•A passenger ship evacuation model has been established by using FDS + EVAC.•The effects of the passenger population composition in an emergency evacuation were analysed.•The effects of the ship ...familiarity in an emergency evacuation were analysed.•The ship's staircase layout was optimised to facilitate the evacuation process.
In this research, the effects of the passenger population composition and ship familiarity in an emergency evacuation are analysed. The results identified that the effects of different population compositions on the Ro-Ro evacuation process vary significantly. It is therefore recommended that a targeted survey of the population on a specific ship should be conducted before the evacuation analysis to improve the analysis accuracy of the evacuation process. It is not always the case that a higher familiarity with the ship staircase layout necessarily results in less time to complete the evacuation, and the issue of balanced exits has to be considered due to its significant impact. The results obtained in this research can be used to aid the ship's staircase layout optimisation to facilitate the evacuation process. Given the type of Ro-Ro vessel in this analysis, it is suggested that adding a staircase towards the bow of the ship can reduce the evacuation time by 13.6%, when considering 95% of the passengers to complete an evacuation. Similarly, adding one staircase at the stern can reduce the time by approximately 10% for all passengers to complete the evacuation. It is not recommended that the size of staircases towards the middle of the ship should be adjusted.
The article presents a new method of predicting the yield-lines of statically loaded slabs, based on roof geometry (straight skeletons) and Voronoi diagrams for a polygon. A surprising analogy was ...found between the layout of the plate’s yield-lines and the edge lines of the embankments created as a result of the free falling of loose material onto the plate-shaped polygon. According to the proposed method, the yield-lines have the shape not only of segment lines, but also parabolas (in 3D interpretation also hyperbolas). The method proposed here is purely geometric and can be used to pre-determine the shape of the yield-lines. It allows to predict the shape of the grid of the yield-lines for plates with various support methods, including point support. In addition, the method is relatively simple and can be implemented in the standard CAD software environment. However, the method requires knowledge of descriptive geometry in the field of roof skeletons design (straight skeletons) and roofs with restriction.
To further develop the advantages of loading artificial material units, layout rules of unit cells were investigated and presented for the first time in this study. Based on the analysis of ...transmission characters of metamaterial unit cells, some tapered slot antennas loaded with different unit layouts were designed. The result comparison showed that after the layout optimisation, the operation frequency band with a gain above 10 dB increased by about 13% and the gain increased by 0.4–2.6 dB in the high frequency band. In addition, the sidelobe level of H-plane also decreased by 0.7–4 dB at different frequency points.
In view of the current global climate challenges, the urgency for reduction of material consumption in the construction sector becomes clear. In this context, the present study concentrates on ...enhancing resource efficiency in concrete construction via the use of structural optimisation software tools as a guide for finding the geometry of optimised, mass-reduced concrete girders. Within a test series of eight specimens, varying parameters regarding the consulted optimisation strategy, the stirrup reinforcement type and concrete coverage were assessed. The experimental investigation was followed by a profound structural analysis, identifying peculiarities in the load-bearing behaviour and stiffness as well as two main failure modes characteristic of the optimised girder geometries. The comparison with full concrete girders illustrates the achieved reduction in concrete mass, the decrease of the Global Warming Potential of the production phase as well as the increase in the overall performance.
•Design of resource-efficient concrete girders assisted by structural optimisation.•Profound analysis of the experiments, with a detailed crack formation history.•Two main failure modes identified for the tested optimised girders.•Less environmental impact of optimised girders than of full pendants.
The achievement of a sustainable industry in the construction sector requires the consideration of environmental and social impacts of the operations involved, along with the traditionally imperative ...economic factors affecting the construction project. An implicit social and environmental factor commonly linked with construction is the noise pollution resulting from activities taking placing during the various construction stages. The levels of sound recorded at receivers positioned in the vicinity of the construction site may be considerably affected by the site layout adopted. Site layout planning with the objective of minimising the construction noise levels has not been investigated in the available literature. To ensure a balance between economic, social and environmental impacts, the planning of the site should also account for the economic factors associated with the monetary costs of material transportation between facilities, rendering the problem a multi-objective one. This paper presents a novel multi-objective mixed integer nonlinear programming model that minimises noise levels at multiple receivers surrounding the construction site, as well as on-land material transportation costs, through site layout optimisation. An improved transportation cost model accounting for several transportation modes is presented. A Pareto front, listing nondominated global optimum solutions, is obtained for a case study tested using the ε-constraint method.
•A multi-objective construction site layout model is proposed.•The overall format of the proposed model is mixed integer nonlinear.•The model minimises noise and cost on construction sites.•Noise is measured at multiple receivers around the construction site.•Cost is taken to represent on-land material handling between facilities.•The Pareto front of the multi-objective model is obtained using ε-constraint method.
Photogrammetry systems are widely used in industrial manufacturing applications as an assistance measurement tool. Not only does it provide high-precision feedback for assembly process inspection and ...product quality assessment, but also it can improve the flexibility and robustness of manufacturing systems and production lines. However, with growing global competition and demands, companies are forced to enhance production efficiency, shorten production lifecycle and increase product variety by incorporating reconfigurable factory design that can meet challenging timeline and requirements. Although dynamic facility layout is widely investigated, the position selection for the photogrammetry system in dynamic manufacturing environment is usually overlooked. In this paper, dynamic layout of the V-STARS photogrammetry system is investigated and optimised in a digital-twin environment using deep reinforcement learning. The learning objectives are derived from the field of view (FoV) evaluation from point clouds 3D reconstruction, and collision detection from the digital twin simulated in Visual Components. The application feasibility of the proposed dynamic layout optimisation of the V-STARS photogrammetry system is verified with a real world industrial application.
Air pollutant distributions identified through monitoring form an important basis for devising adequate emergency responses against sudden air pollution accidents (SAPAs). However, studies on the ...optimisation of monitoring layouts for SAPAs, which can help us better understand air pollutant dispersion, are lacking. We developed an emergency monitoring layout optimisation method for SAPAs that combines an air pollutant dispersion model, a fuzzy comprehensive evaluation method (FCEM), and a post-optimality analysis technique (POAT) to identify the optimal monitoring layout scheme based on a field sulphur hexafluoride (SF6) leakage test. The impact of the number of monitoring sites on the results (coverage rate and accuracy) were investigated and analysed through a proposed comprehensive evaluation method. A monitoring result–monitoring number curve was plotted to determine the optimal number of monitoring sites. Two scenarios, i.e. with and without environmentally sensitive monitoring sites, were analysed. The results showed that the developed optimisation method can effectively consider the role of sensitive sites and obtain a feasible network for monitoring SAPAs. The coverage rates of the optimal monitoring layout schemes were 76.2% and 61.9% for the two case scenarios, respectively; the relative deviations of mean air pollutant concentrations at the sites were 14.6% and −12.2%, respectively. We investigated the effect of incorporating POAT into the method by comparing the optimal emergency monitoring layout schemes based on dispersion model–FCEM and model–FCEM–POAT. The results showed that the coverage rates of the optimised monitoring layout schemes improved when POAT was introduced. The proposed method can help determine an adequate, optimised emergency monitoring network for SAPAs.
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•Diffusion model–FCEM–POAT method was proposed for emergency monitoring layout.•Monitoring performance –number curve was developed to determine monitoring number.•The method can effectively consider the factors influencing emergency monitoring.•The method can get feasible emergency monitoring network for SAPAs.
• New mathematical models for optimising the port layout of an offshore wind farm.• Efficient matheuristics for realistic sized problems are developed.• Generated datasets and a case study (a ...Scottish port) are used to test the methods.
This paper investigates a port layout problem, where the layout of an installation port for an offshore wind farm needs to be generated in an efficient way so as to minimise the transportation cost of main components of an offshore wind turbine within the port. Two mixed integer linear programming (MILP) models are established to configure the optimal port layout, where the shapes of subareas that need to be located in the port are rectangular with several possible dimensional configurations to select from and the shape of the port area can be treated as either a convex or a concave polygon. The MILPs can be solved to optimality for small-sized problems. Matheuristic approaches based on Variable Neighbourhood Search (VNS) and an exact method (MILP) are also proposed to find solutions for medium-sized problems. The methods are assessed using randomly generated data sets. In addition, the area of a proposed Scottish port is used as a case study. The results obtained from the computational experiments validate the effectiveness of the proposed matheuristic approaches.
Optimising the layout of garbage bins is a requirement for improving the utilisation efficiency of rural infrastructure and continuously promoting the renovation of rural human settlements in China. ...This study selects Yuding Village in Chongqing, China, as the study area. The present distribution of garbage bins and the existing problems are analysed on the basis of interview materials and the point on interest data of garbage bins obtained from an on-the-spot investigation. Actor network theory (ANT) is suitable for small-scale micro research, and thus, this study uses ANT to construct a research framework for garbage bin layout optimisation. Then, it designs an optimisation path for the layout of garbage bins in Yuding Village by identifying different actors and their common interests, classifying the transformation of roles amongst various actors and building a stable heterogeneous network that can be used as a guide for determining the optimal spatial layout of garbage bins. This study combines a sociological theory with geospatial phenomena, providing a new idea for studying the optimal layout of infrastructure.
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