Using a 2D profilometer to determine volume and thickness of stockpiles and ground layers of roads

Abstract Construction materials and related management, handling, and storage provisions account for a large portion of road construction expenses. For that reason, improved material flow monitoring techniques can achieve significant cost and time savings, as well as better quality control. This study assessed the performance of a solid-state pulsed time-of-flight laser lidar profilometer in measuring the volume of soil stockpiles and road layer thicknesses. The 3D (X, Y, Z, and intensity) image calculation was based on the analysis of multiple combined point clouds measured with an excavator-integrated profilometer. Error analysis confirmed the accuracy of road layer thickness estimation within one centimeter and an error level of approximately 3% when measuring soil stockpile volumes. In conjunction with a theoretical model of the superstructure, this 3D measurement technique can help contractors and supervisors ensure road quality

Trench visualisation from a semiautonomous excavator with a base grid map using a TOF 2D profilometer

Abstract Real-time, three-dimensional (3D) visualisation technology can be used at construction sites to improve the quality of work. A 3D view of the landscape under work can be compared to a target 3D model of the landscape to conveniently show needed excavation tasks to a human excavator operator or to show the progress of an autonomous excavator. The purpose of this study was to demonstrate surface visualisation from measurements taken with a pulsed time-of-flight (TOF) 2D profilometer on-board a semiautonomous excavator. The semiautomatic excavator was implemented by recording the feedback script parameters from the work performed on the excavator by a human driver. 3D visualisation maps based on the triangle mesh technique were generated from the 3D point cloud using measurements of the trenches dug by a human and an autonomous excavator. The accuracy of the 3D maps was evaluated by comparing them to a high-resolution commercial 3D scanner. An analysis of the results shows that the 2D profilometer attached to the excavator can achieve almost the same 3D results as a high-quality on-site static commercial 3D scanner, whilst more easily providing an unobstructed view of the trench during operation (a 3D scanner placed next to a deep trench might not have a full view of the trench). The main technical advantages of our 2D profilometer are its compact size, measurement speed, lack of moving parts, robustness, low-cost technology that enables visualisations from a unique viewpoint on the boom of the excavator, and readiness for real-time control of the excavator’s system. This research is expected to encourage the efficiency of the digging process in the future, as well as to provide a remarkable view of trench work using an excavator as a moving platform to facilitate data visualisation

Behavioural and socioeconomic factors associated with the simultaneous occurrence of periodontal disease and dental caries

Abstract Objective: The aim was to evaluate the association of behavioural and socioeconomic factors with the occurrence of periodontal disease and dental caries, paying special attention to the simultaneous occurrence of these diseases. Materials and methods: The study population consisted of 5255 dentate persons aged ≥30 years from a nationally representative survey. Caries and probing pocket depth were recorded by tooth and calculated in relation to the number of existing teeth. The groups were: non-affected (A), the two most affected quintiles for periodontal disease with little or no dental caries (B), the two most affected quintiles for dental caries with little or no periodontal disease (C) and the two most affected quintiles for both periodontal disease and dental caries (D). Presence of dental plaque was determined, and behavioural and socioeconomic factors were established. Results: Dental plaque, smoking, lack of regular dental check-ups, older age and a basic level of education were strongly associated with the simultaneous occurrence of periodontal disease and dental caries. Conclusions: There are many behavioural and socioeconomic factors that associate with the occurrence of both periodontal disease and dental caries. These factors also increase the risk of individuals having these diseases simultaneously

4D modeling of soil surface during excavation using a solid-state profilometer mounted on the arm of an excavator

Abstract The aim of this research is to create a 4D point cloud map from a trench through a solid-state 2D profilometer. The profilometer is integrated with an 8.5-ton medium-size excavator’s machine control system with pose calculation. Accordingly, the point cloud was transformed to a work coordinate system. We used a recently developed pulsed time-of-flight laser light detection and ranging profilometer, which makes possible simultaneous depth measurements to 256 directions in an angle range of ±20° and measurement range from 1 m to 8 m with a frame rate of 25 frames per second under sunlight conditions (≈50 Klux). The analysis is based on a 4D map, which consists of 3D data (XYZ) and intensity information. The XYZ coordinates give the position of an object, and the intensity data can be used to roughly identify materials and recognise surface markings, such as texts. An analysis of the results shows that the detection accuracy of the profilometer is better than ±10 mm. The main advantages of our method are accuracy, high update rate, compact size, real-time measurement and a construction without moving parts. Our technique has a great potential in construction applications, where accurate measurements of a surface shape are needed

Climate change in the Baltic Sea:2021 fact sheet

Abstract Climate change effects on the Baltic Sea environment are manifold. It is for example expected that water temperature and sea level will rise, and sea ice cover will decrease. This will affect ecosystems and biota; for example, range shifts are expected for a number of marine species, benthic productivity will decrease, and breeding success of ringed seals will be reduced. The impacts will hence affect the overall ecosystem function and also extend to human uses of the sea; trawling will follow the fish towards southern areas, aquaculture will likely face a shift towards species diversification, and the value of most ecosystem services is expected to change — to name a few. This Climate Change Fact Sheet provides the latest scientific knowledge on how climate change is currently affecting the Baltic Sea and how it is expected to develop in the foreseeable future. It is aimed at guiding policy makers to take climate change into account, but also to the general public. Updated Baltic Sea Climate Change Fact Sheets are expected to be published approximately every seven years