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关键词： UAV tracking   Gm-APD   Cam-Kalm algorithm   laser tracking system   C-UAS  

摘要： With the wide application of UAVs in modern intelligent warfare as well as in civil fields, the demand for C-UAS technology is increasingly urgent. Traditional detection methods have many limitations in dealing with "low, slow, and small" targets. This paper presents a pure laser automatic tracking system based on Geiger-mode avalanche photodiode (Gm-APD). Combining the target motion state prediction of the Kalman filter and the adaptive target tracking of Camshift, a Cam-Kalm algorithm is proposed to achieve high-precision and stable tracking of moving targets. The proposed system also introduces two-dimensional Gaussian fitting and edge detection algorithms to automatically determine the target's center position and the tracking rectangular box, thereby improving the automation of target tracking. Experimental results show that the system designed in this paper can effectively track UAVs in a 70 m laboratory environment and a 3.07 km to 3.32 km long-distance scene while achieving low center positioning error and MSE. This technology provides a new solution for real-time tracking and ranging of long-distance UAVs, shows the potential of pure laser approaches in long-distancelow, slow, and small target tracking, and provides essential technical support for C-UAS technology.

关键词： fixed prosthodontics   full crown   intraoral optical scanning (IOS)   digital dentistry   CAD-CAM  

摘要： Background/Objectives: The technical development of implant-supported fixed dental prostheses (iFDP) initially concentrated on the computer-aided manufacturing of prosthetic restorations (CAM). Advances in information technologies have shifted the focus for optimizing digital workflows to AI-based processes for design (CAD). This pre-clinical pilot trial investigated the feasibility of the automatic design of three-unit iFDPs using CAD software (Dental Manger 2021, 3Shape;DentalCAD 3.1 Rijeka, exocad GmbH). Methods: Two clinical scenarios based on a full dentition were created virtually. Physical models were produced and digitized using two intraoral scanners applying quadrant or full-arch scans (Trios3, 3Shape, Copenhagen, Denmark;and Primescan AC, Dentsply Sirona, Bensheim, Germany). For each scenario, iFDP designs were generated automatically using two laboratory software systems (Dental Manger 2021, 3Shape;DentalCAD 3.1 Rijeka, exocad GmbH resulting in 80 STL datasets (2 scenarios x 2 scan strategies x 2 IOS systems x 5 scan repetitions x 2 software). The files were analyzed clinically for the contact schemes and pontic area. One of the automated designs for each scenario was manually post-processed and one iFDP design for each scenario was manually created by experienced dental technicians (control). The time required for all the design processes was recorded. Results: The automatic design of iFDPs without manual adjustment did not lead to clinically acceptable restorations. The time required for the automatically generated/manually adjusted iFDPs designs was not significantly different to that for the manually designed restorations. Conclusions: Current laboratory software can not automatically generate three-unit iFDPs with clinically acceptable results in terms of the interproximal and occlusal contacts and the pontic design. The automatic iFDP design process currently requires manual adjustment, which means there is no benefit in terms of the working time c

关键词： dental ceramics   dental esthetics   glazing   heat treatments   surface properties   toothbrushing  

摘要： Purpose: To evaluate the effects of 1 versus 2 glaze firings on the color and mechanical properties of an extrinsically characterized lithium disilicate ceramic after thermal cycling, brushing, or both.Materials and methods: Eighty specimens were divided into 2 groups: 1 glaze firing (GL1) and 2 glaze firings (GL2). Each group was subdivided into 4 groups (n = 10 according to the experimental conditions: thermal-cycling, brushing, thermal-cycling + brushing, and immersion in distilled water (control). Color variation, surface roughness, and Vickers microhardness were analyzed before each designated experiment and after the simulated periods of 2.5, 5, and 10 years. Three-way mixed ANOVA was used for all outcomes, followed by 1-way ANOVA, repeated measures 1-way ANOVA, Bonferroni post hoc test, and t-test to check for statistical differences (alpha = 0.05).Results: Thermal cycling generated greater color changes in the GL1 group at 2.5 and 5 years (p < 0.001;p = 0.013). Brushing generated color changes in GL1 at 5 years (p = 0.003) and in GL2 at 10 years (p = 0.017). Regarding surface roughness, the GL1 group suffered alterations in thermal cycling + brushing at 5 years. In the control group, the GL1 group exhibited higher roughness values than GL2 (p < 0.05). Most of the groups experienced an increase in microhardness at 2.5 years (p < 0.05). In the GL1 group, thermal-cycling increased the microhardness at 5 years (p = 0.006);at 5 and 10 years, the GL1 group had a higher microhardness than the GL2 in thermal-cycling + brushing (p < 0.05).Conclusion: Ceramics with 1 glaze firing showed greater color, roughness, and microhardness changes compared to those submitted to 2 firings.

关键词： Alzheimer's disease   CAD   deep learning   image analysis   magnetic resonance  

摘要： Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative condition in the brain that affects memory, thinking, and behaviour. To overcome this problem, which according to the World Health Organization, is on the rise, creating strategies is essential to identify and predict the disease in its early stages before clinical manifestation. In addition to cognitive and mental tests, neuroimaging is promising in this field, especially in assessing brain matter loss. Therefore, computer-aided diagnosis systems have been imposed as fundamental tools to help imaging technicians as the diagnosis becomes less subjective and time-consuming. Thus, machine learning and deep learning (DL) techniques have come into play. In recent years, articles addressing the topic of Alzheimer's diagnosis through DL models are increasingly popular, with an exponential increase from year to year with increasingly higher accuracy values. However, the disease classification remains a challenging and progressing issue, not only in distinguishing between healthy controls and AD patients but mainly in differentiating intermediate stages such as mild cognitive impairment. Therefore, there is a need to develop more valuable and innovative techniques. This article presents an up-to-date systematic review of deep models to detect AD and its intermediate phase by evaluating magnetic resonance images. The DL models chosen by different authors are analysed, as well as their approaches regarding the used dataset and the data pre-processing and analysis techniques.

关键词： digital orthodontics   esthetics   lingual orthodontics  

摘要： BackgroundThe demand for discreet and low-compliance appliances has driven innovation in orthodontics, particularly with technological advances in artificial intelligence, robotics, and CAD/CAM technology. The evolution of Programmed Non-Sliding Mechanics for precise, automated tooth movement is the latest innovation.AimIn this article, we aimed to demonstrate the application of a novel orthodontic lingual appliance, The Gen 2 InBrace system (InBrace, Irvine, CA in the orthodontic-restorative treatment of an adult patient with anterior tooth-size discrepancies, anterior openbite, and incisor proclination. The Gen 2 InBrace system uses a new generation of CAD/CAM Smartwires, including pre-programmed customized multiloop nickel-titanium lingual archwires, which enable light, continuous, and frictionless tooth movements.ConclusionThe Gen 2 InBrace system can enhance esthetic and occlusal outcomes in patients requiring combined orthodontic-restorative treatment via automatic space management with maximum esthetic and minimal compliance.Clinical SignificancePrecision dentistry and orthodontics using esthetic custom appliances have become a reality. The Gen 2 InBrace system, a new generation custom lingual appliance, offers effective treatment solutions for adults who have previously avoided preprosthetic orthodontics due to the esthetic concerns of wearing traditional labial braces or the compliance challenges associated with clear aligners.

关键词： CAD-CAM post and core   Ferrule   Finite element analysis   Endodontically treated teeth   Noncircular root canal  

摘要： Purpose: Restoring ferrule-lacking, noncircular canal endodontically treated teeth (ETT) poses challenges owing to the increased susceptibility to root fracture and post dislodgement. We aimed to evaluate the influence of different post and core materials on the stress distribution and maximum Von Mises stress in ETT. Methods: Four three-dimensional models were generated using different customized post and core materials: gold alloy, resin nanoceramic, polyetheretherketone (PEEK and polyetherketoneketone (PEKK). A static load of 200 N was applied at an angle of 45 degrees to the occlusal surface. The stress distribution and maximum Von Mises stress were analyzed using finite element analysis. Results: The stress distribution patterns in all the models were concentrated in the tooth structure, post and core, and cortical bone. The gold model exhibited stress accumulation predominantly on the buccal side along the post length, with the highest maximum Von Mises stress value (330.69 MPa). The resin nanoceramic model exhibited an even stress distribution. The PEEK and PEKK models showed stress transfer to adjacent structures with the lowest maximum Von Mises stress values in the post and core sections (21.50 MPa and 29.46 MPa, respectively). Conclusions: Different post and core materials influenced the stress distribution and maximum Von Mises stress values in ferrule-lacking, noncircular canal ETT. Resin nanoceramics have emerged as promising alternative materials, exhibiting an even stress distribution owing to their similar elasticity to dentin, thus potentially mitigating the risk of root fracture and post debonding.

关键词： human-robot collaboration (HRC)   assembly sequence planning (ASP)   CAD   human-robot interaction   adaptive collaboration  

摘要： The combination of human cognitive skills and dexterity with the endurance and repeatability of robots is a promising approach to modern assembly. However, efficiently allocating tasks and planning an assembly sequence between humans and robots is a manual, complex, and time-consuming activity. This work presents a framework named "Extract-Enrich-Assess-Plan-Review" that facilitates holistic planning of human-robot assembly processes. The framework automatically Extracts data from heterogeneous sources, Assesses the suitability of each assembly step to be performed by the human or robot, and Plans multiple assembly sequence plans (ASP) according to boundary conditions. Those sequences allow for a dynamic adaptation at runtime and incorporate different human-robot interaction modalities that are Synchronized, Cooperative, or Collaborative. An expert remains in the loop to Enrich the extracted data, and Review the results of the Assess and Plan steps with options to modify the process. To experimentally validate this framework, we compare the achieved degree of automation using three different CAD formats. We also demonstrate and analyze multiple assembly sequence plans that are generated by our system according to process time and the interaction modalities used.

关键词： cemented paste backfill   high and low confinement   triaxial test   binder optimization   modified structured Cam-Clay model  

摘要： Cemented paste backfill (CPB) is a cemented void filling method gaining popularity over traditional hydraulic or rockfill methods. As mining depth increases, CPB-filled stopes are subjected to higher confining pressures. Due to the soil triaxial apparatus limitations, as the conventional method of triaxial testing on CPB, no confining pressures higher than 5 MPa can be applied to CPB over a range of curing time. This lack of data introduces uncertainty in predicting CPB behavior, potentially leading to an overestimation of the required strength. To address this, this study introduces a new testing method that allows for higher confinement beyond traditional limitations by modifying the Hoek triaxial cell to accommodate low-strength materials. This study then investigates the coupled influence of confining pressure and curing time (hydration) on CPB characteristics, specifically examining the impacts of different curing times and confining pressures on the mechanical and rheological properties of CPB. A total of 75 triaxial tests were conducted using 42 mm cylinder shape samples at five various curing times from 7 to 96 days, and applied at low and high confinement condition levels (0.5 to 30 MPa). The results reveal that hydration and confinement positively impact the CPB strength. The modified structured Cam-Clay model was selected to predict the behavior, and its yield surface was updated using the experimental results. The proposed yield model can be utilized to describe CPB material subjected to various curing and pressure conditions underground.