Incorporation of BIM-based probabilistic non-structural damage assessment into agent-based post-earthquake evacuation simulation

Earthquakes can cause severe damage to structural and non-structural elements of buildings; consequently, they pose high risks to human lives. To mitigate such risks, attention has been paid to enhancing the indoor environment for increased building safety. Yet little effort has been made to assess a building occupants' evacuation behaviors in response to damage to the indoor environment. This paper addresses this issue with a novel simulation framework that couples human behaviors with changes to the indoor building environment during post-earthquake evacuation. In particular, we present a building information modelling (BIM)-based prototype that simulates seismic damage to the non-structural indoor elements and visualizes its impacts on evacuation using a color-coded heat map. The simulated damage is then used as input to an agent-based model for post-earthquake evacuation. Using a probabilistic method to assess the non-structural elements' damage states, we are able to evaluate the impact of indoor damage on the evacuation process. We performed a trial of our prototype for a hypothetical earthquake in an educational building. The results revealed how the average evacuation time would increase as the earthquake intensity increases (from 38.6 s for the no-damage scenario to 122.9 for the highest-damage scenario). The proposed prototype has the potential to be joined with other tools, such as finite-element-based simulation, to incorporate structural analysis as well. Planners and designers can explicitly use our model's output to analyze the post-earthquake evacuation with the indoor non-structural damage to assess different building design geometries that increase the chances of a suitable evacuation process.     

A BIM-based simulation framework for fire safety management and investigation of the critical factors affecting human evacuation performance

Fire hazards are a big threat to human life and property safety. The U.S. fire statistics reveal that, in 2017 alone, 1,319,500 fires caused 3400 deaths and 14,670 injuries, which resulted in a loss of $23 billion [1]. Effective evacuation planning in densely occupied buildings should be primarily put in place if both the number of injuries/fatalities and the level of property loss are to be minimized. However, it is not realistic, and is unethical to study human evacuation performance under a burning building. For this reason, computational tools tend to be the best approach for simulating fire growth as well as human response to fire hazards. This study aims to develop a BIM-based simulation framework that implements the Fire Dynamic Simulator (FDS) and agent-based modeling (ABM) for simulating fire growth and evacuation performance for different building layout scenarios. An experimental implementation is conducted to validate the proposed framework, which verified the benefits of (1) using BIM to offer a platform for conducting simulation design and visualizing the simulation results of (a) hazardous fire zones and (b) effective escape routes; (2) simulating fire growth using the FDS tool; (3) developing an agent-based model that accounts for the critical factors affecting evacuation performance; and (4) applying a statistical analysis for investigating the effects of influential parameters from the proposed model. As a result, the simulation outputs can be used to optimize the building design and to investigate the influential factors on human evacuation efficiency. The proposed framework contributes to building fire safety management by enabling to minimize both injuries/fatalities and property loss.     

A graph-based algorithm for extracting units and loops from architectural floor plans for a building evacuation model

This article presents the development of an automatic process in transforming computer-drawn architectural plans into a building fire evacuation simulator—spatial-grid evacuation model (SGEM). The SGEM has been developed to model the dynamic positions of each occupant of a building at every time point under an evacuation process. The presented process, termed automatic unit generator (AUG), is developed on the basis of a graph-based approach. It captures the architectural information originally produced by architects/building designers in CAD plans and rebuilds the units and their topological relationships, as well as determines the evacuation direction at every portal. As limited pre-defined information is needed, this proposed process could be employed at any stage of the design process. It makes the SGEM capable of integrating into CAD system to set up a smooth architectural design workflow.     

Applications of interval computations to earthquake-resistant engineering: How to compute derivatives of interval functions fast

One of the main sources of destruction during earthquake is resonance. Therefore, the following idea has been proposed. We design special control linkages between floors that are normally unattached to the building but can be attached if necessary. They are so designed that adding them changes the building's characteristic frequency. We continuously monitor displacements within the structure, and when they exceed specified limits, the linkages are engaged in a way to control structural motion. This idea can also be applied to avoid vibrational destruction of large aerospace structures.     

An Evacuation Decision Model based on perceived risk,social influence and behavioural uncertainty

The behaviour of people in the first stage of an evacuation can have a significant impact on the time required to reach a safe place. This behaviour is known in literature as pre-evacuation behaviour and it has been studied for many different evacuating scenarios. Despite the large number of studies, the representation of this behaviour is often oversimplified in most of the existing evacuation models. This paper aims to introduce a novel Evacuation Decision Model, allowing predicting the pre-evacuation state of an evacuee among three possible states (normal, investigation and evacuation) considering perceived risk for an evacuation scenario. The proposed model assumes that evacuees’ perceived risk is affected by several environmental and social cues as well as by demographics and personal characteristics of evacuees. The concept of behavioural uncertainty is also included in the model and a formulation to calibrate the proposed model using a likelihood function is then provided.     

考虑疏散安全和效率的室内障碍物布局优化

室内障碍物的布局会对人群时空分布、疏散安全和效率产生重要影响.为调查其影响,构建带有障碍物的单室单出口人群疏散模型.同时,通过3种不同的影响因素(即障碍物长度、障碍物与出口距离、障碍物偏离出口中心距离)来分析它们对人群疏散效率和安全的影响.研究结果发现障碍物长度与疏散效率成正向关系,而与疏散安全成反向关系;障碍物与出口距离与疏散效率和安全皆成正向关系;障碍物偏离出口中心距离与疏散效率和安全成反向关系.此外,本研究还使用多目标进化算法来对室内障碍物布局进行优化,所得结果可以为决策者平衡疏散安全和效率问题提供重要参考.     

Simulation-based evacuation planning using state-of-the-art sensitivity analysis techniques

With the continuous growth of cities and the issues of insufficient space, indoor parking garages have become a vital component of transportation systems. Since emergencies will occur sooner or later, planning and organizing a successful evacuation plan for parking garages, with the aim of reducing the evacuation time and improving the driver's behavior during evacuations, is needed. This research presents a systematic approach for the development and evaluation of evacuation strategies in such environments, through state-of-the-art sensitivity analysis that provides faster convergence and lower computational burden. To demonstrate the proposed methodology, a simulation model is developed using AIMSUN for a three-level indoor parking garage located in Athens, Greece. Four scenarios with different evacuation strategies and plans are considered. A multi-step sensitivity analysis framework is implemented to overcome the uncertainties that emerge from the model assumptions, model inaccuracy and shortage of data. Sensitivity analysis is used to evaluate the consequences of the proposed scenarios and estimate the total time to evacuate the parking garage. The full experimental design resulted in the automated execution of more than 80 thousand simulations, corresponding to approximately 65 processor-days. The results of this research show that the developed methodology provides significant reduction in evacuation time (from 35% to over 40%). This process provides useful and credible ranges of expected evacuation times under all plausible outcomes.     

An immersive virtual reality serious game to enhance earthquake behavioral responses and post-earthquake evacuation preparedness in buildings

Enhancing the earthquake behavioral responses and post-earthquake evacuation preparedness of building occupants is beneficial to increasing their chances of survival and reducing casualties after the mainshock of an earthquake. Traditionally, training approaches such as seminars, posters, videos or drills are applied to enhance preparedness. However, they are not highly engaging and have limited sensory capabilities to mimic life-threatening scenarios for the purpose of training potential participants. Immersive Virtual Reality (IVR) and Serious Games (SG) as innovative digital technologies can be used to create training tools to overcome these limitations. In this study, we propose an IVR SG-based training system to improve earthquake behavioral responses and post-earthquake evacuation preparedness. Auckland City Hospital was chosen as a case study to test our IVR SG training system. A set of training objectives based on best evacuation practice has been identified and embedded into several training scenarios of the IVR SG. Hospital staff (healthcare and administrative professionals) and visitors were recruited as participants to be exposed to these training scenarios. Participants’ preparedness has been measured along two dimensions: 1) Knowledge about best evacuation practice; 2) Self-efficacy in dealing with earthquake emergencies. Assessment results showed that there was a significant knowledge and self-efficacy increase after the training. In addition, participants acknowledged that it was easy, helpful, and engaging to learn best evacuation practice knowledge through the IVR SG training system.     

Model testing and assessment: Perspectives from a swarm intelligence,agent-based model of forest insect infestations

Model testing procedures represent a major challenge in the development of agent-based models (ABMs). However, they are required stages for a model to be accepted and to serve as a forecasting, management or decision-making tool. This study presents a comprehensive approach for testing ForestSimMPB, an agent-based model (ABM) designed to simulate mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, outbreaks at the scale of individual trees. ForestSimMPB is a complex system model that is using swarming intelligence, capable to represent individuals’ behaviours and spatial interactions that influence their surrounding environment. Swarm Intelligence (SI) methods are integrated into the ABM in order to reproduce the collective reasoning and indirect communication of autonomous agents representing MPB behaviour within the forest environment. Model testing approach consist of verification, calibration, sensitivity analysis, validation and qualification stages. Model testing is accomplished by simulating MPB infestations using both the ForestSimMPB model and a Random–ABM model that serves as a null model. Outcomes comparison and assessment are performed using raster-based techniques as well as spatial metrics. Aerial photographs of the British Columbia, Canada study sites are used in this model testing approach. Results indicate that ForestSimMPB model representations of MPB outbreaks are more similar than Random model representations to the spatial distribution of MPB-dead trees.     

Cellular automaton model of crowd evacuation inspired by slime mould

In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum’s behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism’s growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model’s efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity–density and flow–density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum’s recorded behaviour derived from observation of the aforementioned biological laboratory experiments.     

Interior design decoration simulation based on wireless sensors

Over the last few decades, there has been an evolution in global communications and network interior design decoration technology. These connectivity features allow it to detect the decorative behavior of interior design as possible. The previous system is very difficult to analyze at the interior design level. The sensing systems need to be integrated into the home's typical components as a decoration for such a design. One reason, the work is considered as an interesting decorative design position sensor element. To introduce a decoration of objects is everywhere; they can be found anywhere in the home or office and can be integrated and hidden sensor networks based on the proposed Design Markov Model (DMM). DMM involves indoor decorative effects, a detailed investigation, and a lack of signal loss.Moreover, an easy-to-use tool has been proposed to estimate the communication channel's robustness between the wireless sensor nodes and the gateway. The communication link evaluation source in a material loss of a signal in the sensor network. This DMM presents a network tool that can assess the impact of a given set of communication interior materials and collect the interior design level results. The maximum distance between the integral batteries lives. Specifically, the sensor node provides the best furniture sensor or the sensor node.     

Event-driven modeling of elevator assisted evacuation in ultra high-rise buildings

In the past few decades, numerous ultra high-rise buildings have been erected in the metropolitan areas of many cities around the world. For the related building designers, building occupants and the governments, fire safety problem is certainly a major concern, especially after the collapse of World Trade Center in the 9/11 event. That disaster makes people reconsider ultra high-rise building evacuation strategies. Of the current strategies, using elevators in ultra high-rise buildings to assist evacuation seems to be promising in improving evacuation efficiency. To quantitatively evaluate elevator assisted evacuation process, an event-driven agent-based modeling approach is proposed in the present paper. This modeling approach could capture not only the movement characteristics of stair-using occupants but also the detailed elevator motion features. The combined effects of occupants’ and elevators’ parameters on the evacuation efficiency have been investigated. Results indicated that the model is helpful to reveal the dynamics of elevator assisted evacuation, and sometime, using elevators to move all occupants to ground safety point may not be an optimal solution.     

Container spaces and functional features for top-down 3D layout design

Although there have been many advances in computer-aided modelling techniques and representations of mechanical parts, there are areas where exact modelling is a handicap. One of these is 3D layout design. Here, simpler models are useful for initial design sketches to verify kinematic behaviour and organise product structure before the detailed component design phase begins. A commitment to exact, or close approximational geometry too early can imply a commitment to form before functionality has been finalised. This paper describes a system for top-down 3D layout design based on simple conceptual elements which can be used as a basis for visualisation, discussion, definition of product structure and kinematic functionality in the conceptual design phase before the embodiment or detailing begins. This tool forms a bridge between the abstract nature of the conceptual design phase and the geometric nature of the embodiment phase. The 3D layout module uses design spaces with simple geometry and kinematic connections to represent a product. The design spaces act as containers or envelopes within which the final component design is to be realised. The kinematic connections allow the behaviour of the product to be simulated to gain more information (such as overall component dimensions and areas of potential collisions) for the detailed design phase. In addition the paper describes the design process based on the proposed 3D layout design system and contrasts this with the traditional design process. An industrial case study is presented to illustrate the following advantages of the proposed approach: (i) the design process proceeds faster because unnecessary layout parameter and constraint modifications are avoided since kinematic functionality verification precedes the detail design, (ii) the design process can produce better designs since alternative solution principles can be explored early in the design process. Theoretical issues are discussed concerning kinematic constraint inheritance during design space decomposition and concerning computer support for non-rigid design spaces.     

Two-phase evacuation route planning approach using combined path networks for buildings and roads

This paper addresses the problem of modeling evacuation routes from a building and out of an affected area. The evacuation route involves pathways such as corridors, and stairs in buildings and road networks and sidewalks outside the building. To illustrate such an approach, we consider the problem of finding evacuation paths from an urban building and out of a predetermined neighborhood of the building on foot. A case study for a college campus building and small set of road around it is provided. There are a pre-defined set of exit points out of the target building and out of the road network serving the building. A two-step approach with an uncapacitated network model for route finding and a capacitated scheduling algorithm for evacuation time computation is proposed. A recent efficient heuristic algorithm is selected as a reference for comparative analysis. The process of creating a combined building and road path network data is discussed. The key results are the competitive evacuation time provided by the proposed uncapacitated route planning model, simple pedestrian flow capacity formulas for corridors and roads from readily available geometric data, and the illustration of the creation and use of combined building and road path network.     

贪心选择在地铁站内行人疏散中的应用

大型室内场所空间布局较为复杂(如地铁站), 人群的高密度聚集往往存在一些潜在的风险. 本文在分析国内外人群快速疏散研究现状的基础上, 提出了一种基于贪心选择的行人疏散方法. 该方法以地铁站内复杂场景作为研究背景: 首先, 针对地铁站内的行人的行动轨迹难以获取问题, 本文利用地铁站内行人真实出站数据, 基于元胞自动机, 构建了行人疏散轨迹半仿真模型, 并利用实际流量数据优化该半仿真模型; 其次, 基于该轨迹模型, 为了满足高动态场景中的实时性, 采用复杂度较低的贪心选择策略分配最优疏散出口; 最后, 以杭州武林广场地铁站为例, 使用真实出站数据设计对比实验, 验证行人轨迹模型的有效性以及出口分配方法的性能. 结果表明, 本文所提出的行人轨迹模型能够较好的模拟行人的轨迹, 仿真中各出口疏散人数同真实出站数据拟合程度的可决系数R2达到了0.67. 相较于最短路径和最短时间出口分配方法, 本文所提出的方法在整体疏散效率上分别提高了27.2%和16.5%.     

Environment optimization for crowd evacuation

The layout of a building, real or virtual, affects the flow patterns of its intended users. It is well established, for example, that the placement of pillars at proper locations can often facilitate pedestrian flow during the evacuation of a building. Such considerations are therefore important for architects, game level developers, and others whose domains involve agents navigating through buildings. In this paper, we take the first steps towards developing a simulation framework that can be used to study the optimal placement of architectural elements, such as pillars or doors, for the purposes of facilitating dense pedestrian flow during the evacuation of a building. In particular, we show that the steering algorithms used to model the local navigation abilities of the agents significantly affect the results, which motivates the need for a statistically valid approach and further study. Copyright © 2015 John Wiley & Sons, Ltd.     

论湘南(永州)地区门窗雕饰艺术的趣味变迁

隔扇门窗雕饰艺术在古建筑中是最富于变化的装饰部分;现代建筑与室内设计,由于追求外在形式,忽略了隔扇门窗内在的审美性与装饰趣味。以生活艺术化的审美观为出发点,从湘南(永州)地区传统隔扇门窗雕刻艺术的"形"、"意"、"神"等方面思考,使现代室内设计更好的继承传统雕饰艺术与传统元素。     

基于FPGA的智能建筑湿度检测控制系统设计

在信息化社会,智能建筑越来越多的被提及,智能建筑是指对建筑内外信息交换、舒适性、便利性和节能性的要求;建筑物室内湿度是人们在其中生活、工作、生产的重要考量因素;而随着技术发展,以高效稳定的FPGA芯片为核心的控制系统开始向智能建筑领域应用部署;因此文章提出并设计了基于FPGA的智能建筑湿度检测控制系统方案;文中采用硬件分析和软件设计相结合的方法;硬件分析需要对系统做一个整体把握并寻找经济实惠、稳定可靠的芯片,硬件的可靠是系统稳定工作的前提;软件设计需要将系统的工作方式和实际可能遇到的问题考虑进去,提高系统的容错能力;最后软硬结合并实验实践操作验证系统的可靠性;在实验结果中,该系统可以有效的调节室内的湿度并根据遇到的问题发出警告提示;得出结论,以FPGA控制器为核心的系统,可以担起智能建筑的湿度检测控制任务,并稳定工作。     

RAID小数据随机访问性能分析与优化

RAID采用条纹结构,使多块磁盘可并行访问,提高了带宽,适合于大块数据顺序访问,而对小块数据随机访问影响不大。针对Stripe条纹大小对RAID的读写性能进行分析,探讨多用户小数据访问模式下的IOPS(IOs per second)问题,提出粗粒度条纹布局模型。仿真实验表明：该模型的性能优于现有布局方式,显著提高小块数据随机访问性能。     

Protocol modelling: A modelling approach that supports reusable behavioural abstractions

We describe a behavioural modelling approach based on the concept of a “Protocol Machine”, a machine whose behaviour is governed by rules that determine whether it accepts or refuses events that are presented to it. We show how these machines can be composed in the manner of mixins to model object behaviour and show how the approach provides a basis for defining reusable fine-grained behavioural abstractions. We suggest that this approach provides better encapsulation of object behaviour than traditional object modelling techniques when modelling transactional business systems. We relate the approach to work going on in model driven approaches, specifically the Model Driven Architecture initiative sponsored by the Object Management Group. Communicated by August-Wilhelm Scheer Ashley McNeile is a practitioner with over 25 years of experience in systems development and IT related management consultancy. His main areas of interest are requirements analysis techniques and model execution and in 2001 he founded Metamaxim Ltd. to pioneer new techniques in these areas. He has published and presented widely on object oriented development methodology and systems architecture. Nicholas Simons has been working with formal methods of system specification since their introduction, and has over 20 years experience in building tools for system design, code generation and reverse engineering. In addition, he lectures on systems analysis and design, Web programming and project planning. He is a co-founder and director of Metamaxim Ltd.