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Abstract: Recycling activities have demonstrated a remarkable increase over the last decade due to the economic and environmental dimensions of sustainability. In particular, capacity planning in production facilities has become a strategic issue of key importance affecting the profitability of the recycling industry. By integrating the simulation discipline and the feedback control theory into a dynamic consideration of recycling networks, this paper proposes a System Dynamics (SD) model for strategic capacity planning in the recycling industry. The decision-making process is based on a balanced tradeoff between profit and capacity utilization for a single producer with closed-loop recycling activities. The SD model captures physical stocks and flows apparent in real-world recycling networks and includes the feedback mechanisms which regulate these flows. When used as an “experimental tool”, the model tests alternative capacity planning policies and demonstrates policy suggestions for the forward and reverse channels, which maximize profitability over a strategic planning horizon. This experimentation is illustrated by using data from a paper producer with recycling activities, as a real-world test case. Extensive simulation runs, investigate the efficiency of a wide range capacity acquisition decisions, using total company profit as the measure of performance. Although such an analysis may differ from one recycling network to another, it has been kept as generic as possible to facilitate its applicability to a wide-spectrum of real-world local, regional or global networks. [Copyright &y& Elsevier]

A three-dimensional model of the steam ejector heat pump for the dryer section of the paper machine was developed by applying the Computational Fluid Dynamics (CFD) technique, which provided the pressure and velocity distributions of fluid flow in heat pump. The results indicated that the fluid velocity field in heat pump has an incomplete axially symmetrical distribution. The entrainment ratio of the heat pump initially increases rapidly with the increase of the ejected steam inlet pressure and then decreases after the inlet pressure exceeds one certain value. There exists a critical value for the mixed fluid pressure under the given operating conditions. The optimal ratio of the diameter of constant area mixing section to the steam nozzle throat diameter is about 3.4 and the optimal ratio of length to diameter of constant area mixing section L/D m is 6. An optimal divergence angle of diffuser was observed under different diffuser length. There is an optimized steam nozzle position under the given operating condition where the maximum of entrainment ratio was observed. The CFD technique is found to be an efficient alternative to predict the ejector performance and the conclusions of the research can provide a beneficial reference for structural optimization design of ejector. [ABSTRACT FROM AUTHOR]

Paper is a stochastic network of fibres, water and additives, and in that sense it may be envisaged as a composite material. Since fibres are much longer than the thickness of the paper sheet, the network is planar and almost two-dimensional. The two-dimensional structure governs many paper properties but the three-dimensional porous structure is also important. Insight into the structural changes that take place when paper is compressed in the paper machine may be gained by modelling and simulation of its viscoelastoplastic behaviour. The present work describes a mathematical model based on the cellular solids theory, characterising the nonlinear rheologic behaviour of the material. This approach results in an unsteady state problem and the resulting set of ODEs is solved by means of the DLSODES subroutine, which uses an integrator based in the Gear method. Experiments were conducted on a laboratory-scale dynamic press in order to validate the mechanical model. [Copyright &y& Elsevier]

Macroscopic traffic flow models are powerful tools for assessing the level of service on freeway segments. One popular model is the Cell Transmission Model (CTM) proposed by Daganzo. The US highway capacity manual (HCM) operationalizes this model in the form of the simulation tool FREEVAL for assessing sequences of freeway segments. The conceptual CTM also supports networks of freeway segments. In the literature this was implemented and applied to a mid-scale freeway network of 340 km. However, the literature lacks research in efficient implementations of CTM, which becomes relevant when applying it to large-scale networks at national scale like the German Autobahn with a length of 260 000 km. In this paper we propose a vectorized formulation of the CTM for networks. Boolean vectors are employed for vectorized case distinction. Furthermore, we exploit the properties of adjacency matrices to achieve shifting operation on complex network structures. To evaluate the vectorized CTM implementation, we simulate synthetic freeway network grids of varying size and complexity for different simulation periods. The results show that the network complexity has no influence on computation time, while it scales linear in simulated hours. A quadratic regression was applied to the measured computation times over varying network sizes. For large network sizes, the vectorized CTM implementation achieves a speedup factor of 9 compared to a sequential implementation. When simulating 2880 kilometers of freeway, the computation time of 2.3 hours is reduced to 16 minutes. [ABSTRACT FROM AUTHOR]

This paper introduces a flexible framework to enable high-fidelity simulations of the fuel slosh dynamics for verification of the Guidance, Navigation and Control (GNC) algorithms. The sloshing phenomenon must be tackled during the control system design phase and the GNC software run and validated within appropriate simulation frameworks. Equivalent mechanical models can well approximate sloshing under specific assumptions, allowing the derivation of the multibody vehicle's equations of motion; however, while suitable for analysis and control synthesis purposes, this approach presents several limitations for implementation as a simulation model. In this work, the multibody plant embedding slosh dynamics is modeled by means of the DLR's Vertical Landing Vehicles Library (VLVLib) written using the object-oriented Modelica modeling language. The advantages of using Modelica are explored throughout the paper. Given that control synthesis, analyses and simulation campaigns are usually performed in the Matlab/Simulink environment, a core point of the proposed solution is to achieve a good synergy within the latter and the Modelica plant model with the least readaptation burden for the developer. The strategies to achieve a full integration and verification tool chain are illustrated. The potential of this approach is demonstrated via two different test cases: a lunar landing scenario of the ALINA spacecraft developed by PTS, and CALLISTO reusable rocket demonstrator. • A flexible framework to enable high-fidelity simulations of the fuel slosh dynamics for verification of the GNC algorithms is introduced. • The spacecraft model embedding the slosh dynamics is implemented exploiting Modelica language. • A GNC testing framework is obtained with the integration of the causal Simulink environment with the compiled Modelica model. • Two test cases are presented: the ALINA spacecraft lunar landing scenario and CALLISTO reusable Vertical-Takeoff–Vertical-Landing demonstrative mission. [ABSTRACT FROM AUTHOR]

Swarm Production is a novel paradigm promoting a high degree of flexibility in material flow and reconfigurability in shop floor layout, enabling high-mix production in manufacturing through the induction of autonomous robots. The conceptual description promises a leap within smart manufacturing and the Industry 4.0 domain. Implementing this theoretical concept becomes crucial to the self-organising production domain and gradually learning the relevant technological stack, optimisation methods, objective functions, and shop floor constraints needed for Swarm Production. This research paper addresses the challenges of the simulation of autonomous mobile robots in the production environment and concludes with an exemplified case simulation. A simulation testbed visually demonstrates the concept with planning, scheduling and control systems, providing their feasibility and reliability. [ABSTRACT FROM AUTHOR]

Abstract: This paper concerns the modelling of an accumulator used in industrial elastic web processing plant such as paper mills, fabric, rolling mills etc. Accumulators are used to allow rewind or unwind core changes while the process continues at a constant web velocity. A new nonlinear model of a pneumatic actuated industrial accumulator including pneumatic jack model, static friction representation and web weight is first detailed which enables to deduce a linear model. These models are derived from physical laws that describe web tension and velocity dynamics in each web span. In a second part, the effects of time-varying mechanical parameters, such as web Young modulus, web length and rollers inertia on accumulator dynamics are presented. The performances of the modeled accumulator are illustrated by simulations in Matlab/Simulink software environment. [Copyright &y& Elsevier]

The interbank lending network, while facilitating transactions, poses risk contagion in the banking system. To address challenges in existing research, this paper models the interbank lending network using a multi-agent approach and generates a dynamic network through a bidirectional matching mechanism(BiMM). Additionally, We divide banks into three categories based on realistic bank balance sheet data. Given the fact that banks of different categories exhibit different degrees of contagion, we propose the weighted DebtRank (W-DebtRank). Then, comprehensive simulation analysis is conducted on the risk contagion of heterogeneous banks in the dynamic network using W-DebtRank. The proposed method addresses four issues: the heterogeneity of banks, the dynamic nature of networks, the practicality of lending strategies, and the comprehensiveness of risk analysis. The model is validated using the SRISK metric and the Monte Carlo-based SYMBOL simulation model. Through multiple perspectives in simulation experiments, the risk contagion process among banks is deeply investigated in our paper. [ABSTRACT FROM AUTHOR]

This paper presents a method to automatically improve simulation model accuracy by using a stochastic gradient descent algorithm. The proposed algorithm updates models' parameters based on data collected from the actual domain under investigation. Collected data and feedback are fed into the simulation model to get predictions. In a linear prediction model, this data, along with the predictions, would form a typical regression problem; however, the stochastic gradient descent algorithm was modified to update the simulation model parameters. A tunneling case study is presented here, and the results show that the proposed algorithm can decrease simulation error by more than 50%, even in the case of incomplete simulation models or a missing inter-relationship between elements. Besides improving initial models, this paper provides a new approach for achieving data-driven simulation models that are updated in real time based on feedback from the actual domain. • Proposing a data-driven approach to enhance simulation performance. • Using stochastic gradient descent algorithm to update simulation parameters. • Deriving mathematical model to calculate error rate from a simulation model. • Applying the proposed method in a real case study of a tunneling project. • Suggesting a new approach for fitting data to model a simulation. [ABSTRACT FROM AUTHOR]

The paper describes the state-of-the-art in modeling and simulation of surface texture and topography generation at micro and nano dimensional scales. Three main classes of manufacturing processes used for the generation of engineering surfaces are considered: material removal processes, material conservative processes, and material additive processes. Types of modeling techniques for the simulation of surface generation are reviewed and discussed including analytical models, numerical multi-physics models, and data-driven methods. After presenting the application of those modeling techniques for the prediction of characteristics and geometry of surfaces generated by different manufacturing processes, their performance, implementation, and accuracy are discussed. Finally, a roadmap for the realization of a complete surface generation digital twin in manufacturing is outlined. [ABSTRACT FROM AUTHOR]

Abstract: Closure of water circuits in papermaking is of vital importance for achieving a more sustainable and economic manufacturing of paper. The most important limiting factor for a further closure is the accumulation of dissolved and colloidal materials (DCM). The extent to which DCM can become enriched in the water depends not only on how many times water is reused but also on the degree to which this matter becomes reattached to the fibers and other solid components of the paper furnish. This study analyzes the accumulation of the most typical contaminants in newsprint (NP) and light weight coated (LWC) paper production. Results show that the release of DCM depends on the present contaminant load in the waters: higher at low contaminant load and lower at high contaminant load. A simulation was carried out to analyze the differences between assuming a constant and a variable release of contaminants to waters. Important differences were observed, especially at low fresh water consumption for those species with a major affinity for the fibers. [Copyright &y& Elsevier]

A Physical Internet of hubs ('PI-hubs') is a network of logistics terminals that allow shipments to flow through, similar to the flow of Internet data packets. PI-hub networks are a recent proposal and their properties have not been studied in detail. In this paper we model PI-hub networks using the theory of queuing networks, particularly, Jackson queuing networks. Under certain assumptions, PI-hub networks behave like Jackson queuing networks, and thus analytical methods can be used to calculate important properties such as throughputs, processing times, traffic size etc. In this paper we analyse the performance characteristics (throughput, queue size) for each PI-hub and for the whole PI-hub network. [ABSTRACT FROM AUTHOR]

The computational fabrication community is developing an increasing interest in the use of patterned surfaces, which can be designed to show ornamental and unconventional aesthetics or to perform as a proper structural material with a wide range of features. Geometrically designing and controlling the deformation capabilities of these patterns in response to external stimuli is a complex task due to the large number of variables involved. This paper introduces a method for generating sets of tileable and exchangeable flat patterns as well as a model-reduction strategy that enables their mechanical simulation at interactive rates. This method is included in a design pipeline that aims to turn any general flat surface into a pattern tessellation, which is able to deform under a given loading scenario. To validate our approach, we apply it to different contexts, including real-scale 3D printed specimens, for which we compare our results with the ones provided by a ground-truth solver. [Display omitted] • Patterns are interesting from a visual and a mechanical perspective. • Their computational design is complex and an intriguing task. • We provide an efficient simulation model with our generated flat patterns. • Pipeline for direct design of tiled patterns' assemblies. • Design exploration with an interactive tool that manages geometry and loads. [ABSTRACT FROM AUTHOR]

Ethylene and propylene are among the light olefins which are the main building blocks in the petrochemical and chemical industry. They are produced from thermal/catalytic cracking of gaseous and liquid hydrocarbons and recently from methanol. This paper continues the two review articles published before entitled thermal and catalytic cracking of hydrocarbons for the production of light olefins. In the last two review articles, the processes and the kinetics of thermal and catalytic cracking have been discussed in details. This paper reviews the mathematical modeling and simulation of the olefin plants including mechanisms and kinetic models, CFD simulations, rigorous models, and abstract models. [ABSTRACT FROM AUTHOR]

A Physical Internet of hubs ('PI-hubs') is a network of logistics terminals that allow shipments to flow through, similar to the flow of Internet data packets. PI-hub networks are a recent proposal and their properties have not been studied in detail. In this paper we model PI-hub networks using the theory of queuing networks, particularly, Jackson queuing networks. Under certain assumptions, PI-hub networks behave like Jackson queuing networks, and thus analytical methods can be used to calculate important properties such as throughputs, processing times, traffic size etc. In this paper we analyse the performance characteristics (throughput, queue size) for each PI-hub and for the whole PI-hub network. [ABSTRACT FROM AUTHOR]

Abstract This research paper is developed as a practical guide on preparedness against possible threats that are usually unconsidered or undermined in Egyptian conservation schemes and agendas. The unequivocal importance of the Karnak temple (KT) in Luxor, Egypt presented this monument as a major target for investigation. Reviews of recent conservation endeavors in the KT unveil a clear lack of awareness concerning preparedness against fast, sudden and unpredictable threats. The preparedness plan developed in this research paper for the KT tackles the relationship between sources of threats, past disaster incidents, inducible risks and the process of generating interventions to contain risks and minimize damages. Issues of scientific uncertainty are transcended for the greater aim of preparing a preparedness plan against possible and potentially harmful threats. [ABSTRACT FROM AUTHOR]

Abstract The development of reliable controllers can be a complex task, mainly because there is no well-established systematic methodology developed specifically for this purpose, considering all range, from requirements analysis till code implementation in real controller and considering real-time implementation issues. This paper introduces a design strategy as a proposal for obtaining reliable controllers for critical mechanical systems, which is based on the integrated application of four analysis techniques usually used in dependable systems development: modeling, simulation, formal verification and conformance testing. The paper demonstrates, by means of a case study, that the adequate integrated implementation of such techniques results in a systematic concurrent approach for the development of reliable automatic control systems. The case study consists of a detailed application of the proposed approach in the synthesis of the automatic train control (ATC) system of an automated people mover (APM) operating in accordance within the concept of communication-based systems (CBTC - Communication-Based Train Control). This case study is used to illustrate the method, presenting and discussing the steps necessary to implement the proposed design strategy in the development of a typical piece of control software for critical mechanical systems. [ABSTRACT FROM AUTHOR]

The “Who said what?” protocol is a popular experimental paradigm and has been used for 40 years to study spontaneous mental categorization. This paper offers a crucial methodological improvement to calculate unbiased estimates in multidimensional “Who said what?” studies. Previous studies predominantly corrected for base rates by first correcting the base rates and consequently aggregating errors for the two dimensions separately. The paper demonstrates that this procedure's estimates are biased. A large simulation of over 175,000 experiments and the re-analysis of a pivotal study show that this may increase both false-positive and false-negative error rates in treatment effects and might therefore, respectively, strengthen or weaken evidence for past hypotheses. The paper offers a simple remedy: researchers should first aggregate errors for each dimension and then correct for base rates relying on the method known from single-dimensional studies. [ABSTRACT FROM AUTHOR]

This paper is motivated by the discussion in the literature about the strengths and weaknesses of the Multi-Level Perspective framework and aims to provide a response to a number of criticisms. The paper proposes retroduction as a transition research methodology that is used to identify and test social mechanisms for their explanatory power. The methodology consists in the joint use of case study and system dynamics as modeling and simulation method. The paper discusses how the two methods are used iteratively, and each one complements the strengths and counters the weaknesses of the other. The methodology has particular strengths and implications for the agenda of issues that research on future transitions to sustainability faces currently. [ABSTRACT FROM AUTHOR]

Systematically assessing the influence of new urban plans is an important challenge for designing them efficiently. In this paper, we propose a method to assess the influence of local ‘Right to Build’ regulations on constructibility. Our method is based on an optimization algorithm that generates building configurations. This method requires a geographic model that supports the formalization of the Right to Build regulation in order to check if a building respects it. The proposed approach relies on the trans-dimensional simulated annealing optimization method, which produces building configurations composed of a set of parametric objects (boxes in our implementation). Our proposition is released as the SimPLU3D Open-Source project ( http://ignf.github.io/simplu3D/ ). In this paper, we present some tests and results based on this implementation and a use related to the assistance to ‘Right to Build’ designers. [ABSTRACT FROM AUTHOR]

The replacement of living lawns with synthetic (plastic) grass seems to be on the increase in cities. This paper presents some environmental and societal considerations relating to the installation of artificial lawns to encourage research of the phenomenon at this early stage of emergence. After first discussing the development of ‘third generation’ synthetic grasses that have made artificial lawns more appealing, it then considers how the replacement of living lawns with plastic grass represents a potentially concerning step towards ecological simulation, or the replacement of real ecosystems with simulacra that address cultural desires but remove nature altogether. The paper then examines some of the possible environmental and societal impacts that may result from the replacement of living lawns with their artificial counterparts, and concludes with the presentation of a research framework for investigation of the emerging artificial urban lawnscape. [ABSTRACT FROM AUTHOR]

This paper presents a review of the design parameters, mathematical techniques and simulations used in the design of parabolic trough solar systems, along with a review on their applications. Recent studies that analyze the deployment of solar parabolic trough collectors (SPTC) in different countries and the operational SPTC plants are also presented and discussed. The paper also discusses the different kinds of software and test methods of solar collectors developed since 1981 which can be distinguished by their particular mathematical models or tracking techniques. In particular, since the mathematical models are especially required for the design, analysis, testing and validation of the systems results as they provide an approximation of the dynamic behavior of the physical properties of the system, they are discussed in depth. The mathematical models allow the calculation of different parameters of the solar parabolic trough system, the angle of inclination of the collecting surface and the forces acting on the system. The validity and experimental validation of the major mathematical models on practical solar parabolic trough concentrators, receivers and other components of different dimension are also reviewed. The paper showed the optical efficiency values are close to 63% and the theoretical peak optical efficiency reached 75%. [ABSTRACT FROM AUTHOR]

The paper develops strong approximation schemes for solutions of stochastic differential equations with Markovian switching (SDEwMSs). The convergent orders of existing strong numerical schemes all are 0.5. This paper provides a convergence theorem for the construction of strong approximations of any given order of convergence for SDEwMSs, and then constructs the order 1 scheme, the order 1.5 scheme. The paper also develops a new way to simulate the Markov chain and hence the order 1 scheme. Finally, a numerical example is provided to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

In this paper it is presented a new open source tool for evaluating data fusion systems, mainly related to the maritime surveillance domain. This tool provides specific utilities for designing and simulating synthetic maritime environments to assists in the fusion development process, like designing vessels trajectories, placing different types of sensors, simulating vessels dynamics, or simulating sensors detections. This synthetic information can be used to feed a data fusion system to evaluate its response in a reproducible way under different conditions. This tool can be used to optimize the data fusion evaluation process, since testing a fusion system is a quite complex task, as the fusion output depends on the combination of multiple algorithms, configurations, measures, timing, and so on. Then, having reproducible synthetic environments can be quite useful when evaluating fusion results, system performance in dense scenarios, vessel trajectories with different dynamics, sensor coverages, and so on. This tool has been used with success for evaluating different fusion systems, and now it is presented as an open source tool, so it can be easily adapted to different environments, be used by other researchers, or extended by the community. This paper presents how it is built, the underlying algorithms, and presents some example use cases. [ABSTRACT FROM AUTHOR]

In this paper we present a multiphysics simulation model of Halcyon, an autonomous unmanned surface vehicle (USV). The simulation model presented in this paper has been developed to rapidly progress the design, development and validation of Halcyon’s autonomy management system, particularly in challenging sea conditions. Using simulation for this purpose enables extensive testing across the full environmental operating envelope of the vessel, hence greatly reducing the need for real-world sea-trials. The simulator is comprised of a novel and comprehensive sea-surface wave environment model, a six degree of freedom nonlinear unified seakeeping and manoeuvring boat dynamics model, an actuation dynamics model, an autopilot and an interface with an autonomy management system. Results are presented that show good agreement between real-world and simulated sea-trials data. [ABSTRACT FROM AUTHOR]

Customers all over the world have great expectations in terms of the delivery and availability of supplied items. It is thought that the most important, both for suppliers and their customers, are short-term orders realisation and flexible services. Simulation methods can be a strongly support for an entrepreneur in decision making process connected to these expectations or short-period and long-period planning. Simulation methods ensure possibilities to test and analyse different kind of “what-if” scenarios of distribution systems such as: potential surplus of orders or other untypical things mostly describes as force majeure. The main aim of the paper is to consider simulation model of distribution system that occur in one international entrepreneur that operates in the area of Poland. The paper consists of literature review, a reference model of the original system with elementary formal notation included and a reference model implementation into simulation software (in form of simulation model), conclusions and potential directions on the model development. The model of the distribution system consists of vertices and edges. Chosen vertices are elementary form of logistics facilities such as warehouses and production facilities such as factories. Meanwhile, edges are real shaped routes between verticals, if they exist. [ABSTRACT FROM AUTHOR]

Because of the lack of satisfactory solutions to explain biological systems, biologists usually focus on modelling and simulation tools to understand the behaviour of these complex organisms. Indeed, computational modelling and simulation of cells plays a pivotal role in systems biology. In this paper, we tackle the problem of studying the behaviour of human cells by reproducing the behaviour of complex biomolecular networks. To this end, we present in this paper an approach for simulating complex biomolecular networks inspired by the discrete-event simulation model (DEVS), a formalism developed for supporting the modelling of complex systems. In this paper, we propose a simulation tool, named ”CBNSimulator”, based on a logical model of the biomolecular network and taking advantage of the performance of a discrete-time simulation model for understanding the evolution and the behaviour of complex biomolecular networks as a discrete sequence of events in time. The proposed tool has been applied to the case study of a ribosomal protein regulation network, named ”the bacteriophage T4 gene 32”, and results given by this simulation tool are in agreement with the expert’s judgement. Moreover, the graphical user interface of CBNSimulator allows biologists to easily reproduce, analyse and understand behaviour of complex biomolecular networks through discrete simulation. [ABSTRACT FROM AUTHOR]

Several researchers have adapted the data envelopment analysis (DEA) models to deal with two inter-related problems: weak discriminating power and unrealistic weight distribution. The former problem arises as an application of DEA in the situations where decision-makers seek to reach a complete ranking of units, and the latter problem refers to the situations in which basic DEA model simply rates units 100% efficient on account of irrational input and/or output weights and insufficient number of degrees of freedom. Improving discrimination power and yielding more reasonable dispersion of input and output weights simultaneously remain a challenge for DEA and multiple criteria DEA (MCDEA) models. This paper puts emphasis on weight restrictions to boost discriminating power as well as to generate true weight dispersion of MCDEA when a priori information about the weights is not available. To this end, we modify a very recent MCDEA models in the literature by determining an optimum lower bound for input and output weights. The contribution of this paper is sevenfold: first, we show that a larger amount for the lower bound on weights often leads to improving discriminating power and reaching realistic weights in MCDEA models due to imposing more weight restrictions; second, the procedure for sensitivity analysis is designed to define stability for the weights of each evaluation criterion; third, we extend a weighted MCDEA model to three evaluation criteria based on the maximum lower bound for input and output weights; fourth, we develop a super-efficiency model for efficient units under the proposed MCDEA model in this paper; fifth, we extend an epsilon-based minsum BCC-DEA model to proceed our research objectives under variable returns to scale (VRS); sixth, we present a simulation study to statistically analyze weight dispersion and rankings between five different methods in terms of non-parametric tests; and seventh, we demonstrate the applicability of the proposed models with an application to European Union member countries. [ABSTRACT FROM AUTHOR]

This study proposes a methodology to simulate the cutting process in a digital manufacturing platform for the flexible planning of nuclear facility decommissioning. During the planning phase of decommissioning, visualization and verification using process simulation can be powerful tools for the flexible planning of the dismantling process of highly radioactive, large and complex nuclear facilities. However, existing research and commercial solutions are not sufficient for such a situation because complete segmented digital models for the dismantling objects such as the reactor vessel, internal assembly, and closure head must be prepared before the process simulation. The preparation work has significantly impeded the broad application of process simulation due to the complexity and workload. The methodology of process simulation proposed in this paper can flexibly handle various dismantling processes including repetitive object cuttings over heavy and complex structures using a digital manufacturing platform. The proposed methodology, which is applied to dismantling scenarios of a Korean nuclear power plant in this paper, is expected to reduce the complexity and workload of nuclear dismantling simulations. [ABSTRACT FROM AUTHOR]

Abstract: This research paper is a literature review on the behavioral shift using agent-based modeling. We will go through different topics based on agent-based modeling. This research paper points out on different sayings on behavioral shifts. Moreover, it explains the modern research on this topic and many pros and cons on a behavioral shift by using agent-based modeling. [ABSTRACT FROM AUTHOR]

In many transformer applications, it is necessary to have a core magnetization model that takes into account both magnetic and electrical effects. This becomes particularly important in three-phase transformers, where the zero-sequence impedance is generally high, and therefore affects the magnetization very strongly. In this paper, we demonstrate a time-step topological simulation method that uses a lumped-element approach to accurately model both the electrical and magnetic circuits. The simulation method is independent of the used hysteresis model. In this paper, a hysteresis model based on the first-order reversal-curve has been used. [ABSTRACT FROM AUTHOR]

Modular multilevel inverters are promising candidates for next generation of efficient, robust and reliable inverters in large scale photovoltaic system. A modular cascaded multilevel inverter based shunt hybrid active power filter (SHAPF) for three phase grid-connected large scale PV systems is represented in this paper. The main contribution of this paper is to model and control of grid interfaced large scale photovoltaic system with embedded hybrid active power filter functions. In proposed system, the features of hybrid active power filter have been amalgamated in the control circuit of the voltage controlled voltage source inverter interfacing the photovoltaic system to the grid. As a result, the same inverter part of SHAPF is utilized to inject power generated from photovoltaic source to the grid and also to act as hybrid active power filter to compensate harmonics and reactive power demand. With using compensation ability, the grid currents are sinusoidal and in phase with grid voltages. The whole system is modeled in PSCAD/EMTDC. The simulation results are demonstrated to verify the operation and the control system of the proposed system. [ABSTRACT FROM AUTHOR]

This paper proposes a framework for electronic engine-control unit (ECU) inspection in manufacturing phase. Although various methodologies have been developed for the ECU verification at the development phase, the ECU verification in the manufacturing phase has rarely been brought into focus. ECUs in the manufacturing phase need the verification process in the unified way of the ECU software and hardware components by three major causes: 1) ECU software revision, 2) incomplete installation of software, and 3) quality variation of hardware. For the effective ECU verification in the manufacturing phase, we propose a simulation-based ECU testing methodology. The proposed framework configures virtual vehicle environment to simulate an ECU using a “virtual engine system (VES) model” that specifies the operations of every ECU function during a simulation. The proposed framework employs a reverse engineering approach to identify the operation state transition of an ECU function by reference vehicle states from vehicle experimental data. The main objective of this paper is to design a VES model-based inspection system that simulates an ECU without software modification in brief time for set-up and execution. The proposed framework has been implemented and successfully applied to a Korean automotive company. [ABSTRACT FROM AUTHOR]

Hybrid systems are inherently fragile with respect to perturbations when their state experiences jumps on surfaces. Zero-crossing detection algorithms are capable of robustly detecting the crossing of such surfaces, but, up to now, the effects of adding such algorithms to the system being simulated are unknown. In this paper, we propose a mathematical model for hybrid systems that incorporates zero-crossing detection as well as a hybrid simulator for it. First, we discuss adverse effects that measurement noise and discretization can have on hybrid systems jumping on surfaces and prove that, under mild regularity conditions, zero-crossing detection algorithms can robustify the original system. Then, we show that integration schemes with zero-crossing detection actually compute a robustified version of the fragile nominal model. In this way, we rigorously characterize their effect on solutions to the simulated system. Finally, we show that both the model and simulator are not only robust, but also that the hybrid simulator preserves asymptotic stability properties, semiglobally and practically (on the step size), of the original system. Several examples throughout the paper illustrate these ideas and results. [ABSTRACT FROM AUTHOR]

Prediction of failures induced during system level ESD stress is mainly related to the transient waveforms at chip level. To investigate hard and soft failures a precise modeling of the system is required. On-chip protection models can be obtained using quasi-static measurements. Even if such models can achieve good ESD simulations the impact of the external elements are more important. Paper deals with non-linear behaviors of the external elements related to the on-chip protections. Characterization techniques and models are presented, based on two types of capacitances, two different values, placed in parallel to on-chip protections. The paper shows the important variations of X7R capacitances during stresses that change the waveforms at the input of the chip. In measurements different behaviors are observed and reproduced by simulation. The methodology to build model and simulation will be presented. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of incorporating occupant behavior into building performance simulation models used during the design process—that is, before the actual occupants are known. It proposes the use of synthetic population data, an approach that is novel in building performance modeling although common in urban planning and public health. A simpler approach embodied in the ASHRAE Fundamentals volume is to report standard distributions of values for behavioral variables, assuming that parameters vary independently of one another when in fact many co-vary or are interdependent. An alternative approach calibrates models of occupant behavior against actual occupants in specific existing buildings, but this raises questions of transferability. Needed is a database of “generic” occupants that designers can use prospectively during the design process. This paper documents a process of combining disparate field studies of commercial buildings into a larger occupant behavior database and generating a statistically similar synthetic data set that can be shared without compromising confidentiality requirements associated with field studies. The synthetic data set successfully incorporates much of the covariance structure of the underlying field data and supports multivariate modeling. Its scope and structure necessarily serve the needs of the associated modeling framework. Cooperative and systematic sharing of data by field researchers is crucial for building large enough data sets to serve as a behaviorally-robust basis for building design. [ABSTRACT FROM AUTHOR]

Construction site layout changes dynamically depending on the progress of construction activities in ways that may constrain access routes and paths of mobile resources. Discrete event simulation is a useful tool for modeling time dependent activities and resource interactions but usually cannot depict spatial changes in a natural way. This paper describes a framework for integrating 3D visualization components with discrete event simulations to model the movement of mobile cranes on industrial construction projects and facilitate tempo-spatial planning of site layout. The paper focuses on the integration approach using distributed simulation standards and spatial analysis using a dedicated visualization component with pathfinding algorithm. The A* algorithm is used in conjunction with mesh generation mechanism for developing the proposed framework. The benefits of the proposed framework emerge from taking full advantage of the geometrical and special processing strengths of the visualization component through loose coupling with simulation components. The paper describes the main components of the framework and the two-way communication mechanism between them based on distributed simulation standards. It also presents a case example of a real world project to demonstrate the proposed framework and compare the outcome to a traditional solution that uses a probability distribution to model crane travel times. [ABSTRACT FROM AUTHOR]

This paper explores the effect of entrance channel dimensions on berth occupancy of a container terminal when making master planning for a new container terminal, to avoid possible bottlenecks for port's future performance. Therefore, a process-interaction-based simulation model is first developed to simulate container terminal operation, especially ship operation in entrance channel. Then a series of simulation experiments are conducted, in which dozens of container terminals with different numbers of berths and channel dimensions are considered to reproduce the microscopic, stochastic, real-time environment. Finally, simulation results show that the berth occupancy depends on entrance channel dimensions, and more berths, two-way traffic channel and less travel time in channel have higher berth occupancy given the same port service level. So that the effect of entrance channel dimensions, especially very long one-way traffic channels, on berth occupancy should be quantified when determining berth capacities at the master planning stage. Moreover, the analysis and simulation model presented in this paper may help port authorities and the planners to achieve a harmonized overall design in practice. [ABSTRACT FROM AUTHOR]

When using alpha-design for plant variety testing under space restrictions, ex post design modifications must be implemented to prevent variety self-proximity on plots and, consequently, to prevent damage-induced loss of experimental information. This is done ad hoc for each experiment; the unsystematic modification is, however, commonly not only unable to resolve all existing proximities, but may introduce secondary undesired proximities. In this paper, a procedure is developed for the universal construction of modified alpha-design that covers all existing proximity constraints while keeping the efficiency level of the original design. Using extensive real data simulation, we validate the procedure and confirm high damage robustness of the modified designs. The procedure has been implemented as a Matlab function and is available as on-line supplement to the paper. The function enables to design the damage-robust experiments automatically using only standard computer equipment. [ABSTRACT FROM AUTHOR]

This paper presents an approximate model for the simulation of pulsar aided navigation systems. High fidelity simulations of these systems are computationally intensive and impractical for simulating periods of a day or more. Simulation of yearlong missions is done by abstracting navigation errors as periodic Gaussian noise injections. This paper presents an intermediary approximate model to simulate position errors for periods of several weeks, useful for building more accurate Gaussian error models. This is done by abstracting photon detection and binning, replacing it with a simple deterministic process. The approximate model enables faster computation of error injection models, allowing the error model to be inexpensively updated throughout a simulation. Testing of the approximate model revealed an optimistic performance prediction for non-millisecond pulsars with more accurate predictions for pulsars in the millisecond spectrum. This performance gap was attributed to noise which is not present in the approximate model but can be predicted and added to improve accuracy. [ABSTRACT FROM AUTHOR]

This paper investigates the environmental parameters favoring significant tornadoes in Bangladesh through a simulation of ten high-impact events. A climatological perspective is first presented on classifying significant tornadoes in Bangladesh, noting the challenges since reports of tornadoes are not documented in a formal manner. The statistical relationship between United States and Bangladesh tornado-related deaths suggests that significant tornadoes do occur in Bangladesh so this paper identifies the most significant tornadic events and analyzes the environmental conditions associated with these events. Given the scarcity of observational data to assess the near-storm environment in this region, high-resolution (3-km horizontal grid spacing) numerical weather prediction simulations are performed for events identified to be associated with a significant tornado. In comparison to similar events over the United States, significant tornado environments in Bangladesh are characterized by relatively high convective available potential energy, sufficient deep-layer vertical shear, and a propensity for deviant (i.e., well to the right of the mean flow) storm motion along a low-level convergence boundary. [ABSTRACT FROM AUTHOR]

Inconsistencies in the empirical support for balance theory are often explained by recourse to competing mechanisms that reduce the total degree of balance in the network. These mechanisms (such as differential popularity and subgroup hostility) may depend on exogenous properties of the nodes. This paper offers an alternative explanation for the departure of networks from global balance, according to which the myopic nature of sign adjustment in accordance with a pressure for local balance may reduce the global degree of balance and impede the formation of groups, whereas competing mechanisms that rely on exogenous node properties (e.g., homophily) facilitate these processes. The paper describes a set of simulations designed to study the evolution of complete signed networks under a local sign-change regime, induced by structural balance, homophily and heterophobia. Tolerance for local violation of balance and homophily is allowed to vary with a consequent impact upon the global degree of balance and group formation processes. We find the conditions under which the pressure towards local homophily and balance operate against each other culminating in a (locally) dynamic yet (globally) stationary state in which homophily adjusts towards group formation and balance undermines this process. [ABSTRACT FROM AUTHOR]

The paper demonstrates the possibility of using simulation modelling for improving the processes of managing the development of the terminal at a strategic level, taking into account, first of all, security and safety aspects of quality of services. The described in the paper developed simulation model based on the AnyLogic software could be treated as decision support tool for management of the passenger terminal. The background of the problem is related with the started reconstruction process of the terminal with no ability to close it for reconstruction period. The decision to temporary close different parts of the platforms and make step-by-step reconstruction was done by management. But this decision causes a number of question regarding safety aspects of the passengers. The developed simulation model is directed on estimation of the passengers’ density in terminal. The higher density directly influences the safety issues. The primary task of the developed decision support tool is to support management of the terminal with quantitative values of passenger density for different scenarios of reconstruction. [ABSTRACT FROM AUTHOR]

This paper deals with research on the impact of material properties (material thickness and type) on stress/strain curves of the layered materials based on hard and soft wood during bending. Reference curves, obtained for the bending of real samples, were the base for the simulation. Subsequently, the recorded curves were imported into SolidWorks application, where they served as the data source for the simulation. The results, as well as model analysis of two-layer materials, have proven that the bendability is better for the composition with soft material in the bottom layer. This can be explained by the fact that the soft material under tensile strength shows greater deflections than the hard one before the breaking. For three-layer compositions, similar behavior can be concluded. This part did not deal with connection among the layers. The paper gives a possibility to predict the behavior of layered materials if the characteristics of its layers are known. [ABSTRACT FROM AUTHOR]

Many studies have been carried out separately on combined heat and power and district heating. However, little work has been done considering the heat source, the district heating network and the heat users simultaneously, especially when it comes to the heating system with large-scale combined heat and power plant. For the purpose of energy conservation, it is very important to know well the system performance of the integrated heating system from the very primary fuel input to the terminal heat users. This paper set up a model of 300 MW electric power rated air-cooled combined heat and power plant using Ebsilon software, which was validated according to the design data from the turbine manufacturer. Then, the model of heating network and heat users were developed based on the fundamental theories of fluid mechanics and heat transfer. Finally the combined heat and power based district heating system was obtained and the system performances within multiscale scope of the system were analyzed using the developed Ebsilon model. Topics with regard to the heat loss, the pressure drop, the pump power consumption and the supply temperatures of the district heating network were discussed. Besides, the operational issues of the integrated system were also researched. Several useful conclusions were drawn. It was found that a lower design primary supply temperature of the district heating network would give a higher seasonal energy efficiency of the integrated system throughout the whole heating season. Moreover, it was not always right to relate low design supply temperatures to high pump power consumptions and high heat losses in the district heating network, since the results showed that the seasonal pump power consumption and the heat loss would decrease with a lower design primary supply temperature. Therefore, from the perspective of seasonal consideration, low temperature district heating has an even more bright future compared to just considering the design heat load condition. Both the combined heat and power plant and the low temperature district heating network were simulated in detail and integrated, including the part heat load conditions, which is one novelty of this article. The simulation in this paper could be considered as the basis for the further improvement and optimization of combined heat and power based district heating systems. [ABSTRACT FROM AUTHOR]

Pedestrian and driver behaviors as well as their interactions, are essential in planning, designing and operating highway facilities. Pedestrian crossing outside of a marked or unmarked crosswalk (i.e. jaywalking), is one of those pedestrian behaviors that may highly affect safety and operations. Unlike permissible crossings at crosswalks, jaywalking events are not often anticipated by drivers, which may result in less driver reaction time and different vehicle operation dynamics. It is important to understand pedestrian crossing behavior outside of crosswalks, as well as driver yielding behavior towards them. To date, limited quantitative and behavioral research has been conducted to investigate this interaction or simulate it microscopically. This paper aims to explore both pedestrian jaywalking behavior (gap acceptance and speeds) and the corresponding driver reactions (yielding behavior) for modeling the vehicle–pedestrian interactions (VPI) outside the crosswalks in a micro-simulation environment. The study also quantifies the differences between vehicle–jaywalker and vehicle-permissible crossing. An observational study and an instrumented vehicle study were conducted on the campus of the University of Florida to collect data from pedestrian and driver perspectives, respectively. Crossing speed, yield acceptance and delay of jaywalking crossings and permissible crossings were observed in the study and these attributed can be used for replicating pedestrian operations in simulators. Moreover, behaviors of driver approaching jaywalkers versus pedestrians crossing at designated crosswalks were compared on the basis of yield rates, and vehicle speed profiles. Vehicle yield dynamics were analyzed to model the driver reactions towards jaywalkers. Lastly, it was found that the locations of jaywalking events are highly concentrated and influenced by the crossing environment, such as pedestrian and vehicular volume, bus stops presence and crossing distance. This paper establishes several quantitative relationships describing interactions between pedestrians crossing outside of crosswalks and approaching drivers, which provide the basis and assumptions for modeling such interactions in a micro-simulation environment for traffic operational analyses. [ABSTRACT FROM AUTHOR]

Cross-border transit facilities constitute major public investment, and thus must serve the long-term needs of the communities, such as providing access to schools and businesses, contributing to a shared regional culture and lifestyle, fostering international trade, and supporting jobs for the region’s residents. Numerous studies have been conducted to evaluate the economic implications of vehicular flow delays at border crossings, however none of the studies focused on assessing cross-border flow of bus passengers and pedestrians. Since pedestrians are considered to be autonomous, intelligent, and perceptive, it is a challenging task to predict pedestrian movement and behavior in comparison to vehicular flows which follow a specific set of traffic rules. This paper presents a multiagent based multimodal simulation model to evaluate the capacity and performance of a cross-border transit facility. The significance of this research is the use of dynamic mode choice functionality in the model, which allows an individual person to make instantaneous choices between available modes of transportation. The scope of interest of the paper is limited to simulating access interface, circulation areas, ancillary and processing facilities. The developed model was calibrated to ensure realistic performance, and validated against specific performance criteria such as throughput per processing facility. In order to demonstrate the applicability of the developed simulation model, capacity and operational planning of a pedestrian transit facility was performed. The relative performance of alternative design or configuration was evaluated using the level of service criteria. Lastly, the effectiveness of each proposed capacity or operational improvement strategy was compared to the “do-nothing” scenario. [ABSTRACT FROM AUTHOR]

This paper presents the application of multi-objective genetic algorithms for holistic building design that considers multiple criteria; building energy use, capital cost, daylight distribution and thermal indoor environment. The optimization focus is related to building envelope parameters. To obtain relevant feedback from multi-objective optimizations in early design stages, evaluation speed is a key concern. The paper presents a fast evaluation method fit for the early design stages. It uses a combination of two different quasi-steady-state methods for energy and indoor environment evaluations, a Radiance implementation for daylight simulations and a scripted algorithm for capital cost evaluations. The application of the method is developed around an integrated dynamic model which allows visual design feedback from all evaluations to be an integrated part of the design tool experience. It is concluded, that quasi-steady-state methods implemented as part of integrated dynamic models are fast and flexible enough to support building energy-, indoor environment- and cost-optimization the early design stages. [ABSTRACT FROM AUTHOR]

• Modelling effects of information flow on the performance of global production networks. • Revealing cause-effect relationships based on multi-method simulation and statistical analysis. • Identifying target configurations for information exchange using surrogate modeling and robust optimization. Low information exchange in global production networks results in long response time to disruption and negative performance impact. Digitalization enables a more intensive information exchange. This paper analyses the performance of order management, quality problem resolution and engineering change management in production networks with respect to different disruptions and information flows. Cause-effect relationships are revealed based on a multi-method simulation model and statistical experiments. Using surrogate modelling and robust optimization, a target picture for information exchange is determined. The benefits of the approach are demonstrated using a case study for the production of metal-plastic parts for the automotive supplier industry. [ABSTRACT FROM AUTHOR]

• A first comprehensive overview of core contents of DT technology for rolling bearings is presented. • The development history of DT is analyzed and the definition is clarified. • Three core technologies of rolling bearings for the DT construction are reviewed. • Challenges for the employment of these technologies in a rolling bearing DT system are discussed. Digital Twin (DT) is acknowledged as a promising technology for life-cycle management of industrial products. Rolling bearings, the joints of machines, are largely responsible for the service performance and life of various high-end equipment. Up to now, there are still few investigations on rolling bearings under the concept of DT technology. The present paper reviews the brief history of DT technology and clarifies its definition. Then, the core technologies of rolling bearings for DT construction, including detection, modeling, and Prognostics Health Management (PHM) techniques are investigated through an extensive literature survey. Based on the above, this paper analyzes the challenges in the development of DT technology for rolling bearings and directions for future research. [ABSTRACT FROM AUTHOR]