We define the notion of mock hyperbolic reflection spaces and use it to study Frobenius groups, in particular in the context of groups of finite Morley rank including the so-called bad groups. We show that connected Frobenius groups of finite Morley rank and odd type with nilpotent complement split or interpret a bad field of characteristic zero. Furthermore, we show that mock hyperbolic reflection spaces of finite Morley rank satisfy certain rank inequalities, implying in particular that any connected Frobenius group of odd type and Morley rank at most ten either splits or is a simple non-split sharply 2-transitive group of characteristic different from 2 and of Morley rank 8 or 10.
{"title":"Mock hyperbolic reflection spaces and Frobenius groups of finite Morley rank","authors":"Tim Clausen, Katrin Tent","doi":"10.2140/mt.2023.2.137","DOIUrl":"https://doi.org/10.2140/mt.2023.2.137","url":null,"abstract":"We define the notion of mock hyperbolic reflection spaces and use it to study Frobenius groups, in particular in the context of groups of finite Morley rank including the so-called bad groups. We show that connected Frobenius groups of finite Morley rank and odd type with nilpotent complement split or interpret a bad field of characteristic zero. Furthermore, we show that mock hyperbolic reflection spaces of finite Morley rank satisfy certain rank inequalities, implying in particular that any connected Frobenius group of odd type and Morley rank at most ten either splits or is a simple non-split sharply 2-transitive group of characteristic different from 2 and of Morley rank 8 or 10.","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135463657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using an infinitary version of the Hypergraph Removal Lemma due to Towsner, we prove a model-theoretic higher amalgamation result. In particular, we obtain an independent amalgamation property which holds in structures which are measurable in the sense of Macpherson and Steinhorn, but which is not generally true in structures which are supersimple of finite SU-rank. We use this to show that some of Hrushovski's non-locally-modular, supersimple $omega$-categorical structures are not MS-measurable.
{"title":"Higher amalgamation properties in measured structures","authors":"David M. Evans","doi":"10.2140/mt.2023.2.233","DOIUrl":"https://doi.org/10.2140/mt.2023.2.233","url":null,"abstract":"Using an infinitary version of the Hypergraph Removal Lemma due to Towsner, we prove a model-theoretic higher amalgamation result. In particular, we obtain an independent amalgamation property which holds in structures which are measurable in the sense of Macpherson and Steinhorn, but which is not generally true in structures which are supersimple of finite SU-rank. We use this to show that some of Hrushovski's non-locally-modular, supersimple $omega$-categorical structures are not MS-measurable.","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Models, algorithms, and equilibrium conditions for the simulation of autonomous vehicles in exclusive and mixed traffic","authors":"M. Gallo","doi":"10.2139/ssrn.4362708","DOIUrl":"https://doi.org/10.2139/ssrn.4362708","url":null,"abstract":"","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"34 1","pages":"102838"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86688709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An evolutionary routing protocol for load balancing and QoS enhancement in IoT enabled heterogeneous WSNs","authors":"Abdelkader Benelhouri, H. Idrissi-Saba, J. Antari","doi":"10.2139/ssrn.4135169","DOIUrl":"https://doi.org/10.2139/ssrn.4135169","url":null,"abstract":"","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"105 1","pages":"102729"},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73104451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.1177/00375497231171140
Cristina Ruiz Martin
{"title":"Theory and foundations of modeling and simulation","authors":"Cristina Ruiz Martin","doi":"10.1177/00375497231171140","DOIUrl":"https://doi.org/10.1177/00375497231171140","url":null,"abstract":"","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"14 1","pages":"431-432"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78483551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Real-time crowd formation control in virtual scenes","authors":"Wu He, Gaofeng Pan, Xuan Wang, Jim X. Chen","doi":"10.2139/ssrn.4045899","DOIUrl":"https://doi.org/10.2139/ssrn.4045899","url":null,"abstract":"","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"31 1","pages":"102662"},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89783359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Improving emergency evacuations is a top priority in human safety and in pedestrian dynamics. In this paper, we use the social force model, in order to optimize high-anxiety pedestrian evacuations. We explore two architectural layouts, the 1-door vestibule, and the 2-doors vestibule. The"vestibule"is defined as the room next to the exit door and it is characterized by two structural parameters: the vestibule width ($d$) and the vestibule door width ($w$). We found that, specific values of $d$ and $w$, can almost double the evacuation flow compared to the no-vestibule scenario. The key to this achievement is that the density (close to the exit door) can be controlled by $d$ and $w$. Therefore, it is possible to tune these parameters to a density that maximizes the available space while preventing the formation of blocking clusters at the exit door ($rho sim 2.5,$p/m$^2$). As opposed to the optimal condition, low-density values ($rho sim 1,$p/m$^2$) lead to suboptimal flow since there is unused space left; while higher density values ($rho sim 4,$p/m$^2$) also lead to suboptimal flow due to the presence of blocking clusters at the exit. Moreover, we take into account the usually foreseen fact that high pressures can actually be reached at the exit, threatening the health of pedestrians. Therefore, we studied the crowd pressure using the agents' overlap as an indicative. We found that the explored vestibules reduce the crowd pressure compared to the no-vestibule situation. In particular, we show that the 2-doors vestibule scenario performs better than the 1-door vestibule, because it reduces the overall local density (by enforcing the crowd to spread out more).
{"title":"Faster and safer evacuations induced by closed vestibules","authors":"I. Sticco, G. Frank, C. Dorso","doi":"10.2139/ssrn.4233917","DOIUrl":"https://doi.org/10.2139/ssrn.4233917","url":null,"abstract":"Improving emergency evacuations is a top priority in human safety and in pedestrian dynamics. In this paper, we use the social force model, in order to optimize high-anxiety pedestrian evacuations. We explore two architectural layouts, the 1-door vestibule, and the 2-doors vestibule. The\"vestibule\"is defined as the room next to the exit door and it is characterized by two structural parameters: the vestibule width ($d$) and the vestibule door width ($w$). We found that, specific values of $d$ and $w$, can almost double the evacuation flow compared to the no-vestibule scenario. The key to this achievement is that the density (close to the exit door) can be controlled by $d$ and $w$. Therefore, it is possible to tune these parameters to a density that maximizes the available space while preventing the formation of blocking clusters at the exit door ($rho sim 2.5,$p/m$^2$). As opposed to the optimal condition, low-density values ($rho sim 1,$p/m$^2$) lead to suboptimal flow since there is unused space left; while higher density values ($rho sim 4,$p/m$^2$) also lead to suboptimal flow due to the presence of blocking clusters at the exit. Moreover, we take into account the usually foreseen fact that high pressures can actually be reached at the exit, threatening the health of pedestrians. Therefore, we studied the crowd pressure using the agents' overlap as an indicative. We found that the explored vestibules reduce the crowd pressure compared to the no-vestibule situation. In particular, we show that the 2-doors vestibule scenario performs better than the 1-door vestibule, because it reduces the overall local density (by enforcing the crowd to spread out more).","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"5 1","pages":"102818"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73332876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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