Arthur W T Leung, C M Tam
Assessment of Impacts of Project Technical Complexity on Building Production Using Clustering and Knowledge-Based System
Abstract: Site production layout planning is highly correlated with the technical complexity of a building project. Building structures, building layouts, scales of project and external site conditions are the major components affecting allocation and positioning of site facilities and construction plant. The relationships between these attributes are well known by experienced project managers. In the planning and tendering process, project managers and planners would assess and decide the site production layout by applying their cognitive knowledge using intuitive rather than quantitative approaches. They recognize the benefit of using quantitative models in decision making, which however present much difficulty when modeling the intwined and complex relationships between large numbers of variables. This study proposes an assessment model to examine impacts of technical designs, building layout designs and site conditions on building production with respect to the site layout plan using a data-based platform, which can assist decision making in site planning.The system consists of two components, the Building Production Impact Assessment Model (BPIA) and the Building Production Impact Database (BPIDB). The BPIA adopts the natural clustering technique, the self-organizing Map (SOM), to classify building project samples in terms of technical complexity to compute the technical complexity index for the sample projects. The sample projects and their index are uploaded to the BPIDB forming the data records. In the assessment platform, planners can input the project information of a new project, and the system will return with a complexity index and three sample projects with the highest similarity. The objective of the proposed system is to generate both a quantitative complexity index derived by the clustering model and the cognitive knowledge through the selected projects to improve the quality of decisions. The conceptual framework of the system will be discussed and illustrated with examples.
Keywords: technical complexity, building production, clustering, database
Full text: content.pdf (73,314 bytes) (available to registered users only)
Blanca Quintana, Samuel A. Prieto, Antonio Adan and Frédéric Bosché
Scan-To-BIM for Small Building Components
Abstract: Scan-to-BIM works have so far mainly focused on 'structural' components such as floors, ceiling, walls (with doors and windows). But, the control of new facilities and the production of their corresponding as-is BIM models requires the identification and inspection of numerous other building components and objects, e.g. MEP components such as plugs, switches, ducts, and signs. In this paper, we present a novel 6D-based (XYZ + RGB) approach that processes dense coloured 3D points provided by terrestrial laser scanners to recognize such smaller objects that are commonly located on walls. This paper focuses on the recognition of objects such as sockets, switches, signs, and extinguishers. After segmenting the point clouds corresponding to the walls of a building, a set of candidate objects are detected independently in the colour and geometric spaces, and a consensus procedure integrates both results to infer recognition. The method has been tested on real indoors yielding promising results.
Keywords: Object Recognition, Scan-To-BIM, Automatic BIM, 3D Data Processing
Full text: content.pdf (1,613,364 bytes) (available to registered users only)
Faisal Manzoor Arain
IT-based approach for effective management of project changes: a change management system (CMS)
Abstract: In a perfect world, changes will be confined to the planning stages. However, late changes often occur during construction, and frequently cause serious disruption to the project. The need to make changes in a construction project is a matter of practical reality. Even the most thoughtfully planned project may necessitate changes due to vari-ous factors. The fundamental idea of any variation management system in a building project is to anticipate, recognize, evaluate, resolve, control, document, and learn from past variations in ways that support the overall viability of the project. Learning from past variations is imperative because the professionals can then improve and apply their experi-ence in the future. Primarily, the study proposes six principles of change management. Based on these principles, a theoretical model for change management system (CMS) is developed. The theoretical model consists of six fundamen-tal stages linked to two main components, i.e., a knowledge-base and a controls selection shell for making more in-formed decisions for effective management of variations. This paper argues that the information technology can be ef-fectively used for providing an excellent opportunity for the professionals to learn from similar past projects and to better control project variations. Finally, the study briefly presents a knowledge-based decision support system (KBDSS) for the management of variations in educational building projects in Singapore. The KBDSS consists of two main components, i.e., a knowledge-base and a controls selection shell for selecting appropriate controls. The KBDSS is able to assist project managers by providing accurate and timely information for decision making, and a user-friendly system for analyzing and selecting the controls for variation orders for educational buildings. The CMS will enable the project team to take advantage of beneficial variations when the opportunity arises without an inordinate fear of the negative impacts. By having a systematic way to manage variations, the efficiency of project work and the likelihood of project success should increase. The study would assist building professionals in developing an effective variation management system. The system would be helpful for them to take proactive measures for reducing variation orders. Furthermore, with further generic enhancement and modification, the KBDSS will also be useful for the man-agement of variations in other types of building projects, thus helping to raise the overall level of productivity in the construction industry. Hence, the system developed and the findings from this study would also be valuable for all building professionals in general.
Keywords: CMS, information technology, KBDSS, changes, management
Full text: content.pdf (4,582,108 bytes) (available to registered users only)
G Chen, L He
Re-Recognize BIM from a FM Perspective: Observations about Misunderstandings of BIM-FM in China
Full text: content.pdf (474,155 bytes) (available to registered users only)
Ivan Mutis, Raja R.A. Issa
THE INTEROPERABILITY ACT FOR EMCOMPASING SEMANTICS IN CONSTRUCTION DOCUMENTS
Abstract: Actors generate, share, and ultimately communicate information with other construction project actors. The content of this information is described within construction documents such as drawings, schedules, and specifications. Poor understanding of the content of the documents has been a factor in the escalation of construction project complexity. The result is a lack of efficiency in the communication that has been documented as failures to interoperate among actors during any construction process. As a consequence, actors need to employ additional resources for aiding the understanding of the shared information therefore significantly raising costs and reducing project productivity. Current research efforts are aimed at aiding interoperability by sharing common vocabulary and models among project actors. These efforts have been addressed through the development of common, shared models and construction industry standards. The objective is that multiple construction participants ultimately recognize the shared models and set a universal language. The implementation and use of the models and the common vocabulary provides the possibility of reusing the information within the construction documents by project actors. However, the industry has failed to adopt the commonly shared models and the universal language to effectively share information. The assumption in the construction industry is that the creation of an a priori consensus over the content of what is described within the information is a condition for interoperability. This paper questions this assumption by diverging into another paradigm, the semantics of the represented information. As an alternative, our research focuses on the semantic paradigm. We move away from the attempts to find consensus through common vocabulary and shared models to new methods that benefit from precise meanings. Our assumption is that strategies for exchanging, sharing, and integrating information will not reduce the lack of full automatic interoperability without working first on strategies for understanding the information from other sources.One of the steps proposed here towards this paradigm is the interpretation of the represented information by other construction actors. Our research explores the relationship between the represented information and the interpreter. For this purpose, a parallel of the interpretation of shared information has been made through the Speech Act Theory (Searle 1969). The objective is to understand what background information is pertinent to the conversation and what assumptions and inferences are needed to capture the intended meaning within the expressed utterance in order to parallel the speech act with the shared represented information between two construction participants. This research proposes the interoperability act concept for construction documents. The significant implications of this effort are the characterization of the interoperability act with the purpose of developing new forms of representing semantics within the construction documents, which provide a method to successfully share and communicate information.
Keywords: Interoperability act, construction concepts, interoperability actions, forms of representation
Full text: content.pdf (181,020 bytes) (available to registered users only)
Converting CAD drawings to product models
Abstract: Methods to automatically recognize building elements in CAD drawings for use in product model orobject based AEC systems are investigated. The need for this is shown by the fact that none of theexisting commercial model based systems are able to read drawings produced by earlier vectorbased systems. Although the scope of this study is limited to use information stored in layerseparated vector databases, much like the main bulk of drawings produced in the 20th century, it isbelieved that the methods can be applied to scanned drawings too. The methods presented aredescribed and followed by a discussion of its application to different types of geometricrepresentations. Prototype implementations have shown that it is possible to acquire good results ofrecognition on a specific subset of symbols, predetermined by the domain of interest.
Keywords: Shape recognition, shape interpretation, product models
Full text: content.pdf (246,720 bytes) (available to registered users only)
Sound: read aloud.
Converting CAD Drawings to Product Models
Abstract: The fundamental aim of this study is to examine whether it is
possible to automatically convert vector-based drawings to product
models. The reason for doing this is that the new object-based
systems cannot make use of the information stored in CAD
drawings, which limits the usability of these systems.
Converting paper drawings to vector-format is used today and
provides recognition of lines and text, but does not interpret what
the shapes represent. A language for describing the geometrical
representations that could be processed directly into a recognition
program for building elements is missing. It is easier to describe
how to recognize a line as a series of dots in a raster image, than it
is to describe how a complex symbol of a building element looks
The approach in this research work has been to test different
shape recognition algorithms. The proposed method can be divided
into four processes: grouping of geometrical primitives, classifying
these groups, interpreting the content and analyzing the
relationships between the groups. The algorithms developed here
are based on research within related domains, such as pattern
recognition and artificial intelligence.
The algorithms have been developed in a prototype implementation
and were tested with three layer-structured drawings used in
practice. The results of the tests show that there are no crucial
obstacles to recognizing a large part of the symbols of building
elements in a CAD drawing. The requirement is that the
recognition system is able to differentiate one from another and be
tolerant of errors and variations in the shapes.
Keywords: Product Model, CAD
Full text: content.pdf (1,170,022 bytes) (available to registered users only)
Ruodan Lu and Ioannis Brilakis
Recursive Segmentation for As-Is Bridge Information Modelling
Abstract: Prior studies reported that the time needed to manually convert a point cloud to an as-is geometric model using cutting edge modelling software is ten times greater than the time needed to obtain the point cloud. The laborious nature of manually modelling infrastructure such as bridges is the reason behind the significant cost of modelling which impedes the proliferation of the usage of Bridge Information Models (BrIM) in Bridge Management Systems. Existing commercial solutions can automatically recognize geometric shapes embedded in segmented point cloud data (PCD) and generate the corresponding IFC objects. Researchers have taken further studies and have additionally automated surface reconstruction through generating parametric surface-based primitives in order to automate the segmentation process. However, surface-based segmentation for bridge modelling is an unsolved problem, which is neither straightforward nor consistent, thus hinders the automation of BrIM.This paper presents a top-down PCD detection solution that follows a knowledge-based heuristic approach for BrIM generation that can semi-automatically segment a bridge point cloud recursively. We leverage bridge domain knowledge as strong priors through a histogram-based algorithm to conduct the tasks of segmentation and classification. We implemented this solution and tested on one highway bridge. The experimental results indicated that the detection precision of this solution is 92%.
Keywords: As-Is Brim, Laser Scanning, Point Cloud Data, Recursive Segmentation
Full text: content.pdf (1,880,873 bytes) (available to registered users only)
An object-based building product model: from modeling to documentation
Abstract: In Korea, construction industries have started to recognize
the importance of the conceptual model of building objects
to integrate various information from different views on a
project. An object-oriented model was proposed and
implemented partially. The implemented system of the model
at this stage aims at the automatic generation of two
dimensional drawings from three dimensional objects even
though the objects defined in the system carry more
information than just geometric properties. Information
regarding structural analysis, construction planning, and
scheduling is represented in the model. It was concluded
that three separate modules need to be developed to cover
the most popular structural types of current projects :
reinforced concrete, steel, and shear wall. However, these
modules share many objects which represent architectural
components like non-bearing walls, openings, stairs, rooms,
doors and windows. To be a flexible design tool, an input
mechanism for a model should facilitate a three dimensional
CAD system. Once objects are defined and placed through a
user interface in a CAD environment, the system creates
objects which in turn are checked for consistency. There
are access functions to retrieve data for other application
Full text: content.pdf (556,626 bytes) (available to registered users only)
Cluster: papers of the same cluster (result of machine made clusters)
Class: class.man-software (0.079608)
class.software development (0.033644)
Sound: read aloud.
Permission to reproduce these papers has been graciously provided by the Stanford University, USA. The support of the editors, particularly Prof. Fischer is gratefully appreciated.
Wagter H, Smeltzer G, Roelen W
A realistic view to virtual reality: new possibilities in construction
Abstract: The world of computer aided design has been characterized for many years be a constant flow of new approaches and techniques. Itis difficult to recognize the real value of the different items. Some of these techniques are computer aided (stereo)imaging, animation, holography and virtual reality. These systems and thesetechniques are mainly used for the presentation of a final design.Because of the constantly improving performance of CAD systems andtheir users, these systems are more and more useful for the evaluation of several design proposals during the design process. However, because of the great impact that artistic images and advanced animations have on a presentation of a designit seems tobe more rewarding to use CAD systems for this purpose only. Even new techniques like Virtual Reality systems seem to be valued in relation with their presentation capabilities instead of their possibilities to support design modeling and evaluation during thedesign process. This paper describes the main results of research and development work on a Virtual Reality system. One of the results is a Virtual Reality application that will allow differentparticipants in the designprocess to work together in a virtual building on a scale of 1:1. This system, a multi user design system, will offer modules for modeling and for evaluation. With these modules this system will show that new media are not only useful for the improvement of design presentations but that they can also be used for the improvement of the building performance. Virtual Reality systems are based on different existing presentation techniques, like photo-realistic images, stereo-images and real time- animation. The added value of this kind of CAD systems is determined by a new kind of interface (a sensored interface) for the control over the animation, displayed through the head-mounted displays oreye phone and for the controlover a 3D pointer for the selection of commands and objects in a model. For a bett
Full text: content.pdf (939,094 bytes) (available to registered users only)
Cluster: papers of the same cluster (result of machine made clusters)
Class: class.synthesis (0.055779)
Sound: read aloud.
Permission to reproduce these papers has been graciously provided by Research Press of the National Research Council of Canada. The support of the editor, Dr. Dana Vanier, is gratefully appreciated.