scholarly journals Bayesian Changepoint Detection Through Switching Regressions: Contact Point Determination in Material Indentation Experiments

2007 ◽  
Author(s):  
Shelten G. Yuen ◽  
Daniel Rudoy ◽  
Robert D. Howe ◽  
Patrick J. Wolfe
Keyword(s):  
Contact Point ◽  
Changepoint Detection ◽  
Point Determination

scholarly journals Three-dimensional contact point determination and contour reconstruction during active whisking behavior of the awake rat

2020 ◽  
Author(s):  
Lucie A. Huet ◽  
Hannah M. Emnett ◽  
Mitra J. Z. Hartmann
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Three Dimensional ◽  
Contact Points ◽  
Unique Mapping ◽  
Contour Reconstruction ◽  
Awake Rat ◽  
Exact Shape ◽  
Point Determination ◽  
Open Question

AbstractThe rodent vibrissal (whisker) system has been studied for decades as a model of active touch sensing. There are no sensors along the length of a whisker; all sensing occurs at the whisker base. Therefore, a large open question in many neuroscience studies is how an animal could estimate the three-dimensional location at which a whisker makes contact with an object. In the present work we simulated the exact shape of a real rat whisker to demonstrate the existence of a unique mapping from triplets of mechanical signals at the whisker base to the three-dimensional whisker-object contact point. We then used high speed video to record whisker deflections as an awake rat whisked against a peg and used the mechanics resulting from those deflections to extract the contact points along the peg surface. A video shows the contour of the peg gradually emerging during active whisking behavior.

Survival of Short and Ultra-Short Locking-Taper Implants Supporting Single Crowns in the Posterior Mandible: A 3-Year Retrospective Study

2020 ◽  
Vol 46 (4) ◽  
pp. 396-406 ◽  
Author(s):  
Giorgio Lombardo ◽  
Annarita Signoriello ◽  
Miguel Simancas-Pallares ◽  
Mauro Marincola ◽  
Pier Francesco Nocini
Keyword(s):  
Retrospective Study ◽  
Bone Loss ◽  
Contact Point ◽  
Implant Survival ◽  
Point Position ◽  
Crestal Bone Loss ◽  
Short Implants ◽  
Single Crown ◽  
Bone To Implant Contact ◽  
Single Crowns

The purpose of this retrospective study was to determine survival and peri-implant marginal bone loss of short and ultra-short implants placed in the posterior mandible. A total of 98 patients received 201 locking-taper implants between January 2014 and January 2015. Implants were placed with a 2-stage approach and restored with single crowns. Clinical and radiographic examinations were performed at 3-year recall appointments. At that time, the proportion of implant survival by length, and variations of crestal bone levels (mean crestal bone loss and mean apical shift of the “first bone-to-implant contact point” position) were assessed. Significance level was set at 0.05. The total number of implants examined 36 months after loading included: 71 implants, 8.0 mm in length; 82 implants, 6.0 mm in length; and 48 implants, 5.0 mm in length. Five implants failed. The overall proportion of survival was 97.51%, with 98.59% for the 8.0-mm implants, 97.56% for the 6.0-mm implants, and 95.83% for the 5.0-mm implants. No statistically significant differences were found among the groups regarding implant survival (P = .73), mean crestal bone loss (P = .31), or mean apical shift of the “first bone-to-implant contact point” position (P = .36). Single-crown short and ultra-short implants may offer predictable outcomes in the atrophic posterior mandibular regions, though further investigations with longer follow-up evaluations are necessary to validate our results.

Qualitative anatomical restoration of the contact point of teeth – prevention of localized forms of periodontal diseases

2020 ◽  
Vol 25 (1) ◽  
pp. 10-15
Author(s):  
L. Yu. Orekhova ◽  
O. V. Prokhorova ◽  
V. Yu. Shefov
Keyword(s):  
Comparative Analysis ◽  
Computer Simulations ◽  
Periodontal Diseases ◽  
Contact Point ◽  
Clinical Stage ◽  
High Quality ◽  
Cross Sectional ◽  
Clinical Stages ◽  
Anatomical Restoration ◽  
Approximal Surfaces

Relevance. The restoration of a high-quality anatomical and functional contact point of teeth plays an important role in preventing the development of localized forms of periodontal disease.Purpose. Development of recommendations for qualitative anatomical restoration of the contact point of teeth for the prevention of localized forms of periodontal diseases.Materials and methods. In our study, which consisted of pre-clinical and clinical stages, were analyzed 50 CT scan of the chewing group teeth calculated the ratio of approximal surfaces of molars and premolars to the width of their crowns and computer simulations of the results of restoration of contact point. We also conducted a comparative analysis of wedges of different material with different cross-sectional shapes. At the clinical stage, the restoration of the contact point of teeth in patients according to our recommendations was carried out.Results. On the basis of the data obtained during the study, a formula for calculating the height and size of the restored contact point was compiled. Recommendations for anatomical restoration of the contact point are formulated.Conclusion. The application of the recommendations developed by us allows anatomically qualitatively restore the contact point and prevent the development of localized periodontal diseases.

scholarly journals Numerical Parametric Study on the Effectiveness of the Contact-Point Response of a Stationary Vehicle for Bridge Health Monitoring

2021 ◽  
Vol 11 (15) ◽  
pp. 7028
Author(s):  
Ibrahim Hashlamon ◽  
Ehsan Nikbakht ◽  
Ameen Topa ◽  
Ahmed Elhattab
Keyword(s):  
Numerical Model ◽  
Health Monitoring ◽  
Contact Point ◽  
Response Spectra ◽  
Roughness Effects ◽  
Moving Vehicle ◽  
Bridge Health Monitoring ◽  
Vehicle Response ◽  
Instrumented Vehicle ◽  
The Time Domain

Indirect bridge health monitoring is conducted by running an instrumented vehicle over a bridge, where the vehicle serves as a source of excitation and as a signal receiver; however, it is also important to investigate the response of the instrumented vehicle while it is in a stationary position while the bridge is excited by other source of excitation. In this paper, a numerical model of a stationary vehicle parked on a bridge excited by another moving vehicle is developed. Both stationary and moving vehicles are modeled as spring–mass single-degree-of-freedom systems. The bridges are simply supported and are modeled as 1D beam elements. It is known that the stationary vehicle response is different from the true bridge response at the same location. This paper investigates the effectiveness of contact-point response in reflecting the true response of the bridge. The stationary vehicle response is obtained from the numerical model, and its contact-point response is calculated by MATLAB. The contact-point response of the stationary vehicle is investigated under various conditions. These conditions include different vehicle frequencies, damped and undamped conditions, different locations of the stationary vehicle, road roughness effects, different moving vehicle speeds and masses, and a longer span for the bridge. In the time domain, the discrepancy of the stationary vehicle response with the true bridge response is clear, while the contact-point response agrees well with the true bridge response. The contact-point response could detect the first, second, and third modes of frequency clearly, unlike the stationary vehicle response spectra.

Sign in / Sign up

Export Citation Format

Share Document