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Zawidzki M., Szklarski J., Multi-objective optimization of the floor plan of a single story family house considering position and orientation,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2019.102766, Vol.141, pp.1-16, 2020Abstract: Improving the architectural layout for diverse objectives using rigorous mathematical optimization methods gradually receives more attention by the researchers. Such optimization however, is usually reduced to a much simpler and relatively well-defined problem such as: facility layout optimization, quadratic assignment problem, rectangle partitioning. Nonetheless, architects are usually skeptical about such approaches since they produce solutions which lack certain architectural qualities. This paper proposes a framework where architectural functional layout (FL) is optimized for the following objectives: functionality (defined by users), insolation (calculated according to geographical conditions), outside view attractiveness (assessed on-site) and external noise (measured on-site). Incorporating the latter two and simultaneous optimization of FLs for objectives related specifically to the site: position and orientation are the novel contributions of this paper. Firstly, a set of candidate FLs is generated, next they are evaluated for optimal location and orientation on a given site. Optimality is conceived here as maximization of real-valued objective function combining: user's satisfaction level of the outside views, shielding from external noise, and insolation
preference. The importance of these factors for each type of room is assessed by the user (as weights). A case study on an existing site is presented. The view quality was arbitrarily assessed and the noise map was assessed by A-weighted equivalent sound level measurements. A general gradient-based method for finding optimal and near-optimal solutions was applied. The output of this optimization is a set of room configurations with their locations and orientations on the site returned to the user for final selection. Keywords: architectural optimization, subjective evaluation, functional layout, acoustic comfort, coarse grid Affiliations:
Zawidzki M. | - | IPPT PAN | Szklarski J. | - | IPPT PAN |
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2. |
Zawidzki M., The Overview of Optimization Methods Applied to Truss-Z Modular System,
COMPUTER ASSISTED METHODS IN ENGINEERING AND SCIENCE, ISSN: 2299-3649, DOI: 10.24423/cames.291, Vol.27, No.2-3, pp.155-176, 2020Abstract: Extremely Modular Systems (EMSs) are comprised of as few types of modules as possible and allow creating structurally sound free-form structures that are not constrained by a regular tessellation of space. Truss-Z is the first EMS introduced, and its purpose is to create free-form pedestrian ramps and ramp networks in any given environment. This paper presents an overview of various multi-objective optimization methods applied to Truss-Z structures. Keywords: Truss-Z, extremely modular system, discrete optimization, multi-objective Affiliations:
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3. |
Zawidzki M., Jankowski Ł., Multiobjective optimization of modular structures: weight versus geometric versatility in a Truss-Z system,
Computer-Aided Civil and Infrastructure Engineering, ISSN: 1093-9687, DOI: 10.1111/mice.12478, Vol.34, No.11, pp.1026-1040, 2019Abstract: This paper proposes an approach for multicriterial optimization of modular structures with respect to their structural and geometrical properties. The approach is tested using the quickly deployable and reconfigurable modular ramp system Truss-Z intended for pedestrian traffic. The focus is on modular structures composed of a moderate number of relatively complex modules, which feature an irregular, noncuboidal geometry. Such modules can be assembled into a variety of geometrically different configurations which do not adhere to any predefined spatial grid; their global geometry can be treated as free-form and determined in situ during construction. The optimization variables represent local-level geometrical and structural properties of a single module. The Pareto front is used to balance between two kinds of objectives. The geometrical objective quantifies the ability of the modules to generate geometrically versatile global structures that are well-suited to comply with spatial constraints of real construction sites. The structural objective is formalized in analogy to the minimum weight problem with upper bound constraints imposed on the von Mises stress and the Euler buckling load ratio. A two-level optimization scheme is employed with NSGA-II at the top level and a simulated annealing with adaptive neighborhood at the lower level. Keywords: modular structures, multicriterial optimization, shape optimization, sizing optimization, NSGA-II, simulated annealing with adaptive neighborhood Affiliations:
Zawidzki M. | - | IPPT PAN | Jankowski Ł. | - | IPPT PAN |
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4. |
Zawidzki M., Szklarski J., Effective Multi-objective Discrete Optimization of Truss-Z Layouts Using a GPU,
APPLIED SOFT COMPUTING, ISSN: 1568-4946, DOI: 10.1016/j.asoc.2018.05.042, Vol.70, pp.501-512, 2018Abstract: Truss-Z (TZ) is an Extremely Modular System for creating skeletal free-form ramps and ramp networks. The TZ structures are comprised of four variations of two types of basic unit subjected to rotation. The two types of units are: R and L being a mirror reflection of each other. This paper presents a novel method based on image processing, evolutionary algorithm and intensive parallelization of multi-objective optimization of TZ layouts.
The algorithm returns a sequence of modules. The result guarantees a TZ connection between two given points (regions) and minimizes the fitness function representing certain costs associated with setting up the TZ structure.
The fitness function depends on the cost of TZ structure as well as the variety of costs related to the environment where the it is to be placed. E.g.: the earthworks, vegetation removal, obstacles avoidance, etc. There are no restrictions on the fitness function definition. It can depend on any variable which can be represented by a two-dimensional map of any property of the environment.
The formulation of the presented method is suited for application of well-established image processing methods which efficiently evaluate candidate solutions on a GPU. As a result, the employed genetic algorithm efficiently probes the search space. The practical applicability of this approach is demonstrated with three case-studies:
1) simultaneous paving of a path with congruent units in a hilly environment with trees & bushes and finding the best location for a pier over an existing river;
2) constructing of a TZ connector spanning over a mountain valley with lakes (where supports can not be placed);
3) retrofitting of an existing railway station with a large wheelchair TZ ramp of over 10 m elevation while preserving trees and minimizing the earthworks. Keywords: Truss-Z, Extremely Modular System, Retrofitting, accessibility, multi-objective, discrete, combinatorial, optimization, genetic algorithm, parallel computing, GPU, GPGPU Affiliations:
Zawidzki M. | - | IPPT PAN | Szklarski J. | - | IPPT PAN |
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5. |
Zawidzki M., Szklarski J., Transformations of Arm-Z modular manipulator with Particle Swarm Optimization,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2018.05.003, Vol.126, pp.147-160, 2018Abstract: A novel concept of hyper-redundant, snake-like manipulator is presented. It is based on the reconfigurable modular construction system–Arm-Z (AZ). AZ is comprised of linearly joined congruent modules with possibility of relative twist. AZ is an Extremely Modular System, i.e. it is composed of a single basic unit and allows for creating free-form shapes. Required level of usefulness and efficiency are among the most challenging design aspects of such reconfigurable systems. Here AZ is considered in the context of kinematics of robotic arms. In general, due to its highly non-linear nature, it is very difficult to find transitions between given states (configurations), especially under realistic environmental and structural constraints. As a way to control the manipulator, an implementation of Particle Swarm Optimization (PSO) for finding transitions between AZ states in realistic scenarios is proposed. Four practical examples are presented which are variations of two distinct problems: bending of a hexagonal AZ in a narrow slot (strong environmental constraints), and reaching a given point in 3D space by the tip of dodecagonal AZ (acting as a robotic arm). The problem of AZ transformation has been defined as a multi-objective optimization. The methodology is general with no restrictions to the objective function. Since the problem is strongly non-linear, in order to cover large space of potential solutions, the algorithm runs for a relatively large number of random initial swarms. This task was distributed on a computer cluster. Although the nature of AZ reconfiguration is discrete, the optimization algorithm is continuous. Keywords: Extremely modular system, Arm-Z, Pipe-Z, Discrete optimization, Dihedral rotation, Reconfiguration, Particle Swarm Optimization, Redundant robot, Hyper-redundant manipulator Affiliations:
Zawidzki M. | - | IPPT PAN | Szklarski J. | - | IPPT PAN |
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6. |
Zawidzki M., Jankowski Ł., Optimization of modular Truss-Z by minimum-mass design under equivalent stress constraint,
SMART STRUCTURES AND SYSTEMS, ISSN: 1738-1584, DOI: 10.12989/sss.2018.21.6.715, Vol.21, No.6, pp.715-725, 2018Abstract: Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks. The previous research on TZ focused on global discrete geometric optimization of the spatial configuration of modules. This paper reports on the first attempts at structural optimization of the module for a single-branch TZ. The internal topology and the sizing of module beams are subject to optimization. An important challenge is that the module is to be universal: it must be designed for the worst case scenario, as defined by the module position within a TZ branch and the geometric configuration of the branch itself. There are four variations of each module, and the number of unique TZ configurations grows exponentially with the branch length. The aim is to obtain minimum-mass modules with the von Mises equivalent stress constrained under certain design load. The resulting modules are further evaluated also in terms of the typical structural criterion of compliance. Keywords: Extremely Modular System, Truss-Z, structural optimization, modular structures, minimum mass design, frame structures Affiliations:
Zawidzki M. | - | IPPT PAN | Jankowski Ł. | - | IPPT PAN |
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7. |
Zawidzki M.^{♦}, Deployable Pipe-Z,
Acta Astronautica, ISSN: 0094-5765, DOI: 10.1016/j.actaastro.2016.05.023, Vol.127, pp.20-30, 2016Abstract: This paper presents a concept of deployable Pipe-Z (dPZ): a modular structural system which takes advantage of the robustness of rigid-panel mechanism and allows to create free-form links which are also reconfigurable and deployable. The concept presented can be applied for building habitats and infrastructures for human exploration of oceans and outer space. dPZ structures can adapt to changing requirements e.g. mission objectives, crew condition and technological developments. Furthermore, such lightweight and adaptable structural concept can assist in sustainable exploration development. After brief introduction, the concept of Pipe-Z (PZ) is presented. Next, the reconfigurability of PZ is explained and illustrated with continuous and collision-free transition from a PZ forming a Trefoil knot to a Figure-eight knot. The following sections introduce, explain and illustrate the folding mechanism of a single foldable Pipe-Z module (fPZM) and entire dPZ structure. The latter is illustrated with asynchronous (delayed) unfolding of a relatively complex Unknot. Several applications of PZ are suggested, namely for underwater and deep-space and surface habitats, for permanent, but in particular, temporary or emergency passages. As an example, a scenario of a failure of one of the modules of the International Space Station is presented where a rigid structure of 40 fPZMs bypasses the “dead link”. A low-fidelity prototype of a 6-module octagonal dPZ is presented; several folding schemes including concentric toric rings are demonstrated. Practical issues of pressurization and packing are briefly discussed. Keywords: Ocean and space outpost, Banana-split, Deployable structure, Rigid-panel folding, Free-form Affiliations:
Zawidzki M. | - | other affiliation |
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8. |
Zawidzki M.^{♦}, Optimization of Multi-branch Truss-Z based on Evolution Strategy,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2016.07.015, Vol.100, pp.113-125, 2016Abstract: This paper concerns multi-branch Truss-Z networks (MTZ). A possible scenario for creating a “multi-branch bridge” linking 6 terminals of pedestrian and cycling communication is presented. This process is formulated as a constrained minimization problem. New, biology-inspired nomenclature for MTZ and encoding for MTZ are introduced. Several operations for MTZs are introduced and illustrated. The functionality of these operations is illustrated with transformation from a random MTZ to a “proper” 6-branch MTZ network. A population-based heuristic experiment is presented to demonstrate that the introduced operators allow us to create any desirable MTZ. A cost function for the considered scenario is introduced. The genetic operations are interpreted and visualized. A number of feasible MTZ layouts produced by an evolution strategy-based algorithm are presented. One of these layouts is used for creation of the spatial 6-terminal MTZ, which is also visualized. Keywords: Extremely modular system, Modular ramp system, Multi-branch network, Modular structure encoding, Evolution strategy, Discrete layout optimization Affiliations:
Zawidzki M. | - | other affiliation |
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9. |
Zawidzki M.^{♦}, Automated geometrical evaluation of a plaza (town square),
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2016.01.018, Vol.96, pp.58-69, 2016Abstract: This paper presents a method for an automated geometrical evaluation (AGE) intended as a design support tool for urban design of a plaza (P). AGE is based on three normalized properties derived from a plan of P, namely: smallness, enclosure, and regularity. 19 worldwide plazas have been evaluated by 20 respondents in, what is called here, human subjective evaluation (HSE). A brief analysis of HSE including the identification of redundant categories is presented. Two P evaluation methods based on all four (S,C,E,R) and selected three (S,E,R) properties are discussed. Good agreement of AGE based on S,E, and R (NPSER) with HSE is shown. P quality rating (excellent, good, fair) based on NPSER is introduced. Exceptional cases are briefly discussed Keywords: Urban composition, Public square, Plaza, Layout evaluation, Design support tool, Normalized accumulated quality Affiliations:
Zawidzki M. | - | other affiliation |
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Zawidzki M.^{♦}, Dynamic shading of a building envelope based on rotating polarized film system controlled by one-dimensional cellular automata in regular tessellations (triangular, square and hexagonal),
Advanced Engineering Informatics, ISSN: 1474-0346, DOI: 10.1016/j.aei.2014.09.008, Vol.29, No.1, pp.87-100, 2015Abstract: The original prototype of the cellular automaton (CA) shading system (CASS) for building facades was based on rectangular array of cells and used liquid crystal technology. This paper introduces polarized film shading system (PFSS) – an alternative approach based on opto-mechanical modules whose opacity is a function of the rotation of polarized film elements. PFSS in regular tessellations: triangular, square and hexagonal are discussed. Simulations for each type of tessellation are presented and visualized. Visual attractiveness of emergent CA patterns manifested by ‘‘particles’’ and ‘‘solitons’’ is discussed. Keywords: Adaptive architecture, Organic architecture, Building envelope, CA shading Affiliations:
Zawidzki M. | - | other affiliation |
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Zawidzki M.^{♦}, Retrofitting of pedestrian overpass by Truss-Z modular systems using graph-theory approach,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2014.11.004, Vol.81, pp.41-49, 2015Abstract: Installing pedestrian ramps is a common improvement towards a barrier-free environment. This paper introduces a graph-theoretical method of retrofitting of a single-branch Truss-Z (TZ) ramp in a constrained environment. The results produced by this exhaustive search method are usually ideal and better than those produced previously with meta-heuristic methods. A large case study of linking two sections of the Hongo Campus of Tokyo University using an overpass in an extremely constrained environment is presented. TZ modules with 1:12 (8.3%) slope are used, which is allowable in most countries for ramps for self-powered wheelchairs. The results presented here are highly satisfactory both in terms of structural optimization and aesthetics. Visualizations of the TZ ramp system, composed of 124 units, are presented. Keywords: Truss-Z, Modular lightweight system, Organic design, Discrete structural optimization, Retrofitting, Pedestrian ramp, Breadth-first search, Wavefront algorithm, Unknown graph exploration Affiliations:
Zawidzki M. | - | other affiliation |
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Zawidzki M.^{♦}, Chraibi M.^{♦}, Nishinari K.^{♦}, Crowd-Z: The user-friendly framework for crowd simulation on an architectural floor plan,
Pattern Recognition Letters, ISSN: 0167-8655, DOI: 10.1016/j.patrec.2013.10.025, Vol.44, pp.88-97, 2014Abstract: This paper introduces Crowd-Z (CZ): a framework that provides a user-friendly platform where architects can perform simple crowd simulations on floor plans. A simple but robust and flexible agent-based system is used for modeling of the crowd dynamics. Such simulations can be performed at any stage of design – from rough sketches to the final blueprints. CZ allows acquiring the layouts for the simulations in a number of ways: freehand sketches, importing already prepared images and appropriating preprocessed images from commercially available Computer Aided Design programs. These three methods are illustrated with practical examples, followed by a number of simulations compared with the literature or other commercially available programs. Keywords: Pedestrian dynamics, Agent based modeling, Design support, Digitized floor plan Affiliations:
Zawidzki M. | - | other affiliation | Chraibi M. | - | Jülich Supercomputing Centre (DE) | Nishinari K. | - | The University of Tokyo (JP) |
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Zawidzki M.^{♦}, Nishinari K.^{♦}, Application of evolutionary algorithms for optimum layout of Truss-Z linkage in an environment with obstacle,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2013.04.022, Vol.65, pp.43-59, 2013Abstract: Truss-Z (TZ) is a concept of a modular system for creating free-form links and ramp networks. It is intended as a universal transportation system for cyclists and pedestrians, especially ones with strollers or carts, and in particular – by persons on wheelchairs, the elders, etc. In other words, TZ is for people who have difficulties using regular stairs or escalators. With only two types of modules, TZ can be designed for nearly any situation and therefore is particularity suited for retrofitting to improve the mobility, comfort and safety of the users. This paper presents an application of evolution strategy (ES) and genetic algorithm (GA) for optimization of the planar layout of a TZ linkage connecting two terminals in a given environment. The elements of the environment, called obstacles, constrain the possible locations of the TZ modules. Criteria of this multi-objective optimization are: the number of modules to be the smallest, which can be regarded as quantitative economical optimization, and the condition that none of the modules collides with any other objects, which can be regarded as qualitative satisfaction of the geometrical constraints. Since TZ is modular, the optimization of its layout is discrete and therefore has combinatorial characteristic. Encoding of a planar TZ path, selection method, objective (cost) function and genetic operations are introduced. A number of trials have been performed; the results generated by ES and GA are compared and evaluated against backtracking-based algorithm and random search. The convergence of solutions is discussed and interpreted. A visualization of a realistic implementation of the best solution is presented. Further evaluation of the method on three other representative layouts is presented and the results are briefly discussed. Keywords: Truss-Z, Modular skeletal system, Organic design, Meta-heuristic discrete optimization, Retrofitting, Pedestrian ramp Affiliations:
Zawidzki M. | - | other affiliation | Nishinari K. | - | The University of Tokyo (JP) |
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Zawidzki M.^{♦}, Bator M.^{♦}, Application of Evolutionary Algorithm for Optimization of the Sequence of Initial Conditions for the Cellular Automaton-Based Shading,
Journal of Cellular Automata, ISSN: 1557-5969, Vol.7, pp.363-384, 2013Abstract: This paper presents an application of evolutionary algorithm (EA) for multi-objective optimization of the sequence of initial conditions (SIC) for a cellular automaton (CA) used for a potential implementation in the field of architecture. In the proposed application, a modular shading system for building facade is driven by a two color, one dimensional, range 2 CA rule {3818817080,2,2}. The SIC optimization criteria are: visual attractiveness, gradual and intuitive transition from one density level to another and even distribution of the pattern over the entire array. The ideal solutions for 10 square arrays of 7×7, 8×8,..., 16×16 cells are found by an exhaustive search method – the backtracking. The encoding of SICs using the order-based representation is introduced. A cost function evaluating both monotonicity of the average density transition, and the distribution of shading pattern is introduced. For a 100×100 cell array EA is implemented with three setups: without crossover but with intensive mutation, with crossover and without mutation, and with both crossover and mutation. Two types of crossover operations are used: uniform (UX) and one-point (OPX). A number of experiments with various combinations of parameters were performed. The results are compared and the recommended strategy is briefly discussed. The best result was produced by EA with OPX and mutation rate 0.4. Keywords: Modular shading system, initial conditions, multi-objective optimization, discrete optimization, backtracking, order-based representation, evolutionary algorithm Affiliations:
Zawidzki M. | - | other affiliation | Bator M. | - | Warsaw University of Life Sciences (PL) |
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15. |
Zawidzki M.^{♦}, Nishinari K.^{♦}, Shading for Building Facade with Two-Color One-Dimension Range-Two Cellular Automata on A Square Grid,
Journal of Cellular Automata, ISSN: 1557-5969, Vol.8, pp.147-163, 2013Abstract: A practical application of cellular automata (CA) in the field of Architecture is presented, where one-dimensional CA on a square grid drives a modular shading system of a building facade. Examples of three classes: general, semi-totalistic and totalistic of two-color one-dimension range-two automata are analyzed for potential practical use. The problem of desired change in the opacity of the shading array as a function of the sequence of initial conditions (SIC) is discussed. The ideal SlCs for selected CAs on 12 x 12 cell arrays found by backtracking algorithm are presented. The influenee of the type of boundary conditions (BC) is discussed and a special type of a fixed BC is introduced. The robustness of the system under two types of permanent failure is analyzed - the single cell failure, and deactivation of a single column of cells. Keywords: Adaptive architecture, modular shading system, fixed boundary conditions, Robustness, failure Affiliations:
Zawidzki M. | - | other affiliation | Nishinari K. | - | The University of Tokyo (JP) |
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16. |
Zawidzki M.^{♦}, Nishinari K.^{♦}, Modular Truss-Z system for self-supporting skeletal free-form pedestrian networks,
Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2011.12.012, Vol.47, No.1, pp.147-159, 2012Abstract: This paper presents the concept of Truss-Z (TZ) – a skeletal system for pedestrian traffic which is composed of only two modules and allows the creation of complex three-dimensional self-supporting networks connecting any number of terminals in a given environment. TZ is intended as a universal, feasible and practical system for newly designed situations and most importantly, for retrofitting, especially where the use of heavy equipment is impossible or uneconomic.
TZ allows automated creation of optimal spatial links where the only required inputs are the coordinates of the terminals and the geometry of the obstacles. As an example a six-terminal network created with a backtracking based algorithm is shown. An alternative method of aligning consecutive modules to a given 3D path is also presented. A preliminary static analysis of the TZ module is carried out – the topological qualities of rigidity and independence are demonstrated. Keywords: Truss-Z, Modular skeletal system, Self-supporting structure, Organic design, Discrete structural optimization, Retrofit pedestrian link, Pathfinding with backtracking Affiliations:
Zawidzki M. | - | other affiliation | Nishinari K. | - | The University of Tokyo (JP) |
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17. |
Zawidzki M.^{♦}, Tateyama K.^{♦}, Nishikawa I.^{♦}, The constraints satisfaction problem approach in the design of an architectural functional layout,
ENGINEERING OPTIMIZATION, ISSN: 0305-215X, DOI: 10.1080/0305215X.2010.527005, pp.1-24, 2011Abstract: A design support system with a new strategy for finding the optimal functional configurations of rooms for architectural layouts is presented. A set of configurations satisfying given constraints is generated and ranked according to multiple objectives. The method can be applied to problems in architectural practice, urban or graphic design—wherever allocation of related geometrical elements of known shape is optimized. Although the methodology is shown using simplified examples—a single story residential building with two apartments each having two rooms—the results resemble realistic functional layouts. One example of a practical size problem of a layout of three apartments with a total of 20 rooms is demonstrated, where the generated solution can be used as a base for a realistic architectural blueprint. The discretization of design space is discussed, followed by application of a backtrack search algorithm used for generating a set of potentially ‘good’ room configurations. Next the solutions are classified by a machine learning method (FFN) as ‘proper’ or ‘improper’ according to the internal communication criteria. Examples of interactive ranking of the ‘proper’ configurations according to multiple criteria and choosing ‘the best’ ones are presented. The proposed framework is general and universal—the criteria, parameters and weights can be individually defined by a user and the search algorithm can be adjusted to a specific problem. Keywords: Architecture, design support, architectural layout optimization, multi-objective, discrete Optimization, CSP Affiliations:
Zawidzki M. | - | other affiliation | Tateyama K. | - | Ritsumeikan University (JP) | Nishikawa I. | - | Ritsumeikan University (JP) |
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