Derivation of Minimum Required Model for Augmented Reality Based Stepwise Construction Assembly Control

The global 3D imaging market is expected to reach $26 billion by 2024 with an annual growth of 23.7% (3D Imaging Market Global Scenario, Market Size, Trend and Forecast, 2015 – 2024. 2018). Various industries are extensively involved in this emergence including the healthcare and entertainment industries, the architecture and construction industries. Additionally, global steel pipe demand is predicted to rise by 3.5% annually until 2019. The combination of the two growths raises the potential of 3D imaging technologies in the construction industry, especially in the piping industry. Thanks to the virtuous cycle between growth and innovation, development and applications of new 3D vision technologies and techniques has become a need for the construction industry facing harsh competition globally. Similarly, prefabrication has been boosted in the construction industry, reducing costs and optimizing time of fabrication. It also copes with the increased demand of small tolerances which sets the industry and its labor under high pressure. Thus, quality control is reinforced in fabrication facilities, and innovations can be deployed in that domain to preclude assemblies from any incompliance. Employing 3D scanners is one effective way to do so, and the recent emergence of handheld laser scanners has created the opportunity to develop efficient new methods to be used for quality control. This thesis proposes a novel methodology for deriving 3D models for assemblies to be fabricated, breaking down a barrier that previously inhibited the utilization of small-range handheld 3D laser scanners. The process is applicable for industrial assembly lines, which present a stepwise fabrication process such as that for pipe spools. The methodology also aims at streamlining the fabrication flow for workers, and can provide as-built information to the management team. To do so, piping assemblies are thoroughly analyzed and decomposed at each and every step around the weld of interest: one part is being added with respect to the other. From this decomposition of a pipe spool, the challenge of the methodology is to shrink down to the minimum the amount of components that have to be investigated to control the geometry of the assembly. The key concept of solid of revolution is introduced and permits the derivation of the Minimum Required Model (MRM). Examples are generated and experiments are conducted to test the effectiveness of the presented method. This is mainly realized by implementing the algorithm within an in-house software, developed along with another PhD student, a master’s student and a co-op student. The software enables the comparison of the acquired scene to the 3D model by segmenting piping components individually, and generating the as-modelled point cloud. Consequently, piping components can directly be segmented within the software, and the MRM can be derived and compared to the expected model. In order to evaluate the efficiency of the method, three criteria are proposed: (1) the level of spatial complexity between the derived Minimum Required Model and the initial 3D model, (2) the capacity to use a handheld scanner with or without the MRM, and finally (3) the accuracy of the comparison between the acquired scan and the 3D model

Telomere shortening occurs in Asian Indian Type 2 diabetic patients

Aim: Telomere shortening has been reported in several diseases including atherosclerosis and Type 1 diabetes. Asian Indians have an increased predilection for Type 2 diabetes and premature coronary artery disease. The aim of this study was to determine whether telomeric shortening occurs in Asian Indian Type 2 diabetic patients. Methods: Using Southern‐blot analysis we determined mean terminal restriction fragment (TRF) length, a measure of average telomere size, in leucocyte DNA. Type 2 diabetic patients without any diabetes‐related complications (n = 40) and age‐ and sex‐matched control non‐diabetic subjects (n = 40) were selected from the Chennai Urban Rural Epidemiology Study (CURES). Plasma level of malondialdehyde (MDA), a marker of lipid peroxidation, was measured by TBARS (thiobarbituric acid reactive substances) using a fluorescence method. Results: Mean (± SE) TRF lengths of the Type 2 diabetic patients (6.01 ± 0.2 kb) were significantly shorter than those of the control subjects (9.11 ± 0.6 kb) (P = 0.0001). Among the biochemical parameters, only levels of TBARS showed a negative correlation with shortened telomeres in the diabetic subjects (r = −0.36; P = 0.02). However, telomere lengths were negatively correlated with insulin resistance (HOMA‐IR) (r = −0.4; P = 0.01) and age (r = −0.3; P = 0.058) and positively correlated with HDL levels (r = 0.4; P = 0.01) in the control subjects. Multiple linear regression (MLR) analysis revealed diabetes to be significantly (P < 0.0001) associated with shortening of TRF lengths. Conclusions: Telomere shortening occurs in Asian Indian Type 2 diabetic patients

Measuring vertebrate telomeres: applications and limitations

Telomeres are short tandem repeated sequences of DNA found at the ends of eukaryotic chromosomes that function in stabilizing chromosomal end integrity. In vivo studies of somatic tissue of mammals and birds have shown a correlation between telomere length and organismal age within species, and correlations between telomere shortening rate and lifespan among species. This result presents the tantalizing possibility that telomere length could be used to provide much needed information on age, ageing and survival in natural populations where longitudinal studies are lacking. Here we review methods available for measuring telomere length and discuss the potential uses and limitations of telomeres as age and ageing estimators in the fields of vertebrate ecology, evolution and conservation