Image registration, accuracy, processing time and occlusions are the main limitations of augmented reality (AR) based jaw surgery. Therefore, the main aim of this paper is to reduce the registration error, which will help in improving the accuracy and reducing the processing time. Also, it aims to remove outliers and remove the registration outcomes trapped in local minima to improve the alignment problems and remove the occlusion caused by surgery instrument. The enhanced Iterative Closest Point (ICP) algorithm with rotation invariant and correntropy was used for the proposed system. Markerless image registration technique was used for AR-based jaw surgery. The problem of occlusion caused by surgical tools and blood is solved by using stereo based tracing with occlusion handling techniques. This research reduced alignment error 0.59 mm?~?0.62 mm against 0.69?~?0.72 mm of state-of-the-art solution. The processing time of video frames was enhanced to 11.9?~?12.8 fps against 8?~?9.15 fps in state-of-the-art solution. This paper is focused on providing fast and accurate AR-based system for jaw surgery. The proposed system helps in improving the AR visualization during jaw surgery. The combination of methods and technology helped in improving AR visualization for jaw surgery and to overcome the failure caused by a large rotation angle and provides an initial parameter for better image registration. It also enhances performance by removing outliers and noises. The pose refinement stage provides a better result in terms of processing time and accuracy.
Multimedia Tools and Applications - The natural population-based prediction of type 2 diabetes is costly since it needs a high number of resources. Even though much research has used machine... 相似文献
The aim of this paper is to study the effect of N+ ion implantation on corrosion and phase formation on the implanted surfaces of Ti-6Al-4V and Ti-6Al-7Nb alloys. Nitrogen ion was implanted on Ti-6Al-4V and Ti-6Al-7Nb alloys at an energy of 70 and 100 keV, respectively using a 150 keV accelerator at different doses ranging from 5 × 1015 to 2.5 × 1017 ions/cm2. Electrochemical studies have been carried out in Ringer’s solution in order to determine the optimum dose that can give good corrosion resistance in a simulated body fluid condition. The implanted surfaces of such modified doses were electrochemically passivated at 1.0 V for an hour. Secondary ion mass spectroscopy was used to study and characterize titanium oxide and titanium nitride layers produced on implanted surface and to correlate them with the corrosion resistance. The nature of the passive film of the implanted-passivated specimen was compared with the unimplanted-passivated as well as as-implanted specimens. 相似文献
Accurate fall detection for the assistance of older people is crucial to reduce incidents of deaths or injuries due to falls. Meanwhile, vision‐based fall detection system has shown some significant results to detect falls. Still, numerous challenges need to be resolved. The impact of deep learning has changed the landscape of the vision‐based system, such as action recognition. The deep learning technique has not been successfully implemented in vision‐based fall detection system due to the requirement of a large amount of computation power and requirement of a large amount of sample training data. This research aims to propose a vision‐based fall detection system that improves the accuracy of fall detection in some complex environments such as the change of light condition in the room. Also, this research aims to increase the performance of the pre‐processing of video images. The proposed system consists of Enhanced Dynamic Optical Flow technique that encodes the temporal data of optical flow videos by the method of rank pooling, which thereby improves the processing time of fall detection and improves the classification accuracy in dynamic lighting condition. The experimental results showed that the classification accuracy of the fall detection improved by around 3% and the processing time by 40–50 ms. The proposed system concentrates on decreasing the processing time of fall detection and improving the classification accuracy. Meanwhile, it provides a mechanism for summarizing a video into a single image by using dynamic optical flow technique, which helps to increase the performance of image preprocessing steps. 相似文献
The Journal of Supercomputing - Detection of threat objects concealed in passenger clothing and baggage poses a challenge to aviation security. At present, the detection technology is capable of... 相似文献
This paper reports the effect of the various ceramic coatings viz., hydroxyapatite (HA) and partially stabilized zirconia (PSZ) on the bond strength between the bone and implant, and cell compatibility of screw-shaped Ti-6Al-7Nb dental implants. Electrophoretic deposition technique (EPD) was used to obtain a uniform coating of one of the three types of ceramic layers (HA, PSZ and 50%HA + 50%PSZ) on the screws. Structural investigations were carried out on the prepared HA powder and the modified surfaces of the Ti-6Al-7Nb alloy using different techniques, namely X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The in vivo studies were performed by the implantation of screw-shaped uncoated and coated implants in the tibia of white New Zealand rabbits. To understand the bone-implant interface, biomechanical test was carried out after 2, 6 and 18 weeks healing periods. There was increased mechanical strength (torque value) of bone-implant interface with time, and the highest increment in the bond strength was recorded for implants coated with a 50% HA and 50% PSZ. Histological results show that the coated Ti-6Al-7Nb screws after 18 weeks of the implantation seem to be well-tolerated by the bone since no adverse tissue reaction was evident. However, there was a faster reaction of bone towards the coated implants compared to the uncoated one. The histochemical stain studies shows higher cellular activity and mature bone formation on all the samples. 相似文献
Water Resources Management - The aim of this study was to show the importance of exploiting the appropriate sites for construction of dams on the borders of riparian countries. To achieve this aim,... 相似文献
Whatever the synthesis technique used, the growth of ropes of single-wall carbon nanotubes requires the assistance of a metallic catalyst. In this paper, the role played by the catalyst is studied both experimentally and theoretically. Experimentally, the similarities between the samples synthesized from different techniques suggest a common growth mechanism proceeding via the precipitation of excess carbon on metallic nanoparticles. In this paper, the correlation between ropes and catalytic particles is investigated in detail in the case of the Ni-Y catalyst used in the arc discharge technique by combining high resolution transmission electron microscopy, X-ray and electron energy loss spectroscopy. It is shown that the ropes are always found attached to metallic particles about ten times larger than the tube diameter. A further remarkable proof of this relationship is provided by the chemical analyses of the metallic particles. These are found to be free of carbon and to always display the same Ni:Y composition range, whatever the initial Ni:Y composition of the catalyst mixture used in the synthesis, whereas the composition of other particles is highly dispersed. These experimental results support a mechanism of formation based on a vapor-liquid-solid model, in which the tubes of a given bundle nucleate in a cooperative manner and grow at the surface of a same metallic particle. This phenomenological scheme is supported by quantum molecular dynamics simulations which show that carbon atoms are incorporated at the root of a growing tube by a diffusion-segregation process occurring at the surface of the catalytic particle. 相似文献
Solution treatment and ageing (STA) is an effective strengthening method for α + β titanium alloys. This paper reports the effect of solution treatment and aging on the corrosion behaviour of Ti‐6Al‐7Nb alloy in a simulated body fluid (Ringer's solution). Ti‐6Al‐7Nb alloy is hot rolled in the α + β field and subjected to solution treatment above and below its beta transus temperature (1283 K). The solution treated specimens are water quenched (WQ), air‐cooled (AC), and furnace cooled (FC) at three different rates, and subsequently aged at 823 K for 4 h. Microstructural changes were examined using optical microscopy and phases developed were analyzed using XRD. The influence of microstructure on the corrosion performance of the alloys are discussed in detail based on the Open Circuit Potential (OCP), passive current density and area of repassivation loop values obtained from the cyclic polarization study in Ringer's solution. The passive current density was low (0.5 μA/cm2) for the specimen with duplex microstructure obtained for specimen solution treated at 1223 K, air‐cooled, and aged, in comparison with that for as‐rolled specimen (1.5 μA/cm2). The corrosion aspects resulting from various heat treatments are discussed in detail. 相似文献