International Journal of Simulation and Process Modelling (34 papers in press)
Crowd evacuation simulation based on emotion contagion
by Xuemei Du, Wu He, Yan Mao
Abstract: Simulation study on evacuation scenarios has an important influence on public safety. Unfortunately, the traditional evacuation-drill approach for emergency situations focuses on the physiological interaction between individuals/crowds, but ignores psychological interaction. In this paper, we present an emotion contagion model that associates components, such as physiological demand, security requirement and personality traits with individual agents comprising a crowd, and produces emergent behaviours in the crowd as a whole. The emotion contagion model realises the interaction of physiological and psychological factors. Personality traits are associated with emotions by using the OCEAN, OCC and PAD models. To reflect the complexity of emotion contagion of crowd, we consider three processes: contagion, update, and decay. We also consider the effect of emotions on the movement. Testing results demonstrate that the proposed method is effective and realistic for simulating the movement of a heterogeneous crowd in emergency situations.
Keywords: simulation; emergency; emotion contagion; OCEAN model; OCC model; PAD model.
Supporting collaborative business processes: a BPaaS approach
by Lai Xu, Paul De Vrieze
Abstract: Collaborative business processes are increasingly driven by business flexibility and agility. Cloud-based business process management services have provided small and medium enterprises (SMEs) with a pay-per-use manner for their daily business needs, i.e. some simple business process applications, e.g. salesforce provides cloud-based CRM to boost SMEs' sales. This raises the question of how cloud-based business process management solutions can support the fast pace of change of business collaborations among business partners. For example, collaborative processes for managing industrial incidents are short term, low frequency processes. This paper proposes an architecture meta-model, which is used to design the concrete architecture and to further analyse the performance of the proposed solution. A real world case of collaborative processes for incident and maintenance notifications is used to explain the design and implementation of the cloud-based solution for supporting collaborative business processes. Service improvement of the new solution and computing power costs are analysed accordingly.
Keywords: business process as a service; incident management; business process mashup; cloud computing; service-oriented computing.
Modelling and analysis of multi-agent systems using UPPAAL SMC
by Christian Nigro, Libero Nigro, Paolo F. Sciammarella
Abstract: This paper proposes a novel approach to modelling and analysis of complex multi-agent systems. The approach is based on actors and asynchronous message passing, and exploits the UPPAAL Statistical Model Checker (SMC) for the experiments. UPPAAL SMC is interesting because it automates simulations by predicting the number of executions capable of ensuring a required output accuracy, it uses statistical techniques (Monte Carlo-like simulations and sequential hypothesis testing) for extracting quantitative measures from the simulation runs, and it offers a temporal logic query language to express property queries tailored to the application needs. The paper describes the approach, clarifies its structural translation on top of UPPAAL SMC and demonstrates its practical usefulness through modelling and analysis of a large scale and adaptive version of the Iterated Prisoners Dilemma (IPD) problem. The case study confirms known properties, namely the emergence of cooperation under context preservation, that is when the player interaction links are preserved during the game, but it also suggests some new quantitative measures about the temporal behaviour which were not previously pointed out.
Keywords: modelling and simulation; multi-agent systems; actors; statistical model checking; UPPAAL; iterated prisoner’s dilemma.
Hybrid flow shop scheduling with finite buffer
by Zhonghua Han, Yue Sun, Xiaofu Ma, Zhe Lv
Abstract: In this paper, the scheduling problem for hybrid flow shops is investigated with the consideration of finite buffers. Different from the existing works, which focus on the makespan minimisation under the constraints of given intermediate buffer sizes, this paper investigates how to decide the reasonable size of the intermediate buffer. Firstly, the problem is modelled with the design of the accurate and reasonable buffer space without affecting the flow shop production efficiency. Then, a hybrid heuristic method is proposed to reduce the algorithm complexity. Specifically, the buffer size is estimated based on the theory of probability distribution, and the searching for the global optimal solution is processed by using a novel and effective self-adaptive differential evolution algorithm. The proposed algorithm can adjust parameters intelligently for stopping unnecessary iterations as well as avoiding the stagnant situation of the local optimum. Lastly, a wide range of practical scenarios are considered for algorithm evaluation, and the numerical results show that the proposed approach is effective on (1) reducing the buffer size and (2) guaranteeing the hybrid flow shop efficiency.
Keywords: hybrid flow shop; buffer size; probability distribution; self-adaptive differential evolution algorithm.
Towards improving yields of oil palm fresh fruit bunches in Malaysia: a system dynamics approach
by Mohd Faeid Zabid, Norhaslinda Zainal Abidin, Shri Dewi Applanaidu
Abstract: Malaysia is one of the largest producers and exporters of palm oil in the world market. However, it is still difficult to retain Malaysia's status quo with the current stagnating fresh fruit bunch (FFB) yield. The source of this problem may have come from the accumulation of ageing oil palm plantation area, which can be tackled through effective replanting plan. This study thus develops a system dynamics model of the oil palm plantation sector in Malaysia to understand its behaviour towards currently implemented policies. Several simulation runs have been performed to test various scenarios of policy interventions with the objective to reduce the accumulation of ageing area and subsequently increase the FFB yield. The findings suggest that, apart from improving the policies such as promoting replanting and expanding the implementation of good agricultural practices, the most important thing is to have high commitment from planters, especially the independent smallholders, in participating the replanting campaign.
Keywords: system dynamics; oil palm plantation; replanting; fresh fruit bunch yield; policies.
Simulation-based optimisation and analysis for CO2 pipeline transportation system with uncertainties
by Qunhong Tian, Dongya Zhao, Zhaomin Li, Quanmin Zhu
Abstract: Carbon capture, utilisation and storage (CCUS) technology is one of the main measures to achieve greenhouse gas emission reduction. As an important link in CCUS technology, pipeline transportation is the most cost-effective mode to transport large-scale CO2. In order to investigate the effect caused by parameter uncertainties such as temperature, mass flowrate, electricity, and equipment cost, a simulation based techno-economic optimisation model is proposed to describe the complicated pipeline design problem in this paper, which takes into account engineering and economic modelling. Penalty function and Newtons method are presented to optimise the pipeline. Based on the obtained optimal inlet pressure, pipe diameter, wall thickness, number of pump stations and levelised cost, uncertain parameters analysis is presented to research the pipeline optimisation design. Based on the pipeline optimisation modelling, simulation results demonstrate the effectiveness of the proposed optimisation approach, and analysis gives the levelised cost change caused by uncertainties, which can provide a theoretical basis to design pipeline.
Keywords: CCUS technology; CO2 transportation; pipeline modelling; simulation; optimisation and analysis.
Simulating effect of parameters variation on the performance of an educational system
by Najat Messaoudi, Jaafar Khalid Naciri, Bahloul Bensassi
Abstract: The present study proposes a first model simulating the effect of variations of a group of parameters on the global performance of an educational system. To achieve the simulation, each training cycle of the educational system is broken down into different levels. The training unit is defined as the lowest component of this decomposition. A generic processor is selected for modelling each training unit. A mathematical modelling enabling simulation of the increase of learner's competence, based on a production function for each learner, is proposed. In order to perform a simulation it is necessary to specify the production function f, which relates the increase of the level of competencies of each learner to a set of parameters. Some parameter variations are studied, such as the time dependency (or on the training's duration), the class size, the personal capacity of each learner, which make it possible to obtain approximate expressions useful to carry out simulations. The obtained results show the variation of performance of a training unit versus number of learners, i.e the class size effect on the performance. The obtained curves clearly show the relationship between performance, variation in the number of learners and sensitivity of the pedagogical method, and establish that the performance ratio has different behaviors depending on the sensitivity of the pedagogical method to the number of learners. Thereafter, simulations of the effect of group homogeneity on the performance versus class size curves are presented.
Keywords: educational system; modelling; simulation; performance; assessment; class size; training program; competence; generic processor.
Numerical simulation of a cinema fire based on a fire dynamics simulator
by Zhian Huang, Yaru Meng, Rui Yang, Yukun Gao, Zhang Yinghua, Shuyi Wang
Abstract: In this paper, large-scale FDS (Fire Dynamics Simulator) model software was used to simulate a cinema fire. The reliability of the simulation results was verified by comparison with relevant research results, and some fire precaution measures were put forward. Based on the physical fire model of 1:1 a full-scale simulation of a cinema fire was carried out. By studying the flue gas, temperature and variation law of the CO concentration during the fire, it is found that the mechanical air-intake damages the stratification of smoke and air in the burning room to a certain extent. The lower air in the theatre is mixed with the upper high-temperature flue gas so that the temperature of the lower air is higher than that of the upper air. Meanwhile, the mechanical air-intake enhances the reducing speed of visibility. The results of this research provide a reference for the fire protection design of cinemas.
Keywords: cinema; fire dynamics simulator; evacuation time; numerical simulation.
Efficient modelling and simulation tool for nanoscale transistor sizing
by Abdoul Rjoub, Shihab AlKattab
Abstract: This paper proposes an efficient Delay Enhancement and Leakage Optimisation based on Transistor Sizing (DELOTS) algorithm for optimisation of digital CMOS at the transistor level for low power and high performance at 22 nm technology. The proposed algorithm integrates three models, Graph Model (GM), Mathematical Model (MM), and Heuristic Model (HM), working in a structured sequence to achieve the highest level of optimisation. Applying the proposed DELOTS algorithm shows significant improvement of PDP in the Full Adder circuit, 31%, and in the ISCAS C17 benchmark, 43%. DELOTS is proven to be one of the most efficient algorithms in digital CMOS optimisation at transistor level. In addition to simplicity and speed, DELOTS ensures finding the optimal solution and offers multi-purpose optimisation, where each parameter can be optimised as a stand-alone parameter or in combination with other parameters requiring optimisation.
Keywords: CMOS; algorithm; DELOTS; dissipation; leakage; propagation delay.
Optimisation of high efficiency tin halide perovskite solar cells using SCAPS-1D
by Usha Mandadapu, S. Victor Vedanaykam, K. Thyagarajan, B.J. Babu
Abstract: Hybrid perovskite solar cells are creating attention owing to the enormous growth of efficiency, exceeding 20%, indicating in the near future that these cells will become an alternative to the traditional silicon photovoltaics. For the commercialisation of low-cost, high efficiency perovskite solar cells, it is necessary to investigate the relation between the various material parameters, the device architectures and power conversion efficiency (PCE) of the devices. Three types of architecture are designed and simulated using the solar cell capacitance simulator (SCAPS-1D), used for the analysis of thin film photovoltaic architecture. One architecture is glass/ZnO:Al/TiO2/CH3NH3SnI3/Au, the second one is glass/TiO2/ZnO:Al/CH3NH3SnI3/CuI/Au, and glass/ZnO:Al/TiO2/CH3NH3SnI3/CH3NH3SnBr3/CuI/Au is the architecture of the third. Analysis was done by studying the effect of various material parameters on the device performance. It was observed that the second one (Model 2) shows the maximum PCE of 25.91%. This simulation work is useful to researchers in the design of low cost, non-toxic, high efficiency tin halide perovskite solar cells.
Keywords: optimisation; SCAPS-1D; material parameters; solar cell; efficiency; tin halide; perovskite.
CCUS evaluation and simulation in a Chinese oilfield
by Dongya Zhao
Abstract: This paper studies the evaluation issue of a preparatory CCUS in China. Economic and environmental evaluation are presented with the delicate simulations. The analysis of the evaluation results show that the CCUS project will be feasible if the oil price is enough high or the storage allowance can be given. The results will be useful for the future CCUS projects and for government decisions on CCUS.
Keywords: CCUS; economic evaluation; environmental evaluation; simulation.
A simulation technique for designing next-generation information and communication systems based on off-the-shelf microwave electronics computer tool
by Mikhail Belkin
Abstract: We review our known, updated, and newer models and simulation results using power microwave-electronics off-the-shelf computer tool NI AWRDE to pursue advanced performances corresponding to the last generation of key microwave photonics elements, such as semiconductor laser, photodiode, two types of electro-optic modulator, and multichannel reflecting Bragg grating. Based on them, the models of two key microwave photonics devices that fulfill particular basic processing procedures of a microwave-band network: microwave signal oscillation and microwave frequency conversion, and super-wide bandwidth photonic beam former for microwave photonics phased array antenna, are introduced and studied. As a result, we proposed and validated experimentally a new approach to model a broad class of promising analogue microwave radio-electronics systems based on microwave photonics technology.
Keywords: microwave photonics; nonlinear equivalent models; microwave-band optoelectronic circuitry elements and devices; optical beam-forming network; computer aided design.
An interactive, interoperable and ubiquitous mixed reality application for a smart learning experience
by Francesco Longo, Letizia Nicoletti
Abstract: This article presents an innovative comprehensive platform that includes an interactive, interoperable and ubiquitous mixed reality application that will extend the ways cultural digital resources are created, disseminated, preserved and re-used. As part of an extensive research effort carried out by the authors to foster the use of the most recent technologies in the field of cultural heritage, this article goes further in the design and development of a prototype of an Intelligent, Interactive and Interoperable Comprehensive Platform for the 21st century Museums (I3-CPM). Since I3-CPM explores unconventional ways to deliver cultural contents (virtual and augmented reality, serious games, holography, simulation, knowledge-based systems, vocal interaction technologies, etc.), it is expected to provide users with a new and smart learning experience. The OUTSIDE-REAL application is here described as part of the I3-CPM framework: it provides intuitive navigation of mixed reality cultural contents and storytelling through an intelligent knowledge navigator and vocal assistant, called SOPHOS, thus offering the visitors a user-driven, interactive and meaningful learning experience at the cultural heritage site.
Keywords: cultural heritage; digital museum; mixed reality; augmented reality; intelligent agents; vocal assistant; smart learning; storytelling.
Simulation and design optimisation of broach tool geometry for enhancing material removal rate
by Vivek Kalyankar, Amey Pujari
Abstract: In this work, a broach tool geometry is considered and an attempt is made to simulate and optimise the geometry so as to enhance the material removal rate (MRR). Highly efficient DEFORM 3 D software is used for simulation and optimisation of the broaching tool, which is also reported in the literature and being used by various industries. The modified tool design is considered for machining of AISI 1045 and brass materials, and the optimised tool geometry has reduced the number of broach teeth from 44 to 14 in case of AISI 1045 work material and from 44 to seven in the case of brass material, thereby considerably reducing the tool cost. Moreover, the proposed optimum tool geometry has also given considerable improvement in the MRR for both the materials compared with previous results. Hence, the present approach may become useful to industries to improve the MRR and tool cost.
Keywords: design optimisation; broach tool geometry; tool design; DEFORM software; simulation.
Special Issue on: The Latest Technologies for Building a Smart City
A novel visible-infrared image fusion framework for smart cities
by Zhinqin Zhu, Guanqiu Qi, Yi Chai, Hongpeng Yin, Jian Sun
Abstract: Image fusion technology is widely used in different areas and can integrate complementary and relevant information of source images captured by multiple sensors into a unitary synthetic image. Image fusion technology, as an efficient way to integrate information from multiple images, plays a more and more important role in smart cities. The quality of the fused image affects the accuracy, efficiency, and robustness of the related applications. Existing sparse representation-based image fusion methods consist of overly complete and redundant dictionary learning and sparse coding. However, overly complete and redundant dictionary does not consider the discriminative ability of dictionaries that may seriously affect the image fusion. A good dictionary is the key to a successful image fusion technique. To construct a discriminative dictionary, a novel framework that integrates an image-patches clustering and online dictionary learning methods is proposed for visible-infrared image fusion. The comparison experiments with existing solutions are used to validate and demonstrate the effectiveness of the proposed solution for image fusion.
Keywords: image fusion; sparse representation; dictionary learning; sub-space clustering; smart city.
Container-as-a-service architecture for business workflow
by Ye Tao, Xiaodong Wang, Xiaowei Xu, Guozhu Liu
Abstract: The massive amount of data makes the work of building a smart city more and more data-driven. However, data collection and its analysis in such a large system are often separated and executed by different vendors. Owing to volume, security and privacy reasons, data migration can be difficult. To build a bridge between data owners and data analysers, service migration is applied, which forms the infrastructures, applications and services for different vendors. This paper presents a Container-as-a-Service (CaaS) framework for data processing in a smart city environment. We design and implement a multi-layered container service construction and deployment environment, and we employ the business workflow orchestration technologies in this environment. By using containers, local cluster resources are virtualised and isolated to simplify the creation and deployment of multiple applications autonomously across multiple vendor systems. Inside a container, computational tasks and worker processes are encapsulated into web services, in order to leverage service-based workflow technologies to develop timely and effective workflows for a smart city environment. A use case of smart transportation is studied to validate the usefulness and evaluate the performance of the presented architecture. Results show that the approach can be beneficial to the scientific tasks in regard to its flexibility and re-usability.
Keywords: container; service computing; scientific workflow; BPEL for web services; Hadoop.
Software behaviour analysis method based On behaviour template
by Yingxu Lai, Zenghui Liu, Tao Ye
Abstract: This paper proposes a software behaviour analysis method based on behaviour template (SABT) which, according to the context of source code, builds a behaviour template to detect software malicious behaviour based on a function transfer map and minimum function blocks. Many methods use state transfer diagrams to build software behaviour models. Our method is based on the corresponding relationship between the functions and system call sequence, which ensures accurate detection of malicious behaviour. Compared with traditional methods, such as N-gram, FSA, and Var-gram, SABT can get higher cover rate of code and detect abnormal behaviour more effectively and efficiently.
Keywords: software behaviour, software interrupt, behaviour template, minimum function block
Boundary estimating of urban road network for traffic impact analysis when reconstructing intersections: methodology and evaluation
by Yingying Ma, Ying Zeng
Abstract: Intersections are major points of conflict for road users and the key parts of urban road networks. It is necessary to reconstruct some intersections to improve capacity and safety. A methodology to estimate the boundary of a road network for traffic impact analysis of intersection improvements is discussed in this paper. Firstly, models are presented for two types of degree of correlation. The degree of saturation and free-flow travel time are considered in the model for the degree of correlation between two adjacent intersections, and the degree of correlation between any two intersections in the network is analysed using a Laplacian matrix algorithm. Secondly, a new method to estimating a road network boundary is proposed. Thirdly, two measures are adopted to evaluate the boundary of road networks: the minimum average cut degree of correlation and the minimum traffic influence on intersections outside the boundary. Finally, the method is demonstrated using a city road network. The results of the case study confirm the validity of the proposed approach.
Keywords: boundary estimating, traffic impact analysis, intersection reconstruction, Laplacian matrix
Knowledge extraction based on linked open data for clinical documentation
by Mazen Alobaidi, Khalid Mahmood, Susan Sabra
Abstract: Smart cities are becoming a reality in the near future to transform many sectors and activities in our lives. Smart city systems, such as healthcare systems, will have new functionality to improve the quality of life of its citizens. Electronic health records are an essential component of healthcare systems. They are valuable for medical research, but much of the information is recorded as unstructured free text. Knowledge extraction from unstructured text in electronic health records is a problem that is well-documented but still not totally resolved. Knowledge extraction is very challenging because medical language has ungrammatical and fragmented constructions. We have implemented a unique framework knowledge extraction based on linked open data for clinical documentation (KE-LODC) that generates accurate and high quality triples transforming unstructured text from clinical documentation into well-defined and ready-to-use linked open data for diagnosis and treatment. We used Name Entity Recognition and Disambiguation (NERD) because it proved to be highly more precise than other available tools in entity recognition. Our framework proved to produce highly qualified big number of triple candidates, which improves the likelihood of better classification. Also, we evaluate our framework by comparing its precision and recall with two benchmark algorithms. The results show that KE-LODC performs better.
Keywords: healthcare, smart city, linked open data; semantic web; knowledge extraction;
Technologies for developing a smart city in computational thinking
by Yinong Chen, Gennaro De Luca
Abstract: Building a smart city involves almost all the aspects of social, economic, and technological issues. This paper gives a brief survey and overview of the latest technologies for building a smart city. It covers IoT, device as a service, service-oriented computing and cloud computing as the infrastructure, big data analysis and processing for data mining, and artificial intelligence. A visual programming language for IoT and robotics application development is also introduced, which offers a tool for architects and developers to define the applications using computational thinking and workflow of existing services and components.
Keywords: IoT; cloud computing; big data; artificial intelligence; workflow.
Special Issue on: ACECS-2016 Advances and Applications of Process Modelling and Simulation
Modelling and hardware co-simulation of a quadrotor unmanned aerial vehicle
by Soufiene Bouallegue, Rabii Fessi
Abstract: This paper deals with the modelling and hardware (HW) co-simulation of a Quadrotor Vertical Take-Off and Landing (VTOL) type of Unmanned Aerial Vehicle (UAV). The developed HW co-simulation platform is based on a reconfigurable I/O (RIO) board of National Instruments (NI) Company, called sbRIO-9636, and a host PC with a Real-Time Operating System (RTOS). The Control Design and Simulation (CDSim) module of LabVIEW environment, as well as an established Network Streams data communication protocol, are used to emulate and co-simulate all flight dynamics within a Processor-In-the-Loop (PIL) framework. The flight motion principle of the quadrotor, i.e. lift, rotation and translation, is firstly described as a function of changes in the angular speed of the rotors. All aerodynamic forces and moments of such a vehicle are then described within an inertial earth frame, and a nonlinear dynamical model is established thanks to the Newton-Euler formalism. The dynamics of the propellers' brushless DC motors, accelerometer and gyroscope types of sensor are also modelled and co-simulated in order to complete the established model of the studied VTOL rotorcraft. HW simulations are carried out and compared with those obtained with software (SW) simulations in order to show the effectiveness of the proposed PIL co-simulation strategy.
Keywords: quadrotor UAV; modelling; aerodynamic effects; rotors and sensors dynamics; Newton-Euler equations; PIL co-simulation; NI single-board RIO; LabVIEW.
Artificial neural networks for acquisition and processing of sensors data in a radiotherapy application
by Kheireddine Lamamra
Abstract: This paper presents a practical aspect of work that we have planned for several steps. It describes the acquisition and processing of coded data from temperature sensors of type MS6503 used in radiotherapy rooms of the hospital PMCC (Hospital Pierre and Marie Curie Centre). The aim is to acquire and check remotely the temperatures of rooms to trigger alarms and their control thereafter in order to avoid mistakes of manipulation which are deadly for patients if they happen or arise. For this, a system modelling is made before proceeding to the implementation in practice. During the implementation, several problems have occurred such as the legibility of the received data that has been encrypted. To overcome this problem, an artificial neural networks type of Multi-Layer Perceptron (MLP) is used to acquire and decrypt the temperature data received from the sensors placed in the treatment rooms. The obtained results show that the neural network used has decrypted well the received data, hence this technique has been implemented in the realised solution.
Keywords: data acquisition and processing; temperature sensor; radiotherapy room control; artificial neural network; modelling.
Continuous Petri nets and hybrid automata: two bisimilar models for the simulation of positive systems
by Latefa Ghomri, Hassane Alla
Abstract: Petri nets (PNs) are a well-known modelling tool for discrete event systems. Continuous PN were introduced in order to avoid the combinatory explosion of the number of states, when considering real life systems. The constant speed continuous Petri nets (CCPN) where constant maximal firing speeds are associated with transitions allow very fast simulations. They can be used to model discrete events systems; in that case, they constitute an approximation, which is often satisfactory. They can also model positive continuous systems. Hybrid automata (HA) are a less compact and expressive model, but, they can be used to perform powerful analysis. In this paper, we first present the continuous PN and its modelling advantages. Then we present the main contribution of this paper, that is a structural translation algorithm from a CCPN into a HA. The goal of this translation algorithm is to combine advantages of both tools. The first one is an elegant modelling tool; with the second one, it is possible to compute the reachable state space. The translation algorithm is structural in the sense that it does not depend on the initial marking of the Petri net. We present the principal characteristics of the CCPN and the HA, and we prove the timed bisimilarity between the two models. Then it will be possible to deduce properties of the CCPN from the HA. An example of a manufacturing system is used throughout the paper to illustrate the different results, and a water supply system is presented as a more complex example.
Keywords: discrete event systems modelling; constant speed continuous Petri nets; hybrid automata; bisimulation.
Modelling and simulation of analytical approach to handle real-time traffic in VoIP network
by Sakshi Kaushal, Harish Kumar, Sarbjeet Singh, Sundarapandian Vaidyanathan, Jasleen Kaur, Shubhani Aggarwal
Abstract: In recent years, Internet Protocol (IP) has become a good choice over Public Switched Telephone Network (PSTN). A Voice over IP (VoIP) communication supports a number of users with an acceptable voice quality. VoIP implementation uses hard IP phones and soft IP phones, does not rely on a traditional PBX and uses Softswitch for call signalling, access control, etc. The Erlang B model is used to determine the number of trunks in a circuit-switched network and find traffic intensity and grade of service. This paper uses an extension of the Erlang B model for traffic engineering of VoIP, i.e., Extended Erlang B model. The main purpose for Extended Erlang B is that has better efficiency to handle the percentage of blocked calls by choosing a threshold value (). We propose a new measurement scheme based on an extended Erlang B model using FreeSWITCH to simulate and analyse VoIP traffic. Simulations are done in the QualNet 7.3 Network simulator using SIP protocol for VoIP traffic. We compare our version with the original definition of the Erlang B model and present further results from simulations. Experiments are conducted based on different voice codecs such as G.711, G.729A and G.723.1 for measuring packetisation intervals and for calculating bandwidth. The proposed scheme is also analysed for other QoS parameters, i.e, jitter, end-to-end delay and mean opinion score.
Keywords: VoIP; SIP; Softswitch; call admission control; traffic load measurement; Erlang B model.
Special Issue on: Computational Thinking and the Development of Complex Systems
Morphology-based visible-infrared image fusion framework for smart city
by Guanqiu Qi, Zhiqin Zhu, Yinong Chen, Jinchuan Wang, Qiong Zhang, Fancheng Zeng
Abstract: Following the development of smart city, informative images play a more and more important role in recognition, detection, and perception. As an efficient way, the image fusion technique integrates information from multiple images. Sparse-representation based approaches are often applied to image fusion. Although an informative and compact dictionary is a key component of the sparsity-based image fusion method, it is difficult to obtain such a complete and non-redundant dictionary. This paper proposes a hierarchical image fusion framework that applies layer-by-layer deep learning techniques to explore the detailed information of images and extract key information of images for dictionary learning. According to morphological similarities, this paper clusters source image patches into smooth, stochastic, and dominant orientation patch groups. Thus more detailed information can be extracted from source images for dictionary construction. Three clustered image-patch groups are decomposed into high-frequency and low-frequency components by using Gaussian blur. High-frequency and low-frequency components are fused by Max-L1 and L2-norm based weighted average fusion rules, respectively. The fused low-frequency and high-frequency components are combined to obtain the final fusion results. The comparison experimentations are simulated to evaluate the fused image in image feature, information, structure similarity, and visual perception. The results confirm the feasibility and effectiveness of proposed image fusion solution.
Keywords: image fusion; sparse representation; dictionary learning; geometric information classification; smart city.
Special Issue on: I3M2016 New Advances of Modelling and Simulation for BusinessProcesses, Production, Services and Supply Chain
The role of horizontal cooperation to improve service quality in last-mile distribution
by Adrian Serrano-Hernandez, Patrick Hirsch, Javier Faulin, Christian Fikar
Abstract: Horizontal cooperation has revealed itself as a new catalyser for goods distribution optimisation in order to achieve greater efficiency. Moreover, urban distribution is facing a new paradigm as e-commerce is growing rapidly and traffic restrictions in inner cities are becoming more frequent. While the economic benefit derived from the application of horizontal cooperation has been widely analysed by practitioners and in academia, this paper assesses the impact of horizontal cooperation on service quality in a business-to-business relationship. An agent-based simulation model is presented to measure savings in lead times due to various horizontal cooperation agreements under consideration of trust-related factors. Additionally, the effect of the store-wholesaler topology is investigated, providing meaningful insights on the potentials of horizontal cooperation. Results of computational experiments show that cooperation enables companies to reduce lead times substantially, which increases service quality and competitiveness.
Keywords: horizontal cooperation; lead time; coalition; service quality; simulation; last-mile distribution; trust; sharing.
Simulation of counter drugs operations based on geospatial technology for use in a military training simulator
by Ornprapa Robert, Chamnan Kumsap, Ampun Janpengpen
Abstract: This article reports the adoption of Potential Surface Analysis (PSA) to model drug trafficking routes in Thailand for military training scenarios of a small-arms simulator. GIS data layers were used for the analytic hierarchy process. Experts were gathered to brainstorm for potential factors and their ratings based on knowledge, expertise and judgements. Physical, drug-aspect and socio-demographic factors were the main factors, and were further separated into sub-factors. The Consistency Ratio (CR) was calculated at 0.09, the significance of the factors became less than 0.10, making the consistency acceptable. The PSA revealed potential drug-trafficking routes that were cross-checked with genuine routes. The created military training scenarios were validated by experienced military and security officials. The average satisfaction of 3.92 with the standard deviation of 0.75 confirms that the integrated methodology of modelling drug trafficking routes using PSA is another optional approach to upgrade the military small-arms training simulator.
Keywords: modelling and simulation; drug trafficking; geospatial technology; analytic hierarchy process; military simulation and training.
A case of a modelled saturation level for cooperative flight departures
by Nina Schefers, Juan José Ramos González, Jenaro Nosedal-Sánchez
Abstract: Owing to increasing air traffic operations, the development of advanced Decision Support Tools (DSTs) in Air Traffic Management (ATM) is driven forward to guarantee sustainable transport logistics to balance airspace capacity with user demands. In this paper, the tuning of Calculated Take-Off Times (CTOTs) as a tool for mitigating the propagation of perturbations between trajectories in dense sectors is analysed. The proposed methodology uses a powerful tool for predicting potential spatio-temporal concurrence events between trajectories over the European airspace. In the first place, the aim is to remove the detected concurrence events by considering bounded time stamp adjustments on strategic agreed points of the aircraft trajectory. In the second place, the model is extended to identify route interdependencies of over-constraint topologies that could lead to a saturation event. The approach is based on a robust constraint programming model aiming to determine the feasible time stamp changes considering reference-based trajectories.
Keywords: air transportation; constraint programming; air traffic management; decision support tools; airspace capacity; trajectory-based operations; air traffic control; air traffic flow management; conflict detection; scheduling; reference-based trajectory; calculated take-off time; reification.
Special Issue on: I3M2016 Recent Developments of Simulation Theories, Methodologies, Techniques and Tools
Analysis of fraud controls using the PaySim financial simulator
by Edgar Alonso Lopez-Rojas, Stefan Axelsson, Dejan Baca
Abstract: Fraud controls for financial transactions are needed and required by law enforcement agencies to flag suspicious criminal activity. These controls, however, require deeper analysis of the effectiveness and the negative impact for the legal customers.
Owing to the intrinsically private nature of financial transactions, this analysis is often performed after several months of actively using fraud controls. In this paper, we present an analysis of different fraud prevention controls on a mobile money service based on thresholds using a simulator called PaySim. PaySim uses aggregated data from a sample dataset to generate a synthetic dataset that resembles the normal operation of transactions and injects malicious behaviour. With technology frameworks such as agent-based simulation techniques, and the application of mathematical statistics, we show in this paper that the simulated data can be as prudent as the original dataset for setting optimal controls for fraud detection.
Keywords: Multi-agent-based simulation; MABS; financial fraud; mobile money; fraud detection; synthetic data.
Novel robustness measures for engineering design optimisation
by Philipp Fleck, Michael Kommenda, Thorsten Prante, Michael Affenzeller
Abstract: This paper presents novel robustness measures to analyse and compare the robustness of solutions for constrained optimisation problems in the field of engineering design optimisation. First, we define uncertainty in production processes and present a method to quantify uncertainty. Based on the variations of a solution that are introduced by uncertainty, we want to assess the robustness of those solutions towards those variations. We show how a solution's quality and feasibility (with regards to constraint violation) change with increasing uncertainty and discuss how those changes determine the robustness of that solution. Furthermore, we present a method of aggregating that information into a single, real-valued robustness measure.
This novel robustness measure can be used to select solutions that have a high robustness along with a high quality. To test the presented measures extensively, we apply them to various solutions for benchmark problems from published literature in the field of engineering design optimisation.
Keywords: engineering design optimisation; uncertainty; robustness; optimisation; benchmark; constrained optimisation; multi-objective.
Setting up a serious game for a major incident in industrial plant management: investigation of the learning effect
by Ivan Ferretti, Simone Zanoni, Lucio Enrico Zavanella
Abstract: In recent years, the introduction of virtual simulation has allowed improvement of the management of major incidents by developing tools (or serious games) able to increase awareness of coordination and decision-making abilities in emergency situations. This study presents the results of a new serious game that simulates activities, procedures and processes planned to be implemented to manage the aid during a major incident that may occur in industrial plants. In particular, the serious game presented is based on a discrete event simulator, and it is able to reproduce emergency situations in which the players can improve their own management abilities through repetitive random sessions. A detailed analysis of the learning effect over different scenario settings has been investigated through the initial application of the tool to differently experienced set of users. The results presented show how the use of the simulator may significantly improve the awareness of coordination and decision-making abilities in emergency situations.
Keywords: simulation; serious games; major incident; training; decision-making.
System dynamics for the water footprint assessment and simulation in the bioethanol production
by Armin Trujillo-Mata, Guillermo Cortes-Robles, Cuauhtemoc Sanchez-Ramirez, Julio Blanco-Fernandez, Emilio Jimenez-Macias
Abstract: The bioethanol industry is one of the growing sectors worldwide which is seeking for sustainability along its supply chain. The increasing demand for bioethanol means this industry faces a conflict: to increase productivity without compromising the future natural resources such as water. This work proposes to integrate the water footprint assessment methodology to the supply chain analysis using system dynamics. In this paper, the application of the synergy is to assess and simulate the water footprint of the bioethanol production stage using the system dynamics methodology. System dynamics could be a useful approach to model and simulate the water footprint of bioethanol supply chain and estimate its impact on water resources for the next years.
Keywords: bioethanol supply chain; system dynamics modelling; water footprint assessment; causal loops diagram.
Enterprise operating system framework: federated interoperability based on HLA
by Joseph Rahme Youssef, Gregory Zacharewicz, David Chen, Zhiying Tu
Abstract: Operating System (OS) is a well-known concept in computer science as an interface between human and computer hardware (MacOS, Windows, IOS, Android,). In the perspective of developing the future generation of enterprise systems based on IoT and cyber-physical system principles, this paper proposes to develop an Enterprise Operating System (EOS) that will act as an interface between enterprise business managers and enterprise resources performing enterprise operations. The paper presents at first a set of requirements and functionalities of EOS. Then a survey on existing relevant works is given and mapped to the requirements. After that the existing models related to the federated enterprise interoperability are presented. The architectures of envisioned EOS and the federated interoperability are outlined. The last part draws some conclusions and gives future perspectives.
Keywords: operating system; architecture; model; infrastructure; interoperability.
Simulation model generation for warehouse management: case study to test different storage strategies
by Antonio Vieira, Guilherme Pereira, Luis Dias, Jose Oliveira
Abstract: A simulation model generator was developed to help a company of the Bosch Group to reduce costs in time and space within its warehouse. The simulation models are automatically created in Simio and can simulate pickers riding milk runs to collect containers from the warehouse, to satisfy the needs of production lines, enabling warehouse management by testing different storage strategies. Thus, the purpose of this paper is to present the developed generator and to use it in a case study, to test different storage policies for the company. The generator was validated, and the simulation model was automatically created. With this tool, some suggestions could be made to the company in question. Namely, it was shown that it would not be possible to maintain the FIFO rule and, at the same time, eliminate the upper floor of all racks for ergonomic reasons. To allow this, the rate of replacing containers should be synchronised with the needs of production lines. Alternatively, it was also shown that the performance of the warehouse would improve by dividing it into zones allocated to each milk run.
Keywords: simulation; warehouse management; milk run; picking; object modelling; Simio; simulation model generator.