Robust knowledge sharing frameworks between different stakeholders in a building project is of high priority. Industry Foundation Classes (IFC) provides a rich schema for interoperability through object-based transactions. However, IFC lacks semantic clarity in mapping entities and relationships, resulting in multiple definitions to map the same information between different federated models. The objective of this research is to examine IFC from a perspective of an ontological framework, which can make the IFC definitions more formal, consistent and unambiguous. Different methods of ontological approaches to engineering knowledge are reviewed. Various issues such as the need for a logical framework, the current semantic approaches in the AEC/FM industry, and advantages of building an ontology structure are addressed. A comparative study of the ontology and segments of the existing IFC schema definition are performed. This exercise reveals the ambiguous nature of current IFC definitions and proposes reforms such that data exchanges would be more semantically robust. An ontology would structure the overall interoperability of BIM tools by providing a formal and consistent taxonomy and classification structure for extending IFC and for defining subsets as model view definitions (MVD).

The precast concrete National BIM Standard (NBIMS) initiative is an industrywide effort encompassing the major building model exchanges dealing with precast concrete and addressing a range of contracting and procurement methods. The standard was developed according to the guidelines described within the NBIMS for facilitating information exchanges and improving interoperability. The precast concrete NBIMS effort is the first of its kind to deal with a large set of exchanges. The tradeoffs and advantages of this large-scale approach are reviewed as well as areas that require additional attention. Two demonstrations were conducted to showcase the functionality that the software companies are developing in support of the standard and to provide an example of the potential of open BIM. They also revealed the importance of full validation testing and certification.

Construction safety is a national and worldwide issue. This paper contributes in solving this problem by applying automated safety rule checking to Building Information Models (BIM). Algorithms that automatically analyze a building model to detect safety hazards and suggest preventive measures to users are developed for different cases involving fall related hazards. As BIM is changing the way construction can be approached, the presented work and case studies extend BIM to include automated hazard identification and correction during construction planning and in certain cases, during design. A rule-based engine that utilizes this framework is implemented on top of a commercially available BIM platform to show the feasibility of the approach. As a result, the developed automated safety checking platform informs construction engineers and managers by reporting, why, where, when, and what safety measures are needed for preventing fall-related accidents before construction starts. The safety area reviewed is fall protection. An example case study of such a system is also provided.

Nanotechnology research and product development are actively conducted in many industries, (such as industries that manufacture advanced materials and semiconductors) and in medicine. Few studies have presented the potential application areas of nanotechnology in, and the needs of, the construction industry while identifying the benefits and barriers of entry in research and development. Some construction industry sectors follow research and development in nanotechnology; however, the industry does not take on a leadership role. With proper knowledge of the potential products and techniques offered through an investment in nanotechnology, the construction industry may potentially improve the efficiency of its processes and offer better products to clients such as those that exist in building and infrastructure construction and in environmental and petroleum engineering. This paper analyzes the understanding of nanotechnology in the context of construction and explores the current status of nanotechnology in the construction industry. Findings from a literature review, from a survey among construction industry professionals, and from expert interviews with leading researchers in construction-related nanotechnology research and development are presented to identify the potential benefits and existing barriers of using nanotechnology in construction. A multi-criteria decision analysis (MCDA) framework was developed to rank application areas of nanotechnology that will have major effects in the construction industry. Tasks were identified that will make the application of nanotechnology in construction successful in the future. DOI: 10.1061/(ASCE)CO.1943-7862.0000467. (C) 2012 American Society of Civil Engineers.

Building Information Modeling realm is expanding with the advent of new technologies, processes and software for Architecture, Engineering, Construction and Facility Management industry. The importance of robust knowledge sharing between different stakeholders in a project is of highest priority in such scenarios. model diew definitions provides an empirical specification for the implementation of the Industry Foundation Class (IFC) schema by software companies. The objective of this research is to create an ontological framework, which makes the IFC definitions more formal and consistent. A formal specification of IFC entities to create taxonomy of classes and subclasses between them is adopted for this research. Such an approach will make model view specifications unambiguous and reusable thereby reducing the development time of model views. The precast/pre-stressed concrete industry is selected as the domain for the ontology definitions. Case studies developed illustrating the exchange of a fabrication model between architect/engineer, precast detailer and fabricator shows the feasibility of this approach. The outcome of this research provides the mechanism for applications such as modular MVDs, smart and complex querying of building models, making data sharing across applications simpler with limited rework.

In the past two decades more than 26,000 U.S. construction workers have died at work. Of these fatalities, 40% involved falls. It is indicated that safety in construction remains a big problem. Safe construction requires planning throughout the project lifecycle, from design, planning, through construction execution and extending into operations and maintenance. The literature and past research show that there is a lack of tools and resources to assist designers and engineers with addressing construction safety. Despite the implementation of safety practices, most of them applied in the field are primarily text-based checklist. Further improvements can be gained in construction safety through the use of technology. This paper contributes in solving this problem by developing a framework of automatic safety checking to Building Information Models (BIM). The presented framework and case study extends BIM to include automated hazard identification and correction during construction planning and in certain cases, during design. As a result, the developed automated safety checking platform informs construction engineers and managers in knowing, why, where, when, and what safety measures are needed for preventing fallrelated accidents before construction starts.

Empirical approaches to define Model View Definitions (MVD) for exchange specifications exist and are expensive to build, test, and maintain. This paper presents the novel idea of developing modular and reusable MVDs from IFC Product Modeling Concepts. The need and application for defining model views in a more logical manner is illustrated with examples from current MVD development. A particular focus of this paper is on precast entities in a building system. Presented is a set of criteria to define fundamental semantic concepts articulated within the Industry Foundation Classes (IFC) to improve the robustness of model exchanges.

The data schema of the Industry Foundation Classes (IFC) schema is generic, designed to support the full range of model exchanges needed in the construction industry. While it has a rich ontology of building part entities and relationships, it does not impose any fixed structure on the ways in which entities should be aggregated or represented, with the exception of the project-building-space containment hierarchy. Thus the IFC model, in and of it-self, is inadequate for ensuring interoperability between software applications. For any given set of use cases for a sub-domain of building construction, a set of model view definitions (MVD) is required to specify exactly what information should be exchanged, and in what form and structure the IFC entities are to be used. Compiling a model view definition, presently based on human intuition of industry knowledge, is challenging. What should be the level of detail to be included in case of geometry, classification and aggregations, and parts and relationships etc.? IFC, which is based on STEP and is represented in EXPRESS language, is known to be good in expressivity but lacks in a formal definition of its concepts. Thus in preparing a set of MVDs, information modellers must determine the appropriate level of meaning to require and they must define the typing structure to be used. If the structure is too simple, the exchanges will only have value for importing software able to apply some level of expert knowledge to interpret the information. If it is too rigid, then it will only be appropriate for a narrow range of use case exchanges and a large number of model view definitions will be required, which also implies that software companies will need to prepare multiple export and import routines. This paper discusses the spectrum of possibilities, using examples from concrete construction in general and precast concrete construction in particular.

The Industry Foundation Classes (IFC) create a neutral environment for interoperability by providing a comprehensive specification of the information throughout the AEC/FM project lifecycle, globally, across disciplines and software applications. However, the IFC schema does not capture the ways in which information is created and shared by practitioners; and the lack of specific definition of users' exchange requirements has made it difficult to implement IFC compliant software solutions. The Information Delivery Manual (IDM) responds to these problems by proposing a methodology that captures business processes in AEC/FM projects and developing specifications of detailed user information exchange requirements. A progressive methodology to develop IDMs is presented in this paper. In this method Exchange Models (EMs) are utilized to provide the content of information exchange between users and/or software applications. Exchange Objects (EOs) are introduced as the fundamental elements in an exchange model, which contain the description of information units in non-technical terms that need to be exchanged in an exchange model. EOs are then developed further to provide the detailed technical attributes of the information categories in exchange models. EOs may be used in several exchange requirement definitions. Therefore, they are defined to be reusable within many exchange models. The level of detail and precision, and the representation type of EOs may vary in exchange models in different stages of the project lifecycle and are determined based on the business rules and with participation of industry experts. The details of the information capture to develop the IDM such that the IFC schema can be applied in national, local, or even project contexts are further illustrated. The paper finally presents the application of the introduced approach, using examples of architectural and structural precast concrete as a test base.

Emerging wireless remote sensing technologies offer significant potential to improve the management of construction resources in lay down yards by tracking the location of personnel, yard vehicles, and materials in real-time. This paper presents a theoretical concept for real-time lay down yard asset management. A field trial using Ultra Wideband (UWB) positioning technology is presented to track spatial and temporal location of resources (workforce, equipment, material) that are present in lay down yards. The benefits and limitations of the technological approach which were applied in this research will be explained in detail and recommendations for its use in field tracking applications in large and open construction environments will be given. A particular focus of the paper is on the comparison of the accuracy of real-time location data from a commercial UWB system with ground truth measurements from a robotic total station.

Nanotechnology research and product development is actively conducted in many industries, for example, in manufacturing, electronics, and health sectors. As many research studies show, the construction industry follows these trends, but does not take a leadership role in most of the current efforts in Nanotechnology. With proper knowledge about the products and techniques offered by nanotechnology, the construction industry has the potential to improve the efficiency of some of its own processes and offer better products to customers and clients. This research tries to understand nanotechnology in the context of construction and explores the current scenario of nanotechnology in the construction industry. In order to identify the potential benefits and existing barriers, an extensive literature review and survey were conducted, which is supplemented by several personal interviews. This paper also performed an impact analysis to evaluate existing and developing nanotechnology products and their applications in construction. Recommendations and guidelines for a path forward for nanotechnology in construction industry are provided.

Management of construction resources, such as workforce, equipment, and material, is critical to project success. Completion of work tasks on schedule, safely and within the proposed budget requires a coordinated planning effort that allocates adequate availability of project resources. Because this task alone can become a challenging and time-consuming effort for many field personnel, several existing technologies are reviewed for their benefits and limitations in keeping oversight of resource location and status at job sites. To ensure the optimal solution using the right resources, such knowledge becomes even more meaningful when optimizing construction logistics and safety at the same time. This paper introduces an emerging sensing technology called ultrawideband (UWB) that is capable of determining three-dimensional resource location information in object-cluttered construction environments in real time (up to 60 Hz). The use of UWB is explained in a variety of construction applications including simplifying on-site management, improving resource productivity and usage, reducing schedule and cost, and increasing work zone safety. UWB technology and its advantages and limitations are compared with the state of the art in positioning technologies. Results of preliminary UWB experiments in the laboratory and construction environment are presented using developed data processing algorithms and a method to determine the accuracy of UWB position measurements. The paper discusses the feasibility of using ultrawideband as a data collection and decision support tool for robotic (automated) infrastructure construction applications in the areas of real-time three-dimensional material flow and workforce location tracking, optimized machine positioning and automated navigation, and proactive work zone safety.

This paper describes a new framework and its algorithms of using frequent positioning data to entitle rapid learning among construction site managers and workers for safety. If collected accurately and in real-time, the location, speed, and trajectory of construction resources (e.g., workers, equipment, materials) can lead to important information regarding travel patterns. This information can then be shared among project stakeholders to improve work practices, e.g. the preconditions for safe construction operations. Additionally, the overall analyses of travel patterns on construction sites can help in the process of allocating resources more effectively to overall increase productivity and safety. Tracking and analyzing the paths of construction resources has multiple applications in construction and is not limited to important tasks such as monitoring the idle time of machines to reduce inefficiencies, tracking the path and location of materials to reduce search times, or signalling hazardous zones to workers to improve work zone safety.

A model for excitation characteristic of a magnetic circuit has been assumed. An algorithm for finding the values of the parameters from known data which results in least square error is given. The power of the method is such that there is no constraint on the initial values chosen.