Construction Method of Virtual Visualization Shipyard

Tooth wear is an unavoidable process associated with aging. Currently, virtual three-dimensional dental models are widely used and provide an advantage for studying tooth wear. However, there are no wear assessment parameters using virtual tooth models for the quantitative analysis of wear. Therefore, the aim of this study is to develop and evaluate quantitative wear measurement parameters. Ninety maxillary and mandibular dental casts were prepared and rendered as virtual three-dimensional models. For qualitative wear scoring, Hooper's new tooth wear index (NTWI) was used. For quantitative wear measurement, virtual vectors and occlusal planes were generated with reference points. Angles, height, and distance parameters were measured from reference points, vectors or planes. Intra- and interobserver reproducibility was determined for NTWI scoring and quantitative measurements. Quantitatively measurements for all parameters were subgrouped according to age groups and NTWI score groups. The mean and standard deviation were calculated for each group. One-way analysis of variance (ANOVA) test and the coefficients test were performed on the groups. Overall, intra- and interobserver reproducibility was good for both qualitative and quantitative measurement. In the ANOVA test, angle and height parameters showed significant differences between groups, whereas distance parameters did not. Similar results were observed in the coefficients test. However, plane heights and lingual side measurement parameters of the mandible are not recommended. In conclusion, this study indicates that all angle or height parameters of the maxilla and angle or vector height parameters of the buccal side of the mandible can be used as meaningful parameters in a quantitative wear study.

Acquisition of a three-dimensional virtual model using popular cameras

Objective To provide evidence of applied anatomy for the placement of pereutaneoas retrograde lag screws in the treatment of posterior column fractures of acetabulum. Methods Virtual three-dimensional models were reconstructed from computed tomography (CT) scans obtained from 60 adult patients without any bony problem. Virtual cylindrical implants were placed intraosscously into the posterior column of acetabulum. The maximum diameter, length and insertion direction were determined for screws.The distance between the insertion point (A) of virtual cylindrical implant and the distal end of the ischiadic tuberosity (B) was measured. In the same model, cross-sections of the pelvic posterior column was made at interval of 1 cm to measure their diameters. Results One hundred and twenty (58 male, 62 female) hemi-pelvic models were obtained. The mean maximum diameter of virtual cylindrical implant was 13. 16 ±1.45 mm and the mean angles to the transverse, coronal and sagittal planes were 72.02°± 6. 05°, 14. 71°±6. 98° and 8.61°±3.96° respectively. The insertion point was on the central line between the medial and lateral margins of ischiadic tuberosity. The distance between points A and B was 15.18 ± 1.97 mm. The smallest diameter of the posterior column was larger than the maximum diameter of the corresponding virtual cylindrical implant. Differences in the diameter, length, angle to sagittal plane of virtual cylindrical implant between the male and female were of statistical significance ( P ＜ 0. 001 ). Conclusions The posterior column can accommodate screws of 7.3 mm, but the insertion angle should vary from the male to female. The screw size for percutaneous fixation of posterior column fractures of aeetabulum should not be based solely on the measurement of cross-sectional diameter. Key words: Acetabulum; Fracture fixation, internal; Anatomy

Vestibular information is available to the brain during navigation, as are the other self-generated (idiothetic) and external (allothetic) sensorimotor cues that contribute to central estimates of position and motion. Rodent studies provide strong evidence that vestibular information contributes to navigation but human studies have been less conclusive. Furthermore, sex-based differences have been described in human navigation studies performed with the head stationary, a situation where dynamic vestibular (and other idiothetic) information is absent, but sex differences in the utilization of vestibular information have not been described. Here, we studied men and women with severe bilateral vestibular damage as they navigated through a visually barren virtual reality environment and compared their performance to normal men and women. Two navigation protocols were employed, which either activated dynamic idiothetic cues ('dynamic task', navigate by turning, walking in place) or eliminated them ('static task', navigate with key presses, head stationary). For both protocols, we employed a standard 'triangle completion task' in which subjects moved to two visual targets in series and then were required to return to their perceived starting position without localizing visual information. The angular and linear 'accuracy' (derived from response error) and 'precision' (derived from response variability) were calculated. Comparing performance 'within tasks', navigation on the dynamic paradigm was worse in male vestibular-deficient patients than in normal men but vestibular-deficient and normal women were equivalent; on the static paradigm, vestibular-deficient men (but not women) performed better than normal subjects. Comparing performance 'between tasks', normal men performed better on the dynamic than the static paradigm while vestibular-deficient men and both normal and vestibular-deficient women were equivalent on both tasks. Statistical analysis demonstrated that for the angular precision metric, sex had a significant effect on the interaction between vestibular status and the test paradigm. These results provide evidence that humans use vestibular information when they navigate in a virtual visual environment and that men and women may utilize vestibular (and visual) information differently. On our navigation paradigm, men used vestibular information to improve navigation performance, and in the presence of severe vestibular damage, they utilized visual information more effectively. In contrast, we did not find evidence that women used vestibular information while navigating on our virtual task, nor did we find evidence that they improved their utilization of visual information in the presence of severe vestibular damage.

The identification of the modernization is the modernization of the education to important teaching means. Now modern virtual visualization technology in higher education is more and more widely used. Sports as one of the disciplines with a financial knowledge, and skills training, and physical exercise, and molding temperament is a play. This paper mainly put forward the ways of how to use modern virtual visualization technology to aid teaching of physical education.

This paper describes in details the evaluation procedure developed in this paper for the measurement of the Kinect sensors accuracy and robustness in the detection process of the user hand and recognizing human hand gestures. Furthermore, the results are transferred to a robotic gripper in virtual environment for visualization. The research started with consideration on the current state of the methods and sensors used for the detection of the hand gestures. It was seen that the detection of human hand and gestures recognition represent an important research study in the field of robotics controls and automation. Through the time, different methods [7, 13] and sensors [12] were developed for the action of detection which became, with the passing of time, better and better, reaching today, a point, when Kinect sensor was constructed as a combination between mature sensor technology and efficient algorithms for detection. The goal of this paper is represented by the analysis, if the XBox 360 (TM) Kinect sensor, developed by Microsoft, is accurate enough to be used as a mean to control a robotic hand in virtual environment. To find this out, the main objectives of this paper represents the measurement of the accuracy of Kinect sensor action for the capture of gestures performed by a human hand in a repeatable manner. As a second objective, in order to be able to visualize the result, the gestures are translated into virtual environment. In order achieve the main scope of this paper, two metrics were defined, according to ISO standard for measurement. Those are: Accuracy/Precision using ISO 5725: 1994 [16] Repeatability - ISO 21748: 2010 [17] The result of the captured hand posture with the highest accuracy are then moved to a robotic hand simulated in virtual environment executing an object grasping and releasing.

Virtual reality technology has promoted the reform of education. This research mainly discusses college physical education teaching assisted by artificial intelligence-based virtual reality technology. According to the position change of the virtual human’s center of gravity, the spline keyframe interpolation method is used for interpolation, and the model pose obtained in each frame is rendered to obtain the virtual human’s animation. After synthesizing a virtual human animation with three-dimensional human motion data, the animation can have functions such as video storage, fast playback, slow playback, and freeze. At the same time, the system can also display and play the virtual human animation and the video shot by the camera on the same screen, in order to make an intuitive comparison of the athletes’ movements. Coaches can edit by hand or shoot the sports of outstanding domestic and foreign athletes on the spot and then use VC++6.0 as a development tool to analyze and get the simulation video of the 3D virtual human body. The virtual human animation technology in the motion analysis system is to relocate the three-dimensional motion data extracted from the video captured by the camera to the three-dimensional virtual human model we have established, and the three-dimensional virtual human will then simulate the technical actions of the athletes, which indirectly reflects that the three-dimensional movement information of the athletes enables coaches and athletes to observe the athletes’ technical movements in a three-dimensional space in real time, repeatedly, and from multiple angles so that the coach can accurately guide the athletes’ technical movements. Finally, a neural network based on artificial intelligence technology is used to evaluate the teaching effect. In the comparative experiment, 35% of the people in the virtual teaching experiment group were excellent, while the control group had only 10% in this excellent range (90–100). This research contributes to the smooth progress of VR technology teaching in colleges and universities.

Objective: The objective of this study was to relate the dimensions of the mandibular condyle with sex and age by means of three-dimensional models obtained by cone-beam computed tomography images (CBCT). Material and Methods: 120 CBCT examinations were selected belonging to the archives of the ICT-UNESP Clinic of Radiology. They were divided into five age groups, each containing 12 individuals of each sex. Virtual three-dimensional models were then created and two measurements from each mandibular condyle were taken: anteroposterior (AP) and mediolateral (ML). The t-test was used for independent samples to compare the measurements. Results: The AP measurements only of the left side showed a statistical difference between the sexes between 31 to 40 years of age; in the ML measurements, there were statistical differences between the sexes in all age groups on both sides, except in the age group above 60 years. Conclusion: The ML measurements of the mandibular condyles, regardless of side, showed significant statistical differences between sexes and age groups, with a tendency to greater values in males, and may be a determinant factor of sexual dimorphism.KeywordsX-Ray computed Tomography; Radiology; Sexual characteristics; Forensic anthropology; Forensic dentistry.

Reviving both the tangible and intangible aspects of lost heritage is essential to preserve awareness for future generations. The 9th-century city of Al-Qaṭāʾi in Egypt has been repeatedly destroyed during the conflicts between the Tulunids and the Abbasids. Virtual technologies and three-dimensional (3D) reconstruction serve to digitally raise awareness of the city and its historical significance, especially since it no longer exists. The challenge of digital revival in this project's framework is to imagine how life unfolded in the city during the 9th century. Our goal in this project is to leverage the advancements in 3D modelling technologies to reconstruct the lost historical Egyptian city. The methodology report begins with a description of the foundation for the 3D model reconstruction of the historically lost city, which serves as the main case study for this project. The methodology for this reconstruction is achieved through scope definition, wherein the main structures and complementary elements of the scene are identified. This is followed by the documentation phase, during which all available information on the scene is gathered through sketches, engravings, photographs, plans, and other sources. The next phase involves establishing hypotheses, where 2D and 3D sketches are produced to propose the general volumes of structures and elements. Finally, the creation of 3D models brings the structures and associated elements to life through the texturing process, as well as the inclusion of terrain, vegetation, fauna, characters, and other components, allowing the complete scene to emerge. The objective of the article is to revive the destroyed architecture of the non-existent city and communicate its value to the public through interactive virtual exploration. This study aims to demonstrate how the combination of digital methods for virtual reconstruction is valuable for both knowledge dissemination and research, through the case study of Al-Qaṭāʾi in Egypt.

Geological strata conditions is restriction to the design and construction of projects .The significance of three-dimensional modeling of engineering rock mass is obviously for both construction and monitoring.However,the existing three-dimensional modeling methods have the disadvantages of low productivity and huge amounts of data . Focusing on these problems, a fast modelling method used to build geological model is presented in this paper. Compared with the special geological 3D modeling and analysis software ,VRML has many merits such as flexible visualization method, good transplantation of the visualization achievements , and independent platform . VRML also has the feasibility of low-bandwidth and the real-time visualization and browsing of the models .It is well suited to the visualization requirement of drilling data and cross-sectional data ,and provides a new solution for the realization of the geological visualization.

Clinical relevance Patients forget up to 80% of verbal communication. Visual aids improve understanding and information retention. A virtual, three-dimensional, interactive eye model (the One Right Eye model) is a new tool for eye care providers. The utility of three-dimensional models has been studied in other specialities, but never in ophthalmology. Background This study investigates whether the One Right Eye model improves patient satisfaction and understanding during ophthalmic outpatient appointments. Methods In a single-centre, open-label, randomised controlled trial, 92 patients were divided into two groups: a control group receiving a standard face-to-face consultation (n = 45) or an interventional group receiving the same consultation supplemented with a virtual eye model demonstration (n = 47). Key outcomes included patient satisfaction, understanding of their ocular condition, and rating of their explanation from their doctor. Results The interventional group rated their explanation from their doctor statistically significantly higher than the control group (89% versus 69% ‘very good’, p = 0.03). Trends also indicated improved understanding (81% versus 62%, ‘completely understood’, p = 0.05) and greater satisfaction (83% versus 69% ‘very satisfied’, p = 0.12) in the interventional group compared to controls. While the latter two results did not reach statistical significance, the data suggest clinical improvements. Conclusion The virtual three-dimensional eye model improved patients’ perception of their explanation from their doctor and likely improved patient satisfaction and understanding of their ophthalmic condition. The One Right Eye, a virtual eyeball model, shows promise to enhance ophthalmic communication.

Three-dimensional Augmented Reality–guided Robotic-assisted Kidney Transplantation: Breaking the Limit of Atheromatic Plaques

A detailed visualization of the interocclusal relationship is essential in a three-dimensional virtual planning setup for orthognathic and facial orthomorphic surgery. The purpose of this study was to introduce and evaluate the use of a wax bite wafer in combination with a double computed tomography (CT) scan procedure to augment the three-dimensional virtual model of the skull with a detailed dental surface. A total of 10 orthognathic patients were scanned after a standardized multislice CT scanning protocol with dose reduction with their wax bite wafer in place. Afterward, the impressions of the upper and lower arches and the wax bite wafer were scanned for each patient separately using a high-resolution standardized multislice CT scanning protocol. Accurate fitting of the virtual impressions on the wax bite wafer was done with surface matching using iterative closest points. Consecutively, automatic rigid point-based registration of the wax bite wafer on the patient scan was performed to implement the digital virtual dental arches into the patient's skull model (Maxilim, version 2.0; Medicim NV, St-Niklaas, Belgium). Probability error histograms showed errors of < or =0.16 mm (25% percentile), < or =0.31 mm (50% percentile), and < or =0.92 (90% percentile) for iterative closest point surface matching. The mean registration error for automatic point-based registration was 0.17 +/- 0.07 mm (range, 0.12-0.22 mm). The combination of the wax bite wafer with the double CT scan procedure allowed for the setup of an accurate three-dimensional virtual augmented model of the skull with detailed dental surface. However, from a clinical workload, data handling, and computational point of view, this method is too time-consuming to be introduced in the clinical routine.

An application to simulate and control industrial robot in virtual reality environment integrated with IR stereo camera sensor

Differences of percutaneous retrograde screw fixation of anterior column acetabular fractures between male and female: A study of 164 virtual three-dimensional models