International Journal of Simulation and Process Modelling (31 papers in press)
Stability-based model for evacuation system using agent-based social simulation and Monte Carlo method
by Makhlouf Naili, Mustapha Bourahla, Mohamed Naili
Abstract: The agent-based modelling is used for modelling many complex dynamic systems, especially those including autonomous individuals, such as human beings' societies, animal societies, robots, insect societies, etc. Evacuation systems such as those needed for supermarket buildings are considered as complex dynamic systems. In these systems, we have to deal with the problem of rescuing a high number of people of different ages, sex, physical characteristics, etc. Furthermore, this process mostly runs in buildings with different constraints such as locations of the rows of shelves, exit gates, etc. On one hand, in order to deal with disasters such as fire propagation, studying this kind of system using a dynamic model has a great importance in order to avoid the maximum of casualties. On the other hand, the model that represents this kind of system must take into account several factors, such as time, the buildings characteristics and peoples characteristics. In this study, an agent-based model has been designed to visualise the dynamic system behaviour via these internal entities that often interact. Additionally, we use some dynamic data mining methods such as Monte Carlo method to calculate the stable characteristics of this model via a probabilistic approach.
Keywords: agent-based modelling; dynamic data mining; dynamic models; evacuation building system; Monte Carlo simulation; stability; steady state.
Swarm intelligent algorithm For re-entrant hybrid flow shop Scheduling Problems
by Zhonghua Han, Xutian Tian, Xiaoting Dong, Fanyi Xie
Abstract: In order to solve the Re-entrant Hybrid Flowshop (RHFS) scheduling problems and establish mathematics scheduling models, this paper uses Wolf Pack Algorithm (WPA) as the global optimisation. For local assignment, it takes maximum residential time-oriented rule. Scouting behaviours of wolves are changed in the former optimisation by means of levy flight, extending searching ranges and increasing the rapidity of convergence. When it comes to local extremum of wolves, the individual with high similarity of dynamic changes adds diversity. Hanming distance is used to judge individual similarity for increased quality of new one, strong algorithm ability and energetic revolution. A painting workshop in a bus manufacture enterprise have some typical features of re-entrant hybrid flowshop. Regarding it as the algorithm applied target, this paper focus on resolving this problem with WPA and various advanced algorithms. The results show that advanced algorithms can solve re-entrant hybrid flowshop scheduling problems effectively.
Keywords: re-entrant hybrid flow shop; mathematics scheduling models; Hanming distance; levy flight; swarm intelligent algorithm.
The structure optimisation of hydraulic mechanical screw pump
by Zhenfu Ma
Abstract: In the current stage of oilfield development, the screw pump is an advanced mechanical oil recovery process. In the process of lifting oil and other liquids in the well, the screw pump has good and stable characteristics of pumping force under high pressure This paper takes Shengli Oilfield water flooding development as the engineering background, aiming at the problem that the flow ratio of the screw motor and the screw pump affects the efficiency. The changing rules of influencing factors, such as luffing coefficient and eccentric coefficient, over the flow area, and the relative sliding velocity are modelled and analysed. With the amplitude coefficient and eccentric coefficient as decision variables, the equatorial short hypochromic curve is optimised to get the best ratio of each head of the parameters and end line type.
Keywords: screw pump; screw motor; luffing coefficient; eccentricity coefficient; optimisation.
Cogent: a coherence-driven cognitive agent modelling and experimentation framework
by Sunit Sivaraj, Levent Yilmaz
Abstract: Most agent modelling and simulation languages lack high-level syntactic features necessary for cognitive modelling. In this paper, we present Cogent, an interactive coherence-driven agent specification and simulation platform and demonstrate its use in ethical decision-making. The underlying strategy is based on the concept of a connectionist, interactive activation model that implements the theory of coherence. Agents in the Cogent language are specified by a Domain Specific Language (DSL). The DSL provides the syntax for specifying the decision- making strategy along with its cognitive coherence model. The framework also provides the ability to model complex hierarchical cognitive network structures. To illustrate the utility of Cogent, we explore a machine ethics case study.
Keywords: cognitive agent; coherence; ethical decision making; cognitive computing; domain-specific language.
Modelling, simulation, and resource optimisation of complex development project by fusion of multiple-domain matrix and coloured Petri nets methods
by Gordan Topic, Dragan Jevtic
Abstract: In this research, a fusion of two methods is developed as a suitable strategy and procedure for dynamic management of complex project systems: the first method of Multiple-Domain Matrix (MDM), includes modelling complex relations between resources and activities, using rearrangement of these elements to minimize feedbacks. The second method provides an insight into the project system dynamics by performing Coloured Petri Net (CPN) simulation based on the model of project system obtained by the first method. The focus is on the unique conversion of the MDM method to CPN, where the static system description of the MDM method was expanded by the capabilities of the dynamic system description of the CPN method. The objective was to evaluate an effective technique to analyse a complex project system of software development, which enables detailed planning and optimal management to shorten the production cycle of the appropriate quality with the lowest cost.
Keywords: design/dependency structure matrix; multiple-domain matrix; coloured Petri net; conversion; simulation; project management; process modelling; software development process; complex project system.
Developing an evolution software architecture framework based on six dimensions
by Noureddine Gasmallah, Abdelkrim Amirat, Mourad Oussalah, Siridi Hassina
Abstract: Because of the vital need for software systems to evolve and change over time in order to account for new requirements, software evolution at higher levels of modelling is considered as one of the main foundation within software engineering used to reduce complexity and ensure flexibility, evolvability and usability. With the growing number of evolution methods, the need to develop a framework based on well defined dimensions to analyse these approaches, is now a prerequisite for practitioners in order to analyse, compare and classify methods within the field of architectural evolution. In similar studies for migration techniques and software engineering, presenting a framework does not usually cover the specification of systems based on software architecture subsequently, it does not give the opportunity to shape the interior design of software in terms of specific metrics. In this paper, we propose an evolution software architecture based on six dimensions for analysing, comparing and classifying existing and future evolution methods. The proposed architectural evolution framework adopts Zackman analytic tool by providing answers to What, Why, Where, Who, When and How questions. The process to formalize a framework for evolution methods relies upon identifying dimensions on which researchers would take into account while developing a new approach. The set of the proposed dimensions whether combined or individually can serve as a basis to explore further classification paradigms. Six explicit dimensions are identified confirming the conceptual framework consistency in accordance with the architectural view-point of the software. The proposed framework is supported by an empirical study that involves surveying and analysing 119 research methods related to area of architectural evolution from the literature. Furthermore, these dimensions are quantified and then analysed within a case study. This framework provides a blueprint to guide practitioners to position architectural evolution approaches and maps them according to a selected set of dimensions.
Keywords: conceptual framework; software architecture; classification; taxonomy.
Simulation-based structural design of diesel generator mufflers and their performance analysis
by Li Wei, Yusheng Luo
Abstract: Aiming at the frequency spectrum characteristics of diesel generator noise, this paper simulates the structure of diesel generator mufflers by means of theoretical analysis, GT-power simulation and experimental tests, and calculates and analyzes their noise reduction performance. Research results show that elliptical cross-section mufflers show almost the same muffling effect as square cross-section mufflers, while square cross-section mufflers are more suitable for mass production; the length of the first cavity and that of the overlapped section of the insertion pipe present a remarkable noise reduction effect on low-and mid-frequency noise; shortening the distance between the 1/4 wavelength pipe and the main pipes confluence is more conducive to noise reduction; the addition of dissipative materials improves the muffling performance. Based on the above structure, a simulated model of impedance composite muffler was designed, with its A-weighting noise level dropped from the original 92.2 dB to 59.7 dB, thus achieving a good noise reduction effect.
Keywords: diesel generator; noise muffling; GT-power simulation; structure design.
Coloured Petri net for modelling and improving emergency department based on the simulation model
by Oussama Derni, Mohamed Faycal Khelfi, Fatma Boufera
Abstract: Emergency departments (ED) is one of the most complex systems throughout the world, owing to their unstable environment and the stochastic characteristics of patients flows, pathologies, and limited resources, which lead to a long waiting time. Effective management of patient flows for ED services has become a critical matter for most hospital supervisors. Many authors have tried to solve those issues based on different methodologies, with shared aims represented in the optimisation of patients care, by minimising patients' waiting time at different levels in the ED. Modern studies mainly focus on limiting these issues by proposing a solution based on extending ED resources. The case study was realised at the ED of the hospital Chalabi Abdelkader, Mascara, Algeria. Then, the system was modelled by a coloured Petri net framework. Afterward, we performed simulations of numerous improvement scenarios using a discrete event simulator. As a result, patient waiting times encountered in ED were reduced, thus also the patient's length of stay.
Keywords: emergency department; patient flow; system modelling; coloured Petri net; Optimisation; waiting time.
Innovative social networks modelling for population simulation
by Marina Massei, Riccardo Di Matteo
Abstract: Today's social networks are an important element of society that requires to develop new models as well as guidelines to create interoperable simulators covering these aspects. These new simulators are expected to enable research and development focused on people's reactions to simulated events social networks. This research area seems promising, however it is necessary to address several challenging issues including proper development of new conceptual models as well as validation and verification processes and definition of human behaviour modifiers. This paper presents a new methodological framework for modelling individuals and populations by means of web social networks, in order to reproduce their dynamics. The article proposes to create interoperable models of social networks along with a real case study related to training and decision making processes for authorities. The paper includes experimentations over a complex scenario where human factors and social networks play a crucial role.
Keywords: interoperable simulation; human behaviour modelling; hybrid warfare; CAX; serious games.
Simulation of a remote runway solution for a congested airport: Mexico City airport
by Miguel Mujica Mota, Paolo Scala
Abstract: The airport of Mexico City has been declared saturated for most of the day. For that reason, the Mexican government announced a couple of years ago the construction of a completely new one which is supposed to be operative in 2020 in its first phase. However, the technical issues and the economic downturn in the country have jeopardised the project; for that reason, it is important to have alternatives that allow investing in a progressive fashion so that the investments are not lost or end up in useless infrastructure like the ones that have taken place in other parts of the world. The current work presents a simulation-based study of the alternative of using one of the runways of the new airport in a remote fashion in case the original project is delayed or even cancelled. The results indicate that the proposed infrastructure alleviates the congestion problem in the current airport, and at the same time allows the traffic growth with performance indicators similar to airports that have remote runways as it is the case of Schiphol in The Netherlands.
Keywords: simulation; airport; congestion; taxi time; failure; downturn; over dimension; NAICM.
Numerical simulation of thermal changes in womens breast tissue during menstrual cycle in different stages of its development
by Akshara Makrariya, K.R. Pardasani
Abstract: Investigators in the past have studied thermoregulation in womens breast tissue under normal conditions without taking into the account the benign changes taking place in the breast due to various physical and physiological conditions. In this paper, a model is proposed to study thermal changes taking place in womens breasts in different stages of its development due to the menstrual cycle. The changes in the physical and physiological parameters, such as blood mass flow rate, metabolic heat generation and thermal conductivity due to benign changes in the breast, have been incorporated into the model. Appropriate boundary conditions have been framed based on the physical conditions of the problem. The finite element method has been employed to obtain the solution for a two-dimensional steady-state case. The temperature profiles have been computed and the thermal changes in the breast have been analysed during the follicular and luteal phases of the menstrual cycle in different stages of its development. The thermal information of such models can be useful for diagnosis and proper health care of womens breast disorders. The finite element method has proved to be quite flexible and powerful in the present study as it was possible to incorporate the minor details of the physiology of breast in the proposed model to generate the thermal information of breast due to benign changes occurring in the breast, such as the menstrual cycle.
Keywords: women’s breast tissue; menstrual cycle; stages of development; mathematical modelling.
Special Issue on: I3M 2017 Systems Modelling and Real-World Industry 4.0 Applications
Investigating small and medium-sized manufacturing enterprises immediate response and short-term recovery from flooding using an agent-based approach
by Meshal Alharbi, Graham Coates
Abstract: The predominance and economic significance of Small and Medium-sized Enterprises (SMEs) means widespread disruption can have severe financial consequences for a nation. This paper presents an agent-based approach enabling simulations to investigate manufacturing SMEs immediate response to and short-term recovery from a flood event to evaluate the effectiveness of combinations of inundation precautions. Manufacturing SME agents exhibit pre- and post-flood behaviours gleaned from interviews with such businesses that have flood experience. Based on a flood event simulated for Sheffield in the UK, results show an individual SME with most precautions implemented in the lightly or moderately flooded area can return to 100% production approximately 7 days earlier than if the fewest precautions were employed. Further, considering the average short-term recovery of all SMEs with most precautions implemented in the lightly or moderately flooded area, 100% production can be achieved almost 20 days before manufacturers located in the severely flooded area.
Keywords: small and medium-sized enterprises; agent-based modelling and simulation; flooding; short-term recovery; manufacturing.
Sustainability of retail store processes: an analytic model for economic and environmental evaluation
by Eleonora Bottani, Giorgia Casella, Simona Arabia
Abstract: This study proposes a model to evaluate the economic and environmental sustainability of retail stores. The model was developed under Microsoft Excel and reproduces the main retail store processes (i.e. product receiving, backroom storage, sales area management and return management) in quantitative terms. As input, the model takes several data about these processes; as output, it provides an evaluation of the total cost and CO2 emissions of the store. The application of the model to a real case, referring to a large-scale retail store of Italy, and the discussion of the key results obtained is presented for all the processes considered. The outcomes show that the most relevant environmental impact and the highest total cost are generated by the sales area management process. Conversely, the return management process contributes to the total cost to a limited extent. A sensitivity analysis was carried out to highlight the key aspect managers should focus on to improve the sustainability of the retail store. The results obtained provide useful guidelines for store managers to optimize the sustainability of their internal processes.
Keywords: sustainability; large-scale retail store; case study; economic and environmental assessment; analytic model.
Properties modelling as design by contract for cyberphysical systems: an example in the smart grid domain
by Andrea Tundis, Max Muhlhauser
Abstract: The development of a cyberphysical system is strongly related to the elicitation of requirements and their fulfilment. Requirements represent the agreement, among the actors involved in the development process of a system (e.g. stakeholders, engineers), of what it is expected to be delivered. As they are neither computable nor verifiable, because typically expressed textually, their misunderstanding could lead to delay or even the failure of the overall system development. In this context, the exploitation of the Properties Modelling (PM) approach combined with the simulation is proposed to enable assessable requirements. In particular, PM is adopted for expressing requirements as computable and verifiable components, whereas simulation techniques are exploited for supporting their automatic verification and to evaluate their level of fulfilment. The simulation model along with the results gathered from the properties evaluation represent the contract (Design-by-Contract) on which the actors can agree before the realization of an actual cyberphysical system. The proposal is tested in the smart grid domain.
Keywords: systems engineering; cyberphysical systems; properties modelling; requirements specification; simulation-based verification; smart grids.
Collaborative training in a virtual environment to increase productivity in a shipyard
by Jose Antonio Muiña Dono, Adolfo Lamas Rodriguez, David Chas Alvarez
Abstract: The paper addresses the potential of the combined use of simulation tools and a game engine for an effective and efficient design to study complex problems. This study is focused on the shipbuilding problem, although the methodology and tools proposed can be extended to another application by other complex problems reaching the same satisfactory results. The innovative use of both tools has important advantages. From the training point of view, an economic saving, dynamism, customisation and motivation could be achieved, facilitating the implementation of a new work culture in the company. In addition, the realism of the simulation makes easier the extrapolation of knowledge to the reality and an estimation of the performance of the improvements. On the other hand, streamlining model development processes is possible using the users as a testers and developers of the model, since the opinions of the users back to the system design.
Keywords: simulation; discrete event simulation; game engine; training; shipbuilding.
An investigation of the interactions between psychosocial risk factors and their health impact: mechanisms and consequences
by Hossein Abaeian, Mohamed Al-Hussein, Osama Moselhi
Abstract: Despite the increase in research on psychosocial hazards, studies have been unable to evaluate the inter-relationships among Psychosocial Risk Factors (PRFs) from a risk network perspective, and their findings are usually limited to bi-variate relationships between PRFs and their adverse outcomes. Also, they are unable to draw the pathways by which PRFs can affect workers health leading to impaired job performance. The present study performs a comprehensive literature review on the psychosocial risk-related research and provides an evidence-based list for major PRFs. In addition, social network analysis is implemented for developing the psychosocial risk network for further evaluation of the interactions between variables, leading to the identification of key PRFs that play important roles in structuring the entire risk network. In the next step, a system dynamic model is developed to provide the mechanism underlying the development of musculoskeletal disorders and productivity loss due to exposure to psychosocial stressors.
Keywords: psychosocial risks; mental process model; strain; impaired job performance; musculoskeletal disorders; system dynamics simulation model; dynamic thinking; social network analysis.
Mixed reality for industrial applications: interactions in human-machine systems and modelling in a immersive virtual environment
by Agostino Bruzzone, Gianfranco Fancello, Mary Daga, Bruno Leban, Marina Massei
Abstract: The authors propose an innovative mixed reality solution representing an immersive intuitive and interoperable environment to support service in industrial plants. These methodologies are related to concepts of Industry 4.0. Proposed solutions are based on a mix of VR and AR (Virtual and Augmented Reality); indeed the authors propose an overview of this approach and other synergistic techniques. Moreover, alternative instruments are presented and their specific advantages and disadvantages are described. Particularly, the paper proposes an innovative approach based on the SPIDER, an advanced interoperable interactive CAVE developed by the authors which supports cooperative work of several users involved in training, troubleshooting and supervision. Last but not least, the uses of these technologies and approaches in other field are presented, such as the validation of a training equipment for bus driving and related motion platform integrated in the SPIDER; in this case the solution is running a simulator, named BBBuS, used for training and R&D activities. In order to perform this validation, an investigation has been conducted to evaluate the accuracy in reproducing the mechanical vibrations generated by the real bus; indeed the vibrations are transmitted from the base of the bus to the driver's seat. Data from real system have been acquired and data analysis was divided into different phases for separate examination of signals in time and frequency domains. The bus simulator satisfactorily reproduces the accelerations recorded over real equipment.
Keywords: augmented reality; virtual reality; mixed reality; industrial plants; maintenance and operation; interoperable simulation; vibrational spectra; mobile platform.
Human factors in Occupational Health & Safety 4.0: a cross-sectional correlation study of workload, stress and outcomes of an industrial emergency response
by Letizia Nicoletti, Antonio Padovano
Abstract: Industrial hazards and emergency response capability assessment studies are still poorly focusing on the impact of human factors in the response phase in the aftermath of an industrial accident. This study pushes for an increased attention on human factors, such as stress and perceived workload, in the Occupational Health and Safety 4.0 and proposes an approach to analyse their effects with the ultimate aim to include them in the design of industrial safety protocols and regulations and in the assessment of hazards. The present paper answers the question whether and to what extent stress and the perceived workload are correlated to the capability of the emergency manager to coordinate and monitor the execution of all the actions intended to deal with an industrial accident and its effects. The findings of a cross-sectional regression of data collected from a series of training sessions carried out by means of virtual reality and serious games technologies show how a balanced workload and the ability to control emotivity are a precondition for mastering procedures and responding in the optimal way to an industrial emergency scenario.
Keywords: Occupational Health & Safety 4.0; human factors; Industry 4.0; stress; workload.
Special Issue on: I3M 2017 Concepts and Methodologies for the Next Generation of Modelling and Simulation Techniques in Industry and Logistics
Individualised modelling of affective data for intelligent tutoring systems: lessons learned
by Keith Brawner
Abstract: One on one tutoring from human expert tutors to human students is the most effective form of instruction found to date. There are many actions that human tutors perform that make them remarkably effective, including the attention that they pay to the cognitive and affective states of the human students that they tutor; and the use of this knowledge to modify the way that they instruct the material. According to theoretical models, learner state data is used to inform instructional data and decisions, which then influences the learning of the student. Naturally, the data about student state must be available in order to be used to adjust the instruction. Success amongst operational systems, however, has been observed with generalised modelling techniques. Individualised and adaptive modelling techniques from other domains in the literature present an alternative to the approach which isnt observing significant operational success. This paper investigates individualised adaptive models, validates the approach, and shows that it can produce models of acceptable quality, but that doing so does not obviate the experimenter from creating quality generalised models prior to individualising.
Keywords: adaptive and predictive computer-based training; intelligent tutoring systems; architectural components; emerging standards.
Identifying and modelling correlation between airport weather conditions and additional time in airport Arrival Sequencing and Metering Area
by Margarita Bagamanova, Juan Jose Ramos Gonzalez, Miquel Angel Piera Eroles, Jose Manuel Cordero Garcia, Alvaro Rodriguez-Sanz
Abstract: Different uncertainties during operational activities of modern airports can significantly delay some processes and cause chain-effect performance drop on the overall Air Traffic Management (ATM) system. The decision-making process to mitigate the propagation of perturbations through the different airport processes can be improved with the support of a causal model, build with a use of data mining and machine learning techniques. This paper introduces a new approach for modelling causal relationships between various ATM performance indicators, which can be used to predict by the means of simulation techniques the evolution of airport operations scenarios. The analysis of reachable airport states is a relevant approach to design mitigation mechanisms on those perturbations which drive the system to poor KPIs.
Keywords: ASMA time; holding; inbound traffic; weather impact; Bayesian networks; Coloured Petri net; airport; decision support tool.
Surrogate-assisted microscopic traffic simulation-based optimisation of routing parameters
by Bernhard Werth, Erik Pitzer, Christian Backfrieder, Gerald Ostermayer, Michael Affenzeller
Abstract: Reactive and predictive routing algorithms have to work fast and reliably for a large number of traffic participants. Therefore, simple rules and thresholds guide routing decisions rather than extensive data collection and machine learning. We optimize some of the thresholds governing the behavior of the PCMA* routing algorithm, by use of the microscopic traffic simulator TraffSim. Microscopic traffic simulation is more exact than its macroscopic counterpart and very well suited to test the efficiency of a reactive/predictive routing algorithm. Sadly, it is also tremendously more computationally expensive, impairing the applicability of 'conventional' heuristic optimization techniques like genetic algorithms or evolutionary strategies. Extensive use of surrogate models in an optimisation procedure is a promising alternative. Several variations of the efficient global optimisation algorithm (EGO) are tested and compared. Furthermore, a new type of surrogate model geared towards overcoming some characteristics of the parameter optimisation is presented.
Keywords: surrogate assisted optimisation; microscopic traffic simulation; TraffSim; HeuristicLab; efficient global optimisation; noisy optimisation; routing algorithms.
Sustainability in logistic hubs: a decision support system for investigating green practices at container terminals
by Francesco Longo
Abstract: Logistic hubs, and especially container terminals, are today responsible for a major percentage of the environmental pollution. Practices such as the Onshore Power Supply (OPS) or cold ironing may have relevant benefits, but it has been argued that container terminal operators perceive a paucity of evidence that the benefits derived from the implementation of green practices exceed the investment costs. In this perspective, there is an urgent need for guidance to sustainability-related decision-making in container terminals. To this end, an advanced decision support system, which leverages on modelling and simulation, is proposed in this article to represent a reliable test environment to investigate the impacts of sustainability practices on container terminals. Results show that the evaluation of the impacts of an OPS system must consider the source of the electric power needed by ships at berth, i.e. coal, biofuels or renewable energies. The study shows that, although a coal-powered OPS system is the most affordable one, pollutant emissions are reduced in the port area but it is not a zero-emission solution. Electric energy generated by biofuels or renewable energies is zero-emissions but results in higher costs. The unit costs of 1 m3 of saved CO2 and NOX (two of the most dangerous pollutants at port areas) by implementing an OPS system are calculated.
Keywords: green port; container terminal; logistics; sustainability; onshore power supply.
Analysing uncertainties and their impacts on deliveries of a logging company: a simulation model to foster supply chain resilience
by Peter Mensah
Abstract: The supply chain in todays competitive world faces uncertainties that might disrupt any part between the upper and lower levels affecting the flow of raw materials and products, as well as information and money. The lower level, consisting of the delivery of goods in the form of raw materials and/or finished products to customers on time, is vital as it enhances customers loyalty. This could boost competitive advantages yielding to higher profitability of organisations over their rivals. However, to achieve and sustain these advantages, organisations need to identify and analyse the risks and their impacts on deliveries especially during strategic and operational decision making processes. Hence, modelling and simulation may be used as an effective tool to support decision making when planning delivery patterns. Consequently, a research is conducted in a logging company, Company L, to comprehend the way uncertainties affect deliveries. This article therefore uses a simulation model as a tool to boost managerial decision making, with reference to Company L, by identifying and analysing uncertainties and portraying their impacts on deliveries. This will enable the organisation to be agile and flexible enough to combat uncertainties.
Keywords: supply chain; deliveries; uncertainties; risk impact; resilience; simulation model.
Microscopic modelling of international (re-)hospitalisation effects in the CEPHOS-LINK setting
by Guenther Zauner, Christoph Urach, Martin Bicher, Niki Popper, Florian Endel
Abstract: Avoiding hospitalisation has become mainstream in healthcare planning and policy, and the urge to identify so-called ambulatory care-sensitive conditions is increasing. In this and other contexts, re-hospitalisation rates have become popular as a quality indicator among healthcare researchers, planners and politicians, both for cost containment and quality improvement. Within the European Commission funded FP7 project CEPHOS-LINK, a dynamic agent-based model is integrated for Austria, Slovenia and the Veneto region of Italy for answering questions regarding long term and planning effects for psychiatric hospitalisation and re-hospitalisation under special constraints, using national routine databases combined by data pooling processes. The agent-based simulation framework is based on a modular concept with the core module GEPOC, a generic population concept developed within the DEXHELPP consortia project in Austria, and parametrised and calibrated using EUROSTAT and national statistics databases for regional forecast. Demographic changes and their simulated effects on (re)-hospitalsation are calculated as well as changes in distance to service and the effect of changes in the diabetes mellitus prevalence as forecast for Austria, Slovenia and the Veneto region. The distance information is calculated for weighted NUTS3 driving time to psychiatric hospitals. All results are gathered on a personal level and depicted and described on age and gender groups. Furthermore the (re)-hospitalisations in each country are mapped to costs, which are calculated with average inflation, based on purchasing power parity to get comparable results.
Keywords: healthcare simulation; agent-based model; spatial dynamics; international claims data; model parameterisation; pathway model; parameter calibration.
Management for safety and efficacy in industrial plan disaster: the medical competence in a simulation project for healthcare emergency.
by Marco Frascio, Katia Cortese, Kirill Sinelshchikov, Francesco Longo
Abstract: Industrial mass casualty incidents are an unfortunate reality in the 21st century, but there are few situational training exercises to prepare and to cope with emergencies management. Each phase of an emergency plan has particular needs, requires distinct tools, strategies, and resources and faces different challenges. This paper describes a project to carry out development of the activities devoted to face the complexities arising from emergencies in industrial plants. The DIEM-SSP is a simulation project working on two interoperable simulators, based on the IEEE 1516 High Level Architecture (HLA), used as a test-bed on specific case studies. The project is aimed to study innovative emergency procedures and proper routing of critical patients with severe traumas toward the most suitable first aid facilities. The project takes into account the emergency procedures considering the human factors and the possibility of mistakes. It is aimed to test and validate these methodologies through a test-bed based on distributed and interoperable simulation. The paper reports the medical contribution in this project.
Keywords: medical simulation; medical emergency management; triage; industrial plan disaster; healthcare emergency.
Special Issue on: ISSPM 2018 Integrating Nodes and Optimisation across Social and Scientific Areas in Sustainability Loops
Error of single-phase proton exchange membrane fuel cell model based on Brinkman-Darcys law in different flow fields
by Shizhong Chen, Zhongxian Xia, Xuyang Zhang, Yuhou Wu
Abstract: The proton exchange membrane (PEM) fuel cell is an auspicious energy device for the future with high energy efficiency and zero emissions. PEM fuel cell performance can be improved by optimising the flow field using numerical models based on Brinkman-Darcys law. However, errors made by applying Brinkman-Darcys law cannot be avoided; errors should be carefully investigated for different flow fields. In this paper, a single-phase PEM fuel cell model based on Brinkman-Darcys law is developed, considering the effects of flow field on both local electrochemical active area and effective permeability. The results showed that the model predicts well the performance of the flow field with a high resolution land width, such as 1 mm, but it over-estimated the performance under the low voltage region when the land width was 2 mm or larger, since the high mass transfer loss was under-estimated by the model.
Keywords: Brinkman-Darcy’s law; flow fields; proton exchange membrane fuel cell; under-land cross-flow.
Dynamic performance of high supporting formwork under horizontal impact load
by Zhengran Lu, Chao Guo, Maosheng Zhang
Abstract: Dynamic performance of a high full-scale supporting formwork (HSF) subjected to horizontal impact loading was examined. It could be concluded that transverse X-bracings in the horizontal impact load direction have a more significant effect on the bearing performance and dynamic characteristics of an HSF than longitudinal X-bracings. An increase in the amount of poured concrete and the failure of the X-bracings reduces the natural frequency of the HSF. With the gradual increase in the amount of poured concrete, the maximum dynamic axial force of posts may increase from 4.33 kN to 12.77 kN under different X-bracing conditions during concrete placement. With failure of some main nodes, any impact load significantly increases the axial force acting on the posts. Dynamic axial force acting on some of the posts can increase by as much as 120% if 5% of fasteners fail during concrete pouring compared with that when all fasteners and X-bracings are intact.
Keywords: high supporting formwork; horizontal impact load; dynamic performance; experimental research.
Cloud resource orchestration optimisation Based on ARIMA
by Hua Qin, Min Yu, YingXu Lai, Liu Zenghui, Liu Jing
Abstract: This paper examines how to solve the problem of resources management in the cloud environment, especially on the PaaS, satisfy the demands of users and relieve the load on the server in high concurrency. After analysing the resource orchestration technology on PaaS, this paper presents a dynamic orchestration optimisation framework based on the ARIMA model. The architecture is based on OpenStack infrastructure as a service, and combines with Cloudify, a resource orchestration software on the PaaS by making adjustments in advance by predicting the resource consumption in the next time period. Experiments showed that this architecture can effectively shorten the concurrent response time and improve the use of memory.
Keywords: Cloudify; OpenStack; cloud computing; orchestration.
Morphological component analysis based on mixed dictionary for signal denoising of ground-penetrating radar
by Jianhua Zhang, Haohao Zhang, Yang Li, Xueli Wu
Abstract: Forward modelling is applied to simulate the ground-penetrating radar (GPR) detection environment, and a modified Morphological Component Analysis (MCA) algorithm is applied to GPR signal denoising. Finite-difference time-domain method (FDTD) is used to perform finite difference approximation to the space and time derivatives of Maxwell's equations. Under the forward simulation framework, The MCA algorithm applies a sparse dictionary to decompose the GPR signal. However, clutter is not represented as there is no corresponding sparse dictionary, the clutter is removed when the signal is reconstructed. The core of the MCA is to select a suitable dictionary. The combination of undecimated discrete wavelet transform dictionary (UDWT) and curvelet transform dictionary (CURVELET) is selected. The improved MCA algorithm is compared with Singular Value Analysis (SVD) and Principal Component Analysis (PCA), to confirm the high performance of the proposed algorithm.
Keywords: FDTD;signal processing; MCA; UDWT; CURVELET; ground-penetrating radar.
Simulation of multilateration system based on Chan algorithm and conjugate gradient optimisation algorithm
by Jianhua Zhang, Feng Gao, Yang Li, Xueli Wu
Abstract: For a multilateration (MLAT) system, the traditional Chan algorithm applies the theory of time-difference-of-arrival (TDOA) to solve the target position of the mathematical model. By introducing intermediate variables, the algorithm adopts a two-step weighted least-squares to locate, which has low computational complexity and high positioning accuracy. The introduction of intermediate variable will make the target position equation produce fuzzy solution, and then lead to the decline of positioning accuracy. Therefore, the location accuracy is directly related to the location algorithm. Conjugate gradient algorithm (CGA) is not only one of the most useful methods for solving large linear equations, but also one of the most effective algorithms in solving large-scale nonlinear optimisation. On the one hand, it avoids solving the inverse of the matrix, on the other hand it can also speed up the solution of the target position and improve the positioning accuracy. The TDOA principle is applied in this article, a four stations multipoint positioning system mathematical model is set up, and then a new fusion algorithm, Chan-CGA, is applied to the MLAT system. CGA is used to optimise the intermediate variable Chan algorithm solving process. Finally, the fusion algorithm is evaluated by simulation and comparison with the Chan-Taylor algorithm.
Keywords: multilateration; time-difference-of-arrival; Chan algorithm; conjugate gradient optimisation algorithm.
Special Issue on: ISSPM 2018 Internet of Things and Smart City Technologies
A DT-CWT-based infrared-visible image fusion method for smart city
by Guanqiu Qi, Mingyao Zheng, Zhiqin Zhu
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, image fusion technique integrates information from multiple images. Multi-scale transform (MST) and sparse representation (SR) are widely used in infrared-visible image fusion. Traditional MST-based fusion methods are difficult to represent all features of source images. At the same time, traditional SR-based fusion methods do not consider morphological information of image features in dictionary learning processes. To overcome the defects of both MST- and SR-based fusion methods, this paper presents a infrared-visible image fusion framework by combining double-tree complex wavelet transform (DTCWT) and SR. The source images are decomposed and clustered into high- and low-pass bands by DTCWT. The high-pass bands are fused by the Sum Modified Laplacian (SML). The low-pass bands are fused by the SR-based approach. The fused high- and low-pass bands are integrated and reconstructed by DTCWT to form the final fused image. Comparing with five mainstream image fusion solutions, the proposed fusion framework can achieve state-of the-art performance in infrared-visible fusion images.
Keywords: DT-CWT; sparse representation; SML; infrared-visible; image fusion.