scholarly journals Influence of additional hierarchical levels on the working characteristics of distributed models

2020 ◽  
Vol 15 (90) ◽  
pp. 78-90
Author(s):  
Alexey A. Veselov ◽  
Keyword(s):  
Simulation Models ◽  
Hierarchical Level ◽  
Maximum Speed ◽  
Distributed Models ◽  
Modern Computer ◽  
Levels Of Detail ◽  
Computer Equipment ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Different Levels

In designing modern computer equipment and digital electronics, the use of simulation models is of great importance. At first, monolithic models were widely used for this. However, they worked well only when their size was relatively small. Because of it developers began to refuse gradually use of monolithic models and to pass to use of the distributed models allowing to increase their speed and to expand borders of their admissible sizes. At the same time, they begin to pay special attention to hierarchical distributed models, which provide the opportunity to investigate the behavior of the created devices at different levels of detail. Similar models made it possible to noticeably expand the permissible boundaries of their sizes and increase the speed of work. However, such distributed models have the disadvantage that their effectiveness is noticeably dependent not only on the number of components included in their composition, but also on the size of these components. he paper presents the results of a study of the effect of introducing an additional upper hierarchical level on the performance of distributed models based on Petri networks. The use of such a method of modifying distributed models leads to an increase in their speed in a wide range of changes in their sizes. At the same time, the most significant effect achieved in distributed models containing a large number of small components. The maximum speed of the thus modified models can be an order of magnitude higher than that of the non-modified ones. As a result, in addition to the overall increase in the efficiency of the modified hierarchical distributed models, this also led to a significant equalization of the performance of the modified distributed models with subordinate components of different sizes.

scholarly journals Modelling Agroforestry’s Contributions to People—A Review of Available Models

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2106
Author(s):  
Philipp Kraft ◽  
Ehsan Eyshi Rezaei ◽  
Lutz Breuer ◽  
Frank Ewert ◽  
André Große-Stoltenberg ◽  
...  
Keyword(s):  
Simulation Models ◽  
Agroforestry Systems ◽  
Ecosystem Functions ◽  
Modelling Framework ◽  
Code Structure ◽  
Wide Range ◽  
Long Time ◽  
Community Effort ◽  
Different Levels

Climate change, increasing environmental pollution, continuous loss of biodiversity, and a growing human population with increasing food demand, threaten the functioning of agro-ecosystems and their contribution to people and society. Agroforestry systems promise a number of benefits to enhance nature’s contributions to people. There are a wide range of agroforestry systems implemented representing different levels of establishment across the globe. This range and the long time periods for the establishment of these systems make empirical assessments of impacts on ecosystem functions difficult. In this study we investigate how simulation models can help to assess and predict the role of agroforestry in nature’s contributions. The review of existing models to simulate agroforestry systems reveals that most models predict mainly biomass production and yield. Regulating ecosystem services are mostly considered as a means for the assessment of yield only. Generic agroecosystem models with agroforestry extensions provide a broader scope, but the interaction between trees and crops is often addressed in a simplistic way. The application of existing models for agroforestry systems is particularly hindered by issues related to code structure, licences or availability. Therefore, we call for a community effort to connect existing agroforestry models with ecosystem effect models towards an open-source, multi-effect agroforestry modelling framework.

scholarly journals Progressive Transmission of 3D Building Models based on String Grammars and Planar Half-Spaces

2014 ◽  
Vol II-2 ◽  
pp. 9-14 ◽  
Author(s):  
M. Kada
Keyword(s):  
End User ◽  
Transmission Scheme ◽  
Levels Of Detail ◽  
Cartographic Generalization ◽  
Building Models ◽  
Wide Range ◽  
Local Range ◽  
Different Levels ◽  
City Models ◽  
Modelling Approach

As there are numerous applications for 3D city models with a wide range of model requirements regarding geometric accuracy and granularity, there is also a high demand for such models at different levels of detail (LOD). And although their reconstruction and cartographic generalization has been widely studied, particularly with regard to 3D building models, their encoding for a progressive storage and transmission is up to now not profoundly explored and sufficiently solved. Most often building models at different LODs are considered as discrete entities that are not related to each other. In this paper we present a progressive encoding and transmission scheme for 3D building models that is easy to understand and implement for the end user as well as flexible and extensible for the model producer. The progressive scheme is based on string grammars and describes a sequence of successive LODs as a dynamic set of production rules. In order to restrict the effects of LOD changes on a local range of the progressive string representation, we use a solid modelling approach based on planar half-spaces to construct 3D buildings. The generation of such progressive string grammars is shown and examples are given.

scholarly journals Scalable processing of massive geodata in the cloud: generating a level-of-detail structure optimized for web visualization

2020 ◽  
Vol 1 ◽  
pp. 1-20
Author(s):  
Michel Krämer ◽  
Ralf Gutbell ◽  
Hendrik M. Würz ◽  
Jannis Weil
Keyword(s):  
Input Data ◽  
Geometric Error ◽  
Level Of Detail ◽  
Divide And Conquer ◽  
Hierarchical Level ◽  
Web Browser ◽  
Hierarchical Tree ◽  
Levels Of Detail ◽  
Web Visualization ◽  
Different Levels

Abstract. We present a cloud-based approach to transform arbitrarily large terrain data to a hierarchical level-of-detail structure that is optimized for web visualization. Our approach is based on a divide-and-conquer strategy. The input data is split into tiles that are distributed to individual workers in the cloud. These workers apply a Delaunay triangulation with a maximum number of points and a maximum geometric error. They merge the results and triangulate them again to generate less detailed tiles. The process repeats until a hierarchical tree of different levels of detail has been created. This tree can be used to stream the data to the web browser. We have implemented this approach in the frameworks Apache Spark and GeoTrellis. Our paper includes an evaluation of our approach and the implementation. We focus on scalability and runtime but also investigate bottlenecks, possible reasons for them, as well as options for mitigation. The results of our evaluation show that our approach and implementation are scalable and that we are able to process massive terrain data.

scholarly journals Development of a Fast Urban Flood Model for Real-Time Applications

10.29007/1chf ◽  
2018 ◽  
Author(s):  
Vincent Wolfs ◽  
Victor Ntegeka ◽  
María Bermúdez ◽  
Patrick Willems
Keyword(s):  
Simulation Models ◽  
Fast Simulation ◽  
Urban Flood ◽  
Study Results ◽  
Surrogate Dual ◽  
Order Of Magnitude ◽  
1D Model ◽  
Urban Flood Modelling ◽  
Different Levels

Detailed 1D/2D models have become standard practice for urban flood modelling. However, many applications require computationally fast simulation models. Due to their prolonged calculation times, these 1D/2D models are unsuited for such applications. This research compares three modelling approaches with different levels of complexity and simulation times: (1) a highly detailed 1D/2D model, (2) a 1D/1D model with two different flood cone parameterizations, and (3) a newly developed surrogate dual drainage model. The three approaches are tested and compared on a Belgian case study. Results show that the surrogate dual drainage model can emulate the results of highly detailed models with calculation time reductions in the order of magnitude of 105.

scholarly journals A Multi-Tier Approach to Estimate Energy Efficiency in Urban Passenger Mobility

2020 ◽  
Author(s):  
Daniel Neves Schmitz Gonçalves ◽  
Renata Albergaria de Mello Bandeira ◽  
Tássia Faria de Assis ◽  
Marcio Almeida D'Agosto ◽  
George Vasconcelos Goes ◽  
...  
Keyword(s):  
Decision Making ◽  
Energy Efficiency ◽  
Urban Areas ◽  
Complex Nature ◽  
Decision Making Process ◽  
Passenger Transport ◽  
Energy Data ◽  
Levels Of Detail ◽  
Wide Range ◽  
Different Levels

Abstract Background: Recent studies evidence a lack of accurate methods to estimate energy efficiency in urban areas. This is due to the complex nature of obtaining wide range of activity and energy data from a single municipality, especially from developing countries, where data is usually scarce. Under these circumstances, this paper develops a method for estimating the energy efficiency in urban passenger mobility, considering three different levels of detail. The innovative factor is the use of a multi-tier approach to compare and adjust outputs. The method was applied in Sorocaba, Brazil, estimating a baseline of energy efficiency in this city. Results: Results show that energy efficiency varied from 0.67 passenger per kilometer/Mega Joule in 2013 to 0.70 passenger per kilometer /Mega Joule in 2017, which are consistent with the Brazilian passenger transport energy efficiency. Conclusions: The method proved to be an important mechanism for benchmarking purposes and for the decision-making process on transport investments. Moreover, it can be applied in cities from countries with different cultural and economic contexts.

scholarly journals Testing the Process of Evacuation from the Passenger Aircraft with the Use of Computer Simulation

2020 ◽  
Vol 56 (2) ◽  
pp. 22-39
Author(s):  
Michał Jasztal
Keyword(s):  
Probability Distributions ◽  
Three Dimensional ◽  
Simulation Models ◽  
Aircraft Design ◽  
Simulation Software ◽  
Maximum Speed ◽  
Evacuation Time ◽  
Wide Range ◽  
Passenger Aircraft ◽  
Passenger Cabin

Aim: The main aim of the study was to investigate the possibility to use the Pathfinder simulation software to determine the duration of an evacuation and to plan its course for various scenarios of evacuation organisation, for specific profiles and behaviours of passengers and on-board personnel, and for a specific geometrical arrangement of the passenger cabin of a selected passenger aircraft. In addition, the paper discusses selected factors that affect the evacuation from the passenger aircraft. Project and methods: The Pathfinder software used in the research has the graphical interface to create an evacuation simulation model (2D and 3D) as well as tools to visualise the results. Pathfinder is based on artificial intelligence algorithms, in which each passenger has a number of individual features that can influence his/her movements and decisions during the simulation. The simulation of people's movement is determined by their profiles and behaviours, the parameters of which can be entered by means of probability distributions, which makes it possible to take into account the stochastic nature of the evacuation process. Results: The Boeing 787 Dreamliner was selected for the study, for which six options for simulating the evacuation of 252 passengers and eight members of on-board personnel were conducted. The shortest evacuation time was achieved by changing the even distribution of the number of passengers to the individual emergency exits, thus avoiding congestions in sensitive areas of the passenger cabin. The increase in passengers' maximum speed has paradoxically increased evacuation times, as it has increased the intensity of passenger collisions. It was found that one of the key issues affecting the timing of an evacuation is the proper organisation of the evacuation by on-board personnel, who, by guiding passengers through the geometrically most advantageous passageways, results in the fastest possible evacuation. The simulations in variants five and six have achieved satisfactory evacuation times, which are within the emergency aircraft evacuation time limit required in a certification process. Conclusions: The presented simulation models, the results obtained, and the wide range of possibilities of three-dimensional visualisation of research results give a rational basis for the use of Pathfinder software for testing the evacuation process and thus: for the usage in the aircraft design process, for preparing aircrafts for tests, for shaping evacuation procedures, for on-board personnel training and for air accident investigation.

Development of a Simulation-Based Process Chain – Strategy for Different Levels of Detail for the Preprocessing Definitions

2011 ◽  
Vol 21 (3-4) ◽  
pp. 135-140 ◽  
Author(s):  
Toni A. Krol ◽  
Sebastian Westhäuser ◽  
M. F. Zäh ◽  
Johannes Schilp ◽  
G. Groth
Keyword(s):  
Process Chain ◽  
Levels Of Detail ◽  
Simulation Based ◽  
Different Levels

scholarly journals Psychology, Meaning Making, and the Study of Worldviews

2018 ◽  
Author(s):  
Ann Taves ◽  
Egil Asprem ◽  
Elliott Daniel Ihm
Keyword(s):  
Meaning Making ◽  
Sense Making ◽  
Evolutionary Perspective ◽  
Cognitive Level ◽  
Multidisciplinary Study ◽  
Human Ability ◽  
Wide Range ◽  
Object Of Study ◽  
Different Levels ◽  
Ways Of Life

To get beyond the solely negative identities signaled by atheism and agnosticism, we have to conceptualize an object of study that includes religions and non-religions. We advocate a shift from “religions” to “worldviews” and define worldviews in terms of the human ability to ask and reflect on “big questions” ([BQs], e.g., what exists? how should we live?). From a worldviews perspective, atheism, agnosticism, and theism are competing claims about one feature of reality and can be combined with various answers to the BQs to generate a wide range of worldviews. To lay a foundation for the multidisciplinary study of worldviews that includes psychology and other sciences, we ground them in humans’ evolved world-making capacities. Conceptualizing worldviews in this way allows us to identify, refine, and connect concepts that are appropriate to different levels of analysis. We argue that the language of enacted and articulated worldviews (for humans) and world-making and ways of life (for humans and other animals) is appropriate at the level of persons or organisms and the language of sense making, schemas, and meaning frameworks is appropriate at the cognitive level (for humans and other animals). Viewing the meaning making processes that enable humans to generate worldviews from an evolutionary perspective allows us to raise news questions for psychology with particular relevance for the study of nonreligious worldviews.

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