Bunhwang Wonhyo and Gyeongheo Sungwoo’s spirits in seeking the Dharma Focusing on the contact point and passage between Wonhyo’s One Mind and Gyeongheo’s Illuminating Mind –

2019 ◽  
Vol 26 ◽  
pp. 241-285
Author(s):  
Yeong - Seob ko
Keyword(s):  
Contact Point

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.

scholarly journals Slipping–rolling transitions of a body with two contact points

2021 ◽  
Author(s):  
Mate Antali ◽  
Gabor Stepan
Keyword(s):  
Rigid Body ◽  
Contact Point ◽  
Static Friction ◽  
Rigid Body Dynamics ◽  
Contact Forces ◽  
Friction Forces ◽  
Contact Points ◽  
Body Dynamics ◽  
Coulomb Model ◽  
Rigid Surfaces

AbstractIn this paper, the general kinematics and dynamics of a rigid body is analysed, which is in contact with two rigid surfaces in the presence of dry friction. Due to the rolling or slipping state at each contact point, four kinematic scenarios occur. In the two-point rolling case, the contact forces are undetermined; consequently, the condition of the static friction forces cannot be checked from the Coulomb model to decide whether two-point rolling is possible. However, this issue can be resolved within the scope of rigid body dynamics by analysing the nonsmooth vector field of the system at the possible transitions between slipping and rolling. Based on the concept of limit directions of codimension-2 discontinuities, a method is presented to determine the conditions when the two-point rolling is realizable without slipping.

scholarly journals Cavitation between cylinder-liner and piston-ring in a new designed optical IC engine

2021 ◽  
pp. 146808742110080
Author(s):  
Jamshid Malekmohammadi Nouri ◽  
Ioannis Vasilakos ◽  
Youyou Yan
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Cylinder Liner ◽  
Optical Methods ◽  
Engine Management System ◽  
Great Success ◽  
Ic Engine ◽  
Contact Points ◽  
Lubricant Flow ◽  
Cavitation Intensity

A new engine block with optical access has been designed and manufactured capable of running up to 3000 r/min with the same specification as the unmodified engine. The optical window allowed access to the full length of the liner over a width of 25 mm to investigate the lubricant flow and cavitation at contact point between the rings and cylinder-liner. In addition, it allowed good access into the combustion chamber to allow charged flow, spray and combustion visualisation and measurements using different optical methods. New custom engine management system with build in LabView allowed for the precise full control of the engine. The design of the new optical engine was a great success in producing high quality images of lubricant flow, cavitation formation and development at contact point at different engine speeds ranging from 208 to 3000 r/min and lubricant temperatures (30°C–70°C) using a high-speed camera. The results under motorised operation confirmed that there was no cavitation at contact points during the intake/exhaust strokes due to low in-cylinder presure, while during compression/expansion strokes, with high in-cylinder pressure, considerable cavities were observed, in particular, during the compression stroke. Lubricant temperatures had the effect of promoting cavities both in their intensity and covered ring area up to 50°C as expected. Beyond that, although the cavitation intensity increases further with temperature, its area reduces due to possible collapse of the cavitating bubbles at higher temperature. The change of engine speed from 208 to 800 r/min increased cavitating area considerably by 52% of the ring area and was further increased by 19% at 1000 r/min. After that, the results showed very small increase in cavitation area (1.3% at 2000 r/min) with similar intensity and distribution across the ring.

scholarly journals Improving the Detection of the Contact Point in Active Sensing Antennae by Processing Combined Static and Dynamic Information

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1808
Author(s):  
Luis Mérida-Calvo ◽  
Daniel Feliu-Talegón ◽  
Vicente Feliu-Batlle
Keyword(s):  
Contact Point ◽  
Load Cell ◽  
Robotic Systems ◽  
Accurate Estimation ◽  
Flexible Beam ◽  
Dynamic Information ◽  
New Developments ◽  
Static Information ◽  
Insect Antennae ◽  
Flexible Antenna

The design and application of sensing antenna devices that mimic insect antennae or mammal whiskers is an active field of research. However, these devices still require new developments if they are to become efficient and reliable components of robotic systems. We, therefore, develop and build a prototype composed of a flexible beam, two servomotors that drive the beam and a load cell sensor that measures the forces and torques at the base of the flexible beam. This work reports new results in the area of the signal processing of these devices. These results will make it possible to estimate the point at which the flexible antenna comes into contact with an object (or obstacle) more accurately than has occurred with previous algorithms. Previous research reported that the estimation of the fundamental natural frequency of vibration of the antenna using dynamic information is not sufficient as regards determining the contact point and that the estimation of the contact point using static information provided by the forces and torques measured by the load cell sensor is not very accurate. We consequently propose an algorithm based on the fusion of the information provided by the two aforementioned strategies that enhances the separate benefits of each one. We demonstrate that the adequate combination of these two pieces of information yields an accurate estimation of the contacted point of the antenna link. This will enhance the precision of the estimation of points on the surface of the object that is being recognized by the antenna. Thorough experimentation is carried out in order to show the features of the proposed algorithm and establish its range of application.

scholarly journals Machine Learning Algorithms, Applied to Intact Islets of Langerhans, Demonstrate Significantly Enhanced Insulin Staining at the Capillary Interface of Human Pancreatic β Cells

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 363
Author(s):  
Louise Cottle ◽  
Ian Gilroy ◽  
Kylie Deng ◽  
Thomas Loudovaris ◽  
Helen E. Thomas ◽  
...  
Keyword(s):  
Machine Learning ◽  
Islets Of Langerhans ◽  
Learning Algorithm ◽  
Contact Point ◽  
Machine Learning Algorithms ◽  
Automated Image Analysis ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Blood Glucose Concentrations ◽  
Insulin Staining

Pancreatic β cells secrete the hormone insulin into the bloodstream and are critical in the control of blood glucose concentrations. β cells are clustered in the micro-organs of the islets of Langerhans, which have a rich capillary network. Recent work has highlighted the intimate spatial connections between β cells and these capillaries, which lead to the targeting of insulin secretion to the region where the β cells contact the capillary basement membrane. In addition, β cells orientate with respect to the capillary contact point and many proteins are differentially distributed at the capillary interface compared with the rest of the cell. Here, we set out to develop an automated image analysis approach to identify individual β cells within intact islets and to determine if the distribution of insulin across the cells was polarised. Our results show that a U-Net machine learning algorithm correctly identified β cells and their orientation with respect to the capillaries. Using this information, we then quantified insulin distribution across the β cells to show enrichment at the capillary interface. We conclude that machine learning is a useful analytical tool to interrogate large image datasets and analyse sub-cellular organisation.

scholarly journals Recruiting for research on sensitive topics in schools: an experience with Vaxcards, a collectable vaccine card game

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
D. S. Epstein ◽  
J. C. Enticott ◽  
H. J. Larson ◽  
C. Barton
Keyword(s):  
Research Team ◽  
Controlled Trial ◽  
Contact Point ◽  
Research Participation ◽  
Cluster Randomised Controlled Trial ◽  
Trial Registration ◽  
Card Game ◽  
Successful Recruitment ◽  
Sensitive Topics ◽  
Randomised Controlled

Abstract Undertaking recruitment for research in schools is an effective way to recruit young people for research participation but it is not without its challenges. Gaining access and coordinating many levels of different organisations and stakeholders whose cooperation and approval are crucial all add time and sometimes logistical challenges for the research team. In addition, recruiting around sensitive research topics can elicit additional barriers to successful research. The research team aimed to conduct a pragmatic cluster randomised controlled trial involving schools in a local government region in Victoria, Australia, to assess the effect of a vaccination-based educational card game called “Vaxcards” on vaccine consent returns. Schools were contacted via phone and email to determine which staff member would best be a contact point for a face-to-face meeting to discuss the methods and purpose of the study. Email follow-ups were scheduled to follow up non-responsive schools and consent forms. The minimum required sample size was 13. Of 31 eligible schools, 13 were recruited. The research team encountered several unanticipated challenges before achieving the recruitment target. The most common reasons for non-participation were being too busy with other commitments, concerns regarding the topic of vaccination being too sensitive, and concerns that key stakeholders in the school would not approve of the research topic of vaccination. One school required a review by a private research ethics board that rejected the study. Significant hesitancy and misinformation about vaccine science was observed that affected engagement with a small number of schools. This paper highlights the challenges of recruiting schools in the context of public anxieties about vaccines and has several important learning lessons for successful recruitment about sensitive topics. This includes navigating approval processes for research in schools, the importance of local champions, dealing with misinformation and the importance of strong relationships and organisational trust. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12618001753246. Prospectively registered on 25 October 2018 8:24:21 AM

scholarly journals Structural Behavior of Prefabricated Ecological Grid Retaining Walls and Application in a Highway in China

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 746
Author(s):  
Xinquan Wang ◽  
Cong Zhu ◽  
Hongguo Diao ◽  
Yingjie Ning
Keyword(s):  
Retaining Wall ◽  
Contact Point ◽  
Retaining Walls ◽  
Wall Structure ◽  
Soil Arching ◽  
Finite Element Software ◽  
Study Results ◽  
Stress And Deformation ◽  
Asymmetrical Condition ◽  
Construction Efficiency

The retaining wall is a common slope protection structure. To tackle the current lack of sustainable and highly prefabricated retaining walls, an environmentally friendly prefabricated ecological grid retaining wall with high construction efficiency has been developed. Due to the asymmetrical condition of the project considered in this paper, the designed prefabricated ecological grid retaining wall was divided into the excavation section and the filling section. By utilizing the ABAQUS finite element software, the stress and deformation characteristics of the retaining wall columns, soil, anchor rods, and inclined shelves in an excavation section, and the force and deformation relationships of the columns, rivets, and inclined shelves in three working conditions in a filling section were studied. The study results imply that the anchor rods may affect the columns in the excavation section and the stress at the column back changes in an M-shape with height. Moreover, the peak appears at the contact point between the column and the anchor rod. The displacement of the column increases slowly along with the height, and the column rotates at its bottom. In the excavation section, the stress of the anchor rod undergoes a change at the junction of the structure. The inclined shelf is an open structure and is very different from the retaining plate structure of traditional pile-slab retaining walls. Its stress distribution follows a repeated U-shaped curve, which is inconsistent with the trend of the traditional soil arching effect between piles, which increases first and then decreases. For the retaining wall structure in the filling section, the numerical simulated vehicle load gives essentially consistent results with the effects of the equivalent filling on the concrete column.

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