An Agent-Based Simulation API for Speculative PDES Runtime Environments

Agent-Based Modeling and Simulation (ABMS) is an effective paradigm to model systems exhibiting complex interactions, also with the goal of studying the emergent behavior of these systems. While ABMS has been effectively used in many disciplines, many successful models are still run only sequentially. Relying on simple and easy-to-use languages such as NetLogo limits the possibility to benefit from more effective runtime paradigms, such as speculative Parallel Discrete Event Simulation (PDES). In this paper, we discuss a semantically-rich API allowing to implement Agent-Based Models in a simple and effective way. We also describe the critical points which should be taken into account to implement this API in a speculative PDES environment, to scale up simulations on distributed massively-parallel clusters. We present an experimental assessment showing how our proposal allows to implement complicated interactions with a reduced complexity, while delivering a non-negligible performance increase

Simulating movement devices used in hospital evacuation

In hospitals, the evacuation of those with severe movement impairments can be highly problematic for the patients, for the staff and for other evacuees. It is critical to understand the performance of horizontal and vertical evacuation procedures, including the means by which people with reduced mobility can be assisted during stair descent. Microsimulation modelling provides a useful tool to assess evacuation strategies, given the challenges of preparing and transporting patients in need of on-going care and the unfeasibility of real evacuation drills. However, current simulation models typically focus on the movement of individual agents, not the staff-patient interactions and sizable equipment required to carry out assisted evacuation. To address this, the buildingEXODUS evacuation model has been enhanced to represent moving objects in addition to moving individual agents. This paper describes the modelling theory behind this development, where dedicated data has been applied to enable the explicit specification of evacuation devices, operated by agents (for instance, representing the vertical travel speeds achieved—with averages ranging between 0.6 m/s and 0.84 m/s—when employing different movement devices). Algorithms are presented that calculate the movement of devices along corridors, through doorways and in stairway descent, including a method of geometric decomposition of the available hospital evacuation routes. This new functionality addresses the key evacuation components of repeated patient collection and has numerous applications, both in simulating hospital evacuation and in representing evacuation of other premises that include people with reduced mobility. Examination of the performance of this functionality found it predicated performance within 6% of expectation. Once further testing is completed, the resultant tool can be used to significantly enhance planning and diagnostic capabilities related to the evacuation of hospital and other healthcare facilities

Holistic Simulation of Mobile Robot and Sensor Network Applications Using TrueTime

The RUNES project defines a complex road tunnel scenario involving multiple mobile robots navigating in sensor network environment. In this paper, a TrueTime simulation model of the tunnel scenario is developed. The TrueTime simulator allows concurrent simulation of the physical robots and their environment, the software in the nodes, the radio communication, the network routing, and the ultra-sound navigation system. The various models are described in detail, and some simulation results obtained from the complete model are presented

Development of a hybrid simulation framework for the production planning process in the atlantic salmon supply chain

The farmed salmon supply chain has a highly complex and integrated structure, where activities occur both in the sea and on land. Due to this complexity, the supply chain needs appropriate decision-support tools to aid the production planning process, which capture the material flows, information flows and behaviours of the decision makers in the chain. This paper proposes a hybrid simulation framework for production planning using the case of the Norwegian Atlantic salmon supply chain. This hybrid simulation comprises agent-based modelling (ABM) to capture the autonomous and interacting decision making behaviour of the supply chain actors, while discrete-event simulation (DES) is employed to model the various production processes within the chain. The simulation is implemented using AnyLogic™ version 8.0 simulation software, using a case study from the Norwegian farmed salmon sector. The proposed modelling framework provides a deeper understanding of the activities in the salmon supply chain, thereby enabling improved decision making.publishedVersio

Using CONFIG for Simulation of Operation of Water Recovery Subsystems for Advanced Control Software Evaluation

A hybrid discrete/continuous simulation tool, CONFIG, has been developed to support evaluation of the operability life support systems. CON FIG simulates operations scenarios in which flows and pressures change continuously while system reconfigurations occur as discrete events. In simulations, intelligent control software can interact dynamically with hardware system models. CONFIG simulations have been used to evaluate control software and intelligent agents for automating life support systems operations. A CON FIG model of an advanced biological water recovery system has been developed to interact with intelligent control software that is being used in a water system test at NASA Johnson Space Cente

On static vs dynamic (switching of) operational policies in aircraft turnaround team allocation and management

Aircraft turnaround operations represent the fulcrum of airport operations. They include all services to be provided to an aircraft between two consecutive flights. These services are executed by human operators, often organised in teams, who employ some related equipment and vehicles (e.g. conveyor belts, trolleys and tugs for baggage loading/unloading and transportation). In this paper, we focus on the real-time management of turnaround operations, and assess the relative merits and limitations of so-called dispatching rules that originate from the manufacturing literature. More precisely, we focus on the real-time allocation, on the day of operation, of teams of ground handling operators to aircraft turnarounds. This is pursued from the viewpoint of third-party service providers. We employ simulation, in conjunction with deep reinforcement learning, and work on the case of a real airport and the entirety of its turnaround operations involving multiple service providers

Novel pathogen introduction rapidly alters the evolution of movement, restructuring animal societies

Animal social interactions are the outcomes of evolved strategies that integrate the costs and benefits of being sociable. Using a novel mechanistic, evolutionary, individual-based simulation model, we examine how animals balance the risk of pathogen transmission against the benefits of social information about resource patches, and how this determines the emergent structure of spatial social networks. We study a scenario in which a fitness-reducing infectious pathogen is introduced into a population which has initially evolved movement rules in its absence. Pathogen introduction leads to a rapid evolutionary shift, within only a few generations, in animal social-movement strategies. Generally, animals adopt a dynamic social distancing behaviour, trading more movement away from individuals (and less intake) for lower infection risk, but there is considerable individual variation in these social movement strategies. Pathogen-adapted populations are more widely dispersed over the landscape, and thus have lessclustered social networks than their pre-introduction, pathogen-naive ancestors. Running simple epidemiological models on these emergent social networks, we show that diseases do indeed spread more slowly through pathogen-adapted animal societies. The post-introduction, pathogen-adapted movement strategy mix is stongly influenced by a combination of landscape productivity and diseasecost. Our model suggests how the introduction of an infectious pathogen to a population rapidly changes social structure. While such events might make populations more resilient to future disease outbreaks, this is at the cost of social information benefits. Overall, we offer both a general modelling framework and initial predictions for the evolutionary consequences of wildlife pathogen spillovers

Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface

The Social Cognitive Actor

Multi-Agent Simulation (MAS) of organisations is a methodology that is adopted in this dissertation in order to study and understand human behaviour in organisations. The aim of the research is to design and implementat a cognitive and social multi-agent simulation model based on a selection of social and cognitive theories to fulfill the need for a complex cognitive and social model. The emphasis of this dissertation is the relationship between behaviour of individuals (micro-level) in an organisation and the behaviour of the organisation as a whole (macro-level)