State of research in automatic as-built modelling

This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.aei.2015.01.001Building Information Models (BIMs) are becoming the official standard in the construction industry for encoding, reusing, and exchanging information about structural assets. Automatically generating such representations for existing assets stirs up the interest of various industrial, academic, and governmental parties, as it is expected to have a high economic impact. The purpose of this paper is to provide a general overview of the as-built modelling process, with focus on the geometric modelling side. Relevant works from the Computer Vision, Geometry Processing, and Civil Engineering communities are presented and compared in terms of their potential to lead to automatic as-built modelling.We acknowledge the support of EPSRC Grant NMZJ/114,DARPA UPSIDE Grant A13–0895-S002, NSF CAREER Grant N. 1054127, European Grant Agreements No. 247586 and 334241. We would also like to thank NSERC Canada, Aecon, and SNC-Lavalin for financially supporting some parts of this research

AN INTEGRATED QUALITY MANAGEMENT SYSTEM FOR PIPING FABRICATION USING 3D LASER SCANNING AND PHOTOGRAMMETRY

ABSTRACT Addressing deficiencies and defects that occur during construction projects is costly and time consuming. The manual quality assurance programs currently used in the industry have certain limitations, including human error and lack of consistency. Hence, there is a need for integrated electronic models that employ new technologies and methods. This research introduces an integrated construction quality control system that has the potential to improve quality management processes in the construction field for piping construction, which is a complex process often requiring rework. The proposed integrated system relies on data collected from construction sites using photogrammetry and laser scanning, which is then used to compare actual work performed to that designed. The proposed system aims to improve the promptness and accuracy of quality assurance processes, in particular dimension measurements, by avoiding human error and integrating defect detection and quality management. The use of this system has highlighted some of the limitations during data fusion and acquisition process, which are highlighted in this paper. These aspects must be considered to increase the reliability of the acquired information

Automated Post-Production Quality Control for Prefabricated Pipe-Spools

Prefabrications has been gaining popularity in the construction industry over the past decade as it provides a safer and more sustainable operation as well as higher quality and cheaper construction components, due to its controlled conditions during fabrication, in-house quality assurance systems, and lower amount of waste. Despite the advantages of prefabrication methods, the current quality management processes, particularly in piping fabrication, are labour-intensive, time-consuming, expensive and rather inaccurate. This paper investigates automated solutions for improving the quality management system associated with the prefabrication of piping assemblies in the industrial sector of the construction industry. The scope of this research is the quality management processes conducted at the post-production stage of the fabrication process. The findings of this paper indicated that 3D laser scanning and photogrammetry techniques can both be successfully used in quality assurance systems for postfabrication of pipe-spools. It was concluded that these methods exceeded the accuracy requirements of the current systems, while substantially improving the efficiencies of the quality assurance processes for prefabrication operations

State of research in automatic as-built modelling

Building Information Models (BIMs) are becoming the official standard in the construction industry for encoding, reusing, and exchanging information about structural assets. Automatically generating such representations for existing assets stirs up the interest of various industrial, academic, and governmental parties, as it is expected to have a high economic impact. The purpose of this paper is to provide a general overview of the as-built modelling process, with focus on the geometric modelling side. Relevant works from the Computer Vision, Geometry Processing, and Civil Engineering communities are presented and compared in terms of their potential to lead to automatic as-built modelling

Evaluation of Proliferation and Development of Mesenchymal Stem Cell on Nanoporous PLLA Membrane Scaffold

Introduction: Scaffold has therole of the extracellular matrix in regulating cell survival and it is an important component in tissue engineering techniques. One of the scaffolds that was used in this field, was PLLA (poly L-lactic acid) which was usually prepared by electro spinning method. The purpose of this study was to evaluate the biocompatibility of nano-porous PLLA membrane on proliferation of mesenchymal stem cells. Method: PLLA nano-porous membranes were prepared by phase separation process. To identify the type of polymer used in its construction, FTIR analysis was performed. Then, dental pulp mesenchymal cells were cultured on a nano-membrane and nano-membrane-free environments ,simultaneously. After attachment of the cells on the bottom of the plate, the biocompatibility and cell proliferation was assessed in a two-week period using MTT test on the fifth, seventh and ninth days of cell culture. The ultra-structure and adhesion of mesenchymal cells on the membrane were evaluated using scaning electron microscopy(SEM). Result: Nano Membrane potential had good biocompatibility and the cells had penetrated into the surface membranes properly. The viability of mesenchymal cells cultured on nano-membranes were significantly higher than the control group. The highest effect of nano-membrane on cell viability was seen on the ninth day and the lowest effect was seen on the fifth day. Conclusion: Due to the biodegradable and non-toxic properties of nano PLLA membrane, it could increase the adhesion and proliferation of mesenchymal stem cells and these effects will exacerbated over time