Towards Automated Defect Detection: Object-oriented Modeling of Construction Specifications

This paper describes an ongoing research on the representation and reasoning about construction specifications, which is part of a bigger research project that aims at developing a formalism for automating the identification of deviations and defects on construction sites. We specifically describe the requirements on product and process models and an approach for representing and reasoning about construction specifications to enable automated detection and assessment of construction deviations and defects. This research builds on the previous research on modeling design specifications and extends and elaborates concept of contexts developed in that domain. The paper provides an overview of how the construction specifications are being modele d in this research and points out future steps that need to be accomplished to develop the envisioned automated deviation and defect detection system

Nighttime Construction: Evaluation Of Lighting Glare For Highway Construction In Illinois

This report presents the findings of a research project that studied the veiling luminance ratio (glare) experienced by driveby motorists in lanes adjacent to nighttime work zones. The objectives of the project are to (1) provide an in-depth comprehensive review of the latest literature on the causes of glare and the existing practices that can be used to quantify and control glare during nighttime highway construction; (2) identify practical factors that affect the measurement of veiling luminance ratio (glare) in and around nighttime work zones; (3) analyze and compare the levels of glare and lighting performance generated by typical lighting arrangements in nighttime highway construction; (4) evaluate the impact of lighting parameters on glare and provide practical recommendations to reduce and control lighting glare in and around nighttime work zones; (5) develop a practical model to measure and quantify levels of glare experienced by drive-by motorists; and (6) investigate and analyze existing studies and recommendations on the maximum allowable levels of veiling luminance ratio (glare) that can be tolerated by nighttime drivers. The research work was performed in four main tasks: literature review, site visits, field studies, and model development. In the first task, a comprehensive literature review was conducted to study the latest research on quantifying and controlling lighting glare. In the second task, several nighttime highway construction sites were visited to identify practical factors that affect the measurement of glare. In the third task, field experiments were conducted to measure the levels of glare generated by commonly used construction lighting equipment and to evaluate the impact of lighting parameters on glare levels. In the fourth task, practical models were developed to enable resident engineers and contractors to measure and control the levels of glare experienced by drive-by motorists in lanes adjacent to nighttime work zones.Illinois Center for Transportationpublished or submitted for publicationis peer reviewe

ASSESSMENT OF VISUALIZATION SOFTWARE FOR SUPPORT OF CONSTRUCTION SITE INSPECTION TASKS USING DATA COLLECTED FROM REALITY CAPTURE TECHNOLOGIES ABSTRACT

Emerging reality capture technologies, such as LADAR and embedded sensing, have potential to increase the efficiency of inspectors by generating detailed data about as-built conditions that can be analyzed in real time and at a later time at an office. The data collected using these systems provide an opportunity to visualize and analyze as-built conditions on construction sites in a more comprehensive way. At the same time, some characteristics of the data collected, such as its size and level of detail, provide unique visualization challenges. Currently available software systems deliver some functionalities to support construction inspection tasks by enabling the visualization and manipulation of the data captured using these reality capture technologies. In this paper, we provide an assessment of some functionalities provided by a set of selected visualization software tools based on the characteristics of the data collected and to be visualized, and on the construction inspection process that need to be supported

Combining reality capture technologies for construction defect detection: A case study

Abstract: Defects that occur during the construction process account for a large percentage of overall defects in the built environment. Defects waste time and money, and affect the overall performance of the built environment. These problems can be minimized with proactive application of advanced scanners, sensing, and data modelling techniques. Researchers in the departments of Architecture, Robotics, and Civil and Environmental Engineering at Carnegie Mellon University are investigating ways to integrate suites of emerging evaluation technologies to help find, record, manage, and limit the impact of construction defects. As part of this effort, the researchers have conducted a case study on a construction site near Pittsburgh, Pennsylvania. The case study serves to identify challenges in applying specific reality capture technologies and in coordinating suites of these tools on construction sites. The researchers conducted the following activities: creation of a 3D design model, generation of strategies and mechanisms to create 3D as-built models; establishment of specific measurement goals; creation of laser scanner and sensor planning software; targeted use of laser scanners and wireless embedded sensing for capturing as-built data; and analysis of captured data for possible defects. This paper discusses the process of deploying sensing and scanning tools on the case study construction site, and the process of implementing components of an integrated early defect detection system

Electrochemical detection of electrochemically inactive cations by self-assembled monolayers of crown ethers

Self-assembled monolayers (SAMs) of 2-[(6-mercaptohexyl)oxy]methyl-12-crown-4 (1) and 2-[(6-mercaptohexyl)oxy]methyl-15-crown-5 (2) on gold are able to bind cations reversibly from aqueous solutions. This binding of the electrochemically inactive cations is monitored by cyclic voltammetry and impedance spectroscopy using the redox couple Ru(NH3)62+/3+ as "reporter ion". Gold electrodes modified with 1 detect Na+ even in the presence of a 100-fold excess of K+; SAMs of 2 are K+ selective. As a result of the high surface density of crown ethers, sandwich complexes are formed. Reduced surface concentrations of receptors in mixed monolayers of 2 with heptanethiol prevent the sandwich complexation and decreases the K+/Na+ selectivity of the SAM. \u