TU-C-BRA-04: A New Approach to Model-Based Dose Calculations for Kilovoltage Beams

2010 ◽  
Vol 37 (6Part26) ◽  
pp. 3382-3382
Author(s):  
J Pawlowski ◽  
C Coffey ◽  
G Ding
Keyword(s):  
Dose Calculations ◽  
New Approach ◽  
Model Based

scholarly journals A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer Models

2008 ◽  
Vol 18 (4) ◽  
pp. 465-476 ◽  
Author(s):  
Antoni Ligęza ◽  
Jan Kościelny
Keyword(s):  
Fault Diagnosis ◽  
Simultaneous Occurrence ◽  
Diagnostic Model ◽  
Rule Based ◽  
New Approach ◽  
Multiple Fault ◽  
Multiple Faults ◽  
Model Based ◽  
Multiple Fault Diagnosis ◽  
System Variables

A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer ModelsThe diagnosis of multiple faults is significantly more difficult than singular fault diagnosis. However, in realistic industrial systems the possibility of simultaneous occurrence of multiple faults must be taken into account. This paper investigates some of the limitations of the diagnostic model based on the simple binary diagnostic matrix in the case of multiple faults. Several possible interpretations of the diagnostic matrix with rule-based systems are provided and analyzed. A proposal of an extension of the basic, single-level model based on diagnostic matrices to a two-level one, founded on causal analysis and incorporating an OR and an AND matrix is put forward. An approach to the diagnosis of multiple faults based on inconsistency analysis is outlined, and a refinement procedure using a qualitative model of dependencies among system variables is sketched out.

scholarly journals Application of Model-Based Tests for Analysing the Consequences of Mine Fires

2018 ◽  
Vol 1 (1) ◽  
pp. 767-774
Author(s):  
Magdalena Tutak
Keyword(s):  
Fire Hazard ◽  
Physical Parameters ◽  
Gas Mixture ◽  
New Approach ◽  
Model Based ◽  
Underground Coal Mines ◽  
Mine Fires ◽  
Underground Mine Workings ◽  
The Subject ◽  
Chemical Products

Abstract One of the most common and most dangerous hazards in underground coal mines is fire hazard. Mine fires can be exogenous or endogenous in nature. In the case of the former, a particular hazard is posed by methane fires that occur in dog headings and longwalls. Endogenous and exogenous fires are large hazard for working crew in mining headings and cause economics losses for mining plants. Mine fires result in emission of harmful chemical products and have a crucial impact on the physical parameters of the airflow. The subject of the article concerns the analysis of the consequences of methane fires in dog headings. These consequences were identified by means of model-based tests. For this purpose, a model was developed and boundary conditions were adopted to reflect the actual layout of the headings and the condition of the atmosphere in the area under analysis. The objective of the test was to determine the effects of methane fires on the chemical composition of the atmosphere and the physical parameters of the gas mixture generated in the process. The results obtained clearly indicate that fires have a significant impact on the above-mentioned values. The paper presents the distributions for the physical parameters of the resulting gas mixture and the concentration of fire gases. Moreover, it shows the distributions of temperature and oxygen concentration levels in the headings under analysis. The methodology developed for the application of model-based tests to analyse fire events in mine headings represents a new approach to the problem of investigating the consequences of such fires. It is also suitable for variant analyses of the processes related to the ventilation of underground mine workings as well as for analyses of emergency states. Model-based tests should support the assessment of the methane hazard levels and, subsequently, lead to an improvement of work safety in mines.

scholarly journals Improving Model-Based Genetic Programming for Symbolic Regression of Small Expressions

2020 ◽  
pp. 1-27 ◽  
Author(s):  
M. Virgolin ◽  
T. Alderliesten ◽  
C. Witteveen ◽  
P. A. N. Bosman
Keyword(s):  
Genetic Programming ◽  
Real World ◽  
Symbolic Regression ◽  
New Approach ◽  
Model Based ◽  
Real World Datasets ◽  
Linkage Learning ◽  
Optimal Mixing ◽  
Crucial Parameter

The Gene-pool Optimal Mixing Evolutionary Algorithm (GOMEA) is a model-based EA framework that has been shown to perform well in several domains, including Genetic Programming (GP). Differently from traditional EAs where variation acts blindly, GOMEA learns a model of interdependencies within the genotype, that is, the linkage, to estimate what patterns to propagate. In this article, we study the role of Linkage Learning (LL) performed by GOMEA in Symbolic Regression (SR). We show that the non-uniformity in the distribution of the genotype in GP populations negatively biases LL, and propose a method to correct for this. We also propose approaches to improve LL when ephemeral random constants are used. Furthermore, we adapt a scheme of interleaving runs to alleviate the burden of tuning the population size, a crucial parameter for LL, to SR. We run experiments on 10 real-world datasets, enforcing a strict limitation on solution size, to enable interpretability. We find that the new LL method outperforms the standard one, and that GOMEA outperforms both traditional and semantic GP. We also find that the small solutions evolved by GOMEA are competitive with tuned decision trees, making GOMEA a promising new approach to SR.

Model-Based Development Process of Cybertronic Products and Production Systems

2014 ◽  
Vol 1018 ◽  
pp. 539-546 ◽  
Author(s):  
Hermann Meissner ◽  
Marcel Cadet ◽  
Nicole Stephan ◽  
Christian Bohr
Keyword(s):  
Development Process ◽  
Production Systems ◽  
Product Lifecycle Management ◽  
Mechatronic Systems ◽  
New Approach ◽  
Model Based ◽  
Open Networks ◽  
Development Processes ◽  
Faster Development ◽  
Lifecycle Management

The shift to satisfied customer markets forces manufacturers to offer customised products. Moreover, product lifecycles are shortened, which requires a faster development of products and corresponding production systems. Both challenges amplify complexity in production. This complexity is usually confronted with flexibility. A new approach offering decentralised structures, and thereby flexibility, comes from cybertronic systems (CTS), which are further developed mechatronic systems with the capability to communicate through open networks with other such mechatronic systems. Up to now no integrated development process to engineer cybertronic products (CTP) and production systems (CTPS) has been developed, although such a process is essential to use their beneficial properties for today’s market conditions. Therefore, research is conducted in the research project mecPro². First, the properties of cybertronic systems are investigated and dissociated from those of mechatronic systems. Based on these properties, the connections of CTP and CTPS are analysed and a systematics for description for both is identified. With this the model-based development processes of CTP and CTPS can be further defined as well as their intersections and afterwards implemented in a data model. Finally, the development process is summarised in a product lifecycle management software to support the development process.

scholarly journals The Influence of the Permeability of the Fractures Zone Around the Heading on the Concentration and Distribution of Methane

2019 ◽  
Vol 12 (1) ◽  
pp. 16 ◽  
Author(s):  
Magdalena Tutak
Keyword(s):  
Ventilation System ◽  
Organizational Factors ◽  
Primary Objective ◽  
Test Results ◽  
Ansys Fluent ◽  
New Approach ◽  
Model Based ◽  
Coal Beds ◽  
Air Stream ◽  
Fluent Software

One of the main problems related to the excavation of dog headings in coal beds is the emission of methane during this process. To prevent the occurrence of dangerous concentration levels of this gas, it is necessary to use an appropriate ventilation system. The operation effectiveness of such a system depends on a number of mining, geological, technical and organizational factors. One of them includes the size and permeability of the fractures zone formed around the excavated dog heading. The primary objective of the paper is to determine the influence of this zone on the ventilation parameters, including the concentration and distribution of methane in the excavated dog heading. In order to achieve the assumed objective, multivariate model-based tests were carried out, which reproduce a real-world dog heading. Literature data and test results in actual conditions were used to determine the size and permeability of the fractures zone around the excavated heading. These data served as the basis to develop a model of the region under analysis and adopt boundary conditions. The analyses were carried out for four permeability values of the fractures zone and for two volumetric flow rates of the air stream supplied to the heading. The results were used to determine the influence of the fractures zone on the distribution and concentration of methane in the heading under analysis. The model-based tests were performed using ANSYS Fluent software. The idea to take into account the fractures zone around the heading represents a new approach to the analysis of ventilation parameters in underground mine headings. The results clearly indicate that this zone affects the ventilation parameters in the heading, including the distribution and concentration of methane. The knowledge obtained from the tests should be used to optimize the ventilation process of dog headings. All authors have read and agreed to the published version of the manuscript.

Model-based dose calculations for125I lung brachytherapy

2012 ◽  
Vol 39 (7Part1) ◽  
pp. 4365-4377 ◽  
Author(s):  
J. G. H. Sutherland ◽  
K. M. Furutani ◽  
Y. I. Garces ◽  
R. M. Thomson
Keyword(s):  
Dose Calculations ◽  
Model Based
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