CumInCAD is a Cumulative Index about publications in Computer Aided Architectural Design
supported by the sibling associations ACADIA, CAADRIA, eCAADe, SIGraDi, ASCAAD and CAAD futures

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_id e825
authors Baybars, Ilker and Eastman, Charles M.
year 1980
title Enumerating Architectural Arrangements by Generating Their Underlying Graphs
source Environment and Planning B. 1980. vol. 7: pp. 289- 310 : ill. includes bibliography. -- See also 'Enumerating Architectural Arrangements: Comment on a Recent Paper by Baybars and Eastman' by C.F. Earl
summary One mathematical correspondence to the partitioning of the plane is a Weighted Plane Graph (WPG). This paper first focuses on the systematic generation of WPGs, in a fashion similar to crystal growth. During this process, the WPGs are represented by adjacency matrices. The authors, thus, present a method for embedding the WPG in the plane, given its adjacency matrix. These graphs can, then, be mapped into floor plans. The common practice here is the use of the `geometric dual' of a WPG. The authors propose, instead, the use of the `Pseudogeometric dual' of a WPG directly to translate (part of) a design brief into alternative spatial layouts. Also discussed is the ability to create courtyards and/or circulation spaces given a specific WPG, without increasing the size of the problem
keywords enumeration, architecture, floor plans, graphs, design process, automation, algorithms, space allocation, CAD
series CADline
last changed 2003/05/17 08:15

_id 88b6
authors Campello, Ruy Eduardo and Maculan, Nelson
year 1983
title A Lower Bound to the Set Partitioning Problem with Side Constraints
source 24 p. : ill. Pittsburgh: Design Research Center, CMU, December, 1983 DRC-70-20-83. includes bibliography.
summary A Lagrangean relaxation approach is proposed to provide a lower bound on the optimal solution of the set partitioning problem with side constraints, which is a general methodology to solve a combinatorial optimization problem. This Lagrangean relaxation approach is accomplished by a subgradient optimization procedure which solves at each iteration a special 0-1 knapsack problem. The approach seems to be promising since it produces feasible integer solutions to the side constraints that can hopefully be the optimal solution to most of the instances of the set partitioning problem with side constraints
keywords mathematics, operations research, relaxation, algorithms, combinatorics, optimization, constraints
series CADline
last changed 2003/06/02 11:58

_id 8239
authors Campello, Ruy Eduardo and Maculan, Nelson
year 1982
title On Deep Disjunctive Cutting Planes for Set Partitioning : A Computationally Oriented Research.
source Pittsburgh: Design Research Center, CMU [DRC-70-11-82], 10 p.
summary Several mathematical programming problems can be formulated as Disjunctive Programming Problems. This approach offers a powerful procedure for the generation of new and strong cutting planes with desirable properties. For general integer programs, the traditional cutting plane methodologies proved less efficient than enumerative techniques. However, for certain classes of problems, such as set partitioning, cutting planes are known to be efficient. Since the disjunctive cuts are strong, they can be expected to perform better. This paper reports on computational results with disjunctive B(.) cuts for the set partitioning problem, evaluated in terms of computer resources and other independent measures in solving specific randomly generated test problems under controlled conditions. [includes bibliography].
keywords Mathematics, Operations Research, Integer Programming, Optimization
series CADline
last changed 1999/02/15 14:17

_id 2f73
authors Coad, P.and Yourdon, E.
year 1991
title Object Oriented Analysis
source 2nd. edition, Englewood Cliffs, NJ., Yourdon Press/ Prentice Hall
summary A step-by-step approach to: defining and communicating system requirements; understanding the application domain in which the user operates; integrating the data and process models; analyzing and specifying systems using self-contained partitioning; gaining leverage through explicit representation of commonality; applying a consistent underlying representation for analysis; and accommodating families of systems.
series other
last changed 2003/04/23 13:14

_id 2068
authors Frazer, John
year 1995
source London: Architectural Association
summary In "An Evolutionary Architecture", John Frazer presents an overview of his work for the past 30 years. Attempting to develop a theoretical basis for architecture using analogies with nature's processes of evolution and morphogenesis. Frazer's vision of the future of architecture is to construct organic buildings. Thermodynamically open systems which are more environmentally aware and sustainable physically, sociologically and economically. The range of topics which Frazer discusses is a good illustration of the breadth and depth of the evolutionary design problem. Environmental Modelling One of the first topics dealt with is the importance of environmental modelling within the design process. Frazer shows how environmental modelling is often misused or misinterpreted by architects with particular reference to solar modelling. From the discussion given it would seem that simplifications of the environmental models is the prime culprit resulting in misinterpretation and misuse. The simplifications are understandable given the amount of information needed for accurate modelling. By simplifying the model of the environmental conditions the architect is able to make informed judgments within reasonable amounts of time and effort. Unfortunately the simplications result in errors which compound and cause the resulting structures to fall short of their anticipated performance. Frazer obviously believes that the computer can be a great aid in the harnessing of environmental modelling data, providing that the same simplifying assumptions are not made and that better models and interfaces are possible. Physical Modelling Physical modelling has played an important role in Frazer's research. Leading to the construction of several novel machine readable interactive models, ranging from lego-like building blocks to beermat cellular automata and wall partitioning systems. Ultimately this line of research has led to the Universal Constructor and the Universal Interactor. The Universal Constructor The Universal Constructor features on the cover of the book. It consists of a base plug-board, called the "landscape", on top of which "smart" blocks, or cells, can be stacked vertically. The cells are individually identified and can communicate with neighbours above and below. Cells communicate with users through a bank of LEDs displaying the current state of the cell. The whole structure is machine readable and so can be interpreted by a computer. The computer can interpret the states of the cells as either colour or geometrical transformations allowing a wide range of possible interpretations. The user interacts with the computer display through direct manipulation of the cells. The computer can communicate and even direct the actions of the user through feedback with the cells to display various states. The direct manipulation of the cells encourages experimentation by the user and demonstrates basic concepts of the system. The Universal Interactor The Universal Interactor is a whole series of experimental projects investigating novel input and output devices. All of the devices speak a common binary language and so can communicate through a mediating central hub. The result is that input, from say a body-suit, can be used to drive the out of a sound system or vice versa. The Universal Interactor opens up many possibilities for expression when using a CAD system that may at first seem very strange.However, some of these feedback systems may prove superior in the hands of skilled technicians than more standard devices. Imagine how a musician might be able to devise structures by playing melodies which express the character. Of course the interpretation of input in this form poses a difficult problem which will take a great deal of research to achieve. The Universal Interactor has been used to provide environmental feedback to affect the development of evolving genetic codes. The feedback given by the Universal Interactor has been used to guide selection of individuals from a population. Adaptive Computing Frazer completes his introduction to the range of tools used in his research by giving a brief tour of adaptive computing techniques. Covering topics including cellular automata, genetic algorithms, classifier systems and artificial evolution. Cellular Automata As previously mentioned Frazer has done some work using cellular automata in both physical and simulated environments. Frazer discusses how surprisingly complex behaviour can result from the simple local rules executed by cellular automata. Cellular automata are also capable of computation, in fact able to perform any computation possible by a finite state machine. Note that this does not mean that cellular automata are capable of any general computation as this would require the construction of a Turing machine which is beyond the capabilities of a finite state machine. Genetic Algorithms Genetic algorithms were first presented by Holland and since have become a important tool for many researchers in various areas.Originally developed for problem-solving and optimization problems with clearly stated criteria and goals. Frazer fails to mention one of the most important differences between genetic algorithms and other adaptive problem-solving techniques, ie. neural networks. Genetic algorithms have the advantage that criteria can be clearly stated and controlled within the fitness function. The learning by example which neural networks rely upon does not afford this level of control over what is to be learned. Classifier Systems Holland went on to develop genetic algorithms into classifier systems. Classifier systems are more focussed upon the problem of learning appropriate responses to stimuli, than searching for solutions to problems. Classifier systems receive information from the environment and respond according to rules, or classifiers. Successful classifiers are rewarded, creating a reinforcement learning environment. Obviously, the mapping between classifier systems and the cybernetic view of organisms sensing, processing and responding to environmental stimuli is strong. It would seem that a central process similar to a classifier system would be appropriate at the core of an organic building. Learning appropriate responses to environmental conditions over time. Artificial Evolution Artificial evolution traces it's roots back to the Biomorph program which was described by Dawkins in his book "The Blind Watchmaker". Essentially, artificial evolution requires that a user supplements the standard fitness function in genetic algorithms to guide evolution. The user may provide selection pressures which are unquantifiable in a stated problem and thus provide a means for dealing ill-defined criteria. Frazer notes that solving problems with ill-defined criteria using artificial evolution seriously limits the scope of problems that can be tackled. The reliance upon user interaction in artificial evolution reduces the practical size of populations and the duration of evolutionary runs. Coding Schemes Frazer goes on to discuss the encoding of architectural designs and their subsequent evolution. Introducing two major systems, the Reptile system and the Universal State Space Modeller. Blueprint vs. Recipe Frazer points out the inadequacies of using standard "blueprint" design techniques in developing organic structures. Using a "recipe" to describe the process of constructing a building is presented as an alternative. Recipes for construction are discussed with reference to the analogous process description given by DNA to construct an organism. The Reptile System The Reptile System is an ingenious construction set capable of producing a wide range of structures using just two simple components. Frazer saw the advantages of this system for rule-based and evolutionary systems in the compactness of structure descriptions. Compactness was essential for the early computational work when computer memory and storage space was scarce. However, compact representations such as those described form very rugged fitness landscapes which are not well suited to evolutionary search techniques. Structures are created from an initial "seed" or minimal construction, for example a compact spherical structure. The seed is then manipulated using a series of processes or transformations, for example stretching, shearing or bending. The structure would grow according to the transformations applied to it. Obviously, the transformations could be a predetermined sequence of actions which would always yield the same final structure given the same initial seed. Alternatively, the series of transformations applied could be environmentally sensitive resulting in forms which were also sensitive to their location. The idea of taking a geometrical form as a seed and transforming it using a series of processes to create complex structures is similar in many ways to the early work of Latham creating large morphological charts. Latham went on to develop his ideas into the "Mutator" system which he used to create organic artworks. Generalising the Reptile System Frazer has proposed a generalised version of the Reptile System to tackle more realistic building problems. Generating the seed or minimal configuration from design requirements automatically. From this starting point (or set of starting points) solutions could be evolved using artificial evolution. Quantifiable and specific aspects of the design brief define the formal criteria which are used as a standard fitness function. Non-quantifiable criteria, including aesthetic judgments, are evaluated by the user. The proposed system would be able to learn successful strategies for satisfying both formal and user criteria. In doing so the system would become a personalised tool of the designer. A personal assistant which would be able to anticipate aesthetic judgements and other criteria by employing previously successful strategies. Ultimately, this is a similar concept to Negroponte's "Architecture Machine" which he proposed would be computer system so personalised so as to be almost unusable by other people. The Universal State Space Modeller The Universal State Space Modeller is the basis of Frazer's current work. It is a system which can be used to model any structure, hence the universal claim in it's title. The datastructure underlying the modeller is a state space of scaleless logical points, called motes. Motes are arranged in a close-packing sphere arrangement, which makes each one equidistant from it's twelve neighbours. Any point can be broken down into a self-similar tetrahedral structure of logical points. Giving the state space a fractal nature which allows modelling at many different levels at once. Each mote can be thought of as analogous to a cell in a biological organism. Every mote carries a copy of the architectural genetic code in the same way that each cell within a organism carries a copy of it's DNA. The genetic code of a mote is stored as a sequence of binary "morons" which are grouped together into spatial configurations which are interpreted as the state of the mote. The developmental process begins with a seed. The seed develops through cellular duplication according to the rules of the genetic code. In the beginning the seed develops mainly in response to the internal genetic code, but as the development progresses the environment plays a greater role. Cells communicate by passing messages to their immediate twelve neighbours. However, it can send messages directed at remote cells, without knowledge of it's spatial relationship. During the development cells take on specialised functions, including environmental sensors or producers of raw materials. The resulting system is process driven, without presupposing the existence of a construction set to use. The datastructure can be interpreted in many ways to derive various phenotypes. The resulting structure is a by-product of the cellular activity during development and in response to the environment. As such the resulting structures have much in common with living organisms which are also the emergent result or by-product of local cellular activity. Primordial Architectural Soups To conclude, Frazer presents some of the most recent work done, evolving fundamental structures using limited raw materials, an initial seed and massive feedback. Frazer proposes to go further and do away with the need for initial seed and start with a primordial soup of basic architectural concepts. The research is attempting to evolve the starting conditions and evolutionary processes without any preconditions. Is there enough time to evolve a complex system from the basic building blocks which Frazer proposes? The computational complexity of the task being embarked upon is not discussed. There is an implicit assumption that the "superb tactics" of natural selection are enough to cut through the complexity of the task. However, Kauffman has shown how self-organisation plays a major role in the early development of replicating systems which we may call alive. Natural selection requires a solid basis upon which it can act. Is the primordial soup which Frazer proposes of the correct constitution to support self-organisation? Kauffman suggests that one of the most important attributes of a primordial soup to be capable of self-organisation is the need for a complex network of catalysts and the controlling mechanisms to stop the reactions from going supracritical. Can such a network be provided of primitive architectural concepts? What does it mean to have a catalyst in this domain? Conclusion Frazer shows some interesting work both in the areas of evolutionary design and self-organising systems. It is obvious from his work that he sympathizes with the opinions put forward by Kauffman that the order found in living organisms comes from both external evolutionary pressure and internal self-organisation. His final remarks underly this by paraphrasing the words of Kauffman, that life is always to found on the edge of chaos. By the "edge of chaos" Kauffman is referring to the area within the ordered regime of a system close to the "phase transition" to chaotic behaviour. Unfortunately, Frazer does not demonstrate that the systems he has presented have the necessary qualities to derive useful order at the edge of chaos. He does not demonstrate, as Kauffman does repeatedly, that there exists a "phase transition" between ordered and chaotic regimes of his systems. He also does not make any studies of the relationship of useful forms generated by his work to phase transition regions of his systems should they exist. If we are to find an organic architecture, in more than name alone, it is surely to reside close to the phase transition of the construction system of which is it built. Only there, if we are to believe Kauffman, are we to find useful order together with environmentally sensitive and thermodynamically open systems which can approach the utility of living organisms.
series other
type normal paper
last changed 2004/05/22 12:12

_id c46e
authors Fuchs, H., Kedem, Z.M. and Naylor, B.F.
year 1980
title On Visible Surface Generation by a Priori Tree Structures
source SIGGRAPH '80 Conference Proceedings. July, 1980. vol. 14 ; no. 3: pp. 124-133 : ill. includes bibliography
summary This paper describes a new algorithm for solving the hidden surface (or line) problem, to more rapidly generate realistic images of 3-D scenes composed of polygons, and presents the development of theoretical foundations in the area as well as additional related algorithms. As in many applications the environment to be displayed consists of polygons many of whose relative geometric relations are static. It is attempted to capitalize on this by preprocessing the environment's database so as to decrease the run-time computations required to generate a scene. This preprocessing is based on generating a 'binary space partitioning' tree whose inorder traversal of visibility priority at run-time will produce a linear order, dependent upon the viewing position, on (parts of) the polygons, which can then be used to easily solve the hidden surface problem. In the application where the entire environment is static with only the viewing-position changing, as is common in simulation, the results presented will be sufficient to solve completely the hidden surface problem
keywords hidden lines, hidden surfaces, algorithms, computer graphics, polygons
series CADline
last changed 2003/06/02 12:42

_id 2363
authors Gross, Mark Donald
year 1986
title Design as exploring constraints
source Massachusetts Institute of Technology, Dept. of Architecture
summary A theory of designing is proposed, developed, and illustrated with examples from the domain of physical form. Designing is seen as the exploration of alternative sets of constraints and of the regions of alternative solutions they bound. Designers with different objectives reach different solutions within the same set of constraints, as do designers with the same objectives operating under different constraints. Constraints represent design rules, relations, conventions, and natural laws to be maintained. Some constraints and objectives are given at the outset of a design but many more are adopted along the way. Varying the constraints and the objectives is part of the design process. The theory accounts for various kinds of expertise in designing: knowledge of particular constraints in a design domain; inference--calculating the consequences of design decisions; preference--using objectives to guide decision-making; and partitioning--skill in dividing a large and complicated design into sets of simpler pieces, and understanding the dependencies between decisions. The ability to manage ambiguity and vagueness is an important aspect of design expertise. A computational model supporting the theory is proposed and its implementation discussed briefly. The constraint explorer, a computational environment for designing based on constraint descriptions is described. We see how the constraint explorer might be used in connection with a simple space- planning problem. The problem is taken from the procedures of the Stichting Architecten Research (S.A.R.), a specific architectural design methodology developed to help architects systematically explore layout variability in alternative floorplan designs. Finally, a selected review of related work in constraint-based programming environments, architectural design methods, and the intersection of the two fields is presented.
series thesis:PhD
last changed 2003/03/15 05:49

_id f251
authors Hui-Ping, T., Veeramani, D., Kunigahalli, R. and Russell, J.S.
year 1996
title OPSALC: A computer-integrated operations planning system for autonomous landfill compaction
source Automation in Construction 5 (1) (1996) pp. 39-50
summary Construction workers and operators associated with sanitary waste landfilling operations face significant health risks because of high levels of exposure to harmful solids and gases. Automation of the spreading and compacting processes of a landfilling operation using an autonomous compactor can reduce exposure of workers to the harmful environment, and thereby lead to improved safety of workers. This paper describes a computer-integrated operations planning system that facilitates (1) the design of landfill cells and (2) the generation of area-covering path plans for spreading and compaction processes by the autonomous compactor. The partitioning of a given landfill site into three-dimensional cells is accomplished by a recursive spatial decomposition technique in which the cell sizes are determined using a probabilistic model for waste generation. A recursive sub-division of each cell into monominoes facilitates the system to automatically deal with any differences between the actual amount of waste generated on a particular day and the amount predicted by the probabilistic model. The partitioned configuration of the landfill site is used to generate the path plan for the autonomous compactor using three motion models, namely straight-up, straight-down, and zig-zag. The computer-integrated system is implemented using PHIGS graphics standard and MOTIF toolkit with C-program binding.
series journal paper
last changed 2003/05/15 19:22

_id 4f90
authors Kalay, Y.E.
year 1998
title P3: Computational environment to support design collaboration
source Automation in Construction 8 (1) (1998) pp. 37-48
summary The work reported in this paper addresses the paradoxical state of the construction industry (also known as A/E/C, for Architecture, Engineering and Construction), where the design of highly integrated facilities is undertaken by severely fragmented teams, leading to diminished performance of both processes and products. The construction industry has been trying to overcome this problem by partitioning the design process hierarchically or temporally. While these methods are procedurally efficient, their piecemeal nature diminishes the overall performance of the project. Computational methods intended to facilitate collaboration in the construction industry have, so far, focused primarily on improving the flow of information among the participants. They have largely met their stated objective of improved communication, but have done little to improve joint decision-making, and therefore have not significantly improved the quality of the design project itself. We suggest that the main impediment to effective collaboration and joint decision-making in the A/E/C industry is the divergence of disciplinary `world-views', which are the product of educational and professional processes through which the individuals participating in the design process have been socialized into their respective disciplines. To maximize the performance of the overall project, these different world-views must be reconciled, possibly at the expense of individual goals. Such reconciliation can only be accomplished if the participants find the attainment of the overall goals of the project more compelling than their individual disciplinary goals. This will happen when the participants have become cognizant and appreciative of world-views other than their own, including the objectives and concerns of other participants. To achieve this state of knowledge, we propose to avail to the participants of the design team highly specific, contextualized information, reflecting each participant's valuation of the proposed design actions. P3 is a semantically-rich computational environment, which is intended to fulfill this mission. It consists of: (1) a shared representation of the evolving design project, connected (through the World Wide Web) to (2) individual experts and their discipline-specific knowledge repositories; and (3) a computational project manager makes the individual valuations visible to all the participants, and helps them deliberate and negotiate their respective positions for the purpose of improving the overall performance of the project. The paper discusses the theories on which the three components are founded, their function, and the principles of their implementation.
series journal paper
last changed 2003/05/15 19:22

_id c100
authors Kulinski, Jaroslaw
year 1996
title Coherency and Automation of the Design Process Applied in CAD Systems
source Education for Practice [14th eCAADe Conference Proceedings / ISBN 0-9523687-2-2] Lund (Sweden) 12-14 September 1996, pp. 243-252
summary The article discusses a few postulates concerning the desirable structure of design data base with the aim of allowing the concurrent work in the design process. It depicts the problems of simultaneous access to the data base, and discusses the problems of redundancy of design information and their consequences in the structure of the design data base. Finally, a few examples of CAD systems are examined in order to find out how they deal with the problems of design partitioning and keeping it automatically coherent as well as some educational remarks are formulated.

series eCAADe
last changed 1998/08/17 13:47

_id 9aa3
authors Michalewicz, Z.
year 1994
title Genetic Algorithms + Data Structures = Evolution Programs
source Springer-Verlag, Berlin
summary Genetic algorithms are founded upon the principle of evolution, i.e., survival of the fittest. Hence evolution programming techniques, based on genetic algorithms, are applicable to many hard optimization problems, such as optimization of functions with linear and nonlinear constraints, the traveling salesman problem, and problems of scheduling, partitioning, and control. The importance of these techniques is still growing, since evolution programs are parallel in nature, and parallelism is one of the most promising directions in computer science. The book is self-contained and the only prerequisite is basic undergraduate mathematics. This third edition has been substantially revised and extended by three new chapters and by additional appendices containing working material to cover recent developments and a change in the perception of evolutionary computation.
series other
last changed 2003/04/23 13:14

_id 59
authors Ozel, Filiz
year 1998
title Geometric Modeling intThe Simulation of Fire - Smoke Spread in Buildings
source II Seminario Iberoamericano de Grafico Digital [SIGRADI Conference Proceedings / ISBN 978-97190-0-X] Mar del Plata (Argentina) 9-11 september 1998, pp. 438-445
summary Since the performance simulation of buildings, such as fire/smoke spread, energy loss/gain, acoustics, etc. greatly rely on building geometry, the way the physical environment is modeled can substantially effect the reliability of the predictions made by such simulations. Most computer models that simulate fire and smoke spread in buildings limit the computer representation of the building to simpler geometries and define rooms as rectangular spaces or as spaces with uniform crossections. Such a definition does not account for the variety of building elements that can exist in a building such as large overhangs, half height walls, etc. Existing simulations are typically developed as mathematical models and use the principles of thermodynamics to represent the spread of the elements of fire through space over a given time period. For example, in zone models each room is defined as a two tier space with heat and smoke exchange between lower and upper tiers as the fire progresses. On the other hand, field models divide the space into small contiguous units where thermodynamic state of each unit is calculated as the simulated fire progresses. Dynamic processes such as fire and smoke spread must recognize both intangible (i.e. voids) and tangible (i.e. solids such as walls, balconies, ceiling, etc.) architectural entities. This paper explores the potential of solid modeling techniques in generating geometric definitions for both solid and void architectural entities that can interact With mathematical models of fire/smoke spread in buildings. The implications of cellular spatial partitioning techniques for zone or field models of fire/smoke spread are investigated, and the methods of creating cellular decomposftion models for architectural spaces as well as for spatial boundaries such as walls are explored. The size of each cellular partition, i.e. the resolution of the partition, and the material and heat transfer attributes of each cell were found to be very critical in modeling the spread fire through voids as well as through solids in a building.
series SIGRADI
last changed 2016/03/10 08:57

_id 2006_276
id 2006_276
authors Rafi, Ahmad
year 2006
title ILUDS - An Interactive Land Use Database System for Intelligent Cities
source Communicating Space(s) [24th eCAADe Conference Proceedings / ISBN 0-9541183-5-9] Volos (Greece) 6-9 September 2006, pp. 276-279
summary This paper presents the i-putra business channel, a portal that has been completed with a comprehensive database of information relating to commercial and residential properties, and other on-going development components of Putrajaya, one of Malaysia’s intelligent cities. Designers were provided with multimedia-rich information of spaces before making a selection through the Interactive Land Use Database System (ILUDS) which hosted more than 67,000 units of residential and commercial areas in Putrajaya. The database was developed based on category searching features that aimed to be the one-stop brief explanatory system on the Internet. ILUDS depicts an innovative idea for city and urban development to prepare information and virtual interactivities for a better usage in a ‘soft city’ design. The system has the underlying structure that allows for partitioning and ease of handling within which the data can be structured under a graphical interface that facilitates editing, manipulation, attribution and updating. This attribute of city information and associate data offers users a different level of interactivity and provides effective use on architectural and city information.
keywords ILUDS; intelligent community; intelligent cities; database
series eCAADe
last changed 2006/08/16 16:54

_id 47e7
authors Segal, Mark and Sequin, Carlo H.
year 1988
source IEEE Computer Graphics and Applications. January, 1988. vol. 8: pp. 53-67 : ill. some col. includes bibliography
summary The article describes an algorithm for partitioning intersecting polyhedrons into disjoint pieces and, more generally, removing intersections from sets of planar polygons embedded in three space. Polygons, or faces, need not be convex and may contain multiple holes. Intersections are removed by considering pairs of faces and slicing the faces apart along their regions of intersection. To reduce the number of face pairs examined, bounding boxes around groups of faces are checked for overlap. The intersection algorithm also computes set theoretic operations on polyhedrons. Information gathered during face cutting is used to determine which portions of the original boundaries may be present in the result of an intersection, a union, or a difference of solids. The method includes provisions to detect, and in some cases overcome, the effects of numerical inaccuracy on the topological decisions that the algorithm must make. The regions in which ambiguous results are possible are flagged so that the user can take appropriate action.
keywords geometric modeling, computer graphics, objects, programming, hidden surfaces, hidden lines, business, practice, systems, user interface, UNIX
series CADline
type normal paper
last changed 2005/10/05 05:39

_id eaff
authors Shaviv, Edna and Kalay, Yehuda E.
year 1992
title Combined Procedural and Heuristic Method to Energy Conscious Building Design and Evaluation
source New York: John Wiley & Sons, 1992. pp. 305-325 : ill. includes bibliography
summary This paper describes a methodology that combines both procedural and heuristic methods by means of integrating a simulation model with a knowledge based system (KBS) for supporting all phases of energy conscious design and evaluation. The methodology is based on partitioning the design process into discrete phases and identifying the informational characteristics of each phase, as far as energy conscious design is concerned. These informational characteristics are expressed in the form of design variables (parameters) and the relationships between them. The expected energy performance of a design alternative is evaluated by a combination of heuristic and procedural methods, and the context-sensitive application of default values, when necessary. By virtue of combining knowledge based evaluations with procedural ones, this methodology allows for testing the applicability of heuristic rules in non-standard cases,Ô h)0*0*0*°° ÔŒ thereby improving the predictable powers of the evaluation
keywords design process, evaluation, energy, analysis, synthesis, integration, architecture, knowledge base, heuristics, simulation
series CADline
last changed 2003/06/02 08:24

_id ecaade2012_142
id ecaade2012_142
authors Shin, Dongyoun; Arisona, Stefan Müller; Georgakopoulou, Sofia; Schmitt, Gerhard; Kim, Sungah
year 2012
title A Crowdsourcing Urban Simulation Platform on Smartphone Technology: Strategies for Urban Data Visualization and Transportation Mode Detection
source Achten, Henri; Pavlicek, Jiri; Hulin, Jaroslav; Matejovska, Dana (eds.), Digital Physicality - Proceedings of the 30th eCAADe Conference - Volume 2 / ISBN 978-9-4912070-3-7, Czech Technical University in Prague, Faculty of Architecture (Czech Republic) 12-14 September 2012, pp. 377-384
wos WOS:000330320600039
summary We propose a crowdsourcing simulation environment that brings human intention into the urban simulator. Our fundamental goal is to simulate urban sustainability by employing direct human interaction. In this paper we present a prototype mobile phone application that implements a novel transportation mode detection algorithm. The mobile phone application runs in the background and continuously collects data from the built-in acceleration and network location sensors. The collected data is analyzed by the transportation mode detection algorithm and automatically partitioned into activity segments. A key observation of our work is that walking activity can be robustly detected in the data stream and acts as a separator for partitioning the data stream into other activity segments. Each vehicle activity segment is then sub-classifi ed according to the type of used vehicle. Our approach yields high accuracy despite the low sampling interval and not requiring GPS data that bring minimized device power consumption. Ultimately, the collected information can be translated into real-time urban behavior and will indicate sustainability, both on the personal and the city level.
keywords Crowdsourcing simulation platform; transport mode detection; social sensing; urban sustainability; mobile application
series eCAADe
last changed 2014/04/14 11:07

_id caadria2016_445
id caadria2016_445
authors Silvestre, Joaquim; Franc?ois Gue?na and Yasushi Ikeda
year 2016
title Edition-Oriented 3D Model Rebuilt from Photography
source Living Systems and Micro-Utopias: Towards Continuous Designing, Proceedings of the 21st International Conference on Computer-Aided Architectural Design Research in Asia (CAADRIA 2016) / Melbourne 30 March–2 April 2016, pp. 445-454
summary The topic of this paper is about a technique to turn pictures into an intuitively modifiable 3D model. The research employs an analytical method using algorithms to conceptualise and digital- ise architectural spaces in order to highlight parametric shapes. Usual- ly, from one group of digital photos, photogrammetry techniques pro- duce a 3D-model mesh through a high-density 3D point cloud. This discordance between our intuitive partitioning of the mesh and its bare polygonal structure makes it interact poorly compared to the af- fordance of shape and component in our daily experience. Through a capture device, a visualisation of architecture in a digital data form is produced. They are processed by computer vision algorithms and ma- chine learning systems in order to be refined into a parametric model. Parametric elements can be described as a compound of formulas and parameters. By keeping the formula and changing the parameters, the- se elements can be easily modified in a range of likenesses. After be- ing detected during scans, these shapes can be adapted to fit the inten- tion of the designer during the design phase.
keywords Photogrammetry; convolutional neural network; 3D model; design tool
series CAADRIA
last changed 2016/03/11 09:21

_id 3283
authors Suter,G., Mahdavi, A. and Kirshnamurti, R.
year 1999
title A Performance-inspired Building Representation for Computational Design
source Proceedings of the Eighth International Conference on Computer Aided Architectural Design Futures [ISBN 0-7923-8536-5] Atlanta, 7-8 June 1999, pp. 117-132
summary A building representation for integrated building performance simulation is described, which addresses several important issues. First, it captures informational requirements for detailed performance analysis and maintains geometric integrity. Second, it provides computational support for efficient spatial queries and convenient building model manipulation. Representational elements include partitioning and refinement rules, containment hierarchies and dimension constraints. These features provide for ease of manipulation, geometric variety and spatial queries and are illustrated with examples. The paper concludes with a discussion of the limitations of the representation.
keywords Performance Simulation, Constraint-based Design, Geometric Modeling
series CAAD Futures
last changed 2006/11/07 06:22

_id caadria2014_139
id caadria2014_139
authors Tong, Ziyu
year 2014
title Comparison of Partitioning Methods for Estimating the Layout of Green Spaces
source Rethinking Comprehensive Design: Speculative Counterculture, Proceedings of the 19th International Conference on Computer-Aided Architectural Design Research in Asia (CAADRIA 2014) / Kyoto 14-16 May 2014, pp. 873–882
summary The urban green space positively affects the quality of the environment and urban life. To estimate the layout of urban green spaces, especially to describe the real difference of regional properties, the influenced zone of each green space should be identified firstly. The influenced zone can be used to quantitatively analyse the difference of regional environmental quality. The identification of the influenced zones of green spaces actually is a problem of space partitioning. The study compared three methods mostly used in space partitioning. The regular grid is a most common partitioning method. It is easy to use, but cannot link the grid with green space separately. Voronoi algorithm is a constructive method which partitions the urban space based on each green. Another approach is the application of gravity models, which assumed analogies between human behaviour and Newtonian gravity laws. The gravity model could calculate the probabilities of residents to choose the green space and partition the urban space. In the comparison of these three methods, we conclude that the gravity model can take more characteristics of the green space as the calculating parameters. The gravity model is a better method to estimate the layout of urban green spaces.
keywords Space partitioning; gravity model; Voronoi algorithm; regular grids; green space
series CAADRIA
last changed 2014/04/22 08:23

_id sigradi2010_388
id sigradi2010_388
authors Triana, Trujillo Jhon Alejandro; Padilla Andres Felipe; Ordoñez Sergio; Hernández José Tiberio
year 2010
title Methodology for Automatic Generation of Distributed Urban Spatial Models from GIS Data
source SIGraDi 2010_Proceedings of the 14th Congress of the Iberoamerican Society of Digital Graphics, pp. Bogotá, Colombia, November 17-19, 2010, pp. 388-391
summary Urban spatial models are important to many professions, and they can be used in a wide range of urban decision - making applications. This paper describes a methodology for automatic generation of an urban spatial model from a GIS source. The methodology uses a Voronoi polygon - based method in order to split the urban space. After partitioning the GIS, functional characteristics are used to generate zones of interest at each Voronoi polygon. The paper also presents examples of applications of the model: a two dimensional model used for microsimulation of traffic, and a three - dimensional model used for simulation of air pollution.
keywords mobility, urban model, Voronoi diagram, GIS, distributed system
series SIGRADI
last changed 2016/03/10 09:01

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