3D Object Classification Using Geometric Features and Pairwise Relationships

Object classification is a key differentiator of building information modeling (BIM) from three-dimensional (3D) computer-aided design (CAD). Incorrect object classification impedes the full exploitation of BIM models. Models prepared using domain-specific software cannot ensure correct object classification when transferred to other domains, and research on reconstruction of BIM models using spatial survey has not proved a full capability to classify objects. This research proposed an integrated approach to object classification that applied domain experts’ knowledge of shape features and pairwise relationships of 3D objects to effectively classify objects using a tailored matching algorithm. Among its contributions: the algorithms implemented for shape and spatial feature identification could process various complex 3D geometry; the method devised for compilation of the knowledge base considered both rigor and confidence of the inference; the algorithm for matching provides mathematical measurement of the object classification results. The integrated approach has been applied to classify 3D bridge objects in two models: a model prepared using incorrect object types and a model manually reconstructed using point cloud data. All these objects were successfully classified

Condition diagnostics of steel water tanks using correlated visual patterns

Insufficient, unreliable, and delayed condition assessment of steel water tanks is causing poor maintenance planning, wastes of maintenance resources, and unexpected structure failures. Visual inspection of water tanks heavily relies on engineers’ experiences for achieving comprehensive and reliable condition assessments. Recent studies reveal the potential of using imaging technology for improving the efficiency and comprehensiveness of capturing visual conditions of large civil infrastructures, but manual interpretation of imagery data still impedes engineers from reliable awareness of structural conditions. On the other hand, some studies show that deteriorations of structures result in correlated visual patterns that can assist engineers in structural diagnosis. The objective of the research presented in this paper is to examine correlated deformation patterns of a steel tank based on analyzing 3D laser-scanned point clouds collected in the field. Specifically, the authors aim at identifying correlated shape change patterns of a water tank through various 3D data analysis algorithms, and synthesize these 3D data patterns as knowledge for guiding data-driven condition assessment of the water tank. The authors examined two 3D data analysis approaches for revealing the deformation patterns of the studied tank. The first approach calculates the deviations of the 3D data points from as-designed shapes of the water tank for identifying structural deformation and defects. The second approach visualized anomalous variations in local shape descriptors, such as curvature, for identifying defects of structures. Correlations between the patterns could then reveal systematic changes of the tank for helping engineers conduct more reliable condition assessments.Non UBCUnreviewedFacultyOthe

Status quo and challenges and future development of fire emergency evacuation research and application in built environment

Fire emergency evacuation study has been conducted for decades. In recent two decades, the fire emergency evacuation studies have been incorporating new technologies due to the high demands on efficient and safe evacuation for occupants who have various needs. The proposed fire emergency evacuation system from academic research and solutions from industry practices adopt different technologies to serve various evacuees. Therefore, this study conducts literature review to understand the status quo of current fire emergency evacuation research and practice. It shows that fire emergency evacuation studies mainly focus on the facility operation stage instead of design and construction stages. The facilities include residential buildings, education buildings, subways, shopping centers, etc. Three critical factors affect efficient and safe fire emergency evacuation in a built environment – facility physical features, fire characteristics, and human behavior. This study categories these new technologies, which are incorporated into the fire emergency evacuation research and practices within the recent two decades, into four groups: (1) Facility geometrical analysis, which includes the technologies such as BIM, GIS, VR and the combination of BIM/GIS/VR (2) Fire and smoke simulation, e.g. FDS and Pyrosim. The simulation output such as fire and smoke dynamics is incorporated into intelligent fire evacuation system (3) Crowd evacuation simulation software, e.g. Pathfinder, Massmotion; the output of simulation is used to develop personalized evacuation system (4) Indoor positioning system and mobile device/IoT technology to track and evacuate occupants intelligently. This study presents these new technologies used in thefire emergency evacuation systems and indicates that the development of an intelligent and personalized emergency evacuation system, which may track the evacuees in real time, is the future research trend.This article is published as Jiang, Aiyin, Yunjeong Mo, and Vamsi Sai Kalasapudi. "Status quo and challenges and future development of fire emergency evacuation research and application in built environment." Journal of Information Technology in Construction 27 (2022). doi: https://dx.doi.org/10.36680/j.itcon.2022.038. COPYRIGHT: © 2022 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/)

Scoping Review of Racial, Ethnic, and Sex Disparities in the Diagnosis and Management of Hemorrhagic Stroke

BACKGROUND AND OBJECTIVES: In the United States, Black, Hispanic, and Asian Americans suffer from excessively high incidence rates of hemorrhagic stroke compared to White Americans. Women suffer from higher rates of subarachnoid hemorrhage than men. Previous reviews detailing racial, ethnic, and sex disparities in stroke have focused on ischemic stroke. We performed a scoping review of disparities in the diagnosis and management of hemorrhagic stroke in the United States to identify areas of disparities, research gaps, and evidence to inform efforts aimed at health equity. METHODS: We included studies published after 2010 that assessed racial and ethnic or sex disparities in the diagnosis or management of patients 18 years or older in the United States with a primary diagnosis of spontaneous intracerebral hemorrhage or aneurysmal subarachnoid hemorrhage. We did not include studies assessing disparities in incidence, risks, or mortality and functional outcomes of hemorrhagic stroke. RESULTS: After reviewing 6161 abstracts and 441 full texts, 59 studies met our inclusion criteria. Four themes emerged. First, few data address disparities in acute hemorrhagic stroke. Second, racial and ethnic disparities in blood pressure control following intracerebral hemorrhage exist and likely contribute to disparities in recurrence rates. Third, racial and ethnic differences in end-of-life-care exist, but further work is required to understand whether these differences represent true disparities in care. Fourth, very few studies specifically address sex disparities in hemorrhagic stroke care. DISCUSSION: Further efforts are necessary to delineate and correct racial, ethnic, and sex disparities in the diagnosis and management of hemorrhagic stroke