SIMULTECH 2013 Abstracts


Area 1 - Simulation Tools and Platforms

Full Papers
Paper Nr: 34
Title:

Simulation of Real-time Multiprocessor Scheduling with Overheads

Authors:

Maxime Chéramy, Anne-Marie Déplanche and Pierre-Emmanuel Hladik

Abstract: Numerous scheduling algorithms were and still are designed in order to handle multiprocessor architectures, raising new issues due to the complexity of such architectures. Moreover, evaluating them is difficult without a real and complex implementation. Thus, this paper presents a tool that intends to facilitate the study of schedulers by providing an easy way of prototyping. Compared to the other scheduling simulators, this tool takes into account the impact of the caches through statistical models and includes direct overheads such as context switches and scheduling decisions.

Paper Nr: 47
Title:

Combining Supervisory Control, Object-oriented Petri-Nets and 3D Simulation for Hybrid Simulation Systems using a Flexible Meta Data Approach

Authors:

Juergen Rossmann, Michael Schluse and Ralf Waspe

Abstract: The idea of Supervisory Control is to regard a control component (Supervisor) as a discreet event simulation. State Oriented Modeling combines the ideas of supervisory control and object-oriented Petri-nets. With these concepts as a starting point, our goal was to realize a truly hybrid simulation system, which allows the simultaneous use of discreet event simulation and continuous 3D-simulation on a unified database. The key component is an active real-time simulation database, which is an object-oriented, self-reflecting graph database, with a powerful meta-information system. All nodes are derived from a common base class and data is stored in properties with standardized getter and setter functions. The object-oriented Petri-nets are formally described in the State Oriented Modeling Language, which is itself an extension scheme of the simulation database.

Short Papers
Paper Nr: 12
Title:

Multi-objective Optimization and Stochastic Analysis in Focused Ultrasonic Therapy Simulation

Authors:

T. Clees, N. Hornung, I. Nikitin, L. Nikitina and D. Steffes-lai

Abstract: We present new results in stochastic multi-objective optimization applied to focused ultrasonic therapy planning. This type of non-invasive therapy uses focused ultrasound for the destruction of tumor cells and magnetic resonance tomography for identification of tumor volume and healthy organs. During the therapy planning the treatment parameters, such as frequency and intensity of ultrasound, are adjusted to achieve maximal tumor destruction and minimal influence to the healthy organs. For this purpose multi-objective optimization is used. RBF metamodeling is employed for continuous representation of discretely sampled results of numerical simulation and for evaluation of inherent uncertainties. We apply two algorithms for multi-objective optimization capable of non-convex Pareto front detection in the considered problem. Cross-validation procedure and sensitivity analysis are used for estimation of uncertainties. A realistic application case demonstrates the efficiency of the approach.

Paper Nr: 41
Title:

Emergency Systems Modelling using a Security Engineering Process

Authors:

Jose Fran. Ruiz, Antonio Maña, Marcos Arjona and Janne Paatero

Abstract: The engineering and development of complex security-sensitive systems is becoming increasingly difficult due to the need to address aspects like heterogeneity (of application domains, requirements, regulations, solutions, etc.), dynamism and runtime adaptation necessities, and the high demands for security and privacy of the users and agencies involved in scenarios where these systems work (natural disasters, accidents, terrorism, etc.). Moreover, security knowledge is highly domain-dependent and dynamic. These characteristics make the development of those systems hard because the amount of security knowledge required to dealing with such a huge variety of situations, which becomes way too large for a human. We propose in this paper a security-oriented engineering process that is especially useful for these systems. It makes security fit naturally in the systems by interleaving security into the initial architecture and system description. In particular, the proposed process provides means to identify and manage security properties in a consistent and intuitive manner. To illustrate our experience we use a real-world emergency response scenario. More concretely, we focus on the establishment of a secure ad-hoc wireless mesh communication, which is a key component in the domain of spontaneous broadband communication among crisis management vehicles.

Paper Nr: 43
Title:

A Bayesian Approach to Modeling Dynamical Systems in the Social Sciences

Authors:

Shyam Ranganathan, Viktoria Spaiser and David J. T. Sumpter

Abstract: The paper presents a new modeling approach using longitudinal or panel data to study social phenomena and to make predictions of dynamic changes. While the most common way in social sciences to study the relations between variables is using regression, our modeling approach describes the changes in variables as a function of all included variables, using differential equations with polynomial terms that capture linear and/or nonlinear effects. The mathematical models represented by these differential equations are derived directly from data. The models can then be run forward to forecast future changes. A two-step model-fitting approach is applied to identify the best-fit models and included visualisation methods based on phase portraits help to illustrate modeling results. We show this approach on an example relating democracy to economic growth.

Paper Nr: 50
Title:

Early Analysis of Ambient Systems SYSML Properties using OMEGA2-IFx

Authors:

Manzoor Ahmad, Iulia Dragomir, Jean-Michel Bruel, Iulian Ober and Nicolas Belloir

Abstract: Formal methods provide tools to verify the consistency and correctness of a specification with respect to the desired properties of the system. This verification is important as the development of an AAL (Ambient Assisted Living) system involves different technologies (medical services, surveillance cameras, intelligent devices, etc.) requiring a strong consistency checking between models. We illustrate in this paper how we prove some of the properties of the system before the development even starts. To model the AAL system, we use the SYSML language. In terms of tools, we use Rational Rhapsody in combination with the OMEGA2 profile which is an executable UML/SYSML profile used for the formal specification and validation of critical real-time systems. This profile is supported by the IFx toolset which provides mechanisms for the model simulation and properties verification of the AAL system.

Paper Nr: 52
Title:

Multiscale Models of Electrochemically-Promoted Large Catalytic Surfaces

Authors:

Ioannis S. Fragkopoulos and Constantinos Theodoropoulos

Abstract: In the current work a multiscale framework for electrochemically promoted catalytic systems is formulated. It integrates a macroscopic model based on commercial CFD software, which simulates the charge transport in the system, and an in-house developed efficient implementation of the kinetic Monte Carlo method for the simulation of reaction-diffusion micro-processes taking place on the catalyst. The “large” catalytic surface is split into a number of smaller “representative” lattices whose total area is only a fraction of the actual catalytic area. Efficient coarse-graining methodologies based on equation free methods (Gear et al., 2002) are employed to simulate the interactions between these lattices including lateral (lattice-to-lattice) transport through diffusion. Hence, the computationally intensive microscopic simulations are handled with efficiency.

Paper Nr: 53
Title:

SHARP: Shade-avoidance Response in Plants - An Evolutionary Simulation Software Package

Authors:

Wen Fung Leong, Sanjoy Das, Stephen M. Welch and Cynthia Weinig

Abstract: Educational simulators take learning to the next level by bringing students’ understanding of a subject closer to their personal experience. In this paper, software to simulate the evolution of shade-avoidance responses in plants is developed. Models and equations to imitate the response are described. An example simulated scenario is illustrated and discussed. This simulation demonstrates typical shade-avoidance response in plants; the competition for sunlight between plants grown in high density conditions channelizes more resources towards longer stems. Additionally, the simulations show how increased competition over plants grown in low density conditions lowers the variability in the overall shapes of the individual plants.

Paper Nr: 67
Title:

From State-transition Models to DEVS Models - Improving DEVS External Interoperability using MetaDEVS - A MDE Approach

Authors:

Stéphane Garredu, Evelyne Vittori, Jean-François Santucci and Paul-Antoine Bisgambiglia

Abstract: In this paper, the issue of the “external” interoperability of DEVS models is discussed. Scientists often need to simulate non-DEVS models using a DEVS-oriented framework, in order, for instance, to make their DEVS and non-DEVS modes interoperate. The source formalisms we propose to transform onto DEVS models are those which are based on the “family” of states and transitions. A general and model-oriented approach called MetaDEVS is presented in this article. MetaDEVS is also the name given to the DEVS metamodel we use. This metamodel allows creating platform-independent DEVS models. This paper shows how models which belong to the state and transitions “family” can be mapped onto DEVS, and more exactly onto MetaDEVS-based DEVS models, following the MetaDEVS approach. Then, the approach is applied to a concrete case: we transform Finite-State Machine (FSM) models into MetaDEVS models, using ATL, a hybrid language (which mixes both declarative and imperative rules), within the Eclipse Modelling Framework. A metamodel to describe the FSM formalism is also proposed.

Paper Nr: 76
Title:

Using Discrete-Event Simulation to Forecast the Volume of Hospital Emergency Services to be delivered at the Regional Level

Authors:

Bożena Mielczarek

Abstract: This paper describes a discrete-event simulation model to estimate the volume of services to be provided by emergency departments located in one sub-region of Lower Silesia, the southernmost province in Poland. Forecasts of the predicted categories of services to be delivered in the following year in emergency departments in the region are formulated based on the simulated demand level. The process of input data analysis is described in detail, and basic assumptions for the simulation model are formulated. The results provide some insights into the relation between sub-regional demographic trends and population needs in relation to hospital emergency arrivals.

Paper Nr: 84
Title:

Response-based Control through Dynamic Optimization in Large-scale Power Systems

Authors:

Sergio Bruno, Matteo D'Aloia and Massimo La Scala

Abstract: Modern real-time measurement equipments and associated communication/computing networks allow developing advanced power system control architectures able to identify dangerous states of power systems, and, when necessary, evaluate and apply remedial control actions. An approach, derived by a dynamic optimization methodology, for evaluating response-based control actions and enhance power system security, is presented. In this paper, studies performed for wide-area control of transient phenomena are reviewed. Despite severe computational efforts and time requirements, the authors’ position is that the nowadays technology can make the approach feasible.

Paper Nr: 86
Title:

Computational Fluid Dynamic Solver based on Cellular Discrete-Event Simulation

Authors:

Michael Van Schyndel, Gabriel Wainer and Mohammad Moallemi

Abstract: Computational Fluid Dynamics (CFD) deals with computing the equations of fluid flows using numerical methods. The Discrete-Event System specification (DEVS) theory has been used to approximate the continuous systems by applying a quantized state system approach. In this research, we employ Cellular DEVS theory (Cell-DEVS) – originally proposed for modeling and simulation of spatial environments – to create a uniform set of rules for CFD. This harmonized set of state changes can effectively render the fluid dynamics, by applying the accurate rule that represents the behavior of the fluid. The combination of the simplicity and the mathematical backbone allows for constructing models computable on an average computer or an array of cluster computers.

Paper Nr: 89
Title:

Simulation of Self Organized Electron Beams in Vacuum Microdiodes

Authors:

Marjan Ilkov, Andreas Pedersen, Andrei Manolescu and Ágúst Valfells

Abstract: Simulation of vacuum micro-diodes can be done quite effectively using molecular dynamics methods. This results in much higher fidelity simulations than can be obtained using the particle-in-cell method (PIC), which is most common for plasma and particle beam simulations. In particular, this method is superior to the PIC method when treating systems where collisional effects are important. In this paper we present some results concerning electron beam structure in a vacuum micro-diode obtained using a molecular dynamics code developed at Reykjavík University.

Paper Nr: 90
Title:

Interaction of Simulation Tools with ERP Systems - Concept and Practical Implementation

Authors:

Arne Koors and Bernd Page

Abstract: The interaction approach introduced in this paper is aiming at coupling a full-fledged discrete event simulator and an operational ERP system in a fully integrated manner. Here, the simulator is representing the complete operative environment of the ERP system, substituting its daily business input. For this, the company-specific utilisation of the ERP system has to be modelled in the simulator. In order to execute its model and process concrete ERP functionality, the simulator is accessing the ERP system via software interfaces, using it like a large subject-specific software library. Thus, the simulator is effectively carrying out a complete remote control of the ERP system, in the sense of software automation. Amongst others, the simulator is inducing arrival and booking events in the ERP system, is continuously triggering internal ERP system processes and is processing the results of revised ERP planning by arranging future events in the ERP system. Altogether, the simulator and the ERP system are interacting mutually with each other in a cyclic process. In this paper, we introduce the core idea of the interaction approach and delineate its potentials. We discuss arising challenges in practical application and describe the current state of implementation.

Posters
Paper Nr: 3
Title:

Simulation Design and Execution - The Case of TRAFIL

Authors:

Christos Bouras, Savvas Charalambides, Michalis Drakoulelis, Georgios Kioumourtzis and Kostas Stamos

Abstract: This paper presents the enhancements that we have done on the TRAFIL (TRAce FILe) framework, which significantly extend its capabilities in the areas of simulation design and execution. In particular, TRAFIL now offers the possibility to design, create, execute and review NS-2 simulation scenarios, on top of its existing post-simulation trace analysis functionalities. The enhancements make TRAFIL a complete wrapper around the NS-2 simulator, allowing the user to perform all steps from pre-simulation design to actual simulation execution in an automated way and fast and convenient post-simulation analysis of potentially large amount of data. The paper describes the new TRAFIL architecture and how these enhancements were implemented with the goal of relieving NS-2 users from the often cumbersome tasks of script writing and validating, while also enabling them at to go behind the TRAFIL environment and into the simulator internals at any time. The paper presents the new GUI functionalities developed for that purpose, the approach that we took for their design and how these fit in the overall TRAFIL architecture.

Paper Nr: 5
Title:

Assisting Data Warehousing Populating Processes Design through Modelling using Coloured Petri Nets

Authors:

Diogo Silva, João M. Fernandes and Orlando Belo

Abstract: Data warehousing systems populating processes are responsible for loading their data repositories – the data warehouses – with information they extract from operational sources. The tasks that integrate these processes are the most complex ones that we can find in a data warehousing system. For a flawless implementation, modelling these processes previously is important so that a correct set of requirements is considered. This paper approaches conceptual modelling and simulation of the populating processes of a DWS, by applying Coloured Petri Nets in the design of independent populating tasks. We adopt a change data capture task as the case study in order to demonstrate the effective application of coloured petri nets for modelling and simulating data warehousing populating processes.

Paper Nr: 16
Title:

Implementation of Simplicial Complexes for CPA Functions in C++11 using the Armadillo Linear Algebra Library

Authors:

Sigurdur Freyr Hafstein

Abstract: Continuous, piecewise affine (CPA) functions can be algorithmically parameterized to deliver Lyapunov functions for compact invariant sets. We discuss flexible structures and algorithms to manipulate CPA functions for these purposes and discuss their implementation in C++11 using the Armadillo linear algebra library. Especially, we discuss some of the new language features in C++11 that lead to simpler and more readable code. The implementation was developed in the freeware Visual Studio Express 2012 for Windows Desktop (VS2012). Apart from a detailed description and code examples for the construction and manipulation of the simplicial complex that serves as a basis for CPA functions, this contribution includes some discussion on practical implementation details when using VS2012, C++11, and the linking to and use of the excellent Armadillo linear algebra library. Thus, some parts of this paper, especially Section 3, might be useful not only for those interested in the implementation of the simplicial complex for computing CPA Lyapunov functions, but also for those generally interested in using the free Armadillo library for computations in VS2012.

Paper Nr: 18
Title:

Numerical Model for the Prediction of Final Mechanical Properties of EPDM Vulcanized with Peroxides - Part I: Basis of the Numerical Model and Experimental Campaign

Authors:

Gabriele Milani and Federico Milani

Abstract: In the paper, a simple but effective mathematical model having kinetic base, to predict the vulcanization degree of rubber vulcanized with peroxides, is presented. The approach takes contemporarily into consideration, albeit within a simplified scheme, the actual reactions occurring during peroxidic curing, namely initiation, H-abstraction, combination and addition, and supersedes the simplified approach used in practice, which assumes for peroxidic curing a single first order reaction. After a suitable re-arrangement of the first order system of differential equations obtained from the actual kinetic system adopted, a single second order non-linear differential equation is obtained and numerically solved by means of a Runge-Kutta approach. Kinetic parameters to set are evaluated by means of a standard least squares procedure where target data are represented by experimental values available, i.e. normalized rheometer curves. In order to assess numerical results, a wide experimental campaign is conducted, varying curing agents, vulcanization temperatures and concentration of the peroxides. Both rheometer curves to compare with those provided by the numerical model and stretch-strain curves of the vulcanized samples are obtained, to have a precise insight into the most suitable parameters to use during curing.

Paper Nr: 19
Title:

Numerical Model for the Prediction of Final Mechanical Properties of EPDM Vulcanized with Peroxides - Part II Results

Authors:

Gabriele Milani and Federico Milani

Abstract: In the present Part II, the kinetic numerical model discussed in detail in Part I, is applied to the huge amount of experimental data collected by the authors. Rheometer curves are fitted numerically for three different curing temperatures, for all the curing agents investigated at a concentration equal to 150%, which have proved to be the most adequate to obtain optimal crosslinking of the EPDM under consideration. The comparisons with experimental data at three different temperatures allow estimating partial kinetic constants of the model as a function of the absolute temperature, with a direct comparison with simplified formulas provided by the peroxide producers. The application of the numerical kinetic model to a large variety of real scale examples allows a direct validation of the capabilities of the approach proposed, as well as an evaluation of the most suitable production parameters to use in practice (curing time and temperature, concentration and typology of the curing agents) in order to maximize rubber output mechanical properties and crosslink homogeneity, without the need to perform costly experimental campaign.

Paper Nr: 24
Title:

Semantic Integration for Model-based Life Science Applications

Authors:

Tomasz Gubała, Katarzyna Prymula, Piotr Nowakowski and Marian Bubak

Abstract: When delivering tools and solutions for modern e-Science applications, the proper transfer of domain knowledge into information models is a crucial design step. In this work we describe the Semantic Integration approach to modeling and transcribing complex science domain knowledge into well-structured information models based on semantics. Apart from a conceptual study and presentation of related work, we also describe how we applied the methodology to deliver a real-life solution for simulation of locations of active binding sites in proteins – an important problem in bioinformatics. Our goal is to show how the Semantic Integration technology can help deliver ready-to-use solutions for scientists.

Paper Nr: 26
Title:

Inter-module Communications for Rear-end Collision Avoidance Messaging in an IEEE 802.11p Interface

Authors:

Juan-Bautista Tomas-Gabarron, Esteban Egea-Lopez and Joan Garcia-Haro

Abstract: In general, computer simulation is the preferred approach when investigating Vehicular Ad-hoc Networks (VANET). During the last years different platforms have emerged, regarding the evaluation of next-generation autonomous vehicular mobility and car-to-car wireless connectivity. NCTUns (now Estinet) is a relevant networking environment that provides support for IEEE 802.11p-based connectivity between cars. This paper describes on the implementation of an inter-module communications’ scheme designed to allow reciprocal message transmission and processing between a mobility and a messaging agent in vehicles supporting Cooperative chain Collision Avoidance (CcCA) for improving safety even under rear-end collision risky circumstances. Novelty holds in the bidirectional inter-module channel that features the management of mobility in these environments according to the communication’s protocol that implements the CcCA application, and viceversa. As an additional characteristic of the implementation, a Nakagami-m channel model is implemented to recreate intervehicular communications more realistically.

Paper Nr: 27
Title:

Performance Aspects of Some Switching Networks

Authors:

Zbigniew Hulicki

Abstract: The intention of this paper is to examine the performance and reliability aspects of switching fabrics which are used for scalable high-performance routers. Topology and capabilities of switching fabrics are discussed, followed by an examination of the performance vs.– reliability trade-off in diverse scenarios of possible failures. It has been shown that the switching fabric based on the PM2I type multistage interconnection network (MIN) outperforms those based on the cube type MIN under any failure scenario. The simulation results presented should be helpful in predicting the performance vs.– reliability trade-off before actual fabrication of the switching fabric.

Paper Nr: 30
Title:

Improving Flow-Based Modeling of Enterprise Systems and Modeling of Custom Warehouse Systems in d3fact

Authors:

Hendrik Renken and Wilhelm Dangelmaier

Abstract: Due to a restrictive design, current enterprise simulation software has shortcomings when it comes to modeling complex business processes and custom warehouse systems. Often, standard processes are altered to add desired functionality. Also, custom (often complex) warehouse components are created by merging readily available components. Typically, this customization has to be done programmatically, which usually results in error-prone and hard to maintain simulation models. In this paper we present a concept to improve the modeling of complex business processes and warehouse systems. Our flexible design allows the combination of business-processes without any programming. It even allows a process to control several information flows at once. This comes in handy when implementing custom warehouse systems.

Paper Nr: 36
Title:

Spectral Solutions of a Combined Multifluid--population Balance ModelDescribing Bubbly Flow - A Numerical Study of weighted Residual Methods

Authors:

Hugo A. Jakobsen and Jannike Solsvik

Abstract: Fluid particle breakage and coalescence phenomena are important for optimal operation for industrial process units like the bobble column reactors. The population balance equation (PBE) can be applied to describe the evolution of populations of countable entities such as the bubbles in the bubble column. In recent literature, the least-squares methods has been adopted for the approximate solution of population balance (PB) models. Adopting a weighted residual method such as the least-squares method, the distribution function resolved instead of obtaining only a few moments of the distribution function. The performance of the least-squares method for PB problems should be compared to other techniques in the family of weighted residual methods. The aim of the present study is to evaluate the orthogonal collocation, tau and last-squares methods for the solution of a combined multifluid-PB model describing bubbly flows.

Paper Nr: 40
Title:

Investigating the Optimal Performance of Multicast Communication by Simulation

Authors:

Eleftherios Stergiou, Dimitrios Liarokapis and Gerasimos Meletiou

Abstract: The multicast mechanism is one method of data communication in data networks which aims to transfer data to a group of receivers on a network in an efficient manner. In this work the performance of four well known and widely used multicast protocols are investigated using OMNeT++ open software, which was chosen for this purpose. Individual performance metrics are determined by executing simulation experiments and in addition a unique overall performance indicator is defined to solve the multi-criteria decision problem that is revealed as the network configuration and the service conditions vary. This performance evaluation approach can be used by network protocol designers for building and exploiting optimal protocols when setting up networks so as to achieve the best performance under the multicast traffic load and quality specifications.

Paper Nr: 44
Title:

Towards an EDSL to Enhance Good Modelling Practice for Non-linear Stochastic Discrete Dynamical Models - Application to Plant Growth Models

Authors:

Benoit Bayol, Yuting Chen and Paul-Henry Cournède

Abstract: A computational formalism is presented that structures a C++ library which aims at the modelling, simulation and statistical analysis of stochastic non-linear discrete dynamical system models. Applications concern the development and analysis of general plant growth models.

Paper Nr: 48
Title:

A Freight Train Simulator - Design and Implementation of a Training Simulator for Freight Train Conductors

Authors:

R. P. Marques, F. Kassab Junior, R. S. Barbosa and K. Nishimoto

Abstract: A training simulator for freight train conductors is presented, including topics on its development, context, architecture, main characteristics, usability issues and human-machine interface concepts and current development status. Only longitudinal dynamics of the train is simulated, although integration with a more complex simulator is possible. It is also ready for integration with future simulators for other elements of the logistic chain. Some important characteristics of the simulator are the used of a shared memory network in order to distribute and modularize the software and the possibility of remote instruction and supervision via web tools.

Paper Nr: 55
Title:

Web-based Metaprogrammable Frontend for Molecular Dynamics Simulations

Authors:

Gergely Varga, Sara Toth, Christopher R. Iacovella, Janos Sallai, Peter Volgyesi, Akos Ledeczi, Gabor Karsai and Peter T. Cummings

Abstract: Molecular dynamics simulators are indispensable tools in the arsenal of chemical engineers and material scientists. However, they are often difficult to use and require programming skills as well as deep knowledge of both the given scientific domain and the simulation software itself. In this paper, we describe a metaprogramming approach where simulator experts can create a library of simulation components and templates of frequently used simulations. Domain experts, in turn, can build and customize their own simulations and the required input for the various supported simulators is automatically synthesized. The web-based environment also supports setting up a suite of simulation jobs, for example, to carry out automated parameter optimization, via a visual programming environment. The entire simulation setup – including the various parameters, the version of tools utilized and the results – is stored in a database to support searching and browsing of existing simulation outputs and facilitating the reproducibility of scientific results.

Paper Nr: 62
Title:

Enhancing VLAM Workflow Model with MapReduce Operations

Authors:

Mikolaj Baranowski, Adam Belloum and Marian Bubak

Abstract: MapReduce frameworks proved to be a good solution for storing and processing large amounts of data. Thanks to data parallelism, they allow to move computations very close to the storage and therefore to reduce an influence of “I/O bottleneck”. Workflow Management Systems, in turn, are widely used for modeling of scientific applications. Users that are willing to use MapReduce frameworks in their workflows have to run separate environment to develop Map/Reduce operations. In this paper we propose an approach that will allow to extend existing application models by MapReduce routines. Our solution bases on DSL constructed on top of Ruby programming language. It follows examples of Sawzall and Pig Latin languages and allows to define Map/Reduce operations in minimalist way. Moreover, because the language is based on Ruby, the model allows to use user defined routines and existing Ruby libraries. A particular model of the workflow management system can be extended with our DSL letting users to use one environment for developing the workflow and MapReduce application.

Paper Nr: 83
Title:

Mathematical Modelling of Smooth and Precise Adaptive Train Braking System

Authors:

A. Potapov, M. Gorobetz and A. Levchenkov

Abstract: This position paper provides a new insight into the smooth and precise adaptive railway transport braking system design. The first phase of the development is described and includes a development of a necessary mathematical and computer model. Components of new adaptive braking system and their interactions are defined. Mathematical model contains equations that describe the movement of the train and the pneumatics braking system of the train, as well as offering new features of the developed system, which will adaptively adjust the service brake modes and will perform real-time system diagnostics without any human interaction. The computer model and simulation results are described in this position paper.

Area 2 - Formal Methods

Short Papers
Paper Nr: 37
Title:

Simulation of Collision Avoidance by Considering Potential Area of Water for Maneuvering based on MMG Model and AIS Data

Authors:

I. Putu Sindhu Asmara, Eiichi Kobayashi and Trika Pitana

Abstract: A vessel should follow a planned route. However, when a target ship deviates from its original track, the subject ship should maneuver to avoid a ship-to-ship collision. This paper presents a trial maneuver-based method for collision avoidance that considers the potential area of water (PAW) for maneuvering that is available to the target ship. The initial conditions, including the position, speed, rudder angle, drift angle, and yaw rate of the target ship, are derived from automatic identification system (AIS) data. AIS data from Madura Strait were used to simulate collision avoidance. The PAW of the target ship was predicted based on a probability distribution of the initial conditions using a mathematical maneuvering group (MMG) model. Finally, a trial maneuver method for the subject ship was simulated to avoid a ship-to-ship collision. The MMG model for the simulation was developed to consider the effects of shallow water and wind and current disturbances.

Posters
Paper Nr: 87
Title:

Abstract Modeling of embedded Systems Hardware

Authors:

Christian Hausner and Frank Slomka

Abstract: Designing cyber-physical systems is a challenge originating from the multidisciplinary and mixed-signal requirements. In order to handle this challenge, many design languages have been developed, but none covers the platform-based design and system view well. In this paper we extend our methodology by considering the aspects of the platform. A new abstraction layer, the domain layer is explained. This new layer allows the description of embedded hardware as well as system on chips in a way which can be easily understood by application or software engineers as well as hardware engineers. It closes the gap between hardware structure diagrams as given by hardware designers on system level and class diagrams as used by software engineers. Together with a new diagram type to describe hardware structures on system level the approach opens a door to describe the binding or deployment of software to operating system services and hardware in a formal way considering aspects of memory management and the structure of address spaces. Aspects not covered by common system description languages.

Area 3 - Complex Systems Modeling and Simulation

Full Papers
Paper Nr: 28
Title:

Agent based Simulations of Epidemics on a Large Scale - Toward the Right Choice of Parameters

Authors:

Robert Elsässer, Adrian Ogierman and Michael Meier

Abstract: In a world where epidemic outbreaks may take many lives, forecasting and analysis tools are of high importance - for an urban area such as New York City, a continent like Africa, as well as for the world itself. Such tools provide valuable insight on different levels and help to establish and improve embankment mechanisms. In this paper, we present an agent-based algorithmic framework to simulate the spread of epidemic diseases. Based on the population structure of Germany, we investigate the impact of the number of agents, representing the population, on the quality of the simulation. Real world data provided by the Robert Koch Institute (Arbeitsgemeinschaft Influenza, 2011; Robert Koch Institute, 2012) is used to evaluate our results. In a second step we empirically analyze the effects of certain non-pharmaceutical countermeasures as applied in the USA against the Influenza Pandemic in 1918-1919 (Markel et al., 2007). Our simulation and evaluation tool partially relies on the probabilistic movement model presented in (Elsässer and Ogierman, 2012). Based on our empirical tests, we conclude that the amount of agents in use can have a huge impact on the accuracy of the achieved simulation results. This reveals several challenges, which have to be taken into account in the design of forecasting and analysis tools for the spread of epidemics. On the other hand, we show that by utilizing the right parameters in our algorithmic framework - some of them being obtained from real world observations (Eubank et al., 2004) - one can efficiently approximate the course of a disease in real world.

Paper Nr: 35
Title:

Tensor Systems - Multilinear Modeling and Applications

Authors:

G. Pangalos, A. Eichler and G. Lichtenberg

Abstract: Tensor systems are a framework for modeling of multilinear hybrid systems with discrete and continuous valued signals. Two examples from building services engineering and multi-agent systems show applications of this framework. A tensor model of a heating system is derived and approximated by tensor decomposition methods first. Second, a tensor model of a multi-agent system with a structure already given in a decomposed form is reduced further by the same decomposition methods. The validity of these low rank approximations is shown for both examples.

Paper Nr: 54
Title:

Composing Variable Structure Models - A Revision of COMO

Authors:

Alexander Steiniger and Adelinde M. Uhrmacher

Abstract: Component-based approaches aim at facilitating the storage, exchange, and reuse of components and their compositions. For this, components provide interfaces that formulate contracts composition can be based upon. Variable structure models imply the change of compositions, couplings, and even interfaces in terms of ports. Thus, combining variable structure models with a component-based approach poses specific challenges. We present a revision of the model composition framework COMO taking the specifics of variable structure models into account, e.g., by specifying interfaces as sets of parameters and supersets of ports, defining couplings intensionally, and introducing supersets of components as part of the compositional description. As target for generating executable simulation models the formalism ML-DEVS has been selected.

Paper Nr: 61
Title:

Assessing the Impact of Policy Changes in the Icelandic Cod Fishery using a Hybrid Simulation Model

Authors:

Sigríður Sigurðardóttir, Björn Johansson, Sveinn Margeirsson and Jónas R. Viðarsson

Abstract: Most of the Icelandic cod is caught in bottom trawlers or longliners. These two fishing methods are fundamentally different and have different economic, environmental and even social effects. In this paper we present a hybrid-simulation framework to assess the impact of changing the ratio between cod quota allocated to vessels with longlines and vessels with bottom trawls. It makes use of conventional bio-economic models, discrete event modelling and provides a framework for simulating life cycle assessment (LCA) for a cod fishery. The model was constructed in AnyLogic and consists of two models, a system dynamics model describing the biological aspect of the fishery and a discrete event model for fishing activities.

Paper Nr: 78
Title:

Adapting Simulation Modeling to Model-Driven Architecture for Model Requirement Verification

Authors:

Fuqi Song, Gregory Zacharewicz and David Chen

Abstract: In order to automate the software development process and enhance interoperability and reusability of it, Model-Driven Architecture (MDA) was proposed aiming to achieving these goals. MDA mainly involves creating models and performing model transformation, it is a high model-intensive process. However, how to verify the models by respecting to the requirements becomes a concern in the automation process. In this paper, we describe the work of proposing a method using ontology as information exchange media to adapt simulation modeling to MDA towards this goal. Simulation is integrated loosely to MDA for verifying the models with the pre-defined requirements to check if expected goals are fulfilled. An illustrative case study is given to explain visually the method.

Paper Nr: 93
Title:

Modeling Interdependent Socio-technical Networks via ABM - Smart Grid Case

Authors:

Daniel Worm, David Langley and Julianna Becker

Abstract: The objective of this paper is to improve scientific modeling of interdependent socio-technical networks. In these networks the interplay between technical or infrastructural elements on the one hand and social and behavioral aspects on the other hand, is of importance. Examples include electricity networks, financial networks, residential choice networks. We propose an Agent-Based Model approach to simulate interdependent technical and social network behavior, the effects of potential policy measures and the societal impact when disturbances occur, where we focus on a use case concerning the smart grid, an intelligent system for matching supply and demand of electricity.

Paper Nr: 95
Title:

Machine Understanding and Avoidance of Misunderstanding in Agent-directed Simulation and in Emotional Intelligence

Authors:

Tuncer Ören, Mohammad Kazemifard and Levent Yilmaz

Abstract: Simulation is being applied in many very important projects and often it is a vitally important infrastructure for them. Several types of computational intelligence techniques have been part of the abilities of simulation. An important aspect of intelligence is the ability to understand. Agent-directed simulation (ADS) is a comprehensive paradigm to cover all aspects of synergy of software agents and simulation and our approach is to develop agents with understanding abilities. After a brief review of ADS, our paradigms of machine understanding is presented. The article clearly indicates types of misunderstandings that might occur. Our research plans are to avoid some of the misunderstandings which could occur and especially to have self-attesting abilities in our applications to document which types of misunderstandings are avoided.

Short Papers
Paper Nr: 14
Title:

The Optimal Quaternion Equilibrium Point - Using an Energy Function to Choose the Optimal Quaternion Equilibrium Point

Authors:

Margrete Djupaa and Rune Schlanbusch

Abstract: By parameterizing the attitude of a rotating rigid body in a closed-loop system with unit quaternions, the existence of dual equilibria leads to new challenges. In order to optimize the energy consumption due to control effort, the choice of the cheapest equilibria, that is, the one which requires least energy to reach, is essential. A new predicting solution of choosing the optimal equilibrium point for rotational maneuvers of a rigid body is presented in this article. This new solution consists of an energy function which base its prediction on the initial attitude on the rotational sphere, taking account for both potential and kinetic energy of the rigid body. The equilibrium energy function is developed through a previously presented statistical analysis for the system behaviour of a rigid body in closed loop attitude control.

Paper Nr: 56
Title:

Effects of Wall Roughness, Impeller Blades and Diffuser Vanes on the Performances of a First Stage Centrifugal Pump

Authors:

Nicolas La Roche-Carrier, Guyh Dituba Ngoma and Walid Ghie

Abstract: In this study, the first stage of a multistage centrifugal pump was numerically investigated to improve its design. The continuity and Navier-Stokes equations with the k- ε turbulence model and standard wall functions were used. The effects of the wall roughness height, impeller blade height and diffuser vane height, and the number of diffuser vanes on the performances of the first pump stage were analyzed. The results achieved demonstrate that the selected parameters affect the pump stage head, brake horsepower and efficiency in a strong yet different manner. To validate the approach developed, the results of the numerical simulations were compared with the experimental results.

Paper Nr: 65
Title:

Crowd Simulation on a Graphics Processing Unit based on a Least Effort Model

Authors:

Sankha B. Dutta and Robert D. McLeod

Abstract: Large crowd simulation is becoming a very important field of study for many researchers. In this paper we endeavour to study large crowds and their interactions with each other and the environment. The interaction is based on a very simple Least Effort Model inspired from a real world pedestrian modelling scenario. The simulation of the crowd is computationally very expensive and GPU modelling and simulation is a viable alternative computational means to accelerate the simulation process. Compute Unified Device Architecture or CUDA is used for GPU implementation.

Paper Nr: 70
Title:

Numerical Simulation of Odorous Dispersion Hydraulics and Aeration Device in WWTP’s

Authors:

Hatem Dhaouadi and Hatem Mhiri

Abstract: Most of the WWTP use biological processes which are intrinsically dynamic because of the large variations in the wastewater flow rate, pollutants concentration and composition. These variations are to a large degree not possible to control and the use of simulator may be helpful. CFD, one of the most used numerical tool, is employed in this study to prospect three particular technical aspects of WWTP, namely odors dispersion, hydraulics of a high rate airlift algal pond and mass transfer performances of surface aerators. Fluent® software is used and the validation of the developed models is made using a real scale WWTP data. This experimental validation is supported by the monitoring of the main odour pollution parameter (gaseous H2S concentration) through different zones around El-Frina WWTP. CFD models are also used to examine the behavior of gas and liquid phase dynamic throughout the high rate airlift algal pond and results are compared to those obtained with measurements made at Sidi Bouali WWTP. Concerning the aeration system capacity, gas liquid mass transfer study of surface aerators has been conducted on a lab scale Rushton blades.

Paper Nr: 79
Title:

Social Network Modelling for Counter Extremism - Comparing Criminality in Two Activist Networks

Authors:

Rosemary Penny, Robert Bowles and Noémie Bouhana

Abstract: This paper examines the phenomenon of extreme protest activities in the environmental and animal rights movements, and how their propagation can be simulated through the construction of agent-based models. It uses criminological theory to examine what factors cause a propensity for violent action to spread across social networks, and uses this as the basis for constructing agent-based models of the activist networks. The differences in the results emerging from the models enable inferences to be made regarding which elements in their construction may cause the differences. Modifying the models to explore how these differences in construction affect the outputs from the models enables us to further understand which real-world factors may contribute to differences in the spread of criminality through the social networks of activists.

Posters
Paper Nr: 6
Title:

A Computerized System, the FANDAS Code, for Design, Flow, Performance and Noise Predicitions of Industrial Axial FAN

Authors:

Chan Lee and Hyun Gwon Kil

Abstract: FANDAS (FAN Design and Analysis System) code is developed for the design, the performance and the noise predictions of industrial axial fan. In the FANDAS code, the 3-D geometrical designs for impeller blades and casing of fan are made through blade angle distribution, camber line determination and blade airfoil thickness distribution processes along blade span height, and their results are shown in GUI( Graphic User Interface ) window. Based on the design fan geometry, the FANDAS code automatically predicts the flow field inside fan and the overall performance map of fan by using flow deviation and pressure loss models. The noise level and spectrum of designed fan are also evaluated by the FANDAS code which contains noise analysis models for discrete frequency and broadband noise components of axial fan. All the performance and the noise prediction results are displayed on GUI windows. The simulation technique of the FANDAS code is coupled with the CFX code and applied to an actual air-conditioning fan design practice for optimizing design variables to maximize efficiency and minimize overall noise level of fan. The optimal fan design obtained from the FANDAS simulation results shows about 10% efficiency improvement and 11dB noise reduction compared with the commercial market product of a reference model, and its simulation results are well-agreed with the measurement within a few percent relative error.

Paper Nr: 8
Title:

A Generalized Model Transformation approach to Link Design Models to Network Simulators - NS-3 Case Study

Authors:

Iyas Alloush, Yvon Kermarrec and Siegfried Rouvrais

Abstract: Telecom service creation (TSC) activity is one of the most important phases of a TS life cycle. There are many efforts that were done to improve this activity recently. The early verification of the TS from its design models give an advantage to the service provider to improve the qualities and to detect design errors before the implementation phase. Simulation makes it possible to predict the system behavior avoiding the cost of real systems. Our objective in this paper is to present our methodology to link high abstract models of telecom services to network simulators. Relying on Model Driven Engineering, we propose a generalization of code generation methodology using an IMS meta-model and simulator-dedicated templates. In our approach, the network simulator specifications are related to the transformation template only, while the underlying platform specifications and standards are included in the meta-model. We illustrate our approach with a new transformation to generate configurations for NS-3. We apply an example of a video conference service to generate the simulation code.

Paper Nr: 49
Title:

Mimicking Complexity - Automatic Generation of Models for the Development of Self-adaptive Systems

Authors:

Jérémy Boes, Pierre Glize and Frédéric Migeon

Abstract: Many methods for complex systems control use a black box approach where the internal states and mechanisms of the controlled process are not needed to be known. Usually, such systems are tested on simulations before their validation on the real world process they were made for. These simulations are based on sharp analytical models of the target process that can be very difficult to obtain. But is it useful in the case of black box methods? Since the control system only sees inputs and outputs and is able to learn, we only need to mimic the typical features of the process (such as non-linearity, interdependencies, etc) in an abstract way. This paper aims to show how a simple and versatile simulator can help the design of systems that have to deal with complexity. We present a generator of models used in the simulator and discuss the results obtained in the case of the design of a control system for heat engines.

Area 4 - Application Domains

Full Papers
Paper Nr: 9
Title:

A Two-step Bidding Price Decision Algorithm under Limited Man-Hours in EPC Projects

Authors:

Nobuaki Ishii, Yuichi Takano and Masaaki Muraki

Abstract: In Engineering-Procurement-Construction (EPC) projects, the contractor accepts an order through a competitive bidding process. If the contractor’s bidding price is set higher than that of a competitor due to cost estimation error, the contractor could fail to receive the order. Conversely, if the cost estimation error results in an underestimation of the cost, the contractor would be granted the order; however, he would eventually suffer a loss on this order. Thus, a bidding price decision in consideration of the cost estimation accuracy and the deficit order probability is essential for the contractor in EPC projects. In this paper, we develop a two-step bidding price decision algorithm. It allocates MH (Man-Hour) for cost estimation, which determines the cost estimation accuracy, to each order under the limited volume of MH, and then determines the bidding price for maximizing the expected profit under the deficit order probability constraint. Numerical examples show that the bidding price decision in consideration of the cost estimation accuracy and the deficit order probability is essential for the contractor to make a stable profit in EPC projects, and that the developed algorithm is effective for making such bidding price decision.

Paper Nr: 91
Title:

HIP_IKEv2: A Proposal to Improve Internet Key Exchange Protocol-based on Host Identity Protocol

Authors:

S. Smaoui, F. Zarai, M. S. Obaidat, K. F. Hsiao and L. Kamoun

Abstract: IKEv2 offers authentication, authorization and key agreement services to establish a security association between two peers bound to IP addresses, but it is still vulnerable to some security problems such as denial of service (Dos) and man-in-the-middle attack. Host Identity Protocol (HIP) is also a security protocol that defines host identifiers for naming the endpoints and performs authentication and creation of IPsec security associations between them bound to identifiers. The purpose of HIP is to support trust systems, enhance mobility and greatly reduce the Denial of Service (Dos) attacks. We focus on an extension to IKEv2 in order to enhance authentication, eliminate man-in-the-middle attack and guarantee denial of service to provide better security between the two peers. In this paper, we describe our proposal that consists of combining the IKEv2 with the HIP to set up a security association based on two parameters which are location and Identity. This combination can provide better security properties than each protocol used alone. This scheme, named (HIP_IKEv2) couples location and identity to define a security association between two peers. We have used the Automated Validation of Internet Security Protocols and Applications (AVISPA) and its Security Protocol Animator (SPAN), and two powerful automated tools in order to formally specify and validate the HIP_IKEv2 protocol.

Paper Nr: 94
Title:

Social Layers and Population Models Directed by Intelligent Agents for Estimating the Impact of Operations and Investments

Authors:

Agostino G. Bruzzone, Marina Massei, Christian Bartolucci and Lorenzo Capponi D’Agostino

Abstract: This research aims to support operations planning and management in complex scenarios where population and interest groups are critical elements; in particular the paper propose experimental analysis carried out on a complex South Asia scenario by running an HLA Federation driven by Intelligent Agents; the context is allows to simulate investments and operations over a an asymmetric mission environment with insurgents, terrorists, different parties and articulated social frameworks. The proposed scenario is characterized by various degrees of freedom and it needs to be modelled and simulated in order to evaluate the evolution of human behaviour and socio-psychological aspects. The authors have developed special models in which Computer Generated Forces (CGF) are driven by Intelligent Agents (IAs) that represents not only units on the battlefield, but also people and interest groups (i.e. Middle Class, Nomads, Clans); the study is focused on Civil Military Co-operations (CIMIC) and Psychological Operations (PSYOPs); while the simulation has been developed using an architecture that involves various federates in different roles. Along the entire life cycle of the research processes of Verification, Validation and Accreditation have been applied in order to determine the correctness and effectiveness of the results and the paper proposes experimental results obtained during the dynamic test of the federations.

Short Papers
Paper Nr: 13
Title:

Viability Study on Supervisory Control for a Solar Powered Train

Authors:

Beatriz Féria and João Sequeira

Abstract: This paper addresses the design and simulation of a control system for a solar powered train. An intelligent control approach using Petri nets is followed aiming at managing the energy consumption such that the train always reaches its destination. The system uses a priori information on the topology of the line, including length and slopes, locations of the intermediate stations, and also on the dynamics of the train, current solar irradiance and weather forecasting, and passenger weight, to determine bounds on the train velocity profile. The whole system was simulated integrating Petri nets in a Matlab/Simulink environment.

Paper Nr: 29
Title:

Simulation Modeling of Maritime Piracy using Discrete Event and Agent-Based Approaches

Authors:

A. Emre Varol and Murat M. Gunal

Abstract: In the last decade, maritime piracy has affected the global economy that forced the countries to react. Most of the reaction is regarding force deployment in the affected regions. In this study, we present a simulation based analysis tool that aims at understanding the relationship between naval forces deployment and preventing piracy. We consider three stakeholders’ views; pirates, maritime transportation, and naval forces. We initially created a classical Discrete Event Simulation (DES) model and adopted event scheduling approach. However, later, we discovered that since the behaviours of entities, interaction between entities, and the autonomy properties of entities are significant, Agent Based Simulation (ABS) concepts are appropriate for modeling. Finally, we ended up with a hybrid DES and ABS model. Our conceptual model is created using event graphs and the model is implemented using SharpSim DES library. Additionally, we coupled an open source Geographic Information System (GIS), GreatMap, with SharpSim.

Paper Nr: 39
Title:

Coordination of Processes as a Starting Point for Simulation-based Management of Biological Incidents

Authors:

Tereza Otčenášková, Vladimír Bureš, Pavel Čech and Jana Prattingerová

Abstract: Biological incidents nowadays represent more often as well as more serious threat endangering important assets. Their management requires complex approach including high demands on technological support. This paper neither contributes with another simulation model or results, nor offers the application of specific technology. It utilises the literature analysis and interviews with experts to reveal the framework for potential options and scenarios for simulation employment in the realm of management of biological incidents. Conceptual issues related to the simulation of biological incidents together with process perspective are provided and advantages as well as prospective utilisation in modelling and simulation are discussed.

Paper Nr: 63
Title:

A Distributed Simulation Model of the Maritime Logistics in an Iron Ore Supply Chain Management

Authors:

Afonso C. Medina, Luis G. Nardin, Newton N. Pereira, Rui C. Botter and Jaime S. Sichman

Abstract: Supply chain management (SCM) has increased its importance in the last decades, accordingly demanding new approaches to support its decision making processes. Simulation has been advised as an adequate approach for fulfilling such demand. However, develop monolithic simulation models representing the whole supply chain can be costly and time consuming. In the iron ore supply chain in which the seaports have the same features, the use of generic models and distributed simulation may be a real alternative in order to reduce the development time and costs. This paper presents a distributed simulation model of the maritime logistics in an iron ore supply chain applied to support fleet management decisions. Such model was used to perform an experiment in order to determine the maximum possible cargo volume supported by a ship fleet.

Paper Nr: 81
Title:

Application of Mathematical Modelling for Simulation of Galvanic Corrosion

Authors:

Vít Jeníček, Martina Pazderová and Linda Diblíková

Abstract: This paper deals with an application of mathematical modelling for simulation of galvanic corrosion. A programme for simulation of galvanic corrosion in a thin film electrolyte layer is presented. The programme comprises some mathematical simplifications bringing significant reduction of computational demands and on the other hand a need of specific form of input data. Necessary background for galvanic corrosion is mentioned and the simplifications are described as well as the form of input data. An example of measured input data and their application is shown. Discussion of used assumptions, input data availability and measuring possibilities of the input data is included.

Posters
Paper Nr: 25
Title:

CFD Simulation of a Large-diameter Combined Gas Distributor

Authors:

Xubo Luo, Jinsheng Sun, Jichao Ren, Hong Gao, Linan Li and Chuanxin Pan

Abstract: In the chemical and process industries, it is a challenge to achieve a uniform initial gas distribution for the packed column with super large diameter and large feed pipeline. This paper suggests a novel combined gas distributor with a large diameter of 6.2m, which integrates a twin-tangential annular flow vapour horn and a shell vane type inlet device (SchoepentoeterTM, Sulzer Ltd., Switzerland). CFD simulations were carried out to evaluate the performance of the distributor in a column of 6.2m in diameter with a feed pipeline of 3m in diameter. The uniformity of the gas flow on a horizontal plane over the gas distributor was assessed by means of pressure drop and the mal-distribution parameter. Several factors that affect gas distribution, such as the gas inlet velocity, the width of the annular channel,and the split ratio between the radial and annular channels, were analysed comparatively. The gas distribution was found to be more uniform when the annular channel width was 500 mm and the split ratio was 4. Several structural improvements were suggested with their proof simulations showing the superiority of the improved structures over the prototype.

Paper Nr: 92
Title:

A Discrete Simulation Framework for Part Replenishment Optimization

Authors:

David Alfred Ostrowski, Bradley Graham and Oleg Gusikhin

Abstract: Supply Chains are difficult to plan as they involve complex relations and maintain dynamically changing variables that influence them. In this paper, we present a discrete event simulation framework for purpose of decision making in a replacement auto parts Supply Chain. Ford Motor’s Parts, Supply and Logistics (PS&L) department supports a Supply Chain that represents a trade-off where parts are either maintained at a central distribution facility or sent directly to local distribution center. This represents a compromise between inventory transportation costs and accessibility in parts distribution. To support decisions within this environment, we present a framework to characterize this scenario as a discrete simulation problem allowing for the means to evaluate controls for the determination of optimal inventory (on-hand inventory dollars), fill rate and labor costs. Our case study results demonstrate the necessary dynamics to support this decision making process.