A Markov Chain Random Field Cosimulation-Based Approach for Land Cover Post-classification and Urban Growth Detection

The recently proposed Markov chain random field (MCRF) approach has great potential to significantly improve land cover classification accuracy when used as a post-classification method by taking advantage of expert-interpreted data and pre-classified image data. This doctoral dissertation explores the effectiveness of the MCRF cosimulation (coMCRF) model in land cover post-classification and further improves it for land cover post-classification and urban growth detection. The intellectual merits of this research include the following aspects: First, by examining the coMCRF method in different conditions, this study provides land cover classification researchers with a solid reference regarding the performance of the coMCRF method for land cover post-classification. Second, this study provides a creative idea to reduce the smoothing effect in land cover post-classification by incorporating spectral similarity into the coMCRF method, which should be also applicable to other geostatistical models. Third, developing an integrated framework by integrating multisource data, spatial statistical models, and morphological operator reasoning for large area urban vertical and horizontal growth detection from medium resolution remotely sensed images enables us to detect and study the footprint of vertical and horizontal urbanization so that we can understand global urbanization from a new angle. Such a new technology can be transformative to urban growth study. The broader impacts of this research are concentrated on several points: The first point is that the coMCRF method and the integrated approach will be turned into open access user-friendly software with a graphical user interface (GUI) and an ArcGIS tool. Researchers and other users will be able to use them to produce high-quality land cover maps or improve the quality of existing land cover maps. The second point is that these research results will lead to a better insight of urban growth in terms of horizontal and vertical dimensions, as well as the spatial and temporal relationships between urban horizontal and vertical growth and changes in socioeconomic variables. The third point is that all products will be archived and shared on the Internet

Study on the control algorithm for lower limb exoskeleton based on ADAMS/Simulink co-simulation

A sliding mode control algorithm based on proportional switching function was developed to make the lower limb exoskeleton more fit the human walking gait trajectory. It could improve the comfort of the exoskeleton wearer and enhance the reliability of the system. The three-dimensional mechanical model of the exoskeleton built using software SolidWorks was introduced to ADAMS and then the model parameters were set. The model was combined with the software MATLAB so that the human-machine cooperation control algorithm for lower limb exoskeleton based on ADAMS and Simulink co-simulation was developed. The simulation result was compared with the desired trajectory and the trajectory under PID control. The research discovered that the ability of trajectory tracking under the sliding mode control was much better than that under PID control. It provided an important theoretical basis for the research on human-machine cooperation control algorithm

Research on dynamic characteristics of spiral basilar membrane after replacing artificial auditory ossicle based on the reconstructed human ear model

In this paper, PATRAN software was used to establish a complete 3D finite element model of human ears, and it was then combined with NASTRAN software to analyze frequency responses. This paper conducted a detailed analysis on the dynamic parameters including umbo and stapes displacements of normal human ears under sound pressures 90 dB and 105 dB. The numerically computational results were compared with experimental data. When the analyzed frequency was less than 1000 Hz, the computational result of numerical simulation was well consistent with the upper limit. When the analyzed frequency was more than 1000 Hz, the computational result of numerical simulation was well consistent with the lower limit. Therefore, the numerically computational model was reliable. In addition, based on the verified model, this paper studied vibration characteristics of spiral basilar membrane after replacing artificial auditory ossicle based on the whole hearing system, and found that vibration characteristics of spiral basilar membrane had an obvious change at low and high frequencies after replacing artificial auditory ossicle TORP. Using finite element method to analyze vibration characteristics of spiral basilar membrane can well predict the hearing recovery effect after replacing artificial auditory ossicle. Compared with normal ears, the vibration level of spiral basilar membrane after replacing artificial auditory ossicle has slowed down in 100 Hz-600 Hz, 2000 Hz-4000 Hz and 7000 Hz-10000 Hz, and has been strengthened in 600 Hz-2000 Hz and 4000 Hz-7000 Hz, which provided some help for the hearing recovery at the high-frequency band

Recent Progress on Digital Twins in Intelligent Connected Vehicles: A Review

As an important enabling technology in the era of Industry 4.0, the intelligent connected vehicle (ICV) facilitates robust data interaction with the outside through sensors and communication technologies, ultimately making scientific decisions based on environmental perception information. However, due to constraints such as limited communication bandwidth and computing resources, the influx of data simultaneously impedes the sustainable optimisation of the vehicle decision making process at the same time. As a novel technology that effectively connects physical and virtual space, the special ability of the digital twin (DT) is to identify characteristics within a certain lifecycle, thereby garnering widespread attention across various industries. The purpose of this paper is to review the contribution of digital twins in the application field of intelligent vehicles and explore its potential for development. First, the key technologies of ICV provide a basis for the embedding of digital twins. Then, by analysing the development process and technical composition of digital twins, readers can better understand the concept of digital twins. Finally, the application of DTs in ICV is reviewed from the perspective of vehicles, traffic facilities, and occupants. Future challenges and opportunities in this direction are described at the same time

Remote Collaborative BIM-based Mixed Reality Approach for Supporting Facilities Management Field Tasks

Facilities Management (FM) day-to-day tasks require suitable methods to facilitate work orders and improve performance by better collaboration between the office and the field. Building Information Modeling (BIM) provides opportunities to support collaboration and to improve the efficiency of Computerized Maintenance Management Systems (CMMSs) by sharing building information between different applications/users throughout the lifecycle of the facility. However, manual retrieval of building element information can be challenging and time consuming for field workers during FM operations. Mixed Reality (MR) is a visualization technique that can be used to improve the visual perception of the facility by superimposing 3D virtual objects and textual information on top of the view of real-world building objects. The objectives of this research are: (1) investigating an automated method to capture and record task-related data (e.g., defects) with respect to a georeferenced BIM model and share them directly with the remote office based on the field worker point of view in mobile situations; (2) investigating the potential of using MR, BIM, and sensory data for FM tasks to provide improved visualization and perception that satisfy the needs of the facility manager at the office and the field workers with less visual and mental disturbance; and (3) developing an effective method for interactive visual collaboration to improve FM field tasks. This research discusses the development of a collaborative BIM-based MR approach to support facilities field tasks. The research framework integrates multisource facilities information, BIM models, and hybrid tracking in an MR-based setting to retrieve information based on time (e.g., inspection schedule) and the location of the field worker, visualize inspection and maintenance operations, and support remote collaboration and visual communication between the field worker and the manager at the office. The field worker uses an Augmented Reality (AR) application installed on his/her tablet. The manager at the office uses an Immersive Augmented Virtuality (IAV) application installed on a desktop computer. Based on the field worker location, as well as the inspection or maintenance schedule, the field worker is assigned work orders and instructions from the office. Other sensory data (e.g., infrared thermography) can provide additional layers of information by augmenting the actual view of the field worker and supporting him/her in making effective decisions about existing and potential problems while communicating with the office in an Interactive Virtual Collaboration (IVC) mode. The contributions of this research are (1) developing a MR framework for facilities management which has a field AR module and an office IAV module. These modules can be used independently or combined using remote IVC, (2) developing visualization methods for MR including the virtual hatch and multilayer views to enhance visual depth and context perception, (3) developing methods for AR and IAV modeling including BIM-based data integration and customization suitable for each MR method, and (4) enhancing indoor tracking for AR FM systems by developing a hybrid tracking method. To investigate the applicability of the research method, a prototype system called Collaborative BIM-based Markerless Mixed Reality Facility Management System (CBIM3R-FMS) is developed and tested in a case study. The usability testing and validation show that the proposed methods have high potential to improve FM field tasks

Biomechanical assessment of brain dynamic responses due to blast-induced wave propagation

Traumatic brain injuries (TBI) due to blast-induced wave propagation are not well studied owing to limited published literatures on the subject. This study demonstrates the utilization of a head-helmet model and investigates the effect of using a faceshield with different configurations of laminate composites of polycarbonate and aerogel materials. The model validation is performed against studies published in the literature. The processes of blast wave propagation in the air and blast interaction with the head are modeled by a Coupled Eulerian-Lagrangian (CEL) multi-material finite element method (FEM) formulation, together with a fluid-structure dynamic interaction algorithm. The effectiveness of the different faceshield configurations when exposed to a frontal blast wave with one atmosphere (atm) peak overpressure is evaluated. Results show that the helmet with faceshield can delay the transmission of blast waves to the face and lower the skull stresses and intracranial pressures (ICP) at the frontal and parietal lobes in the first 1.7 ms. Faceshields with a combination of polycarbonate and aerogel layers perform better than the fully polycarbonate ones. It is also revealed that the single 0.6 mm thick aerogel layer in the 3-layer configuration and two layers of 0.6 mm thick aerogel in the 5-layer configuration are the most effective. The paper provides insights into the interaction mechanics between the biological head model and the blast wave