic energy of the aggregates striking the surface to a recent parameterization based on an analogy with the fragmentation of brittle materials. The main difference between the two dust schemes concerns the mass proportion of fine aerosol which is reduced in the case of the new dust parameterization, with consequences for optical properties. At the episodic scale, comparisons between RegCM-4 simulations, satellite and ground-based data show a clear improvement using the new dust distribution in terms of Aerosol Optical Depth (AOD values and geographic gradients. These results are confirmed at the seasonal scale for the investigated year 2008. A multi-annual simulation is finally carried out using the new dust distribution over the period 2000–2009. This change of dust distribution has sensitive impacts on the simulated regional dust budget, notably dry dust deposition and the regional direct aerosol radiative forcing over the Mediterranean basin. This could clearly modify the possible effects of dust aerosols on the biogeochemical activity and climate of the Mediterranean basin. In particular, we find that the new size distribution produces a higher dust deposition flux, and smaller top of atmosphere (TOA dust radiative cooling.
Kriest, I.; Oschlies, A.
2015-09-01
Global models of the oceanic nitrogen cycle are subject to many uncertainties regarding the representation of the relevant biogeochemical processes and of the feedbacks between nitrogen sources and sinks that determine space- and timescales on which the global nitrogen budget is regulated. We investigate these aspects using a global model of ocean biogeochemistry that explicitly considers phosphorus and nitrogen, including pelagic denitrification and nitrogen fixation as sink and source terms of fixed nitrogen, respectively. The model explores different parameterizations of organic matter sinking speed, oxidant affinity of oxic and suboxic remineralization, and regulation of nitrogen fixation by temperature and different stoichiometric ratios. Examination of the initial transient behavior of different model setups initialized from observed biogeochemical tracer distributions reveal changes in simulated nitrogen inventories and fluxes particularly during the first centuries. Millennial timescales have to be resolved in order to bring all biogeochemical and physical processes into a dynamically consistent steady state. Analysis of global properties suggests that not only particularly particle sinking speed but also the parameterization of denitrification determine the extent of oxygen minimum zones, global nitrogen fluxes, and hence the oceanic nitrogen inventory. However, the ways and directions in which different parameterizations of particle sinking, nitrogen fixation, and denitrification affect the global diagnostics are different suggesting that these may, in principle, be constrained independently from each other. Analysis of the model misfit with respect to observed biogeochemical tracer distributions and fluxes suggests a particle flux profile close to the one suggested by Martin et al. (1987). Simulated pelagic denitrification best agrees with the lower values between 59 and 84 Tg N yr-1 recently estimated by other authors.
Department of Transportation — The Automated Budget System (ABS) automates management and planning of the Mike Monroney Aeronautical Center (MMAC) budget by providing enhanced capability to plan,...
Studies of the Earth Energy Budget and Water Cycle Using Satellite Observations and Model Analyses
Campbell, G. G.; VonderHarr, T. H.; Randel, D. L.; Kidder, S. Q.
1997-01-01
During this research period we have utilized the ERBE data set in comparisons to surface properties and water vapor observations in the atmosphere. A relationship between cloudiness and surface temperature anomalies was found. This same relationship was found in a general circulation model, verifying the model. The attempt to construct a homogeneous time series from Nimbus 6, Nimbus 7 and ERBE data is not complete because we are still waiting for the ERBE reanalysis to be completed. It will be difficult to merge the Nimbus 6 data in because its observations occurred when the average weather was different than the other periods, so regression adjustments are not effective.
Contribution to the study of conformal theories and integrable models
International Nuclear Information System (INIS)
The purpose of this thesis is the 2-D physics study. The main tool is the conformal field theory with Kac-Moody and W algebra. This theory describes the 2-D models that have translation, rotation and dilatation symmetries, at their critical point. The expanded conformal theories describe models that have a larger symmetry than conformal symmetry. After a review of conformal theory methods, the author effects a detailed study of singular vector form in sl(2) affine algebra. With this important form, correlation functions can be calculated. The classical W algebra is studied and the relations between classical W algebra and quantum W algebra are specified. Bosonization method is presented and sl(2)/sl(2) topological model, studied. Partition function bosonization of different models is described. A program of rational theory classification is described linking rational conformal theories and spin integrable models, and interesting relations between Boltzmann weights of different models have been found. With these relations, the integrability of models by a direct calculation of their Boltzmann weights is proved
Classical conformality in the Standard Model from Coleman's theory
Kawana, Kiyoharu
2016-01-01
The classical conformality is one of the possible candidates for explaining the gauge hierarchy of the Standard Model. We show that it is naturally obtained from the Coleman's theory on baby universe.
A price response model developed from perceptual theories
Gurumurthy, K.; Little, John D. C.; University of Texas at Dallas. Marketing Center.
2003-01-01
"June, 1989." "Revised version of a paper originally presented at the Marketing Science in Dallas, March 1986, under the title 'A pricing model based on perception theories and its testing on scanner panel data'."
Endrizzi, S.; Gruber, S.; Dall'Amico, M.; Rigon, R.
2013-12-01
This contribution describes the new version of GEOtop which emerges after almost eight years of development from the original version. GEOtop now integrate the 3D Richards equation with a new numerical method; improvements were made on the treatment of surface waters by using the shallow water equation. The freezing-soil module was greatly improved, and the evapotranspiration -vegetation modelling is now based on a double layer scheme. Here we discuss the rational of each choice that was made, and we compare the differences between the actual solutions and the old solutions. In doing we highlight the issues that we faced during the development, including the trade-off between complexity and simplicity of the code, the requirements of a shared development, the different branches that were opened during the evolution of the code, and why we think that a code like GEOtop is indeed necessary. Models where the hydrological cycle is simplified can be built on the base of perceptual models that neglects some fundamental aspects of the hydrological processes, of which some examples are presented. At the same time, also process-based models like GEOtop can indeed neglect some fundamental process: but this is made evident with the comparison with measurements, especially when data are imposed ex-ante, instead than calibrated.
Convergent perturbation theory for lattice models with fermions
Sazonov, V. K.
2016-05-01
The standard perturbation theory in QFT and lattice models leads to the asymptotic expansions. However, an appropriate regularization of the path or lattice integrals allows one to construct convergent series with an infinite radius of the convergence. In the earlier studies, this approach was applied to the purely bosonic systems. Here, using bosonization, we develop the convergent perturbation theory for a toy lattice model with interacting fermionic and bosonic fields.
Reduction maps and minimal model theory
Gongyo, Yoshinori
2011-01-01
We use reduction maps to study the minimal model program. Our main result is that the existence of a good minimal model for a klt pair $(X,\\Delta)$ can be detected on the base of the $(K_{X}+\\Delta)$-trivial reduction map. Thus we show that the main conjectures of the minimal model program can be interpreted as a natural statement on the existence of curves on $X$.
Directory of Open Access Journals (Sweden)
Antonio Agüera
Full Text Available Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that-matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O
Agüera, Antonio; Collard, Marie; Jossart, Quentin; Moreau, Camille; Danis, Bruno
2015-01-01
Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB) model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that-matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O. validus allowed us to
Consumer preference models: fuzzy theory approach
Turksen, I. B.; Wilson, I. A.
1993-12-01
Consumer preference models are widely used in new product design, marketing management, pricing and market segmentation. The purpose of this article is to develop and test a fuzzy set preference model which can represent linguistic variables in individual-level models implemented in parallel with existing conjoint models. The potential improvements in market share prediction and predictive validity can substantially improve management decisions about what to make (product design), for whom to make it (market segmentation) and how much to make (market share prediction).
Offline and Online Models of Budget Allocation for Maximizing Influence Spread
Avigdor-Elgrabli, Noa; Blocq, Gideon; Gamzu, Iftah
2015-01-01
The research of influence propagation in social networks via word-of-mouth processes has been given considerable attention in recent years. Arguably, the most fundamental problem in this domain is the influence maximization problem, where the goal is to identify a small seed set of individuals that can trigger a large cascade of influence in the network. While there has been significant progress regarding this problem and its variants, one basic shortcoming of the underlying models is that th...
A Dynamic Systems Theory Model of Visual Perception Development
Coté, Carol A.
2015-01-01
This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…
Bianchi class A models in Sàez-Ballester's theory
Socorro, J.; Espinoza-García, Abraham
2012-08-01
We apply the Sàez-Ballester (SB) theory to Bianchi class A models, with a barotropic perfect fluid in a stiff matter epoch. We obtain exact classical solutions à la Hamilton for Bianchi type I, II and VIh=-1 models. We also find exact quantum solutions to all Bianchi Class A models employing a particular ansatz for the wave function of the universe.
Atmospheric water budget over the western Himalayas in a regional climate model
Indian Academy of Sciences (India)
A P Dimri
2012-08-01
During winter months (December, January, February – DJF), the western Himalayas (WH) receive precipitation from eastward moving extratropical cyclones, called western disturbances (WDs) in Indian parlance. Winter precipitation–moisture convergence–evaporation (P–C–E) cycle is analyzed for a period of 22 years (1981–2002: 1980(D)–1981(J, F) to 2001(D)–2002(J, F)) with observed and modelled (RegCM3) climatological estimates over WH. Remarkable model skills have been observed in depicting the hydrological cycle over WH. Although precipitation biases exist, similar spatial precipitation with well marked two maxima is simulated by the model. As season advances, temporal distribution shows higher precipitation in simulation than the observed. However, P–C–E cycle shows similar peaks of moisture convergence and evaporation in daily climatologies though with varying maxima/minima. In the first half of winter, evaporation over WH is mainly driven by ground surface and 2 m air temperature. Lowest temperatures during mid-winter correspond to lowest evaporation to precipitation ratio as well.
Weckmann, Stephanie
1997-01-01
The Clouds and the Earth's Radiant Energy System (CERES) is a program sponsored by the National Aeronautics and Space Administration (NASA) aimed at evaluating the global energy balance. Current scanning radiometers used for CERES consist of thin-film thermistor bolometers viewing the Earth through a Cassegrain telescope. The Thermal Radiation Group, a laboratory in the Department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently studying a new sensor concept to replace the current bolometer: a thermopile thermal radiation detector. This next-generation detector would consist of a thermal sensor array made of thermocouple junction pairs, or thermopiles. The objective of the current research is to perform a thermal analysis of the thermopile. Numerical thermal models are particularly suited to solve problems for which temperature is the dominant mechanism of the operation of the device (through the thermoelectric effect), as well as for complex geometries composed of numerous different materials. Feasibility and design specifications are studied by developing a dynamic electrothermal model of the thermopile using the finite element method. A commercial finite element-modeling package, ALGOR, is used.
Swain, Eric; Decker, Jeremy
2010-01-01
Numerical modeling is needed to predict environmental temperatures, which affect a number of biota in southern Florida, U.S.A., such as the West Indian manatee (Trichechus manatus), which uses thermal basins for refuge from lethal winter cold fronts. To numerically simulate heat-transport through a dynamic coastal wetland region, an algorithm was developed for the FTLOADDS coupled hydrodynamic surface-water/ground-water model that uses formulations and coefficients suited to the coastal wetland thermal environment. In this study, two field sites provided atmospheric data to develop coefficients for the heat flux terms representing this particular study area. Several methods were examined to represent the heat-flux components used to compute temperature. A Dalton equation was compared with a Penman formulation for latent heat computations, producing similar daily-average temperatures. Simulation of heat-transport in the southern Everglades indicates that the model represents the daily fluctuation in coastal temperatures better than at inland locations; possibly due to the lack of information on the spatial variations in heat-transport parameters such as soil heat capacity and surface albedo. These simulation results indicate that the new formulation is suitable for defining the existing thermohydrologic system and evaluating the ecological effect of proposed restoration efforts in the southern Everglades of Florida.
Modeling acquaintance networks based on balance theory
Directory of Open Access Journals (Sweden)
Vukašinović Vida
2014-09-01
Full Text Available An acquaintance network is a social structure made up of a set of actors and the ties between them. These ties change dynamically as a consequence of incessant interactions between the actors. In this paper we introduce a social network model called the Interaction-Based (IB model that involves well-known sociological principles. The connections between the actors and the strength of the connections are influenced by the continuous positive and negative interactions between the actors and, vice versa, the future interactions are more likely to happen between the actors that are connected with stronger ties. The model is also inspired by the social behavior of animal species, particularly that of ants in their colony. A model evaluation showed that the IB model turned out to be sparse. The model has a small diameter and an average path length that grows in proportion to the logarithm of the number of vertices. The clustering coefficient is relatively high, and its value stabilizes in larger networks. The degree distributions are slightly right-skewed. In the mature phase of the IB model, i.e., when the number of edges does not change significantly, most of the network properties do not change significantly either. The IB model was found to be the best of all the compared models in simulating the e-mail URV (University Rovira i Virgili of Tarragona network because the properties of the IB model more closely matched those of the e-mail URV network than the other models
Scattering and short-distance properties in field theory models
International Nuclear Information System (INIS)
The aim of constructive field theory is not only to define models but also to establish their general properties of physical interest. We here review recent works on scattering and on short-distance properties for weakly coupled theories with mass gap such as typically P(φ) in dimension 2, φ4 in dimension 3 and the (renormalizable, asymptotically free) massive Gross-Neveu (GN) model in dimension 2. Many of the ideas would apply similarly to other (possibly non renormalizable) theories that might be defined in a similar way via phase-space analysis
The monster sporadic group and a theory underlying superstring models
International Nuclear Information System (INIS)
The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual and anti-self-dual K3 manifolds joined by Dirac strings and evolving in a 13 dimensional spacetime as the fundamental theory. In addition to the usual graviton and dilaton this theory contains matter-like degrees of freedom resembling the massless states of the heterotic string, thus providing a completely geometric interpretation for ordinary matter. 25 refs
Topological B-model and ${\\hat c}=1$ String Theory
Hyun, S; Park, J D; Yi, S H; Hyun, Seungjoon; Oh, Kyungho; Park, Jong-Dae; Yi, Sang-Heon
2005-01-01
We study the topological B-model on a deformed $\\Z_2$ orbifolded conifold by investigating variation of complex structures via quantum Kodaira-Spencer theories. The fermionic/brane formulation together with systematic utilization of symmetries of the geometry gives rise to a free fermion realization of the amplitudes. We derive Ward identities which solve the perturbed free energy exactly. We also obtain the corresponding Kontsevich-like matrix model. All these confirm the recent conjecture on the connection of the theory with ${\\hat c}=1$ type 0A string theory compactified at the radius $R=\\sqrt{\\alpha'/2}$.
Chen, Yiying; Ryder, James; Bastrikov, Vladislav; McGrath, Matthew J.; NAUDTS Kim; Otto, Juliane; Ottlé, Catherine; Peylin, Philippe; Polcher, Jan; VALADE Aude; Black, Andrew; Elbers, Jan A.; Moors, Eddy; Foken, Thomas; Gorsel, Eva van
2016-01-01
Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the land surface model ORCHIDEE-CAN (Organising Carbon and Hydrology In Dynamic Ecosystems – CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an im...
C. H. Song; Kim, H. S.; Glasow, R.; Brimblecombe, P.; Kim, J; R. J. Park; Woo, J. H.; Kim, Y H
2010-01-01
Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also simulated by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels in the ship plumes as well as their contributions to the elevated HCHO levels (budget) were investigated using a newly-developed ship-plume photochemical/dynamic model: (1) primary HC...
Modeling in applied sciences a kinetic theory approach
Pulvirenti, Mario
2000-01-01
Modeling complex biological, chemical, and physical systems, in the context of spatially heterogeneous mediums, is a challenging task for scientists and engineers using traditional methods of analysis Modeling in Applied Sciences is a comprehensive survey of modeling large systems using kinetic equations, and in particular the Boltzmann equation and its generalizations An interdisciplinary group of leading authorities carefully develop the foundations of kinetic models and discuss the connections and interactions between model theories, qualitative and computational analysis and real-world applications This book provides a thoroughly accessible and lucid overview of the different aspects, models, computations, and methodology for the kinetic-theory modeling process Topics and Features * Integrated modeling perspective utilized in all chapters * Fluid dynamics of reacting gases * Self-contained introduction to kinetic models * Becker–Doring equations * Nonlinear kinetic models with chemical reactions * Kinet...
Measurement-based load modeling: Theory and application
Institute of Scientific and Technical Information of China (English)
MA; Jin; HAN; Dong; HE; RenMu
2007-01-01
Load model is one of the most important elements in power system operation and control. However, owing to its complexity, load modeling is still an open and very difficult problem. Summarizing our work on measurement-based load modeling in China for more than twenty years, this paper systematically introduces the mathematical theory and applications regarding the load modeling. The flow chart and algorithms for measurement-based load modeling are presented. A composite load model structure with 13 parameters is also proposed. Analysis results based on the trajectory sensitivity theory indicate the importance of the load model parameters for the identification. Case studies show the accuracy of the presented measurement-based load model. The load model thus built has been validated by field measurements all over China. Future working directions on measurement- based load modeling are also discussed in the paper.
Sukenik, Miroslav; Sima, Jozef; Vanko, Julius
2000-01-01
Applying the Vaidya metrics in the model of Expansive Nondecelerative Universe (ENU) leads to compatibility of the ENU model both with the classic Newton gravitational theory and the general theory of relativity in weak fields
Optimal transportation networks models and theory
Bernot, Marc; Morel, Jean-Michel
2009-01-01
The transportation problem can be formalized as the problem of finding the optimal way to transport a given measure into another with the same mass. In contrast to the Monge-Kantorovitch problem, recent approaches model the branched structure of such supply networks as minima of an energy functional whose essential feature is to favour wide roads. Such a branched structure is observable in ground transportation networks, in draining and irrigation systems, in electrical power supply systems and in natural counterparts such as blood vessels or the branches of trees. These lectures provide mathematical proof of several existence, structure and regularity properties empirically observed in transportation networks. The link with previous discrete physical models of irrigation and erosion models in geomorphology and with discrete telecommunication and transportation models is discussed. It will be mathematically proven that the majority fit in the simple model sketched in this volume.
Lauer, A.; Eyring, V.; Hendricks, J.; Jöckel, P.; Lohmann, U.
2007-07-01
International shipping contributes significantly to the fuel consumption of all transport related activities. Specific emissions of pollutants such as sulfur dioxide (SO2) per kg of fuel emitted are higher than for road transport or aviation. Besides gaseous pollutants, ships also emit various types of particulate matter. The aerosol impacts the Earth's radiation budget directly by scattering and absorbing incoming solar radiation and indirectly by changing cloud properties. Here we use ECHAM5/MESSy1-MADE, a global climate model with detailed aerosol and cloud microphysics, to show that emissions from ships significantly increase the cloud droplet number concentration of low maritime water clouds. Whereas the cloud liquid water content remains nearly unchanged in these simulations, effective radii of cloud droplets decrease, leading to cloud optical thickness increase up to 5-10%. The sensitivity of the results is estimated by using three different emission inventories for present day conditions. The sensitivity analysis reveals that shipping contributes with 2.3% to 3.6% to the total sulfate burden and 0.4% to 1.4% to the total black carbon burden in the year 2000. In addition to changes in aerosol chemical composition, shipping increases the aerosol number concentration, e.g. up to 25% in the size range of the accumulation mode (typically >0.1 μm) over the Atlantic. The total aerosol optical thickness over the Indian Ocean, the Gulf of Mexico and the Northeastern Pacific increases up to 8-10% depending on the emission inventory. Changes in aerosol optical thickness caused by the shipping induced modification of aerosol particle number concentration and chemical composition lead to a change of the net top of the atmosphere (ToA) clear sky radiation of about -0.013 W/m2 to -0.036 W/m2 on global annual average. The estimated all-sky direct aerosol effect calculated from these changes ranges between -0.009 W/m2 and -0.014 W/m2. The indirect aerosol effect of ships
Directory of Open Access Journals (Sweden)
Ensor Tim
2012-08-01
Full Text Available Abstract Background Allocating national resources to regions based on need is a key policy issue in most health systems. Many systems utilise proxy measures of need as the basis for allocation formulae. Increasingly these are underpinned by complex statistical methods to separate need from supplier induced utilisation. Assessment of need is then used to allocate existing global budgets to geographic areas. Many low and middle income countries are beginning to use formula methods for funding however these attempts are often hampered by a lack of information on utilisation, relative needs and whether the budgets allocated bear any relationship to cost. An alternative is to develop bottom-up estimates of the cost of providing for local need. This method is viable where public funding is focused on a relatively small number of targeted services. We describe a bottom-up approach to developing a formula for the allocation of resources. The method is illustrated in the context of the state minimum service package mandated to be provided by the Indonesian public health system. Methods A standardised costing methodology was developed that is sensitive to the main expected drivers of local cost variation including demographic structure, epidemiology and location. Essential package costing is often undertaken at a country level. It is less usual to utilise the methods across different parts of a country in a way that takes account of variation in population needs and location. Costing was based on best clinical practice in Indonesia and province specific data on distribution and costs of facilities. The resulting model was used to estimate essential package costs in a representative district in each province of the country. Findings Substantial differences in the costs of providing basic services ranging from USD 15 in urban Yogyakarta to USD 48 in sparsely populated North Maluku. These costs are driven largely by the structure of the population
Directory of Open Access Journals (Sweden)
A. Lauer
2007-10-01
Full Text Available International shipping contributes significantly to the fuel consumption of all transport related activities. Specific emissions of pollutants such as sulfur dioxide (SO_{2} per kg of fuel emitted are higher than for road transport or aviation. Besides gaseous pollutants, ships also emit various types of particulate matter. The aerosol impacts the Earth's radiation budget directly by scattering and absorbing the solar and thermal radiation and indirectly by changing cloud properties. Here we use ECHAM5/MESSy1-MADE, a global climate model with detailed aerosol and cloud microphysics to study the climate impacts of international shipping. The simulations show that emissions from ships significantly increase the cloud droplet number concentration of low marine water clouds by up to 5% to 30% depending on the ship emission inventory and the geographic region. Whereas the cloud liquid water content remains nearly unchanged in these simulations, effective radii of cloud droplets decrease, leading to cloud optical thickness increase of up to 5–10%. The sensitivity of the results is estimated by using three different emission inventories for present-day conditions. The sensitivity analysis reveals that shipping contributes to 2.3% to 3.6% of the total sulfate burden and 0.4% to 1.4% to the total black carbon burden in the year 2000 on the global mean. In addition to changes in aerosol chemical composition, shipping increases the aerosol number concentration, e.g. up to 25% in the size range of the accumulation mode (typically >0.1 μm over the Atlantic. The total aerosol optical thickness over the Indian Ocean, the Gulf of Mexico and the Northeastern Pacific increases by up to 8–10% depending on the emission inventory. Changes in aerosol optical thickness caused by shipping induced modification of aerosol particle number concentration and chemical composition lead to a change in the shortwave radiation budget at the top of the
Karabatsos, George
2001-01-01
Describes similarities and differences between additive conjoint measurement and the Rasch model, and formalizes some new nonparametric item response models that are, in a sense, probabilistic measurement theory models. Applies these new models to published and simulated data. (SLD)
Mixed models theory and applications with R
Demidenko, Eugene
2013-01-01
Mixed modeling is one of the most promising and exciting areas of statistical analysis, enabling the analysis of nontraditional, clustered data that may come in the form of shapes or images. This book provides in-depth mathematical coverage of mixed models' statistical properties and numerical algorithms, as well as applications such as the analysis of tumor regrowth, shape, and image. The new edition includes significant updating, over 300 exercises, stimulating chapter projects and model simulations, inclusion of R subroutines, and a revised text format. The target audience continues to be g
Twinlike models in scalar field theories
International Nuclear Information System (INIS)
This work deals with the presence of defect structures in models described by a real scalar field in a diversity of scenarios. The defect structures that we consider are static solutions of the equations of motion that depend on a single spatial dimension. We search for different models, which support the same defect solution, with the very same energy density. We work in flat spacetime, where we introduce and investigate a new class of models. We also work in curved spacetime, within the braneworld context, with a single extra dimension of infinite extent, and there we show how the brane is formed from the static field configuration.
The Jackiw–Pi model: Classical theory
International Nuclear Information System (INIS)
The massive even-parity non-Abelian gauge model in three space–time dimensions proposed by Jackiw and Pi is studied at the tree-level. The propagators are computed and the spectrum consistency is analyzed, besides, the symmetries of the model are collected and established through BRS invariance and Slavnov–Taylor identity. In the Landau gauge, thanks to the antighost equations and the Slavnov–Taylor identity, two rigid symmetries are identified by means of Ward identities. It is presented here a promising path for perturbatively quantization of the Jackiw–Pi model and a hint concerning its possible quantum scale invariance is also pointed out
Young, Paul. J.; Emmons, Louisa K.; Roberts, James M.; Lamarque, Jean-FrançOis; Wiedinmyer, Christine; Veres, Patrick; Vandenboer, Trevor C.
2012-05-01
This study uses a global chemical transport model to estimate the distribution of isocyanic acid (HNCO). HNCO is toxic, and concentrations exceeding 1 ppbv have been suggested to have negative health effects. Based on fire studies, HNCO emissions were scaled to those of hydrogen cyanide (30%), resulting in yearly total emissions of 1.5 Tg for 2008, from both anthropogenic and biomass burning sources. Loss processes included heterogeneous uptake (pH dependent), dry deposition (like formic acid), and reaction with the OH radical (k = 1 × 10-15 molecule-1 cm3 s-1). Annual mean surface HNCO concentrations were highest over parts of China (maximum of 470 pptv), but episodic fire emissions gave much higher levels, exceeding 4 ppbv in tropical Africa and the Amazon, and exceeding 10 ppbv in Southeast Asia and Siberia. This suggests that large biomass burning events could result in deleterious health effects for populations in these regions. For the tropospheric budget, using the model-calculated pH the HNCO lifetime was 37 days, with the split between dry deposition and heterogeneous loss being 95%:5%. Fixing the heterogeneous loss rate at pH = 7 meant that this process dominated, accounting for ˜70% of the total loss, giving a lifetime of 6 days, and resulting in upper tropospheric concentrations that were essentially zero. However, changing the pH does not notably impact the high concentrations found in biomass burning regions. More observational data is needed to evaluate the model, as well as a better representation of the likely underestimated biofuel emissions, which could mean more populations exposed to elevated HNCO concentrations.
Sticker DNA computer model--Part Ⅰ:Theory
Institute of Scientific and Technical Information of China (English)
XU Jin; DONG Yafei; WEI Xiaopeng
2004-01-01
Sticker model is one of the basic models in the DNA computer models. This model is coded with single-double stranded DNA molecules. It has the following advantages that the operations require no strands extension and use no enzymes; What's more, the materials are reusable. Therefore it arouses attention and interest of scientists in many fields. In this paper, we will systematically analyze the theories and applications of the model, summarize other scientists' contributions in this field, and propose our research results. This paper is the theoretical portion of the sticker model on DNA computer, which includes the introduction of the basic model of sticker computing. Firstly, we systematically introduce the basic theories of classic models about sticker computing; Secondly, we discuss the sticker system which is an abstract computing model based on the sticker model and formal languages; Finally, extend and perfect the model, and present two types of models that are more extensive in the applications and more perfect in the theory than the past models: one is the so-called k-bit sticker model, the other is full-message sticker DNA computing model.
Homogeneous cosmological models in Yang's gravitation theory
Fennelly, A. J.; Pavelle, R.
1979-01-01
We present a dynamic, spatially homogeneous solution of Yang's pure space gravitational field equations which is non-Einsteinian. The predictions of this cosmological model seem to be at variance with observations.
Solid mechanics theory, modeling, and problems
Bertram, Albrecht
2015-01-01
This textbook offers an introduction to modeling the mechanical behavior of solids within continuum mechanics and thermodynamics. To illustrate the fundamental principles, the book starts with an overview of the most important models in one dimension. Tensor calculus, which is called for in three-dimensional modeling, is concisely presented in the second part of the book. Once the reader is equipped with these essential mathematical tools, the third part of the book develops the foundations of continuum mechanics right from the beginning. Lastly, the book’s fourth part focuses on modeling the mechanics of materials and in particular elasticity, viscoelasticity and plasticity. Intended as an introductory textbook for students and for professionals interested in self-study, it also features numerous worked-out examples to aid in understanding.
Algorithm for Model Validation: Theory and Implementation
Sornette, D; Ide, K; Kamm, J R; Pisarenko, V; Vixie, K R
2005-01-01
Validation is often defined as the process of determining the degree to which a model is an accurate representation of the real world from the perspective of its intended uses. Validation is crucial as industries and governments depend increasingly on predictions by computer models to justify their decisions. We propose to formulate the validation of a given model/code as an iterative construction process that mimics the often implicit process occurring in the minds of scientists. We offer a formal representation of the progressive build-up of trust in the model. We thus replace static claims on the impossibility of validating a given model/code by a dynamic process of constructive approximation. This approach is better adapted to the fuzzy, coarse-grained nature of validation. Our procedure factors in the degree of redundancy versus novelty of the experiments used for validation as well as the degree to which the model predicts the observations. We illustrate the new methodology first with the maturation of ...
Theory of stellar convection II: first stellar models
Pasetto, S; Chiosi, E; Cropper, M; Weiss, A
2015-01-01
We present here the first stellar models on the Hertzsprung-Russell diagram (HRD), in which convection is treated according to the novel scale-free convection theory (SFC theory) by Pasetto et al. (2014). The aim is to compare the results of the new theory with those from the classical, calibrated mixing-length (ML) theory to examine differences and similarities. We integrate the equations describing the structure of the atmosphere from the stellar surface down to a few percent of the stellar mass using both ML theory and SFC theory. The key temperature over pressure gradients, the energy fluxes, and the extension of the convective zones are compared in both theories. The analysis is first made for the Sun and then extended to other stars of different mass and evolutionary stage. The results are adequate: the SFC theory yields convective zones, temperature gradients of the ambient and of the convective element, and energy fluxes that are very similar to those derived from the "calibrated" MT theory for main s...
Error budget analysis of SCIAMACHY limb ozone profile retrievals using the SCIATRAN model
Directory of Open Access Journals (Sweden)
N. Rahpoe
2013-10-01
Full Text Available A comprehensive error characterization of SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY limb ozone profiles has been established based upon SCIATRAN transfer model simulations. The study was carried out in order to evaluate the possible impact of parameter uncertainties, e.g. in albedo, stratospheric aerosol optical extinction, temperature, pressure, pointing, and ozone absorption cross section on the limb ozone retrieval. Together with the a posteriori covariance matrix available from the retrieval, total random and systematic errors are defined for SCIAMACHY ozone profiles. Main error sources are the pointing errors, errors in the knowledge of stratospheric aerosol parameters, and cloud interference. Systematic errors are of the order of 7%, while the random error amounts to 10–15% for most of the stratosphere. These numbers can be used for the interpretation of instrument intercomparison and validation of the SCIAMACHY V 2.5 limb ozone profiles in a rigorous manner.
Connecting Evaluation and Budgeting
Robinson, Marc
2014-01-01
This paper discusses how evaluation is an essential tool for good budgeting and a core element of any well-designed government wide performance budgeting system. It is organized into 5 sections: (1) Evaluation and performance budgeting- the principle outlines the role which evaluation should, in principle, play in supporting good budgeting. It identifies the key ways performance informatio...
International Nuclear Information System (INIS)
Closing the tropospheric ozone budget requires a better understanding of the role of transport processes from the major reservoirs: the planetary boundary layer and the stratosphere. Case studies lead to the identification of mechanisms involved as well as their efficiency. However, their global impact on the budget must be addressed on a climatological basis. This manuscript is thus divided in two parts. First, we present case studies based on ozone LIDAR measurements performed during the ESCOMPTE campaign. This work consists in a data analysis investigation by means of a hybrid - Lagrangian study involving: global meteorological analyses, Lagrangian particle dispersion computation, and mesoscale, chemistry - transport, and Lagrangian photochemistry modeling. Our aim is to document the amount of observed ozone variability related to transport processes and, when appropriate, to infer the role of tropospheric photochemical production. Second, we propose a climatological analysis of the respective impact of transport from the boundary-layer and from the tropopause region on the tropospheric ozone budget. A multivariate analysis is presented and compared to a trajectography approach. Once validated, this algorithm is applied to the whole database of ozone profiles collected above Europe during the past 30 years in order to discuss the seasonal, geographical and temporal variability of transport processes as well as their impact on the tropospheric ozone budget. The variability of turbulent mixing and its impact on the persistence of tropospheric layers will also be discussed. (author)
Adachi, M.; Ito, A.; Ishida, A.; Kadir, W. R.; Ladpala, P.; Yamagata, Y.
2010-12-01
More reliable estimation of carbon (C) stock within forest ecosystems and C emission induced by deforestation is one of the most urgent tasks for model researchers. A process-based terrestrial biogeochemical model (VISIT) was applied to two types of tropical forests (a seasonal dry forest in Thailand and a moist forest in Malaysia) and one agro-forest (an oil palm plantation in Malaysia) to estimate C budget of tropical ecosystems including the impacts of land use conversion in Southeast Asia. Observation and VISIT model simulation indicated that the two types of tropical forest had a comparably high photosynthetic uptakes; gross primary productions were estimated as 32.2-37.6 t C ha-1 y-1. A rain forest had a higher total C stock (plant biomass and soil organic matter, 301.5 t C ha-1) than that in a seasonal dry forest (266.5 t C ha-1). The VISIT model appropriately captured the impacts of disturbance such as deforestation and land use conversions on C budget, and a sensitivity analysis implied that remaining ratios of abandoned debris would be a key parameter determining soil C budget after deforestation events. Although the model tended to overestimate oil palm biomass in comparison with field data, C stock of the oil palm plantation was about half of the forest C at 30 years following the oil palm plantation formation when the remaining rate of residual debris was about 34%. These results indicated that adequate forest management was important for reducing C emission from soil, and C budget at each ecosystem need evaluate over a long-term using model and observations.
Secondary flow structure in a model curved artery: 3D morphology and circulation budget analysis
Bulusu, Kartik V.; Plesniak, Michael W.
2015-11-01
In this study, we examined the rate of change of circulation within control regions encompassing the large-scale vortical structures associated with secondary flows, i.e. deformed Dean-, Lyne- and Wall-type (D-L-W) vortices at planar cross-sections in a 180° curved artery model (curvature ratio, 1/7). Magnetic resonance velocimetry (MRV) and particle image velocimetry (PIV) experiments were performed independently, under the same physiological inflow conditions (Womersley number, 4.2) and using Newtonian blood-analog fluids. The MRV-technique performed at Stanford University produced phase-averaged, three-dimensional velocity fields. Secondary flow field comparisons of MRV-data to PIV-data at various cross-sectional planes and inflow phases were made. A wavelet-decomposition-based approach was implemented to characterize various secondary flow morphologies. We hypothesize that the persistence and decay of arterial secondary flow vortices is intrinsically related to the influence of the out-of-plane flow, tilting, in-plane convection and diffusion-related factors within the control regions. Evaluation of these factors will elucidate secondary flow structures in arterial hemodynamics. Supported by the National Science Foundation under Grant Number CBET-0828903, and GW Center for Biomimetics and Bioinspired Engineering (COBRE). The MRV data were acquired at Stanford University in collaboration with Christopher Elkins and John Eaton.
What Is Your Budget Saying about Your Library?
Jacobs, Leslie; Strouse, Roger
2002-01-01
Discusses budgeting for corporate libraries and how to keep budgets from getting cut. Topics include whether the budget is considered corporate overhead; recovering costs; models for content cost recovery; showing return on library investment; marketing library value to senior management; user needs and satisfaction; and comparing budgets to other…
Making Performance Budgeting Reform Work : A Case Study of Korea
Park, Nowook; Choi, Jae-Young
2013-01-01
Performance budgeting is considered one of the essential elements of public financial management reform and has been adopted in many countries. However, it continues to present a significant challenge within the budget process. This case study draws from change management theories to tell the inside story of performance budgeting reform in the Republic of Korea, including the background of ...
Microbial community modeling using reliability theory.
Zilles, Julie L; Rodríguez, Luis F; Bartolerio, Nicholas A; Kent, Angela D
2016-08-01
Linking microbial community composition with the corresponding ecosystem functions remains challenging. Because microbial communities can differ in their functional responses, this knowledge gap limits ecosystem assessment, design and management. To develop models that explicitly incorporate microbial populations and guide efforts to characterize their functional differences, we propose a novel approach derived from reliability engineering. This reliability modeling approach is illustrated here using a microbial ecology dataset from denitrifying bioreactors. Reliability modeling is well-suited for analyzing the stability of complex networks composed of many microbial populations. It could also be applied to evaluate the redundancy within a particular biochemical pathway in a microbial community. Reliability modeling allows characterization of the system's resilience and identification of failure-prone functional groups or biochemical steps, which can then be targeted for monitoring or enhancement. The reliability engineering approach provides a new perspective for unraveling the interactions between microbial community diversity, functional redundancy and ecosystem services, as well as practical tools for the design and management of engineered ecosystems. PMID:26882268
Study on Strand Space Model Theory
Institute of Scientific and Technical Information of China (English)
JI QingGuang(季庆光); QING SiHan(卿斯汉); ZHOU YongBin(周永彬); FENG DengGuo(冯登国)
2003-01-01
The growing interest in the application of formal methods of cryptographic pro-tocol analysis has led to the development of a number of different ways for analyzing protocol. Inthis paper, it is strictly proved that if for any strand, there exists at least one bundle containingit, then an entity authentication protocol is secure in strand space model (SSM) with some smallextensions. Unfortunately, the results of attack scenario demonstrate that this protocol and the Yahalom protocol and its modification are de facto insecure. By analyzing the reasons of failure offormal inference in strand space model, some deficiencies in original SSM are pointed out. In orderto break through these limitations of analytic capability of SSM, the generalized strand space model(GSSM) induced by some protocol is proposed. In this model, some new classes of strands, oraclestrands, high order oracle strands etc., are developed, and some notions are formalized strictly in GSSM, such as protocol attacks, valid protocol run and successful protocol run. GSSM can thenbe used to further analyze the entity authentication protocol. This analysis sheds light on why thisprotocol would be vulnerable while it illustrates that GSSM not only can prove security protocolcorrect, but also can be efficiently used to construct protocol attacks. It is also pointed out thatusing other protocol to attack some given protocol is essentially the same as the case of using themost of protocol itself.
$f(T)$ theories from holographic dark energy models
Huang, Peng; Huang, Yong-Chang(Institute of Theoretical Physics, Beijing University of Technology, 100124, Beijing, China)
2013-01-01
We reconstruct $f(T)$ theories from three different holographic dark energy models in different time durations. For the HDE model, the dark energy dominated era with new setting up is chosen for reconstruction, and the radiation dominated era is chosen when the involved model changes into NADE. For the RDE model, radiation, matter and dark energy dominated time durations are all investigated. We also investigate the limitation which prevents an arbitrary choice of the time duration for recons...
Arbitrage theory for non convex financial market models
Lepinette, Emmanuel; Tran Quoc, Tuan
2015-01-01
When dealing with non linear trading costs, e.g. fixed costs, the usual tools from convex analysis are inadequate to characterize an absence of arbitrage opportunity as the mathematical model is no more convex. An unified approach is to describe a financial market model by a liquidation value process. This allows to extend the frictionless models of the classical theory as well as the recent proportional transaction costs models to a large class of financial markets with transaction costs inc...
Directory of Open Access Journals (Sweden)
M. Adachi
2011-03-01
Full Text Available More reliable estimates of carbon (C stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia and one agro-forest (an oil palm plantation in Malaysia to estimate the C budget of tropical ecosystems, including the impacts of land-use conversion, in Southeast Asia. Observations and VISIT model simulations indicated that the primary forests had high photosynthetic uptake: gross primary production was estimated at 31.5–35.5 t C ha^{−1} yr^{−1}. In the VISIT model simulation, the rainforest had a higher total C stock (plant biomass and soil organic matter, 301.5 t C ha^{−1} than that in the seasonal dry forest (266.5 t C ha^{−1} in 2008. The VISIT model appropriately captured the impacts of disturbances such as deforestation and land-use conversions on the C budget. Results of sensitivity analysis implied that the ratio of remaining residual debris was a key parameter determining the soil C budget after deforestation events. The C stock of the oil palm plantation was about 46% of the rainforest's C at 30 yr following initiation of the plantation, when the ratio of remaining residual debris was assumed to be about 33%. These results show that adequate forest management is important for reducing C emission from soil and C budget of each ecosystem must be evaluated over a long term using both the model simulations and observations.
Fuzzy Stochastic Optimization Theory, Models and Applications
Wang, Shuming
2012-01-01
Covering in detail both theoretical and practical perspectives, this book is a self-contained and systematic depiction of current fuzzy stochastic optimization that deploys the fuzzy random variable as a core mathematical tool to model the integrated fuzzy random uncertainty. It proceeds in an orderly fashion from the requisite theoretical aspects of the fuzzy random variable to fuzzy stochastic optimization models and their real-life case studies. The volume reflects the fact that randomness and fuzziness (or vagueness) are two major sources of uncertainty in the real world, with significant implications in a number of settings. In industrial engineering, management and economics, the chances are high that decision makers will be confronted with information that is simultaneously probabilistically uncertain and fuzzily imprecise, and optimization in the form of a decision must be made in an environment that is doubly uncertain, characterized by a co-occurrence of randomness and fuzziness. This book begins...
Computational hemodynamics theory, modelling and applications
Tu, Jiyuan; Wong, Kelvin Kian Loong
2015-01-01
This book discusses geometric and mathematical models that can be used to study fluid and structural mechanics in the cardiovascular system. Where traditional research methodologies in the human cardiovascular system are challenging due to its invasive nature, several recent advances in medical imaging and computational fluid and solid mechanics modelling now provide new and exciting research opportunities. This emerging field of study is multi-disciplinary, involving numerical methods, computational science, fluid and structural mechanics, and biomedical engineering. Certainly any new student or researcher in this field may feel overwhelmed by the wide range of disciplines that need to be understood. This unique book is one of the first to bring together knowledge from multiple disciplines, providing a starting point to each of the individual disciplines involved, attempting to ease the steep learning curve. This book presents elementary knowledge on the physiology of the cardiovascular system; basic knowl...
Theory and Model of Agricultural Insurance Subsidy
Institute of Scientific and Technical Information of China (English)
Wan Kailiang; Long Wenjun
2007-01-01
The issue of agricultural insurance subsidy is discussed in this paper aiming to make it provided more rationally and scientifically.It is started with the connection between agricultural insurance and financial subsidy.It is really necessary and crucial to implement the financial insurance due to the bad operational performance,especially in the developing countries.But the subsidy should be provided more rationally because financial subsidy has lots of negative effects.A model in competitive insurance markets developed by Ahsan et al(1982)and a farmers'decision model arc developed to solve the optimal subsidized rate.Finally,the equation is got to calculate it.But a quantitative subsidized rate is not made here because the calculation should be under some restricted conditions,which are always absent in the developing countries.So the government should provide some subsidy for the ex ante research and preparation to get the scientific probability and premium rate.
de Moor, J. J. W.; Verstraeten, G.
2008-03-01
We used a combined approach of a two-dimensional erosion and hillslope sediment delivery model (WATEM/SEDEM) and detailed geomorphological reconstructions to quantify the different components in a sediment budget for the Geul River catchment (southern Netherlands) since the High Middle Ages. Hillslope erosion and colluvium deposition were calculated using the model, while floodplain storage was estimated using field data. Our results show that more than 80% of the total sediment production in the catchment has been stored as colluvium (mostly generated by hillslope erosion), while almost 13% is stored in the floodplain since the High Middle Ages (this situation resembles a capacity-limited system). Model results for the period prior to the High Middle Ages (with a nearly completely forested catchment) show that far less sediment was generated and that most of the sediments were directly transported to the main river valleys or out of the catchment (a supply-limited system). Geomorphological analysis of a large alluvial fan shows the sensitivity of the study area to changes in the percentage of arable land. Our combined field data-modeling study presents an elegant method to calculate a catchment sediment budget for a longer period and is able to identify and quantify the most important sediment storage elements. Furthermore, it provides a valuable tool to calculate a sediment budget while only limited dated fluvial sediment sequences are available.
Applying learning theories and instructional design models for effective instruction.
Khalil, Mohammed K; Elkhider, Ihsan A
2016-06-01
Faculty members in higher education are involved in many instructional design activities without formal training in learning theories and the science of instruction. Learning theories provide the foundation for the selection of instructional strategies and allow for reliable prediction of their effectiveness. To achieve effective learning outcomes, the science of instruction and instructional design models are used to guide the development of instructional design strategies that elicit appropriate cognitive processes. Here, the major learning theories are discussed and selected examples of instructional design models are explained. The main objective of this article is to present the science of learning and instruction as theoretical evidence for the design and delivery of instructional materials. In addition, this article provides a practical framework for implementing those theories in the classroom and laboratory. PMID:27068989
From integrable models to gauge theories Festschrift Matinyan (Sergei G)
Gurzadyan, V G
2002-01-01
This collection of twenty articles in honor of the noted physicist and mentor Sergei Matinyan focuses on topics that are of fundamental importance to high-energy physics, field theory and cosmology. The topics range from integrable quantum field theories, three-dimensional Ising models, parton models and tests of the Standard Model, to black holes in loop quantum gravity, the cosmological constant and magnetic fields in cosmology. A pedagogical essay by Lev Okun concentrates on the problem of fundamental units. The articles have been written by well-known experts and are addressed to graduate
New theories of root growth modelling
Landl, Magdalena; Schnepf, Andrea; Vanderborght, Jan; Huber, Katrin; Javaux, Mathieu; Bengough, A. Glyn; Vereecken, Harry
2016-04-01
In dynamic root architecture models, root growth is represented by moving root tips whose line trajectory results in the creation of new root segments. Typically, the direction of root growth is calculated as the vector sum of various direction-affecting components. However, in our simulations this did not reproduce experimental observations of root growth in structured soil. We therefore developed a new approach to predict the root growth direction. In this approach we distinguish between, firstly, driving forces for root growth, i.e. the force exerted by the root which points in the direction of the previous root segment and gravitropism, and, secondly, the soil mechanical resistance to root growth or penetration resistance. The latter can be anisotropic, i.e. depending on the direction of growth, which leads to a difference between the direction of the driving force and the direction of the root tip movement. Anisotropy of penetration resistance can be caused either by microscale differences in soil structure or by macroscale features, including macropores. Anisotropy at the microscale is neglected in our model. To allow for this, we include a normally distributed random deflection angle α to the force which points in the direction of the previous root segment with zero mean and a standard deviation σ. The standard deviation σ is scaled, so that the deflection from the original root tip location does not depend on the spatial resolution of the root system model. Similarly to the water flow equation, the direction of the root tip movement corresponds to the water flux vector while the driving forces are related to the water potential gradient. The analogue of the hydraulic conductivity tensor is the root penetrability tensor. It is determined by the inverse of soil penetration resistance and describes the ease with which a root can penetrate the soil. By adapting the three dimensional soil and root water uptake model R-SWMS (Javaux et al., 2008) in this way
Chaos and order in non-integrable model field theories
International Nuclear Information System (INIS)
We illustrate the presence of chaos and order in non-integrable, classical field theories, which we view as many-degree-of-freedom Hamiltonian nonlinear dynamical systems. For definiteness, we focus on the χ4 theory and compare and contrast it with the celebrated integrable sine-Gordon equation. We introduce and investigate two specific problems: the interactions of solitary ''kink''-like waves in non-integrable theories; and the existence of stable ''breather'' solutions -- spatially-localized, time-periodic nonlinear waves -- in the χ4 theory. For the former problem we review the rather well developed understanding, based on a combination of computational simulations and heuristic analytic models, of the presence of a sequence of resonances in the kink-antikink interactions as a function of the relative velocity of the interaction. For the latter problem we discuss first the case of the continuum χ4 theory. We discuss the multiple-scale asymptotic perturbation theory arguments which first suggested the existence of χ4 breathers, then the subsequent discovery of terms ''beyond-all-orders'' in the perturbation expansion which destroy the putative breather, and finally, the recent rigorous proofs of the non-existence of breathers in the continuum theory. We then present some very recent numerical results on the existence of breathers in discrete χ4 theories which show an intricate interweaving of stable and unstable breather solutions on finite discrete lattices. We develop a heuristic theoretical explanation of the regions of stability and instability
Thermodynamic Models from Fluctuation Solution Theory Analysis of Molecular Simulations
DEFF Research Database (Denmark)
Christensen, Steen; Peters, Günther H.j.; Hansen, Flemming Yssing;
2007-01-01
Fluctuation solution theory (FST) is employed to analyze results of molecular dynamics (MD) simulations of liquid mixtures. The objective is to generate parameters for macroscopic GE-models, here the modified Margules model. We present a strategy for choosing the number of parameters included in ...
On Theories and Models in Fuzzy Predicate Logics
Czech Academy of Sciences Publication Activity Database
Hájek, Petr; Cintula, Petr
2006-01-01
Roč. 71, č. 3 (2006), s. 863-880. ISSN 0022-4812 R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : fuzzy logic * model theory * witnessed models * conservative extension * completeness theorem Subject RIV: BA - General Mathematics Impact factor: 0.664, year: 2006
Minimax D-Optimal Designs for Item Response Theory Models.
Berger, Martjin P. F.; King, C. Y. Joy; Wong, Weng Kee
2000-01-01
Proposed minimax designs for item response theory (IRT) models to overcome the problem of local optimality. Compared minimax designs to sequentially constructed designs for the two parameter logistic model. Results show that minimax designs can be nearly as efficient as sequentially constructed designs. (Author/SLD)
Classifying linearly shielded modified gravity models in effective field theory.
Lombriser, Lucas; Taylor, Andy
2015-01-23
We study the model space generated by the time-dependent operator coefficients in the effective field theory of the cosmological background evolution and perturbations of modified gravity and dark energy models. We identify three classes of modified gravity models that reduce to Newtonian gravity on the small scales of linear theory. These general classes contain enough freedom to simultaneously admit a matching of the concordance model background expansion history. In particular, there exists a large model space that mimics the concordance model on all linear quasistatic subhorizon scales as well as in the background evolution. Such models also exist when restricting the theory space to operators introduced in Horndeski scalar-tensor gravity. We emphasize that whereas the partially shielded scenarios might be of interest to study in connection with tensions between large and small scale data, with conventional cosmological probes, the ability to distinguish the fully shielded scenarios from the concordance model on near-horizon scales will remain limited by cosmic variance. Novel tests of the large-scale structure remedying this deficiency and accounting for the full covariant nature of the alternative gravitational theories, however, might yield further insights on gravity in this regime. PMID:25658988
Toy model for tachyon condensation in bosonic string field theory
International Nuclear Information System (INIS)
We study tachyon condensation in a baby version of Witten's open string field theory. For some special values of one of the parameters of the model, we are able to obtain closed form expressions for the stable vacuum state and for the value of the potential at the minimum. We study the convergence rate of the level truncation method and compare our exact results with the numerical results found in the full string field theory. (author)
Network Proactive Defense Model Based on Immune Danger Theory
Zhenxing Wang; Liancheng Zhang; Yazhou Kong; Yu Wang
2016-01-01
Recent investigations into proactive network defense have not produced a systematic methodology and structure; in addition, issues including multi-source information fusion and attacking behavior analysis have not been resolved. Borrowing ideas of danger sensing and immune response from danger theory, a proactive network defense model based on danger theory is proposed. This paper defines the signals and antigens in the network environment as well as attacking behavior analysis algorithm, pro...
FY 1996 Congressional budget request: Budget highlights
Energy Technology Data Exchange (ETDEWEB)
1995-02-01
The FY 1996 budget presentation is organized by the Department`s major business lines. An accompanying chart displays the request for new budget authority. The report compares the budget request for FY 1996 with the appropriated FY 1995 funding levels displayed on a comparable basis. The FY 1996 budget represents the first year of a five year plan in which the Department will reduce its spending by $15.8 billion in budget authority and by $14.1 billion in outlays. FY 1996 is a transition year as the Department embarks on its multiyear effort to do more with less. The Budget Highlights are presented by business line; however, the fifth business line, Economic Productivity, which is described in the Policy Overview section, cuts across multiple organizational missions, funding levels and activities and is therefore included in the discussion of the other four business lines.
Optimal velocity difference model for a car-following theory
International Nuclear Information System (INIS)
In this Letter, we present a new optimal velocity difference model for a car-following theory based on the full velocity difference model. The linear stability condition of the new model is obtained by using the linear stability theory. The unrealistically high deceleration does not appear in OVDM. Numerical simulation of traffic dynamics shows that the new model can avoid the disadvantage of negative velocity occurred at small sensitivity coefficient λ in full velocity difference model by adjusting the coefficient of the optimal velocity difference, which shows that collision can disappear in the improved model. -- Highlights: → A new optimal velocity difference car-following model is proposed. → The effects of the optimal velocity difference on the stability of traffic flow have been explored. → The starting and braking process were carried out through simulation. → The effects of the optimal velocity difference can avoid the disadvantage of negative velocity.
Optimal velocity difference model for a car-following theory
Energy Technology Data Exchange (ETDEWEB)
Peng, G.H., E-mail: pengguanghan@yahoo.com.cn [College of Physics and Electronics, Hunan University of Arts and Science, Changde 415000 (China); Cai, X.H.; Liu, C.Q.; Cao, B.F.; Tuo, M.X. [College of Physics and Electronics, Hunan University of Arts and Science, Changde 415000 (China)
2011-10-31
In this Letter, we present a new optimal velocity difference model for a car-following theory based on the full velocity difference model. The linear stability condition of the new model is obtained by using the linear stability theory. The unrealistically high deceleration does not appear in OVDM. Numerical simulation of traffic dynamics shows that the new model can avoid the disadvantage of negative velocity occurred at small sensitivity coefficient λ in full velocity difference model by adjusting the coefficient of the optimal velocity difference, which shows that collision can disappear in the improved model. -- Highlights: → A new optimal velocity difference car-following model is proposed. → The effects of the optimal velocity difference on the stability of traffic flow have been explored. → The starting and braking process were carried out through simulation. → The effects of the optimal velocity difference can avoid the disadvantage of negative velocity.
Genetic model compensation: Theory and applications
Cruickshank, David Raymond
1998-12-01
The adaptive filtering algorithm known as Genetic Model Compensation (GMC) was originally presented in the author's Master's Thesis. The current work extends this earlier work. GMC uses a genetic algorithm to optimize filter process noise parameters in parallel with the estimation of the state and based only on the observational information available to the filter. The original stochastic state model underlying GMC was inherited from the antecedent, non-adaptive Dynamic Model Compensation (DMC) algorithm. The current work develops the stochastic state model from a linear system viewpoint, avoiding the simplifications and approximations of the earlier development, and establishes Riemann sums as unbiased estimators of the stochastic integrals which describe the evolution of the random state components. These are significant developments which provide GMC with a solid theoretical foundation. Orbit determination is the area of application in this work, and two types of problems are studied: real-time autonomous filtering using absolute GPS measurements and precise post-processed filtering using differential GPS measurements. The first type is studied in a satellite navigation simulation in which pseudorange and pseudorange rate measurements are processed by an Extended Kalman Filter which incorporates both DMC and GMC. Both estimators are initialized by a geometric point solution algorithm. Using measurements corrupted by simulated Selective Availability errors, GMC reduces mean RSS position error by 6.4 percent, reduces mean clock bias error by 46 percent, and displays a marked improvement in covariance consistency relative to DMC. To study the second type of problem, GMC is integrated with NASA Jet Propulsion Laboratory's Gipsy/Oasis-II (GOA-II) precision orbit determination program creating an adaptive version of GOA-II's Reduced Dynamic Tracking (RDT) process noise formulation. When run as a sequential estimator with GPS measurements from the TOPEX satellite and
Adachi, M; Ito, A; A. Ishida; W. R. Kadir; P. Ladpala; Yamagata, Y
2011-01-01
More reliable estimates of carbon (C) stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT) was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia) and one agro-forest (an oil palm plantation in Malaysia) to estimate the C budget of tropical ecosystems, including the impacts of...
Adachi, M; Ito, A; A. Ishida; W. R. Kadir; P. Ladpala; Yamagata, Y
2011-01-01
More reliable estimates of the carbon (C) stock within forest ecosystems and C emission induced by deforestation are urgently needed to mitigate the effects of emissions on climate change. A process-based terrestrial biogeochemical model (VISIT) was applied to tropical primary forests of two types (a seasonal dry forest in Thailand and a rainforest in Malaysia) and one agro-forest (an oil palm plantation in Malaysia) to estimate the C budget of tropical ecosystems in Southeast Asia, including...
Liberati, Stefano
2012-01-01
A number of different approaches to quantum gravity are at least partly phenomenologically characterized by their treatment of Lorentz symmetry, in particular whether the symmetry is exact or modified/broken at the smallest scales. For example, string theory generally preserves Lorentz symmetry while analog gravity and Lifshitz models break it at microscopic scales. In models with broken Lorentz symmetry there are a vast number of constraints on departures from Lorentz invariance that can be established with low energy experiments by employing the techniques of effective field theory in both the matter and gravitational sectors. We shall review here the low energy effective field theory approach to Lorentz breaking in these sectors and present various constraints provided by available observations.
Halyo, Nesim; Choi, Sang H.; Chrisman, Dan A., Jr.; Samms, Richard W.
1987-01-01
Dynamic models and computer simulations were developed for the radiometric sensors utilized in the Earth Radiation Budget Experiment (ERBE). The models were developed to understand performance, improve measurement accuracy by updating model parameters and provide the constants needed for the count conversion algorithms. Model simulations were compared with the sensor's actual responses demonstrated in the ground and inflight calibrations. The models consider thermal and radiative exchange effects, surface specularity, spectral dependence of a filter, radiative interactions among an enclosure's nodes, partial specular and diffuse enclosure surface characteristics and steady-state and transient sensor responses. Relatively few sensor nodes were chosen for the models since there is an accuracy tradeoff between increasing the number of nodes and approximating parameters such as the sensor's size, material properties, geometry, and enclosure surface characteristics. Given that the temperature gradients within a node and between nodes are small enough, approximating with only a few nodes does not jeopardize the accuracy required to perform the parameter estimates and error analyses.
Deboeck, Pascal R.; Nicholson, Jody; Kouros, Chrystyna; Little, Todd D.; Garber, Judy
2015-01-01
Matching theories about growth, development, and change to appropriate statistical models can present a challenge, which can result in misuse, misinterpretation, and underutilization of different analytical approaches. We discuss the use of "derivatives": the change of a construct with respect to the change in another construct.…
Hannah, David R.; Venkatachary, Ranga
2010-01-01
In this article, the authors present a retrospective analysis of an instructor's multiyear redesign of a course on organization theory into what is called a hybrid Classroom-as-Organization model. It is suggested that this new course design served to apprentice students to function in quasi-real organizational structures. The authors further argue…
Artificial Immune Danger Theory Based Model for Network Security Evaluation
Directory of Open Access Journals (Sweden)
Feixian Sun
2011-02-01
Full Text Available Inspired by the principles of immune danger theory, a danger theory based model for network security risk assessment is presented in this paper. Firstly, the principle of the danger theory is introduced. And then, with the improved concepts and formal definitions of antigen, antibody, danger signal, and detection lymphocyte for network security risk assessment presented, the distributed architecture of the proposed model is described. Following that, the principle of network intrusion detection is expounded. Finally, the method of network security risk assessment is given. Theoretical analysis and simulation results show that the proposed model can evaluate the network attack threats in real time. Thus, it provides an effective risk evaluation solution to network security.
Summary of papers presented in the Theory and Modelling session
Directory of Open Access Journals (Sweden)
Lin-Liu Y.R.
2012-09-01
Full Text Available A total of 14 contributions were presented in the Theory and Modelling sessions at EC-17. One Theory and Modelling paper was included in the ITER ECRH and ECE sessions each. Three papers were in the area of nonlinear physics discussing parametric processes accompanying ECRH. Eight papers were based on the quasi-linear theory of wave heating and current drive. Three of these addressed the application of ECCD for NTM stabilization. Two papers considered scattering of EC waves by edge density fluctuations and related phenomena. In this summary, we briefly describe the highlights of these contributions. Finally, the three papers concerning modelling of various aspects of ECE are reported in the ECE session.
Perturbation theory for string sigma models
Bianchi, Lorenzo
2016-01-01
In this thesis we investigate quantum aspects of the Green-Schwarz superstring in various AdS backgrounds relevant for the AdS/CFT correspondence, providing several examples of perturbative computations in the corresponding integrable sigma-models. We start by reviewing in details the supercoset construction of the superstring action in $AdS_5 \\times S^5$, pointing out the limits of this procedure for $AdS_4$ and $AdS_3$ backgrounds. For the $AdS_4 \\times CP^3$ case we give a thorough derivation of an alternative action, based on the double-dimensional reduction of eleven-dimensional super-membranes. We then consider the expansion about the BMN vacuum and the S-matrix for the scattering of worldsheet excitations in the decompactification limit. To evaluate its elements efficiently we describe a unitarity-based method resulting in a very compact formula yielding the cut-constructible part of any one-loop two-dimensional S-matrix. In the second part of this review we analyze the superstring action on $AdS_4 \\ti...
International Trade and CGE Models: Theory, Practice, Problems, Improvements
Sherman Robinson; Karen Thierfelder
2012-01-01
This paper will review the specification of international trade in CGE models, focusing on how the modelers have drawn on trade theory to build empirical models to analyze issues of: trade liberalization, regional integration, trade-wage links, structural adjustment to macro shocks, choice of development strategy, and long-run issues such as the adaptation to climate change. The paper will review the theoretical implications and empirical properties of the widely-used Armington specification,...
Spin-filter modeling by means of extension theory methods
Dmitrieva, L. A.; Krupa, D N; Yu. A. Kuperin
2010-01-01
The problem of spin-dependent transport of electrons through a finite array of quantum dots attached to 1D quantum wire (spin gun) for various semiconductor materials is studied. Unlike the model considered in [1] a model proposed here is based on the extension theory model (ETM) and assumes the quantum dots to have an arbitrary internal structure, i.e. the internal energy levels. The presence of internal structure in quantum dots results in energy-dependent interaction between electrons and ...
Magnetized cosmological models in bimetric theory of gravitation
Indian Academy of Sciences (India)
S D Katore; R S Rane
2006-08-01
Bianchi type-III magnetized cosmological model when the field of gravitation is governed by either a perfect fluid or cosmic string is investigated in Rosen's [1] bimetric theory of gravitation. To complete determinate solution, the condition, viz., = (), where is a constant, between the metric potentials is used. We have assumed different equations of state for cosmic string [2] for the complete solution of the model. Some physical and geometrical properties of the exhibited model are discussed and studied.
MOOCs Meet Measurement Theory: A Topic-Modelling Approach
He, Jiazhen; Rubinstein, Benjamin I. P.; Bailey, James; Zhang, Rui; Milligan, Sandra; Chan, Jeffrey
2015-01-01
This paper adapts topic models to the psychometric testing of MOOC students based on their online forum postings. Measurement theory from education and psychology provides statistical models for quantifying a person's attainment of intangible attributes such as attitudes, abilities or intelligence. Such models infer latent skill levels by relating them to individuals' observed responses on a series of items such as quiz questions. The set of items can be used to measure a latent skill if indi...
Three-generation asymmetric orbifold models from heterotic string theory
International Nuclear Information System (INIS)
Using Z3 asymmetric orbifolds in heterotic string theory, we construct N=1 SUSY three-generation models with the standard model gauge group SU(3)C×SU(2)L×U(1)Y and the left-right symmetric group SU(3)C×SU(2)L×SU(2)R×U(1)B−L. One of the models possesses a gauge flavor symmetry for the Z3 twisted matter
Hydrodynamics Research on Amphibious Vehicle Systems:Modeling Theory
Institute of Scientific and Technical Information of China (English)
JU Nai-jun
2006-01-01
For completing the hydrodynamics software development and the engineering application research on the amphibious vehicle systems, hydrodynamic modeling theory of the amphibious vehicle systems is elaborated, which includes to build up the dynamic system model of amphibious vehicle motion on water, gun tracking-aiming-firing, bullet hit and armored check-target, gunner operating control, and the simulation computed model of time domain for random sea wave.
A Model of Resurgence Based on Behavioral Momentum Theory
Shahan, Timothy A; Sweeney, Mary M.
2011-01-01
Resurgence is the reappearance of an extinguished behavior when an alternative behavior reinforced during extinction is subsequently placed on extinction. Resurgence is of particular interest because it may be a source of relapse to problem behavior following treatments involving alternative reinforcement. In this article we develop a quantitative model of resurgence based on the augmented model of extinction provided by behavioral momentum theory. The model suggests that alternative reinforc...
Directory of Open Access Journals (Sweden)
A. Lauer
2007-07-01
Full Text Available International shipping contributes significantly to the fuel consumption of all transport related activities. Specific emissions of pollutants such as sulfur dioxide (SO_{2} per kg of fuel emitted are higher than for road transport or aviation. Besides gaseous pollutants, ships also emit various types of particulate matter. The aerosol impacts the Earth's radiation budget directly by scattering and absorbing incoming solar radiation and indirectly by changing cloud properties. Here we use ECHAM5/MESSy1-MADE, a global climate model with detailed aerosol and cloud microphysics, to show that emissions from ships significantly increase the cloud droplet number concentration of low maritime water clouds. Whereas the cloud liquid water content remains nearly unchanged in these simulations, effective radii of cloud droplets decrease, leading to cloud optical thickness increase up to 5–10%. The sensitivity of the results is estimated by using three different emission inventories for present day conditions. The sensitivity analysis reveals that shipping contributes with 2.3% to 3.6% to the total sulfate burden and 0.4% to 1.4% to the total black carbon burden in the year 2000. In addition to changes in aerosol chemical composition, shipping increases the aerosol number concentration, e.g. up to 25% in the size range of the accumulation mode (typically >0.1 μm over the Atlantic. The total aerosol optical thickness over the Indian Ocean, the Gulf of Mexico and the Northeastern Pacific increases up to 8–10% depending on the emission inventory. Changes in aerosol optical thickness caused by the shipping induced modification of aerosol particle number concentration and chemical composition lead to a change of the net top of the atmosphere (ToA clear sky radiation of about −0.013 W/m^{2} to −0.036 W/m^{2} on global annual average. The estimated all-sky direct aerosol effect calculated from these changes ranges between −0
Leroux, Estelle; Gorini, Christian; Aslanian, Daniel; Rabineau, Marina; Blanpied, Christian; Rubino, Jean-Loup; Robin, Cécile; Granjeon, Didier; Taillepierre, Rachel
2016-04-01
The post-rift (~20-0 Ma) vertical movements of the Provence Basin (West Mediterranean) are quantified on its both conjugate (the Gulf of Lion and the West Sardinia) margins. This work is based on the stratigraphic study of sedimentary markers using a large 3D grid of seismic data, correlations with existing drillings and refraction data. The post-rift subsidence is measured by the direct use of sedimentary geometries analysed in 3D [Gorini et al., 2015; Rabineau et al., 2014] and validated by numerical stratigraphic modelling. Three domains were found: on the platform (1) and slope (2), the subsidence takes the form of a seaward tilting with different amplitudes, whereas the deep basin (3) subsides purely vertically [Leroux et al., 2015a]. These domains correspond to the deeper crustal domains respectively highlighted by wide angle seismic data. The continental crust (1) and the thinned continental crust (2) are tilted, whereas the intermediate crust, identified as lower continental exhumed crust [Moulin et al., 2015, Afhilado et al., 2015] (3) sagged. The post-break-up subsidence re-uses the initial hinge lines of the rifting phase. This striking correlation between surface geologic processes and deep earth dynamic processes emphasizes that the sedimentary record and sedimentary markers is a window into deep geodynamic processes and dynamic topography. Pliocene-Pleistocene seismic markers enabled high resolution quantification of sediment budgets over the past 6 Myr [Leroux et al., in press]. Sediment budget history is here completed on the Miocene interval. Thus, the controlling factors (climate, tectonics and eustasy) are discussed. Afilhado, A., Moulin, M., Aslanian, D., Schnürle, P., Klingelhoefer, F., Nouzé, H., Rabineau, M., Leroux, E. & Beslier, M.-O. (2015). Deep crustal structure across a young 1 passive margin from wide-angle and reflection seismic data (The SARDINIA Experiment) - II. Sardinia's margin. Bull. Soc. géol. France, 186, ILP Spec. issue, 4
Theory of compressive modeling and simulation
Szu, Harold; Cha, Jae; Espinola, Richard L.; Krapels, Keith
2013-05-01
Modeling and Simulation (M&S) has been evolving along two general directions: (i) data-rich approach suffering the curse of dimensionality and (ii) equation-rich approach suffering computing power and turnaround time. We suggest a third approach. We call it (iii) compressive M&S (CM&S); because the basic Minimum Free-Helmholtz Energy (MFE) facilitating CM&S can reproduce and generalize Candes, Romberg, Tao & Donoho (CRT&D) Compressive Sensing (CS) paradigm as a linear Lagrange Constraint Neural network (LCNN) algorithm. CM&S based MFE can generalize LCNN to 2nd order as Nonlinear augmented LCNN. For example, during the sunset, we can avoid a reddish bias of sunlight illumination due to a long-range Rayleigh scattering over the horizon. With CM&S we can take instead of day camera, a night vision camera. We decomposed long wave infrared (LWIR) band with filter into 2 vector components (8~10μm and 10~12μm) and used LCNN to find pixel by pixel the map of Emissive-Equivalent Planck Radiation Sources (EPRS). Then, we up-shifted consistently, according to de-mixed sources map, to the sub-micron RGB color image. Moreover, the night vision imaging can also be down-shifted at Passive Millimeter Wave (PMMW) imaging, suffering less blur owing to dusty smokes scattering and enjoying apparent smoothness of surface reflectivity of man-made objects under the Rayleigh resolution. One loses three orders of magnitudes in the spatial Rayleigh resolution; but gains two orders of magnitude in the reflectivity, and gains another two orders in the propagation without obscuring smog . Since CM&S can generate missing data and hard to get dynamic transients, CM&S can reduce unnecessary measurements and their associated cost and computing in the sense of super-saving CS: measuring one & getting one's neighborhood free .
Braiding in Conformal Field Theory and Solvable Lattice Models
Gepner, D; Gepner, Doron; Fuchs, Jurgen
1994-01-01
Braiding matrices in rational conformal field theory are considered. The braiding matrices for any two block four point function are computed, in general, using the holomorphic properties of the blocks and the holomorphic properties of rational conformal field theory. The braidings of $SU(N)_k$ with the fundamental are evaluated and are used as examples. Solvable interaction round the face lattice models are constructed from these braiding matrices, and their Boltzmann weights are given. This allows, in particular, for the derivation of the Boltzmann weights of such solvable height models.
Lenses on Reading An Introduction to Theories and Models
Tracey, Diane H
2012-01-01
This widely adopted text explores key theories and models that frame reading instruction and research. Readers learn why theory matters in designing and implementing high-quality instruction and research; how to critically evaluate the assumptions and beliefs that guide their own work; and what can be gained by looking at reading through multiple theoretical lenses. For each theoretical model, classroom applications are brought to life with engaging vignettes and teacher reflections. Research applications are discussed and illustrated with descriptions of exemplary studies. New to This Edition
Effective Field Theory and the No-Core Shell Model
Directory of Open Access Journals (Sweden)
Stetcua I.
2010-04-01
Full Text Available In ﬁnite model space suitable for many-body calculations via the no-core shell model (NCSM, I illustrate the direct application of the eﬀective ﬁeld theory (EFT principles to solving the many-body Schrödinger equation. Two diﬀerent avenues for ﬁxing the low-energy constants naturally arising in an EFT approach are discussed. I review results for both nuclear and trapped atomic systems, using eﬀective theories formally similar, albeit describing diﬀerent underlying physics.
Consistent constraints on the Standard Model Effective Field Theory
Berthier, Laure; Trott, Michael
2016-02-01
We develop the global constraint picture in the (linear) effective field theory generalisation of the Standard Model, incorporating data from detectors that operated at PEP, PETRA, TRISTAN, SpS, Tevatron, SLAC, LEPI and LEP II, as well as low energy precision data. We fit one hundred and three observables. We develop a theory error metric for this effective field theory, which is required when constraints on parameters at leading order in the power counting are to be pushed to the percent level, or beyond, unless the cut off scale is assumed to be large, Λ ≳ 3 TeV. We more consistently incorporate theoretical errors in this work, avoiding this assumption, and as a direct consequence bounds on some leading parameters are relaxed. We show how an S, T analysis is modified by the theory errors we include as an illustrative example.
Theory, modeling and simulation of superconducting qubits
Energy Technology Data Exchange (ETDEWEB)
Berman, Gennady P [Los Alamos National Laboratory; Kamenev, Dmitry I [Los Alamos National Laboratory; Chumak, Alexander [INSTIT OF PHYSICS, KIEV; Kinion, Carin [LLNL; Tsifrinovich, Vladimir [POLYTECHNIC INSTIT OF NYU
2011-01-13
We analyze the dynamics of a qubit-resonator system coupled with a thermal bath and external electromagnetic fields. Using the evolution equations for the set of Heisenberg operators that describe the whole system, we derive an expression for the resonator field, that includes the resonator-drive, the resonator-bath, and resonator-qubit interactions. The renormalization of the resonator frequency, caused by the qubit-resonator interaction, is accounted for. Using the solutions for the resonator field, we derive the equation that describes the qubit dynamics. The dependence of the qubit evolution during the measurement time on the fidelity of a single-shot measurement is studied. The relation between the fidelity and measurement time is shown explicitly. We proposed a novel adiabatic method for the phase qubit measurement. The method utilizes a low-frequency, quasi-classical resonator inductively coupled to the qubit. The resonator modulates the qubit energy, and the back reaction of the qubit causes a shift in the phase of the resonator. The resonator phase shift can be used to determine the qubit state. We have simulated this measurement taking into the account the energy levels outside the phase qubit manifold. We have shown that, for qubit frequencies in the range of 8-12GHZ, a resonator frequency of 500 MHz and a measurement time of 100 ns, the phase difference between the two qubit states is greater than 0.2 rad. This phase difference exceeds the measurement uncertainty, and can be detected using a classical phase-meter. A fidelity of 0.9999 can be achieved for a relaxation time of 0.5 ms. We also model and simulate a microstrip-SQUID amplifier of frequency about 500 MHz, which could be used to amplify the resonator oscillations in the phase qubit adiabatic measurement. The voltage gain and the amplifier noise temperature are calculated. We simulate the preparation of a generalized Bell state and compute the relaxation times required for achieving high
A Model of PCF in Guarded Type Theory
DEFF Research Database (Denmark)
Paviotti, Marco; Møgelberg, Rasmus Ejlers; Birkedal, Lars
2015-01-01
Guarded recursion is a form of recursion where recursive calls are guarded by delay modalities. Previous work has shown how guarded recursion is useful for constructing logics for reasoning about programming languages with advanced features, as well as for constructing and reasoning about elements...... of coinductive types. In this paper we investigate how type theory with guarded recursion can be used as a metalanguage for denotational semantics useful both for constructing models and for proving properties of these. We do this by constructing a fairly intensional model of PCF and proving it...... computationally adequate. The model construction is related to Escardo's metric model for PCF, but here everything is carried out entirely in type theory with guarded recursion, including the formulation of the operational semantics, the model construction and the proof of adequacy....
Cosmological Model Based on Gauge Theory of Gravity
Institute of Scientific and Technical Information of China (English)
WU Ning
2005-01-01
A cosmological model based on gauge theory of gravity is proposed in this paper. Combining cosmological principle and field equation of gravitational gauge field, dynamical equations of the scale factor R(t) of our universe can be obtained. This set of equations has three different solutions. A prediction of the present model is that, if the energy density of the universe is not zero and the universe is expanding, the universe must be space-flat, the total energy density must be the critical density ρc of the universe. For space-flat case, this model gives the same solution as that of the Friedmann model. In other words, though they have different dynamics of gravitational interactions, general relativity and gauge theory of gravity give the same cosmological model.
An introduction to queueing theory modeling and analysis in applications
Bhat, U Narayan
2015-01-01
This introductory textbook is designed for a one-semester course on queueing theory that does not require a course on stochastic processes as a prerequisite. By integrating the necessary background on stochastic processes with the analysis of models, the work provides a sound foundational introduction to the modeling and analysis of queueing systems for a wide interdisciplinary audience of students in mathematics, statistics, and applied disciplines such as computer science, operations research, and engineering. This edition includes additional topics in methodology and applications. Key features: • An introductory chapter including a historical account of the growth of queueing theory in more than 100 years. • A modeling-based approach with emphasis on identification of models. • Rigorous treatment of the foundations of basic models commonly used in applications with appropriate references for advanced topics. • Applications in manufacturing and, computer and communication systems. • A chapter on ...
A model of PCF in guarded type theory
DEFF Research Database (Denmark)
Paviotti, Marco; Møgelberg, Rasmus Ejlers; Birkedal, Lars
2015-01-01
Guarded recursion is a form of recursion where recursive calls are guarded by delay modalities. Previous work has shown how guarded recursion is useful for constructing logics for reasoning about programming languages with advanced features, as well as for constructing and reasoning about elements...... of coinductive types. In this paper we investigate how type theory with guarded recursion can be used as a metalanguage for denotational semantics useful both for constructing models and for proving properties of these. We do this by constructing a fairly intensional model of PCF and proving it...... computationally adequate. The model construction is related to Escardo's metric model for PCF, but here everything is carried out entirely in type theory with guarded recursion, including the formulation of the operational semantics, the model construction and the proof of adequacy...
Directory of Open Access Journals (Sweden)
Pilli R
2015-08-01
Full Text Available In the context of the Kyoto Protocol, the mandatory accounting of Afforestation and Reforestation (AR activities requires estimating the forest carbon (C stock changes for any direct human-induced expansion of forest since 1990. We used the Carbon Budget Model (CBM to estimate C stock changes and emissions from fires on AR lands at country level. Italy was chosen because it has one of the highest annual rates of AR in Europe and the same model was recently applied to Italy’s forest management area. We considered the time period 1990-2020 with two case studies reflecting different average annual rates of AR: 78 kha yr-1, based on the 2013 Italian National Inventory Report (NIR, official estimates, and 28 kha yr-1, based on the Italian Land Use Inventory System (IUTI estimates. We compared these two different AR rates with eight regional forest inventories and three independent local studies. The average annual C stock change estimated by CBM, excluding harvest or natural disturbances, was equal to 1738 Gg C yr-1 (official estimates and 630 Gg C yr-1 (IUTI estimates. Results for the official estimates are consistent with the estimates reported by Italy to the KP for the period 2008-2010; for 2011 our estimates are about 20% higher than the country’s data, probably due to different assumptions on the fire disturbances, the AR rate and the dead wood and litter pools. Furthermore, our analysis suggests that: (i the impact on the AR sink of different assumptions of species composition is small; (ii the amount of harvest provided by AR has been negligible for the past (< 3% and is expected to be small in the near future (up to 8% in 2020; (iii forest fires up to 2011 had a small impact on the AR sink (on average, < 100 Gg C yr-1. Finally the comparison of the historical AR rates reported by NIR and IUTI with other independent sources gives mixed results: the regional inventories support the AR rates reported by the NIR, while some local studies
Modelling machine ensembles with discrete event dynamical system theory
Hunter, Dan
1990-01-01
Discrete Event Dynamical System (DEDS) theory can be utilized as a control strategy for future complex machine ensembles that will be required for in-space construction. The control strategy involves orchestrating a set of interactive submachines to perform a set of tasks for a given set of constraints such as minimum time, minimum energy, or maximum machine utilization. Machine ensembles can be hierarchically modeled as a global model that combines the operations of the individual submachines. These submachines are represented in the global model as local models. Local models, from the perspective of DEDS theory , are described by the following: a set of system and transition states, an event alphabet that portrays actions that takes a submachine from one state to another, an initial system state, a partial function that maps the current state and event alphabet to the next state, and the time required for the event to occur. Each submachine in the machine ensemble is presented by a unique local model. The global model combines the local models such that the local models can operate in parallel under the additional logistic and physical constraints due to submachine interactions. The global model is constructed from the states, events, event functions, and timing requirements of the local models. Supervisory control can be implemented in the global model by various methods such as task scheduling (open-loop control) or implementing a feedback DEDS controller (closed-loop control).
Directory of Open Access Journals (Sweden)
Pilli R
2014-02-01
Full Text Available Historical analysis and modeling of the forest carbon dynamics using the Carbon Budget Model: an example for the Trento Province (NE, Italy. The Carbon Budget Model (CBM-CFS3 developed by the Canadian Forest Service was applied to data collected by the last Italian National Forest Inventory (INFC for the Trento Province (NE, Italy. CBM was modified and adapted to the different management types (i.e., even-aged high forests, uneven-aged high forests and coppices and silvicultural systems (including clear cuts, single tree selection systems and thinning applied in this province. The aim of this study was to provide an example of down-scaling of this model from a national to a regional scale, providing (i an historical analysis, from 1995 to 2011, and (ii a projection, from 2012 to 2020, of the forest biomass and the carbon stock evolution. The analysis was based on the harvest rate reported by the Italian National Institute of Statistics (from 1995 to 2011, corrected according to the last INFC data and distinguished between timber and fuel woods and between conifers and broadleaves. Since 2012, we applied a constant harvest rate, equal to about 1300 Mm3 yr-1, estimated from the average harvest rate for the period 2006-2011. Model results were consistent with similar data reported in the literature. The average biomass C stock was 90 Mg C ha-1 and the biomass C stock change was 0.97 Mg C ha-1 yr-1 and 0.87 Mg C ha-1 yr-1, for the period 1995 -2011 and 2012-2020, respectively. The C stock cumulated by the timber products since 1995 was 96 Gg C yr-1, i.e., about 28% of the average annual C stock change of the forests, equal to 345 Gg C yr-1. CBM also provided estimates on the evolution of the age class distribution of the even-aged forests and on the C stock of the DOM forest pools (litter, dead wood and soil. This study demonstrates the utility of CBM to provide estimates at a regional or local scale, using not only the data provided by the forest
Directory of Open Access Journals (Sweden)
Chung-Hung Tsai
2014-05-01
Full Text Available Telehealth has become an increasingly applied solution to delivering health care to rural and underserved areas by remote health care professionals. This study integrated social capital theory, social cognitive theory, and the technology acceptance model (TAM to develop a comprehensive behavioral model for analyzing the relationships among social capital factors (social capital theory, technological factors (TAM, and system self-efficacy (social cognitive theory in telehealth. The proposed framework was validated with 365 respondents from Nantou County, located in Central Taiwan. Structural equation modeling (SEM was used to assess the causal relationships that were hypothesized in the proposed model. The finding indicates that elderly residents generally reported positive perceptions toward the telehealth system. Generally, the findings show that social capital factors (social trust, institutional trust, and social participation significantly positively affect the technological factors (perceived ease of use and perceived usefulness respectively, which influenced usage intention. This study also confirmed that system self-efficacy was the salient antecedent of perceived ease of use. In addition, regarding the samples, the proposed model fitted considerably well. The proposed integrative psychosocial-technological model may serve as a theoretical basis for future research and can also offer empirical foresight to practitioners and researchers in the health departments of governments, hospitals, and rural communities.
Chern-Simons Theory, Matrix Models, and Topological Strings
Energy Technology Data Exchange (ETDEWEB)
Walcher, J [Institute for Advanced Study, Princeton, New Jersey 08540 (United States)
2006-10-21
This book is a find. Marino meets the challenge of filling in less than 200 pages the need for an accessible review of topological gauge/gravity duality. He is one of the pioneers of the subject and a clear expositor. It is no surprise that reading this book is a great pleasure. The existence of dualities between gauge theories and theories of gravity remains one of the most surprising recent discoveries in mathematical physics. While it is probably fair to say that we do not yet understand the full reach of such a relation, the impressive amount of evidence that has accumulated over the past years can be regarded as a substitute for a proof, and will certainly help to delineate the question of what is the most fundamental quantum mechanical theory. Here is a brief summary of the book. The journey begins with matrix models and an introduction to various techniques for the computation of integrals including perturbative expansion, large-N approximation, saddle point analysis, and the method of orthogonal polynomials. The second chapter, on Chern-Simons theory, is the longest and probably the most complete one in the book. Starting from the action we meet Wilson loop observables, the associated perturbative 3-manifold invariants, Witten's exact solution via the canonical duality to WZW models, the framing ambiguity, as well as a collection of results on knot invariants that can be derived from Chern-Simons theory and the combinatorics of U ({infinity}) representation theory. The chapter also contains a careful derivation of the large-N expansion of the Chern-Simons partition function, which forms the cornerstone of its interpretation as a closed string theory. Finally, we learn that Chern-Simons theory can sometimes also be represented as a matrix model. The story then turns to the gravity side, with an introduction to topological sigma models (chapter 3) and topological string theory (chapter 4). While this presentation is necessarily rather condensed (and the
Excellence in Physics Education Award: Modeling Theory for Physics Instruction
Hestenes, David
2014-03-01
All humans create mental models to plan and guide their interactions with the physical world. Science has greatly refined and extended this ability by creating and validating formal scientific models of physical things and processes. Research in physics education has found that mental models created from everyday experience are largely incompatible with scientific models. This suggests that the fundamental problem in learning and understanding science is coordinating mental models with scientific models. Modeling Theory has drawn on resources of cognitive science to work out extensive implications of this suggestion and guide development of an approach to science pedagogy and curriculum design called Modeling Instruction. Modeling Instruction has been widely applied to high school physics and, more recently, to chemistry and biology, with noteworthy results.
A Study of the Stable Boundary Layer Based on a Single-Column K-Theory Model
Sorbjan, Zbigniew
2012-01-01
We document numerical experiments with a single-column, high-resolution model of the stable boundary layer. The model resolves the logarithmic layer, and does not require inverting the Monin-Obukhov similarity functions in order to calculate the surface fluxes. The turbulence closure is based on the K-theory approach, with a new form of stability functions of the Richardson number, evaluated by using the Surface Heat Budget of the Arctic Ocean (SHEBA) and the Cooperative Atmosphere-Surface Exchange Study (CASES-99) data. A comparison with two, high-resolution large-eddy simulation models shows very good agreement. The reported numerical experiments test the effects of shear, surface cooling, the Coriolis parameter, subsidence, and baroclinicity. The time evolution of the drag coefficient, the heat-transfer coefficient, and the cross-isobar angle is also evaluated.
Executive Office of the President — This dataset includes three data files that contain an extract of the Office of Management and Budget (OMB) budget database. These files can be used to reproduce...
Executive Office of the President — This dataset includes three data files that contain an extract of the Office of Management and Budget (OMB) budget database. These files can be used to reproduce...
Executive Office of the President — This dataset includes three data files that contain an extract of the Office of Management and Budget (OMB) budget database. These files can be used to reproduce...
Montgomery County of Maryland — This dataset includes the Fiscal Year 2015 Council-approved operating budget for Montgomery County. The dataset does not include revenues and detailed agency budget...
Ogden, Daniel M., Jr.
1978-01-01
Suggests that the most practical budgeting system for most managers is a formalized combination of incremental and zero-based analysis because little can be learned about most programs from an annual zero-based budget. (Author/IRT)
Linking Complexity and Sustainability Theories: Implications for Modeling Sustainability Transitions
Directory of Open Access Journals (Sweden)
Camaren Peter
2014-03-01
Full Text Available In this paper, we deploy a complexity theory as the foundation for integration of different theoretical approaches to sustainability and develop a rationale for a complexity-based framework for modeling transitions to sustainability. We propose a framework based on a comparison of complex systems’ properties that characterize the different theories that deal with transitions to sustainability. We argue that adopting a complexity theory based approach for modeling transitions requires going beyond deterministic frameworks; by adopting a probabilistic, integrative, inclusive and adaptive approach that can support transitions. We also illustrate how this complexity-based modeling framework can be implemented; i.e., how it can be used to select modeling techniques that address particular properties of complex systems that we need to understand in order to model transitions to sustainability. In doing so, we establish a complexity-based approach towards modeling sustainability transitions that caters for the broad range of complex systems’ properties that are required to model transitions to sustainability.
Institute of Scientific and Technical Information of China (English)
裴沛
2015-01-01
近几年,许多本土经济型酒店收入增速放缓,甚至出现亏损现象. 想要扭转这种局面,吸引客源提高竞争力,必须改变传统思维方式,为顾客创造酒店新价值. 本文结合顾客价值创新理论,对本土经济型酒店的顾客需求进行深入分析,针对十个维度绘出一条新的经济型酒店顾客价值曲线,提出了若干提升本土经济型酒店竞争力的对策,以客房为中心保证产品质量,注重服务细节提升服务质量,重视酒店网络点评等.%In recent years,many of the budget hotels in China appeared the phenomenon that revenue growth slowed down and even lost.To improve this condition,the budget hotels should change the traditional way of thinking and create a new hotel value for customers in order to attract customers and improve competitiveness. Based on customer value innovation theory,this paper analyzes the value of customers of the budget hotels in China,draws a new curve of customer value,and puts forward some countermeasures to improve the competi-tiveness,such as the room as the center to ensure product quality,pay attention to detail and the hotel network reviews.
The early years of string theory: The dual resonance model
International Nuclear Information System (INIS)
This paper reviews the past quantum mechanical history of the dual resonance model which is an early string theory. The content of this paper is listed as follows: historical review, the Veneziano amplitude, the operator formalism, the ghost story, and the string story
Note on the standard model as an effective theory
Fariborz, Amir H
2015-01-01
We present a criterion of consistency derived from the analogy between the partition function of a quantum field theory and that of a statistical system. Based on this we examine a new class of higher dimension operators that might act in the standard model.
Anisotropic cosmological models and generalized scalar tensor theory
Indian Academy of Sciences (India)
Subenoy Chakraborty; Batul Chandra Santra; Nabajit Chakravarty
2003-10-01
In this paper generalized scalar tensor theory has been considered in the background of anisotropic cosmological models, namely, axially symmetric Bianchi-I, Bianchi-III and Kortowski–Sachs space-time. For bulk viscous ﬂuid, both exponential and power-law solutions have been studied and some assumptions among the physical parameters and solutions have been discussed.
Conceptualizations of Creativity: Comparing Theories and Models of Giftedness
Miller, Angie L.
2012-01-01
This article reviews seven different theories of giftedness that include creativity as a component, comparing and contrasting how each one conceptualizes creativity as a part of giftedness. The functions of creativity vary across the models, suggesting that while the field of gifted education often cites the importance of creativity, the…
Unified theory of particle decay modes in electonic model
Energy Technology Data Exchange (ETDEWEB)
Jian, C.X.
1982-06-01
In a previous paper we have given a reasonable description of the total number of constituents (eletons and antieletons) in Santilli's structure model of hadrons. In this paper we shall extend these results to inlude decays of unstable hadrons. We shall continue to use the theory of stable and unstable groups with particular reference to Euler's function.
Using Conceptual Change Theories to Model Position Concepts in Astronomy
Yang, Chih-Chiang; Hung, Jeng-Fung
2012-01-01
The roles of conceptual change and model building in science education are very important and have a profound and wide effect on teaching science. This study examines the change in children's position concepts after instruction, based on different conceptual change theories. Three classes were chosen and divided into three groups, including a…
A Proposed Model of Jazz Theory Knowledge Acquisition
Ciorba, Charles R.; Russell, Brian E.
2014-01-01
The purpose of this study was to test a hypothesized model that proposes a causal relationship between motivation and academic achievement on the acquisition of jazz theory knowledge. A reliability analysis of the latent variables ranged from 0.92 to 0.94. Confirmatory factor analyses of the motivation (standardized root mean square residual…
Dimensions of Genocide: The Circumplex Model Meets Violentization Theory
Winton, Mark A.
2008-01-01
The purpose of this study is to examine the use of Olson's (1995, 2000) family therapy based circumplex model and Athens' (1992, 1997, 2003) violentization theory in explaining genocide. The Rwandan genocide of 1994 is used as a case study. Published texts, including interviews with perpetrators, research reports, human rights reports, and court…
F-theory duals of singular heterotic K3 models
International Nuclear Information System (INIS)
We study F-theory duals of singular heterotic K3 models that correspond to abelian toroidal orbifolds T4/ZN. While our focus is on the standard embedding, we also comment on models with Wilson lines and more general gauge embeddings. In the process of constructing the duals, we work out a Weierstrass description of the heterotic toroidal orbifold models, which exhibit singularities of Kodaira type I0*, IV*, III*, and II*. This construction unveils properties like the instanton number per fixed point and a correlation between the orbifold order and the multiplicities in the Dynkin diagram. The results from the Weierstrass description are then used to restrict the complex structure of the F-theory Calabi-Yau threefold such that the gauge group and the matter spectrum of the heterotic theories are reproduced. We also comment on previous approaches that have been employed to construct the duality and point out the differences to our case. Our results show explicitly how the various orbifold models are connected and described in F-theory.
A Model of Statistics Performance Based on Achievement Goal Theory.
Bandalos, Deborah L.; Finney, Sara J.; Geske, Jenenne A.
2003-01-01
Tests a model of statistics performance based on achievement goal theory. Both learning and performance goals affected achievement indirectly through study strategies, self-efficacy, and test anxiety. Implications of these findings for teaching and learning statistics are discussed. (Contains 47 references, 3 tables, 3 figures, and 1 appendix.)…
Compositional models and conditional independence in evidence theory
Czech Academy of Sciences Publication Activity Database
Jiroušek, Radim; Vejnarová, Jiřina
2011-01-01
Roč. 52, č. 3 (2011), s. 316-334. ISSN 0888-613X Institutional research plan: CEZ:AV0Z10750506 Keywords : Evidence theory * Conditional independence * multidimensional models Subject RIV: BA - General Mathematics Impact factor: 1.948, year: 2011 http://library.utia.cas.cz/separaty/2012/MTR/jirousek-0370515.pdf
Using SAS PROC MCMC for Item Response Theory Models
Ames, Allison J.; Samonte, Kelli
2015-01-01
Interest in using Bayesian methods for estimating item response theory models has grown at a remarkable rate in recent years. This attentiveness to Bayesian estimation has also inspired a growth in available software such as WinBUGS, R packages, BMIRT, MPLUS, and SAS PROC MCMC. This article intends to provide an accessible overview of Bayesian…
Factorization in Dual Models and Functional Integration in String Theory
Mandelstam, Stanley
2008-01-01
This article contains a summary of the author's contributions, one in collaboration with K. Bardakci, to dual models and string theory prior to the mid-seventies. Other workers' contributions, during and subsequent to this period, are mentioned in order to relate our work to the general development of the subject
A Model to Demonstrate the Place Theory of Hearing
Ganesh, Gnanasenthil; Srinivasan, Venkata Subramanian; Krishnamurthi, Sarayu
2016-01-01
In this brief article, the authors discuss Georg von Békésy's experiments showing the existence of traveling waves in the basilar membrane and that maximal displacement of the traveling wave was determined by the frequency of the sound. The place theory of hearing equates the basilar membrane to a frequency analyzer. The model described in this…
Accounting for Errors in Model Analysis Theory: A Numerical Approach
Sommer, Steven R.; Lindell, Rebecca S.
2004-09-01
By studying the patterns of a group of individuals' responses to a series of multiple-choice questions, researchers can utilize Model Analysis Theory to create a probability distribution of mental models for a student population. The eigenanalysis of this distribution yields information about what mental models the students possess, as well as how consistently they utilize said mental models. Although the theory considers the probabilistic distribution to be fundamental, there exists opportunities for random errors to occur. In this paper we will discuss a numerical approach for mathematically accounting for these random errors. As an example of this methodology, analysis of data obtained from the Lunar Phases Concept Inventory will be presented. Limitations and applicability of this numerical approach will be discussed.
Ian Hawkesworth; Richard Emery; Joachim Wehner; Jannick Saegert
2010-01-01
This report covers the budget process in Lithuania. It discusses the four phases in separate sections: budget preparation, legislative approval, budget execution, and accounting and audit. Each section ends with a list of recommendations. The new strategic planning process should strengthen the policy focus of the budget at the level of the line ministries and could be accompanied by a more robust medium.term fiscal framework. All public.private partnerships (PPPs) should be subject to approv...
Dirk-Jan Kraan; Daniel Bergvall; Ian Hawkesworth; Philipp Krause
2006-01-01
This review of the Hungarian budget process was carried out in May 2006. The review covers budget formulation, budget execution, parliamentary approval, accounting and auditing, and sub-national financing. Hungary has modernised its budget process over the last ten years, first as part of the pre-accession programme and then, since EU accession in 2004, in connection with the Convergence Programme 2005-08. Nevertheless, there remain some shortcomings which include the focus on the actual (non...
MICROCOMPUTER BUDGET MANAGEMENT SYSTEM
McGrann, James M.; Kent D. Olson; Powell, Timothy A.; Nelson, Ted R.
1986-01-01
The enterprise budget, whole farm cash flow, and income statement are fundamental tools of farm and ranch management. The "Microcomputer Budget Management System" (MBMS) is a microcomputer software package that facilitates the storage and use of information for crop and livestock budgeting. It performs the calculations for several enterprise budgeting formats and for preparation of whole farm resource use reports and financial statements. The MBMS also includes internal machinery and irrigati...
Performance Budgeting in Turkey
Sevil Çatak; Canan Çilingir
2010-01-01
The effective and efficient use of public resources has vital importance for Turkey. To serve this purpose, public financial management was reformed and a performance budgeting system was launched in Turkey. This article assesses the current situation of the implementation of the performance budgeting system in Turkey from the perspective of public administrations under the general budget. It examines all stages of the performance budgeting process (strategic planning, performance programming...
Alliance: A common factor of psychotherapy modeled by structural theory
Directory of Open Access Journals (Sweden)
Wolfgang eTschacher
2015-04-01
Full Text Available There is broad consensus that the therapeutic alliance constitutes a core common factor for all modalities of psychotherapy. Meta-analyses corroborated that alliance, as it emerges from therapeutic process, is a significant predictor of therapy outcome. Psychotherapy process is traditionally described and explored using two categorially different approaches, the experiential (first-person perspective and the behavioral (third-person perspective. We propose to add to this duality a third, structural approach. Dynamical systems theory and synergetics on the one hand and enactivist theory on the other together can provide this structural approach, which contributes in specific ways to a clarification of the alliance factor. Systems theory offers concepts and tools for the modeling of the individual self and, building on this, of alliance processes. In the enactive perspective, the self is conceived as a socially enacted autonomous system that strives to maintain identity by observing a two-fold goal: to exist as an individual self in its own right (distinction while also being open to others (participation. Using this conceptualization, we formalized the therapeutic alliance as a phase space whose potential minima (attractors can be shifted by the therapist to approximate therapy goals. This mathematical formalization is derived from probability theory and synergetics. Our conclusions say that structural theory provides powerful tools for the modeling of how therapeutic change is staged by the formation, utilization, and dissolution of the therapeutic alliance. In addition, we point out novel testable hypotheses and future applications.
Chaos and order in non-integrable model field theories
Energy Technology Data Exchange (ETDEWEB)
Campbell, D.K.; Peyrard, M.
1989-01-01
We illustrate the presence of chaos and order in non-integrable, classical field theories, which we view as many-degree-of-freedom Hamiltonian nonlinear dynamical systems. For definiteness, we focus on the {chi}{sup 4} theory and compare and contrast it with the celebrated integrable sine-Gordon equation. We introduce and investigate two specific problems: the interactions of solitary kink''-like waves in non-integrable theories; and the existence of stable breather'' solutions -- spatially-localized, time-periodic nonlinear waves -- in the {chi}{sup 4} theory. For the former problem we review the rather well developed understanding, based on a combination of computational simulations and heuristic analytic models, of the presence of a sequence of resonances in the kink-antikink interactions as a function of the relative velocity of the interaction. For the latter problem we discuss first the case of the continuum {chi}{sup 4} theory. We discuss the multiple-scale asymptotic perturbation theory arguments which first suggested the existence of {chi}{sup 4} breathers, then the subsequent discovery of terms beyond-all-orders'' in the perturbation expansion which destroy the putative breather, and finally, the recent rigorous proofs of the non-existence of breathers in the continuum theory. We then present some very recent numerical results on the existence of breathers in discrete {chi}{sup 4} theories which show an intricate interweaving of stable and unstable breather solutions on finite discrete lattices. We develop a heuristic theoretical explanation of the regions of stability and instability.
Husain-Kuchar model as a constrained BF theory
Montesinos, Merced
2008-01-01
We write the Husain-Kuchar model as a constrained BF theory by giving an action principle for it. The action principle turns out to be very close to Plebanski action for general relativity; the difference with respect to gravity lies in the fact that the condition on the Lagrange multipliers of Plebanski's formulation is not present anymore in the constrained BF action for the Husain-Kuchar model reported in this paper.
Structure and Asymptotic theory for Nonlinear Models with GARCH Errors
Chan, Felix; McAleer, Michael; Medeiros, Marcelo
2011-01-01
textabstractNonlinear time series models, especially those with regime-switching and conditionally heteroskedastic errors, have become increasingly popular in the economics and finance literature. However, much of the research has concentrated on the empirical applications of various models, with little theoretical or statistical analysis associated with the structure of the processes or the associated asymptotic theory. In this paper, we first derive necessary conditions for strict stationar...
Structure and Asymptotic theory for Nonlinear Models with GARCH Errors
Felix Chan; Michael McAleer; Medeiros, Marcelo C.
2011-01-01
Nonlinear time series models, especially those with regime-switching and conditionally heteroskedastic errors, have become increasingly popular in the economics and finance literature. However, much of the research has concentrated on the empirical applications of various models, with little theoretical or statistical analysis associated with the structure of the processes or the associated asymptotic theory. In this paper, we first derive necessary conditions for strict stationarity and ergo...
THE NEW CLASSICAL THEORY AND THE REAL BUSINESS CYCLE MODEL
Oana Simona HUDEA (CARAMAN); Sorin George TOMA; Marin BURCEA
2014-01-01
The present paper aims at describing some key elements of the new classical theory-related model, namely the Real Business Cycle, mainly describing the economy from the perspective of a perfectly competitive market, characterised by price, wage and interest rate flexibility. The rendered impulse-response functions, that help us in revealing the capacity of the model variables to return to their steady state under the impact of a structural shock, be it technology or monetary policy oriented, ...
Cluster variational theory of spin ((3)/(2)) Ising models
Tucker, J W
2000-01-01
A cluster variational method for spin ((3)/(2)) Ising models on regular lattices is presented that leads to results that are exact for Bethe lattices of the same coordination number. The method is applied to both the Blume-Capel (BC) and the isotropic Blume-Emery-Griffiths model (BEG). In particular, the first-order phase line separating the two low-temperature ferromagnetic phases in the BC model, and the ferrimagnetic phase boundary in the BEG model are studied. Results are compared with those of other theories whose qualitative predictions have been in conflict.
Cluster variational theory of spin ((3)/(2)) Ising models
International Nuclear Information System (INIS)
A cluster variational method for spin ((3)/(2)) Ising models on regular lattices is presented that leads to results that are exact for Bethe lattices of the same coordination number. The method is applied to both the Blume-Capel (BC) and the isotropic Blume-Emery-Griffiths model (BEG). In particular, the first-order phase line separating the two low-temperature ferromagnetic phases in the BC model, and the ferrimagnetic phase boundary in the BEG model are studied. Results are compared with those of other theories whose qualitative predictions have been in conflict
DEFF Research Database (Denmark)
Rohde, Carsten
Budgets and budget control has been known since the early 19th century1. However the use of budget control was until the beginning of the 1920ies in US primarily related to governmental units and states and to a minor extent to business units in practice. At that time James McKinsey describes...
Sarndal, Anne G.
1979-01-01
Traditional budgeting starts with the previous year's budget, but zero base budgeting demands that each activity be justified from "scratch," and establishes a number of increments for each unit, in order of priority. Given the set of increments and the money available, management can determine what activities to finance. (Author)
Hartman, William T.
This book is devoted exclusively to the budgeting process in school districts, unlike the more common generic budgeting texts. As such, it allows an in-depth treatment of both conceptual and practical aspects of budgeting in a single volume. By default, school business officials have had to rely on the state education accounting manual as their…
Jón R. Blöndal; Daniel Bergvall
2007-01-01
This article discusses budgeting institutions, processes and practices at the federal level in Austria. Separate sections are devoted to the budget formulation process, the role of parliament, and various aspects of budget implementation and government management issues. Each section highlights the government’s reform agenda and current practices, and analyses the two vis-à-vis OECD best practices.
Performance Budgeting in Korea
John M. Kim; Nowook Park
2007-01-01
Korea is in the initial stages of implementing performance-based budgeting. The system was introduced as part of a comprehensive fiscal reform package in the late 1990s. This article discusses the background, framework and implementation of performance budgeting and its impact in the budget process.
Warner, Alice Sizer
1993-01-01
Discusses the advantages and disadvantages of six types of budgets commonly used by many different kinds of libraries. The budget types covered are lump-sum; formula; line or line-item; program; performance or function; and zero-based. Accompanying figures demonstrate the differences between four of the budget types. (three references) (KRN)
Theory and application of experimental model analysis in earthquake engineering
Moncarz, P. D.
The feasibility and limitations of small-scale model studies in earthquake engineering research and practice is considered with emphasis on dynamic modeling theory, a study of the mechanical properties of model materials, the development of suitable model construction techniques and an evaluation of the accuracy of prototype response prediction through model case studies on components and simple steel and reinforced concrete structures. It is demonstrated that model analysis can be used in many cases to obtain quantitative information on the seismic behavior of complex structures which cannot be analyzed confidently by conventional techniques. Methodologies for model testing and response evaluation are developed in the project and applications of model analysis in seismic response studies on various types of civil engineering structures (buildings, bridges, dams, etc.) are evaluated.
Modeling DNA loops using the theory of elasticity
Balaeff, A; Schulten, K; Balaeff, Alexander; Schulten, Klaus
2003-01-01
A versatile approach to modeling the conformations and energetics of DNA loops is presented. The model is based on the classical theory of elasticity, modified to describe the intrinsic twist and curvature of DNA, the DNA bending anisotropy, and electrostatic properties. All the model parameters are considered to be functions of the loop arclength, so that the DNA sequence-specific properties can be modeled. The model is applied to the test case study of a DNA loop clamped by the lac repressor protein. Several topologically different conformations are predicted for various lengths of the loop. The dependence of the predicted conformations on the parameters of the problem is systematically investigated. Extensions of the presented model and the scope of the model's applicability, including multi-scale simulations of protein-DNA complexes and building all-atom structures on the basis of the model, are discussed.
Misumi, K.; Lindsay, K.; Moore, J. K.; Doney, S. C.; Bryan, F. O.; Tsumune, D.; Yoshida, Y.
2014-01-01
We investigated the simulated iron budget in ocean surface waters in the 1990s and 2090s using the Community Earth System Model version 1 and the Representative Concentration Pathway 8.5 future CO2 emission scenario. We assumed that exogenous iron inputs did not change during the whole simulation period; thus, iron budget changes were attributed solely to changes in ocean circulation and mixing in response to projected global warming, and the resulting impacts on marine biogeochemistry. The model simulated the major features of ocean circulation and dissolved iron distribution for the present climate. Detailed iron budget analysis revealed that roughly 70% of the iron supplied to surface waters in high-nutrient, low-chlorophyll (HNLC) regions is contributed by ocean circulation and mixing processes, but the dominant supply mechanism differed by region: upwelling in the eastern equatorial Pacific and vertical mixing in the Southern Ocean. For the 2090s, our model projected an increased iron supply to HNLC waters, even though enhanced stratification was predicted to reduce iron entrainment from deeper waters. This unexpected result is attributed largely to changes in gyre-scale circulations that intensified the advective supply of iron to HNLC waters. The simulated primary and export production in the 2090s decreased globally by 6 and 13%, respectively, whereas in the HNLC regions, they increased by 11 and 6%, respectively. Roughly half of the elevated production could be attributed to the intensified iron supply. The projected ocean circulation and mixing changes are consistent with recent observations of responses to the warming climate and with other Coupled Model Intercomparison Project model projections. We conclude that future ocean circulation has the potential to increase iron supply to HNLC waters and will potentially buffer future reductions in ocean productivity.
Mahlich J; Nishi M; Saito Y.
2015-01-01
Jörg Mahlich,1,2 Masamichi Nishi,3 Yoshimichi Saito11Health Economics, Janssen Pharmaceutical KK, Tokyo, Japan; 2Düsseldorf Institute for Competition Economics, University of Düsseldorf, Düsseldorf, Germany; 3Pricing, Janssen Pharmaceutical KK, Tokyo, JapanBackground: The cost of schizophrenia in Japan is high and new long-acting injectable (LAI) antipsychotics might be able to reduce costs by causing a reduction of hospital stays. We aim to estimate budget effects of the ...
Mahlich, JÃ¶rg
2015-01-01
Jörg Mahlich,1,2 Masamichi Nishi,3 Yoshimichi Saito11Health Economics, Janssen Pharmaceutical KK, Tokyo, Japan; 2Düsseldorf Institute for Competition Economics, University of Düsseldorf, Düsseldorf, Germany; 3Pricing, Janssen Pharmaceutical KK, Tokyo, JapanBackground: The cost of schizophrenia in Japan is high and new long-acting injectable (LAI) antipsychotics might be able to reduce costs by causing a reduction of hospital stays. We aim to estimate budget...
Hirvonen, Åsa; Kossak, Roman; Villaveces, Andrés
2015-01-01
In recent years, mathematical logic has developed in many directions, the initial unity of its subject matter giving way to a myriad of seemingly unrelated areas. The articles collected here, which range from historical scholarship to recent research in geometric model theory, squarely address this development. These articles also connect to the diverse work of Väänänen, whose ecumenical approach to logic reflects the unity of the discipline.
The Concept of Budgeting in the non stable market environment
Jana Fibírová
2013-01-01
The aim of the Beyond Budgeting concept is to recognize mutual interconnections and relations of budgeting process as a whole, to design the management model of a company operating in turbulent market environment and to specify the principles, rules and tools of the model. The Beyond Budgeting is the management model which emphasizes strategic goal setting, rolling budgeting and performance management based on both financial and nonfinancial indicators and on its relative analysis and evaluat...
A game theory model of urban public traffic networks
Su, B. B.; Chang, H.; Chen, Y.-Z.; He, D. R.
2007-06-01
We have studied urban public traffic networks from the viewpoint of complex networks and game theory. Firstly, we have empirically investigated an urban public traffic network in Beijing in 2003, and obtained its statistical properties. Then a simplified game theory model is proposed for simulating the evolution of the traffic network. The basic idea is that three network manipulators, passengers, an urban public traffic company, and a government traffic management agency, play games in a network evolution process. Each manipulator tries to build the traffic lines to magnify its “benefit”. Simulation results show a good qualitative agreement with the empirical results.
Yang-Mills Theories as Deformations of Massive Integrable Models
Cubero, Axel Cortés
2014-01-01
Yang Mills theory in 2+1 dimensions can be expressed as an array of coupled (1+1)-dimensional principal chiral sigma models. The $SU(N)\\times SU(N)$ principal chiral sigma model in 1+1 dimensions is integrable, asymptotically free and has massive excitations. We calculate all the form factors and two-point correlation functions of the Noether current and energy-momentum tensor, in 't~Hooft's large-$N$ limit (some form factors can be found even at finite $N$). We use these new form factors to calculate physical quantities in (2+1)-dimensional Yang-Mills theory, generalizing previous $SU(2)$ results from Orland to $SU(N)$. The anisotropic gauge theory is related to standard isotropic one by a Wilsonian renormalization group with ellipsoidal cutoffs in momentum. We calculate quantum corrections to the effective action of QED and QCD, as the theory flows from isotropic to anisotropic. The exact principal chiral sigma model S-matrix is also used to examine the spectrum of (1+1)-dimensional massive Yang Mills theor...
Directory of Open Access Journals (Sweden)
C. H. Song
2010-06-01
Full Text Available Elevated levels of formaldehyde (HCHO along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment, and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume photochemical/dynamic model: (1 primary HCHO emission from ships; (2 secondary HCHO production via the atmospheric oxidation of Non-methane volatile organic compounds (NMVOCs emitted from ships; and (3 atmospheric oxidation of CH_{4} within the ship plumes. From multiple ship-plume model simulations, CH_{4} oxidation by elevated levels of in-plume OH radicals was found to be the main factor responsible for the elevated levels of HCHO in the ship corridors. More than ~91% of the HCHO for the base ship plume case (ITCT 2K2 ship-plume case is produced by this atmospheric chemical process, except in the areas close to the ship stacks where the main source of the elevated HCHO levels would be primary HCHO from the ships (due to the deactivation of CH_{4} oxidation from the depletion of in-plume OH radicals. Because of active CH_{4} oxidation (chemical destruction of CH_{4} by OH radicals, the instantaneous chemical lifetime of CH_{4} (τ CH_{4} decreased to ~0.45 yr inside the ship plume, which is in contrast to τ CH_{4} of ~1.1 yr in the background (up to ~41% decrease. A variety of likely ship-plume situations at three locations at different latitudes within the global ship corridors was also studied to determine the extent of the enhancements in the HCHOlevels in the marine boundary layer (MBL influenced by ship emissions. It was found that the ship-plume HCHO levels could be 20.5–434.9 pptv
Lattice methods in gauge theories beyond the standard model
International Nuclear Information System (INIS)
We report extended simulation results and their new analysis in two important gauge theories with twelve fermion flavors in the fundamental SU(3) color representation and two fermions in the sextet representation. We probe the Nf=12 model with respect to the conformal window using mass deformed finite size scaling (FSS) theory driven by the fermion mass anomalous dimension. Our results at fixed gauge coupling show problems with the conformal scenario of the Nf=12 model. In the sextet model with two flavors, under the conformal hypothesis, we determine large values for the anomalous fermion mass dimension with γ ≥ 1. Since our sextet analysis favors the chiral symmetry breaking hypothesis without conformality, the large exponent γ could play an important role in understanding the composite Higgs mechanism. The new results discussed here include our extended data sets and exceed what was presented at the conference. (author)
Modeling Polymorphic Molecular Crystals with Electronic Structure Theory.
Beran, Gregory J O
2016-05-11
Interest in molecular crystals has grown thanks to their relevance to pharmaceuticals, organic semiconductor materials, foods, and many other applications. Electronic structure methods have become an increasingly important tool for modeling molecular crystals and polymorphism. This article reviews electronic structure techniques used to model molecular crystals, including periodic density functional theory, periodic second-order Møller-Plesset perturbation theory, fragment-based electronic structure methods, and diffusion Monte Carlo. It also discusses the use of these models for predicting a variety of crystal properties that are relevant to the study of polymorphism, including lattice energies, structures, crystal structure prediction, polymorphism, phase diagrams, vibrational spectroscopies, and nuclear magnetic resonance spectroscopy. Finally, tools for analyzing crystal structures and intermolecular interactions are briefly discussed. PMID:27008426
Models for probability and statistical inference theory and applications
Stapleton, James H
2007-01-01
This concise, yet thorough, book is enhanced with simulations and graphs to build the intuition of readersModels for Probability and Statistical Inference was written over a five-year period and serves as a comprehensive treatment of the fundamentals of probability and statistical inference. With detailed theoretical coverage found throughout the book, readers acquire the fundamentals needed to advance to more specialized topics, such as sampling, linear models, design of experiments, statistical computing, survival analysis, and bootstrapping.Ideal as a textbook for a two-semester sequence on probability and statistical inference, early chapters provide coverage on probability and include discussions of: discrete models and random variables; discrete distributions including binomial, hypergeometric, geometric, and Poisson; continuous, normal, gamma, and conditional distributions; and limit theory. Since limit theory is usually the most difficult topic for readers to master, the author thoroughly discusses mo...
Integration of mathematical models in marketing theory and practice
Directory of Open Access Journals (Sweden)
Ioana Olariu
2012-12-01
Full Text Available This article is a theoretical approach on the main mathematical models used in marketing practice. Application of general systems theory in marketing involves setting behavior assumptions as models of various processes.These models have, on the one hand, to describe the interactions between ambiance and system factors, and, secondly, to identify causal dependencies existing in these interactions.Since the models are the means by which possible solutions can be drawn consequences, they occupy a central role in the design of a system to solve a marketing problem.The model is a simplified representation which is described and conceptualized phenomena and real life situations.The purpose of a model is to facilitate understanding of the real system. Models are widely used in marketing, it takes different forms that facilitate understanding the realities of marketing.
Matrix models and stochastic growth in Donaldson-Thomas theory
Energy Technology Data Exchange (ETDEWEB)
Szabo, Richard J. [Department of Mathematics, Heriot-Watt University, Colin Maclaurin Building, Riccarton, Edinburgh EH14 4AS, United Kingdom and Maxwell Institute for Mathematical Sciences, Edinburgh (United Kingdom); Tierz, Miguel [Grupo de Fisica Matematica, Complexo Interdisciplinar da Universidade de Lisboa, Av. Prof. Gama Pinto, 2, PT-1649-003 Lisboa (Portugal); Departamento de Analisis Matematico, Facultad de Ciencias Matematicas, Universidad Complutense de Madrid, Plaza de Ciencias 3, 28040 Madrid (Spain)
2012-10-15
We show that the partition functions which enumerate Donaldson-Thomas invariants of local toric Calabi-Yau threefolds without compact divisors can be expressed in terms of specializations of the Schur measure. We also discuss the relevance of the Hall-Littlewood and Jack measures in the context of BPS state counting and study the partition functions at arbitrary points of the Kaehler moduli space. This rewriting in terms of symmetric functions leads to a unitary one-matrix model representation for Donaldson-Thomas theory. We describe explicitly how this result is related to the unitary matrix model description of Chern-Simons gauge theory. This representation is used to show that the generating functions for Donaldson-Thomas invariants are related to tau-functions of the integrable Toda and Toeplitz lattice hierarchies. The matrix model also leads to an interpretation of Donaldson-Thomas theory in terms of non-intersecting paths in the lock-step model of vicious walkers. We further show that these generating functions can be interpreted as normalization constants of a corner growth/last-passage stochastic model.
Forewarning model for water pollution risk based on Bayes theory.
Zhao, Jun; Jin, Juliang; Guo, Qizhong; Chen, Yaqian; Lu, Mengxiong; Tinoco, Luis
2014-02-01
In order to reduce the losses by water pollution, forewarning model for water pollution risk based on Bayes theory was studied. This model is built upon risk indexes in complex systems, proceeding from the whole structure and its components. In this study, the principal components analysis is used to screen out index systems. Hydrological model is employed to simulate index value according to the prediction principle. Bayes theory is adopted to obtain posterior distribution by prior distribution with sample information which can make samples' features preferably reflect and represent the totals to some extent. Forewarning level is judged on the maximum probability rule, and then local conditions for proposing management strategies that will have the effect of transforming heavy warnings to a lesser degree. This study takes Taihu Basin as an example. After forewarning model application and vertification for water pollution risk from 2000 to 2009 between the actual and simulated data, forewarning level in 2010 is given as a severe warning, which is well coincide with logistic curve. It is shown that the model is rigorous in theory with flexible method, reasonable in result with simple structure, and it has strong logic superiority and regional adaptability, providing a new way for warning water pollution risk. PMID:24194413
Capital Budgeting in Arbitrage-Free Markets
Laitenberger, Jörg; Löffler, Andreas
2002-01-01
In capital budgeting problems future cash flows are discounted using the expected one period returns of the investment. In this paper we establish a theory that relates this approach to the assumption that markets are free of arbitrage. Our goal is to uncover implicit assumptions on the set of cash flow distributions that are suitable for the capital budgeting method. As results we obtain that the set of admissible cash flow distributions is large in the sense that no particular structure of ...
Richon, Camille; Dutay, Jean-Claude; Dulac, François; Desboeufs, Karine; Nabat, Pierre; Guieu, Cécile; Aumont, Olivier; Palmieri, Julien
2016-04-01
Atmospheric deposition is at present not included in regional oceanic biogeochemical models of the Mediterranean Sea, whereas, along with river inputs, it represents a significant source of nutrients at the basin scale, especially through intense desert dust events. Moreover, observations (e.g. DUNE campaign, Guieu et al. 2010) show that these events significantly modify the biogeochemistry of the oligotrophic Mediterranean Sea. We use a high resolution (1/12°) version of the 3D coupled model NEMOMED12/PISCES to investigate the effects of high resolution atmospheric dust deposition forcings on the biogeochemistry of the Mediterranean basin. The biogeochemical model PISCES represents the evolution of 24 prognostic tracers including five nutrients (nitrate, ammonium, phosphate, silicate and iron) and two phytoplankton and zooplanktons groups (Palmiéri, 2014). From decadal simulations (1982-2012) we evaluate the influence of natural dust and anthropogenic nitrogen deposition on the budget of nutrients in the basin and its impact on the biogeochemistry (primary production, plankton distributions...). Our results show that natural dust deposition accounts for 15% of global PO4 budget and that it influences primarily the southern part of the basin. Anthropogenic nitrogen accounts for 50% of bioavailable N supply for the northern part. Deposition events significantly affect biological production; primary productivity enhancement can be as high as 30% in the areas of high deposition, especially during the stratified period. Further developments of the model will include 0D and 1D modeling of bacteria in the frame of the PEACETIME project.
Thomas, Yoann; Mazurié, Joseph; Alunno-Bruscia, Marianne; Bacher, Cédric; Bouget, Jean-François; Gohin, Francis; Pouvreau, Stéphane; Struski, Caroline
2011-11-01
In order to assess the potential of various marine ecosystems for shellfish aquaculture and to evaluate their carrying capacities, there is a need to clarify the response of exploited species to environmental variations using robust ecophysiological models and available environmental data. For a large range of applications and comparison purposes, a non-specific approach based on 'generic' individual growth models offers many advantages. In this context, we simulated the response of blue mussel ( Mytilus edulis L.) to the spatio-temporal fluctuations of the environment in Mont Saint-Michel Bay (North Brittany) by forcing a generic growth model based on Dynamic Energy Budgets with satellite-derived environmental data (i.e. temperature and food). After a calibration step based on data from mussel growth surveys, the model was applied over nine years on a large area covering the entire bay. These simulations provide an evaluation of the spatio-temporal variability in mussel growth and also show the ability of the DEB model to integrate satellite-derived data and to predict spatial and temporal growth variability of mussels. Observed seasonal, inter-annual and spatial growth variations are well simulated. The large-scale application highlights the strong link between food and mussel growth. The methodology described in this study may be considered as a suitable approach to account for environmental effects (food and temperature variations) on physiological responses (growth and reproduction) of filter feeders in varying environments. Such physiological responses may then be useful for evaluating the suitability of coastal ecosystems for shellfish aquaculture.
Approximate models for broken clouds in stochastic radiative transfer theory
International Nuclear Information System (INIS)
This paper presents approximate models in stochastic radiative transfer theory. The independent column approximation and its modified version with a solar source computed in a full three-dimensional atmosphere are formulated in a stochastic framework and for arbitrary cloud statistics. The nth-order stochastic models describing the independent column approximations are equivalent to the nth-order stochastic models for the original radiance fields in which the gradient vectors are neglected. Fast approximate models are further derived on the basis of zeroth-order stochastic models and the independent column approximation. The so-called “internal mixing” models assume a combination of the optical properties of the cloud and the clear sky, while the “external mixing” models assume a combination of the radiances corresponding to completely overcast and clear skies. A consistent treatment of internal and external mixing models is provided, and a new parameterization of the closure coefficient in the effective thickness approximation is given. An efficient computation of the closure coefficient for internal mixing models, using a previously derived vector stochastic model as a reference, is also presented. Equipped with appropriate look-up tables for the closure coefficient, these models can easily be integrated into operational trace gas retrieval systems that exploit absorption features in the near-IR solar spectrum. - Highlights: • Independent column approximation in a stochastic setting. • Fast internal and external mixing models for total and diffuse radiances. • Efficient optimization of internal mixing models to match reference models
Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)
2001-01-01
The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is
Husain-Kuchar model as a constrained BF theory
Montesinos, Merced; Velazquez, Mercedes
2008-01-01
The Husain-Kuchar theory is a four-dimensional background-independent model that has long been viewed as a useful model for addressing several conceptual and technical problems appearing in the quantization of general relativity mainly in the loop quantum gravity approach. The model was defined at Lagrangian level in terms of a su(2)-valued connection one-form $A$ coupled through its curvature to a su(2)-valued one-form field $e$. We address here the problem of writing a Lagrangian formulatio...
Nonrelativistic factorizable scattering theory of multicomponent Calogero-Sutherland model
Ahn, C; Nam, S; Ahn, Changrim; Lee, Kong Ju Bock; Nam, Soonkeon
1995-01-01
We relate two integrable models in (1+1) dimensions, namely, multicomponent Calogero-Sutherland model with particles and antiparticles interacting via the hyperbolic potential and the nonrelativistic factorizable S-matrix theory with SU(N)-invariance. We find complete solutions of the Yang-Baxter equations without implementing the crossing symmetry, and one of them is identified with the scattering amplitudes derived from the Schr\\"{o}dinger equation of the Calogero-Sutherland model. This particular solution is of interest in that it cannot be obtained as a nonrelativistic limit of any known relativistic solutions of the SU(N)-invariant Yang-Baxter equations.
Energy Technology Data Exchange (ETDEWEB)
Dubois, C.; Somot, S.; Deque, M.; Sevault, F. [CNRM-GAME, Meteo-France, CNRS, Toulouse (France); Calmanti, S.; Carillo, A.; Dell' Aquilla, A.; Sannino, G. [ENEA, Rome (Italy); Elizalde, A.; Jacob, D. [Max Planck Institute for Meteorology, Hamburg (Germany); Gualdi, S.; Oddo, P.; Scoccimarro, E. [INGV, Bologna (Italy); L' Heveder, B.; Li, L. [Laboratoire de Meteorologie Dynamique, Paris (France)
2012-10-15
Within the CIRCE project ''Climate change and Impact Research: the Mediterranean Environment'', an ensemble of high resolution coupled atmosphere-ocean regional climate models (AORCMs) are used to simulate the Mediterranean climate for the period 1950-2050. For the first time, realistic net surface air-sea fluxes are obtained. The sea surface temperature (SST) variability is consistent with the atmospheric forcing above it and oceanic constraints. The surface fluxes respond to external forcing under a warming climate and show an equivalent trend in all models. This study focuses on the present day and on the evolution of the heat and water budget over the Mediterranean Sea under the SRES-A1B scenario. On the contrary to previous studies, the net total heat budget is negative over the present period in all AORCMs and satisfies the heat closure budget controlled by a net positive heat gain at the strait of Gibraltar in the present climate. Under climate change scenario, some models predict a warming of the Mediterranean Sea from the ocean surface (positive net heat flux) in addition to the positive flux at the strait of Gibraltar for the 2021-2050 period. The shortwave and latent flux are increasing and the longwave and sensible fluxes are decreasing compared to the 1961-1990 period due to a reduction of the cloud cover and an increase in greenhouse gases (GHGs) and SSTs over the 2021-2050 period. The AORCMs provide a good estimates of the water budget with a drying of the region during the twenty-first century. For the ensemble mean, he decrease in precipitation and runoff is about 10 and 15% respectively and the increase in evaporation is much weaker, about 2% compared to the 1961-1990 period which confirm results obtained in recent studies. Despite a clear consistency in the trends and results between the models, this study also underlines important differences in the model set-ups, methodology and choices of some physical parameters inducing
Little string theory from a double-scaled matrix model
International Nuclear Information System (INIS)
Following Lin and Maldacena, we find exact supergravity solutions dual to a class of vacua of the plane wave matrix model by solving an electrostatics problem. These are asymptotically near-horizon D0-brane solutions with a throat associated with NS5-brane degrees of freedom. We determine the precise limit required to decouple the asymptotic geometry and leave an infinite throat solution found earlier by Lin and Maldacena, dual to Little String Theory on S5. By matching parameters with the gauge theory, we find that this corresponds to a double scaling limit of the plane wave matrix model in which N→∞ and the 't Hooft coupling λ scales as ln4(N), which we speculate allows all terms in the genus expansion to contribute even at infinite N. Thus, the double-scaled matrix quantum mechanics gives a Lagrangian description of Little String Theory on S5, or equivalently a ten-dimensional string theory with linear dilaton background
Zero Based Budgeting for Voc Ed
Chuang, Ying C.
1977-01-01
To help vocational education budget planners take a good look each year at where they are going, what they are trying to accomplish, and where to put their money, this article describes the 12 steps in a model commonly used for zero based budgeting. (Author/HD)
Circuit theory and model-based inference for landscape connectivity
Hanks, Ephraim M.; Hooten, Mevin B.
2013-01-01
Circuit theory has seen extensive recent use in the field of ecology, where it is often applied to study functional connectivity. The landscape is typically represented by a network of nodes and resistors, with the resistance between nodes a function of landscape characteristics. The effective distance between two locations on a landscape is represented by the resistance distance between the nodes in the network. Circuit theory has been applied to many other scientific fields for exploratory analyses, but parametric models for circuits are not common in the scientific literature. To model circuits explicitly, we demonstrate a link between Gaussian Markov random fields and contemporary circuit theory using a covariance structure that induces the necessary resistance distance. This provides a parametric model for second-order observations from such a system. In the landscape ecology setting, the proposed model provides a simple framework where inference can be obtained for effects that landscape features have on functional connectivity. We illustrate the approach through a landscape genetics study linking gene flow in alpine chamois (Rupicapra rupicapra) to the underlying landscape.
Budget support, conditionality and poverty.
Mosley, P.; Suleiman, A.
2005-01-01
This paper examines the effectiveness of budget support aid as an anti-poverty instrument. We argue that a major determinant of this effectiveness is the element of trust – or `social capital´, as it may be seen – which builds up between representatives of the donor and recipient. Thus we model the conditionality processes attending budget support aid, not purely in the conventional way as a non-cooperative two-person game, but rather as a non-cooperative game which may mutate into a collabor...
Kubelka-Munk theory for efficient spectral printer modeling
Abebe, Mekides; Gerhardt, Jérémie; Hardeberg, Jon Y.
2011-01-01
In the context of spectral color image reproduction by multi-channel inkjet printing a key challenge is to accurately model the colorimetric and spectral behavior of the printer. A common approach for this modeling is to assume that the resulting spectral reflectance of a certain ink combination can be modeled as a convex combination of the so-called Neugebauer Primaries (NPs); this is known as the Neugebauer Model. Several extensions of this model exist, such as the Yule-Nielsen Modified Spectral Neugebauer (YNSN) model. However, as the number of primaries increases, the number of NPs increases exponentially; this poses a practical problem for multi-channel spectral reproduction. In this work, the well known Kubelka-Munk theory is used to estimate the spectral reflectances of the Neugebauer Primaries instead of printing and measuring them, and subsequently we use these estimated NPs as the basis of our printer modeling. We have evaluated this approach experimentally on several different paper types and on the HP Deskjet 1220C CMYK inkjet printer and the Xerox Phaser 7760 CMYK laser printer, using both the conventional spectral Neugebauer model and the YNSN model. We have also investigated a hybrid model with mixed NPs, half measured and half estimated. Using this approach we find that we achieve not only cheap and less time consuming model establishment, but also, somewhat unexpectedly, improved model precision over the models using the real measurements of the NPs.
MJO theory in relation to comprehensive models and observations
Sobel, A. H.
2015-12-01
I will describe some recent thinking on the fundamental physics of the MJO. Much recent work portrays the MJO as some form of "moisture mode" - meaning that the prognostic variable of greatest importance is moisture or a conserved variable closely related to it, such as moist static energy or moist entropy - and I will argue for this line of thinking, presenting evidence in favor of it, as well as unresolved problems. I will focus on the relationship between theory, numerical modeling at a range of scales, and observations. We have reached a new phase in the study of the MJO: the phenomenon has been described in great detail from an observational point of view, and perhaps even more importantly, the best numerical models can now simulate it well. I will argue that in this situation, theory is most compelling when its core assumptions can be specifically defended using both observations and comprehensive numerical models. I will make connections between the moisture mode view and results from several different types of numerical models: numerical weather prediction models, global climate models, and small-domain high-resolution cloud resolving models.
Multi-Year Budget Forecasting.
Mercure, Donald C.
1995-01-01
The multiyear forecasting model is a device to focus on the input side of the educational process--staff, materials, facilities, and services. An annual budget can be developed from the multiyear work plan, with specific policy statements being made to achieve the outcomes initially determined to be the goals and objectives of the district. (MLF)
Oliveira, Arnaldo
2007-01-01
This paper examines rational and psychological decision-making models. Descriptive and normative methodologies such as attribution theory, schema theory, prospect theory, ambiguity model, game theory, and expected utility theory are discussed. The definition of culture is reviewed, and the relationship between culture and decision making is also highlighted as many organizations use a cultural-ethical decision-making model.
Supersymmetric Theory of Stochastic ABC Model: A Numerical Study
Ovchinnikov, Igor V; Ensslin, Torsten A; Wang, Kang L
2016-01-01
In this paper, we investigate numerically the stochastic ABC model, a toy model in the theory of astrophysical kinematic dynamos, within the recently proposed supersymmetric theory of stochastics (STS). STS characterises stochastic differential equations (SDEs) by the spectrum of the stochastic evolution operator (SEO) on elements of the exterior algebra or differentials forms over the system's phase space, X. STS can thereby classify SDEs as chaotic or non-chaotic by identifying the phenomenon of stochastic chaos with the spontaneously broken topological supersymmetry that all SDEs possess. We demonstrate the following three properties of the SEO, deduced previously analytically and from physical arguments: the SEO spectra for zeroth and top degree forms never break topological supersymmetry, all SDEs possesses pseudo-time-reversal symmetry, and each de Rahm cohomology class provides one supersymmetric eigenstate. Our results also suggests that the SEO spectra for forms of complementary degrees, i.e., k and ...
Conditioning in evidence theory from the perspective of multidimensional models
Czech Academy of Sciences Publication Activity Database
Vejnarová, Jiřina
Heidelberg: Springer, 2012 - (Greco, S.; Bouchon-Meunier, B.; Coletti, G.; Fedrizzi, M.; Matarazzo, B.; Yager, R.), s. 450-459. (Communications in Computer and Information Science. 299). ISBN 978-3-642-31717-0. ISSN 1865-0929. [14th International Conference on Information Processing and Management of Uncertainty in Knowledge -Based Systems, IPMU 2012. Catania (IT), 09.07.2012-13.07.2012] R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : evidence theory * conditioning * multidimensional models * conditional independence * conditional irrelevance Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2012/MTR/vejnarova-conditioning in evidence theory from the perspective of multidimensional models.pdf
Nonlinear structural mechanics theory, dynamical phenomena and modeling
Lacarbonara, Walter
2013-01-01
Nonlinear Structural Mechanics: Theory, Dynamical Phenomena and Modeling offers a concise, coherent presentation of the theoretical framework of nonlinear structural mechanics, computational methods, applications, parametric investigations of nonlinear phenomena and their mechanical interpretation towards design. The theoretical and computational tools that enable the formulation, solution, and interpretation of nonlinear structures are presented in a systematic fashion so as to gradually attain an increasing level of complexity of structural behaviors, under the prevailing assumptions on the geometry of deformation, the constitutive aspects and the loading scenarios. Readers will find a treatment of the foundations of nonlinear structural mechanics towards advanced reduced models, unified with modern computational tools in the framework of the prominent nonlinear structural dynamic phenomena while tackling both the mathematical and applied sciences. Nonlinear Structural Mechanics: Theory, Dynamical Phenomena...
Ranking streamflow model performance based on Information theory metrics
Martinez, Gonzalo; Pachepsky, Yakov; Pan, Feng; Wagener, Thorsten; Nicholson, Thomas
2016-04-01
The accuracy-based model performance metrics not necessarily reflect the qualitative correspondence between simulated and measured streamflow time series. The objective of this work was to use the information theory-based metrics to see whether they can be used as complementary tool for hydrologic model evaluation and selection. We simulated 10-year streamflow time series in five watersheds located in Texas, North Carolina, Mississippi, and West Virginia. Eight model of different complexity were applied. The information-theory based metrics were obtained after representing the time series as strings of symbols where different symbols corresponded to different quantiles of the probability distribution of streamflow. The symbol alphabet was used. Three metrics were computed for those strings - mean information gain that measures the randomness of the signal, effective measure complexity that characterizes predictability and fluctuation complexity that characterizes the presence of a pattern in the signal. The observed streamflow time series has smaller information content and larger complexity metrics than the precipitation time series. Watersheds served as information filters and and streamflow time series were less random and more complex than the ones of precipitation. This is reflected the fact that the watershed acts as the information filter in the hydrologic conversion process from precipitation to streamflow. The Nash Sutcliffe efficiency metric increased as the complexity of models increased, but in many cases several model had this efficiency values not statistically significant from each other. In such cases, ranking models by the closeness of the information-theory based parameters in simulated and measured streamflow time series can provide an additional criterion for the evaluation of hydrologic model performance.
Collective String Field Theory of Matrix Models in the BMN Limit
Koch, Robert de Mello; Jevicki, Antal; Rodrigues, Joao P.
2002-01-01
We develop a systematic procedure for deriving canonical string field theory from large N matrix models in the Berenstein-Maldacena-Nastase limit. The approach, based on collective field theory, provides a generalization of standard string field theory.
Quantile hydrologic model selection and model structure deficiency assessment: 1. Theory
Pande, S.
2013-01-01
A theory for quantile based hydrologic model selection and model structure deficiency assessment is presented. The paper demonstrates that the degree to which a model selection problem is constrained by the model structure (measured by the Lagrange multipliers of the constraints) quantifies structur
Sotnikova, A
2015-01-01
Article is devoted to a problem of effective distribution of the general budget of a portfolio between the IT projects which are its part taking into ac-count their priority. The designated problem is actual in view of low results of activity of the consulting companies in the sphere of information technologies. For determination of priority of IT projects the method of analytical networks developed by T. Saati is used. For the purpose of application of this method the system of criteria (ind...
Holographic Dark Energy Model and Scalar-Tensor Theories
Bisabr, Yousef
2008-01-01
We study the holographic dark energy model in a generalized scalar tensor theory. In a universe filled with cold dark matter and dark energy, the effect of potential of the scalar field is investigated in the equation of state parameter. We show that for a various types of potentials, the equation of state parameter is negative and transition from deceleration to acceleration expansion of the universe is possible.
Properties of lattice gauge theory models at low temperatures
International Nuclear Information System (INIS)
The Z(N) theory of quark confinement is discussed and how fluctuations of Z(N) gauge fields may continue to be important in the continuum limit. Existence of a model in four dimensions is pointed out in which confinement of (scalar) quarks can be shown to persist in the continuum limit. This article is based on the author's Cargese lectures 1979. Some of its results are published here for the first time. (orig.) 891 HSI/orig. 892 MKO
The dorsal stream in speech processing: Model and theory
Keidel JJ, Welbourne SR, Lambon Ralph MA.
2009-01-01
The ability to produce and comprehend spoken language requires an internal understanding of the complex relations between articulatory gestures and their acoustic consequences. Recent theories of speech processing propose a division between the ventral stream, which involves the mapping of acoustic signals to lexical/semantic representations, and the dorsal stream, which mediates the mapping between incoming auditory signals and articulatory output. We present a connectionist model of the dor...
On Theories and Models in Fuzzy Predicate Logics
Czech Academy of Sciences Publication Activity Database
Hájek, Petr; Cintula, Petr
Linz : Johannes Kepler Universität, 2005 - (Gottwald, S.; Hájek, P.; Höhle, U.; Klement, E.). s. 55-58 [Linz Seminar on Fuzzy Set Theory /26./. 01.02.2005-05.02.2005, Linz] R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : predicate fuzzy logic * conservative extensions * wittnessed models Subject RIV: BA - General Mathematics
Stochastic models in risk theory and management accounting
Brekelmans, R.C.M.
2000-01-01
This thesis deals with stochastic models in two fields: risk theory and management accounting. Firstly, two extensions of the classical risk process are analyzed. A method is developed that computes bounds of the probability of ruin for the classical risk rocess extended with a constant interest force. The other extension deals with the insurer's strategy with respect to maintaining the current premium system when the insurer does not have complete knowledge about the distribution of the risk...
Regression modeling methods, theory, and computation with SAS
Panik, Michael
2009-01-01
Regression Modeling: Methods, Theory, and Computation with SAS provides an introduction to a diverse assortment of regression techniques using SAS to solve a wide variety of regression problems. The author fully documents the SAS programs and thoroughly explains the output produced by the programs.The text presents the popular ordinary least squares (OLS) approach before introducing many alternative regression methods. It covers nonparametric regression, logistic regression (including Poisson regression), Bayesian regression, robust regression, fuzzy regression, random coefficients regression,
A model theory for tachyons in two dimensions
International Nuclear Information System (INIS)
The paper is divided in two parts, the first one having nothing to do with tachyons. In fact, to prepare the ground, in part one (sect. 2) it is shown that special relativity, even without tachyons, can be given a form such to describe both particles and antiparticles. The plan of part two is confined only to a model theory in two dimensions, for the reasons stated in sect. 3
Molecular Thermodynamic Modeling of Fluctuation Solution Theory Properties
DEFF Research Database (Denmark)
O’Connell, John P.; Abildskov, Jens
2013-01-01
Fluctuation Solution Theory provides relationships between integrals of the molecular pair total and direct correlation functions and the pressure derivative of solution density, partial molar volumes, and composition derivatives of activity coefficients. For dense fluids, the integrals follow a...... relatively simple corresponding-states behavior even for complex systems, show welldefined relationships for infinite dilution properties in complex and near-critical systems, allow estimation of mixed-solvent solubilities of gases and pharmaceuticals, and can be expressed by simple perturbation models for...
Dynamic density functional theory of solid tumor growth: Preliminary models
Arnaud Chauviere; Haralambos Hatzikirou; Kevrekidis, Ioannis G.; Lowengrub, John S.; Vittorio Cristini
2012-01-01
Cancer is a disease that can be seen as a complex system whose dynamics and growth result from nonlinear processes coupled across wide ranges of spatio-temporal scales. The current mathematical modeling literature addresses issues at various scales but the development of theoretical methodologies capable of bridging gaps across scales needs further study. We present a new theoretical framework based on Dynamic Density Functional Theory (DDFT) extended, for the first time, to the dynamics of l...
Stability Analysis for Car Following Model Based on Control Theory
International Nuclear Information System (INIS)
Stability analysis is one of the key issues in car-following theory. The stability analysis with Lyapunov function for the two velocity difference car-following model (for short, TVDM) is conducted and the control method to suppress traffic congestion is introduced. Numerical simulations are given and results are consistent with the theoretical analysis. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
SIMP model at NNLO in chiral perturbation theory
DEFF Research Database (Denmark)
Hansen, Martin Rasmus Lundquist; Langaeble, K.; Sannino, F.
2015-01-01
We investigate the phenomenological viability of a recently proposed class of composite dark matter models where the relic density is determined by 3 to 2 number-changing processes in the dark sector. Here the pions of the strongly interacting field theory constitute the dark matter particles. By...... phenomenological constraints challenging the viability of the simplest realisation of the strongly interacting massive particle (SIMP) paradigm....