Simulation-Transactions of the Society for Modeling and Simulation International最新文献

{"title":"Modeling and interactive simulation of measures against infection transmission","authors":"M. Abadeer, Sameh Magharious, S. Gorlatch","doi":"10.1177/00375497221133849","DOIUrl":"https://doi.org/10.1177/00375497221133849","url":null,"abstract":"In this paper we develop an approach to modeling and simulating the process of infection transmission among individuals and the effectiveness of protective counter-measures. We base our approach on pedestrian dynamics and we implement it as an extension of the Vadere simulation framework. In order to enable a convenient simulation process for a variety of scenarios, we allow the user to interact with the simulated virtual environment (VE) during run time, for example, by dynamically opening/closing doors for room ventilation and moving/stopping agents for re-positioning their locations. We calibrate and evaluate our approach on a real-life case study—simulating COVID-19 infection transmission in two kinds of scenarios: large-scale (such as the city of Münster, Germany) and small-scale (such as the most common indoor environments—classrooms, restaurants, etc.). By using the tunable parameters of our modeling approach, we can simulate and predict the effectiveness of specific anti-COVID protective measures, such as social distancing, wearing masks, self-isolation, schools closing, etc.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"10 1","pages":"327 - 346"},"PeriodicalIF":1.6,"publicationDate":"2022-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78574026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HLA-based time management and synchronization framework for lean manufacturing tools evaluation","authors":"J. Possik, G. Zacharewicz, Anne Zouggar, B. Vallespir","doi":"10.1177/00375497221132577","DOIUrl":"https://doi.org/10.1177/00375497221132577","url":null,"abstract":"Discrete event simulation (DES) is a method for digitally replicating the behavior and performance of real-world processes, systems, and facilities. DES is widely applied in manufacturing, logistics, healthcare, and military domains. In some cases, DES method is insufficient. On one hand, the simulation must be disassembled into subsystems and then distributed on a multiprocessing environment to enhance the simulation performance. On the other hand, to expand current functionality and prevent future application development, a set of interacting simulations is required. In this project, the IEEE high-level architecture (HLA) standard mechanisms are adopted to solve the interoperability problems between heterogeneous components. Time synchronization between federates is essential to have all DESs running in parallel. In this paper, we present a distributed simulation framework designed to assist decision-makers in making the best decisions and prioritizing the adoption of Lean tools and techniques.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"35 1","pages":"347 - 362"},"PeriodicalIF":1.6,"publicationDate":"2022-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80483252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico analysis of optimum photon energy spectra and beam parameters for iodine nanoparticle–aided orthovoltage radiation therapy of brain tumors","authors":"A. Mesbahi, Maryam Sadeghian, Aisan Mesbahi, H. Smilowitz, J. Hainfeld","doi":"10.1177/00375497221135630","DOIUrl":"https://doi.org/10.1177/00375497221135630","url":null,"abstract":"In this study, the effect of photon energy spectra on the dose enhancement factor (DEF) and other influencing parameters such as skull–tumor dose ratios were estimated for a confined tumor loaded with iodine nanoparticles (INPs). A mathematical brain phantom with a brain tumor was simulated by the MCNP6 Monte Carlo code. A validated commercial computed tomography model consisting of an X-ray tube, Al–Cu filters, and collimators was used to simulate the rotational conformal treatment of the tumor. INPs with a diameter of 20 nm and concentrations of 10–50 mg/g were introduced inside the tumor as homogenously distributed spherical particles. The dose distribution inside the phantom was scored for several orthovoltage beams with the peak voltages of 140, 200, and 320 kVp as well as two 3.5 and 6 MV megavoltage beams. A significant rise of DEF values with nanoparticle (NP) concentration for orthovoltage beams is revealed; no significant dose enhancement was obtained for megavoltage beams. The highest DEF and skull–tumor dose ratio were obtained for the 140 kVp beam which decreased with the number of directional fields. The clinically optimal plan for a brain tumor, with high DEFs of 2.81–2.24 and acceptable skull–tumor dose ratios of 0.61–0.51, would be feasible for treatment using 200 and 320 kVp beams, an iodine concentration of 20 mg/g, and 8–15 fields. Our calculations show that clinically significant radiation dose enhancements can be obtained for tumors loaded with INPs using orthovoltage beams. Optimal treatment regimens are feasible using a proper selection of photon beam spectrum and sufficient numbers of cross-firing beams. The limiting effect of skull bone could be minimized by increasing the number of radiation fields and the use of higher quality of orthovoltage beams.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"16 1","pages":"539 - 552"},"PeriodicalIF":1.6,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73022248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TRAILS mobility model","authors":"Leonardo Sarmiento, Anna Förster","doi":"10.1177/00375497221133847","DOIUrl":"https://doi.org/10.1177/00375497221133847","url":null,"abstract":"According to state-of-the-art research, mobile network simulation is preferred over real testbeds, especially to evaluate communication protocols used in Opportunistic Networks (OppNet) or Mobile Ad hoc NETworks (MANET). The main reason behind it is the difficulty of performing experiments in real scenarios. However, in a simulation, a mobility model is required to define users’ mobility patterns. Trace-based models can be used for this purpose, but they are difficult to obtain, and they are not flexible or scalable. Another option is TRAce-based ProbabILiStic (TRAILS). TRAILS mimics the spatial dependency, geographic restrictions, and temporal dependency from real scenarios. In addition, with TRAILS, it is possible to scale the number of mobile users and simulation time. In this paper, we dive into the algorithms used by TRAILS to generate mobility graphs from real scenarios and simulate human mobility. In addition, we compare mobility metrics of TRAILS simulations, real traces, and another synthetic mobility model such as Small Worlds in Motion (SWIM). Finally, we analyze the performance of an implementation of the TRAILS model in computation time and memory consumption. We observed that TRAILS simulations represent the interaction among users of real scenarios with higher accuracy than SWIM simulations. Furthermore, we found that a simulation with TRAILS requires less computation time than a simulation with real traces and that a TRAILS graph consumes less memory than traces.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"55 1","pages":"385 - 402"},"PeriodicalIF":1.6,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88249661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of disequilibrium and chaos in aggregates of disposable income, wealth, and consumption in EU macroeconomics using nonlinear dynamic analysis","authors":"Damir V Sindik, Vladimir Kašćelan, Ljiljana Kašćelan","doi":"10.1177/00375497221130100","DOIUrl":"https://doi.org/10.1177/00375497221130100","url":null,"abstract":"Economic disequilibrium theory (DT) more realistically represents modern macroeconomic systems than general equilibrium theory. DT coupled with applied mathematical economics and nonlinear dynamical analysis generates multi-dimensional phase spaces. Interdependencies of endogenous variables in state space create a flow of different and “parallel economic realities,” which depend on the initial conditions. By modeling variable changes using the nonlinear least squares (NLLS) method, we define the first-order nonlinear ordinary differential equation (NODE) system. The NODE system is impossible to solve analytically. The numerical solution and visualization requires the MATLAB software package, combined with its specialized applications pplane (two-dimensional (2D)) and MATCONT (three-dimensional (3D)). By analyzing the evolution of flow operators, we can predict the future qualitative behavior of the entire system, determine the model-optimal values, and perform inverse modeling for variables. The obtained data advocate better and more stable macroeconomic paths that economic policymakers can pursue. The proposed methodology’s boundaries have strong links to chaos theory. Chaotic behavior can arise after a certain number of periods. We found very high computation accuracy, transformation of discrete variables to continuous functions, and the implementation of high-order polynomial data fitting offset its effects in part and to some reasonable degree.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"24 1","pages":"137 - 167"},"PeriodicalIF":1.6,"publicationDate":"2022-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75457839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved methodology for assessment of communication protocols for distributed road traffic simulation","authors":"T. Potuzak","doi":"10.1177/00375497221130097","DOIUrl":"https://doi.org/10.1177/00375497221130097","url":null,"abstract":"A computer simulation of road traffic is a commonly used tool, which can help to manage constantly intensifying road traffic. It can help to analyze behavior of existing road traffic networks or to predict the behavior of new designed road traffic structures. There are several existing simulators designed or adapted to run in a distributed computing environment in order to achieve a faster execution. In this environment, the inter-process communication ensured by a high-level communication protocol is one of the main bottlenecks limiting the speed of the entire computation. Various high-level communication protocols can have various efficiency, applicability, and scalability. This paper describes an improved methodology for testing and assessment of high-level communication protocols for micro-scale (or microscopic) distributed road traffic simulations. The methodology investigates the dependencies of the communication protocols’ performance on various features of the simulation and enables to easily calculate score for each of the tested protocols. Using the scores, the tested protocols can be directly compared. This can be useful when designing or improving a distributed road traffic simulation as the best protocol can be used in this simulation to improve its performance (e.g., its speedup or communication time). The improved version of the methodology is an evolution of its original version. It newly incorporates the assessment of the error introduced into the simulation by lossy communication protocols and reduces overall number of performed tests. The improved methodology was tested using a case study assessing several communication protocols of our own design.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"30 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83658951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A grid-shaped cellular modeling approach for wireless sensor networks.","authors":"Khaldoon Al-Zoubi,&nbsp;Gabriel A Wainer","doi":"10.1177/00375497221093379","DOIUrl":"https://doi.org/10.1177/00375497221093379","url":null,"abstract":"<p><p>WSN (Wireless Sensor Network) applications have been widely used in recent years. We introduce a new method for modeling WSN, based on the specification of the WSN using the Cell-Discrete-Event Systems Specification (DEVS) formalism: the space is partitioned into cells where each cell can be considered a sensor, an obstacle, or anything of a behavior with defined rules. This model is then converted automatically into DEVS model at runtime. We present two case studies analyzing the use of energy in WSN member nodes, which have impact on prolonging the overall network lifetime. We study to analyze energy consumption related to routing and data transmission at the node level, and topology residual energy control methods at the cluster level (i.e. group of sensors) level. The goal is to show how these spatial modeling methods can be used for building WSN models in a simple but efficient fashion.</p>","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"98 10","pages":"875-895"},"PeriodicalIF":1.6,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/54/c9/10.1177_00375497221093379.PMC9445403.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33464648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of latent representations for design space exploration of floorplans","authors":"Vahid Azizi, Muhammad Usman, Samuel S. Sohn, M. Schwartz, Seonghyeon Moon, P. Faloutsos, Mubbasir Kapadia","doi":"10.1177/00375497221115734","DOIUrl":"https://doi.org/10.1177/00375497221115734","url":null,"abstract":"Floorplans often require considering numerous factors, from the layout size to cost, numeric attributes such as room sizes, and other intrinsic properties such as connectivity between visible regions. Representing these complex factors is challenging, but doing so in a representative and efficient way can enable new modes of design exploration. Existing image and graph-based approaches of floorplans’ representation often failed to consider low-level space semantics, structural features, and space utilization with respect to its future inhabitants, which are all the critical elements to analyze design layouts. We present a latent-space representation of floorplans using gated recurrent unit variational autoencoder (GRU-VAE), where floorplans are represented as attributed graphs (encoded with the abovementioned features). Two local search approaches are presented to efficiently explore the latent space for optimizing and generating new floorplans for the given environment. Semantic, structural, and visibility metrics are evaluated individually and as a combined objective for optimizations.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"45 1","pages":"1167 - 1179"},"PeriodicalIF":1.6,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84120605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulating invisible light: a model for exploring radiant cooling’s impact on the human body using ray tracing","authors":"D. Aviv, Miaomiao Hou, E. Teitelbaum, F. Meggers","doi":"10.1177/00375497221115735","DOIUrl":"https://doi.org/10.1177/00375497221115735","url":null,"abstract":"Radiant systems are an energy-efficient method for providing cooling to building occupants through active surfaces. To assess the impact of the radiant environment on occupants in space, we develop a ray-tracing simulation, which accounts for longwave radiation. Thermal radiation shares many characteristics with visible light, and thus is highly dependent on surface geometry. Much research effort has been dedicated to characterizing the behavior of visible light in the built environment and its impact on the human experience of space. However, longwave infrared radiation’s effect on the human perception of heat is still not well characterized or understood within the design community. In order to make the embodied effect of radiant surfaces’ geometry and configuration legible, we have developed a Mean Radiant Temperature (MRT) simulation method, which is based on a ray-tracing technique. It accounts for the detailed geometry of the human body and its surrounding environment. We use a case study of a pavilion built with an envelope consisting of active cooling panels in Singapore. Using measured data for the surrounding surface temperatures in the pavilion, we explore the impact of both the active panels and the surrounding passive elements and thermal environment on a person’s radiant heat exchange in different postures. The reflectivity and emissivity values of different surfaces are taken into account, and the ray-tracing process allows for multiple-bounce simulation. The model accounts for both longwave and shortwave radiation, and the simulation results are compared with field measurements for validation. The results are expressed both numerically and as spatial radiant-heat-maps. These show a variation of up to 11°C in MRT across the space studied. Furthermore, a digital manikin is used to assess the impact of the radiant cooling panels across the human body. The results show a 10°C variation in radiant temperature perceived by different regions of the body in one position. The findings reveal a significant heterogeneity of radiant heat transfer that current analysis methods typically overlook for both architectural space and the geometry of the human body.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"3 1","pages":"1147 - 1166"},"PeriodicalIF":1.6,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87145940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the employment status of Iranian public universities graduates and the governmental policy using system dynamics approach","authors":"Nasser Shahsavari-Pour, L. Darabi, Setareh Zaer-Miri","doi":"10.1177/00375497221113329","DOIUrl":"https://doi.org/10.1177/00375497221113329","url":null,"abstract":"The increasing young population of Iran and the subsequent increase in the unemployment rate in recent years make the government adopt temporary policies to solve the unemployment problem. Establishing private universities and increasing the capacity of university admissions in higher education are among these policies. Although these policies can reduce the youth unemployment problem temporarily, it leads to an influx of highly educated people in the labor market in the long term. Creating job opportunities for these young people will be more difficult, which requires the extensive cooperation of universities and higher education institutions to train student entrepreneurs. Hence, in this present study, the employment of university graduates is simulated through system dynamics approach. Then using the experimental design method, sensitivity analysis and optimization of variables are performed. In the following, identifying the variables influencing the employment of university graduates, scenarios are introduced regarding dynamic universities in youth employment.","PeriodicalId":49516,"journal":{"name":"Simulation-Transactions of the Society for Modeling and Simulation International","volume":"21 1","pages":"89 - 109"},"PeriodicalIF":1.6,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90239436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}