An integrated simulation model to evaluate national policies for the abatement of agricultural nutrients in the Baltic Sea

This study introduces a prototype model for evaluating policies to abate agricultural nutrients in the Baltic Sea from a Finnish national point of view. The stochastic simulation model integrates nutrient dynamics of nitrogen and phosphorus in the sea basins adjoining the Finnish coast, nutrient loads from land and other sources, benefits from nutrient abatement (in the form of recreation and other ecosystem services) and the costs of agricultural abatement activities. The aim of this study is to present the overall structure of the model and to demonstrate its potential using preliminary parameters

An integrated simulation model for site layout planning of tunnelling projects

Overlooking site layout in the planning phase of construction projects leads to loss of productivity and incurs extra costs. In tunneling projects, site layout has a significant impact on material flow and tunneling operations, particularly on congested sites. In addition, construction planning decisions can influence the efficiency of the layout. This paper proposes simulation as a decision making tool to model tunnel construction operations and site layout, and capture their mutual influences. To facilitate building the simulation model, even for users with limited simulation knowledge, a special purpose simulation (SPS) tool was customized and developed. This simulation tool provides an integrated environment to model the parameters of different disciplines including site layout, material procurement, tunnel operations and logistics. The developed tool is of great assistance for the planners to make decisions simultaneously on site layout and other construction planning parameters, and find the most cost-efficient plan

An integrated simulation model to evaluate national policies for the abatement of agricultural nutrients in the Baltic Sea

This study introduces a prototype model for evaluating policies to abate agricultural nutrients in the Baltic Sea from a Finnish national point of view. The stochastic simulation model integrates nutrient dynamics of nitrogen and phosphorus in the sea basins adjoining the Finnish coast, nutrient loads from land and other sources, benefits from nutrient abatement (in the form of recreation and other ecosystem services) and the costs of agricultural abatement activities. The aim of this study is to present the overall structure of the model and to demonstrate its potential using preliminary parameters. The model is made flexible for further improvements in all of its ecological and economic components. Results of a sensitivity analysis suggest that investments in reducing the nutrient runoff from arable land in Finland would become profitable only if Finland’s neighbors in the northern Baltic committed themselves to similar reductions. Environmental investments for improving water quality yield the highest returns for the Bothnian Bay and the Gulf of Finland, and smaller returns for the Bothnian Sea. In the Bothnian Bay, the abatement activities become profitable because the riverine loads from Finland represent a high proportion of the total nutrient loads. In the Gulf of Finland, this proportion is low, but the size of the coastal population benefiting from improved water quality is high.ecosystem services, nutrient abatement, Monte Carlo simulation, recreation, valuation, Environmental Economics and Policy, Research Methods/ Statistical Methods,

The market for cocoa powder

The paper analyses the forces that shape demand and supply processes in the market for cocoa powder. A brief statistical summary is given of the main trends in international demand and production, and the spatial shifts in cocoa processing. Ample attention is given to the role of technology substitution and price factors in production decisions. The paper separately analyses the role of price, income levels and government regulation in the demand for cocoa powder. In the final part of the paper, all preceding elements are brought together in an integrated simulation model of the cocoa processing industry, showing the interactions between the market for cocoa powder and other elements of the cocoa industry (cocoa, cocoa butter, cocoa liquor, chocolate). Empirical evidence is presented with regard to main parameters of the model.cocoa, cocoa powder, industry study, simulation model, intermediate products, government regulation

Using firm demographic microsimulation to evaluate land use and transport scenario evaluation - model calibration

Existing integrated land use transport interaction models simulate the level of employment in (aggregated) zones and lack the individual firm as a decision making unit. This research tries to improve the behavioural foundation of these models by applying a firm demographic modelling approach that first of all accounts for the individual firm as a decision making unit and secondly represents the urban system with high spatial detail. A firm demographic approach models transitions in the state of individual firms by simulating transitions and events such as the relocation decision, growth or shrinkage of firms or the death of a firm. Important advantage of such a decomposed approach is that it offers the opportunity to account for accessibility in each event in the desired way. The firm demographic model is linked to an urban transport model in order to obtain a dynamic simulation of mobility (and accessibility) developments. The paper describes the firm demographic model specifications as well as the interaction of the model with the urban transport model. The integrated simulation model can be used to analyse the effects of different spatial and transport planning scenarios on the location of economic activities and mobility.

The Development of an Integrated Simulation Model on Understandings on the Interaction between Electromagnetic Waves and Nanoparticles

To investigate the interaction between nanoparticles and electromagnetic waves, a numerical simulation model based on FEM was built in this thesis. Numerical simulation is an important auxiliary research method besides experiments. The optical properties of nanoparticles consist of scattering, absorption, and extinction, and in the case of nanoparticle suspension, the transmission is also involved. This thesis addressed two typical applications based on the established model, one was regarding the nanofluids for solar energy harvesting, and the other was regarding the optical properties of atmospheric soot. In the case of the nanofluids solar energy harvesting, the established model provided a convenient and rapid screening of potential nanoparticles and nanofluids candidates for solar energy harvesting. A core-shell structure nanoparticle, using Cu as the core material in a diameter of 90 nm coated with 5 nm thickness graphene, exhibited a better photothermal property under the solar radiation. In the second case regarding atmospheric soot, the established model provided an efficient method for understandings on the optical properties and warming effects of realistic soot particles. It was found that the sizes and material characteristics of soot, would greatly affect their scattering and absorption of light. Moreover, two submodels were introduced and integrated, which can better predict behaviors of real atmospheric soot involving their core-shell structures (moisture or organic condensates) and their fractal agglomerate structures. In conclusion, the established model helps to understand the interaction between nanoparticles and electromagnetic waves, which shows great potentials of wide applications

AN INTEGRATED SIMULATION MODEL FOR MANNING MAINTENANCE SHOPS

An effective maintenance system is essential for organizations in order to meet their set objectives. These objectives include meeting deadlines, minimal delays, minimal repair turntime, and effective utilization of maintenance resources. In this paper the elements of an integrated simulation model has been described. The integrated model consists of several modules. These are planning and scheduling, organization, supply, quality control and performance measures. The required data and software for such a model has been described. The model has been tested and applied at the mechanical section at King Fahd University of Petroleum and Minerals maintenance department to determine their manning level. The results showed that the manning level at the mechanical shop are far from the optimal level according to the criteria used. Also the results of this study can be used as an initial input to investigate the manning levels at the maintenance department

Hybrid Simulation between Molecular Dynamics and Binary Collision Approximation Codes for Hydrogen injection onto Carbon Materials

Molecular dynamics (MD) simulation with modified Brenner's reactive empirical bond order (REBO) potential is a powerful tool to investigate plasma wall interaction on divertor plates in a nuclear fusion device. However, MD simulation box's size is less than several nm for the performance of a computer. To extend the size of the MD simulation, we develop a hybrid simulation code between MD code using REBO potential and binary collision approximation (BCA) code. Using the BCA code instead of computing all particles with a high kinetic energy for every step in the MD simulation, considerable computation time is saved. By demonstrating a hydrogen atom injection on a graphite by the hybrid simulation code, it is found that the hybrid simulation code works efficiently in a large simulation box.Comment: 5 pages, 5 figure