Modeling Backlash-Like Hysteresis of Tendon Sheath Mechanism-Pair

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Junho Hong ◽  
Dahie Hong ◽  
Byung Gon Kim

Abstract Tendon sheath mechanism (TSM) is an effective power transmission system to access remote locations through tortuous channels, and it is widely used in endoscopic surgical robots. However, owing to deformation of TSM during power transmission, the input–output hysteresis is expressed in the form of backlash-like hysteresis. This paper is premised on the idea that sheath deformation can occur if the sheath is fixed only at certain points rather than being fully fixed at all points. Based on our hypothesis, a new TSM-pair backlash-like hysteresis model was derived, which considers the deformation property of the sheath. Experimental setups were designed to validate the new model, and its mechanical parameters were identified. The experimental results revealed that the sheath significantly deforms and that such deformation produces backlash-like hysteresis together with the tendon deformation. This model can be used to provide accurate prediction and control of TSM.

Some thirteen years ago, a reduction was noticed in the strength of air insulation when subjected to slowly rising positive impulse voltages such as occur during switching operatons on power systems. Methods for the prediction and control of switching overvoltages have been established and empirical data collected in high voltage laboratories. Insulation against switching surges is now seen as an important factor in the feasibility of power transmission at ultra-high voltages. The strength of large air gaps depends not only on the geometry of the gap (point-plane, rod-rod, etc.), but also on the waveshape of the applied voltage. The practical diversity of gaps and waveshapes is such that a sound theoretical approach must be found if laboratory testing is to be kept within bounds. Qualitative understanding of the breakdown processes in long air-gaps has advanced rapidly in the last two years. Predictive mathematical models are now being constructed.


Author(s):  
Tamara Green

Much of the literature, policies, programs, and investment has been made on mental health, case management, and suicide prevention of veterans. The Australian “veteran community is facing a suicide epidemic for the reasons that are extremely complex and beyond the scope of those currently dealing with them.” (Menz, D: 2019). Only limited work has considered the digital transformation of loosely and manual-based historical records and no enablement of Artificial Intelligence (A.I) and machine learning to suicide risk prediction and control for serving military members and veterans to date. This paper presents issues and challenges in suicide prevention and management of veterans, from the standing of policymakers to stakeholders, campaigners of veteran suicide prevention, science and big data, and an opportunity for the digital transformation of case management.


2009 ◽  
Vol 325 (1-2) ◽  
pp. 85-105 ◽  
Author(s):  
P.A. Meehan ◽  
P.A. Bellette ◽  
R.D. Batten ◽  
W.J.T. Daniel ◽  
R.J. Horwood

1973 ◽  
Vol 4 (3) ◽  
pp. 195-208
Author(s):  
Keith Hoeller

Is death the “enemy” to be avoided at all costs or is it to be faced, engendering liberation and rebirth? Contemporary suicidology concerns itself with the “causes” of suicide, placing great emphasis on prediction and control However, when the “meaning” of suicide is studied, understanding it as a human phenomenon becomes of major concern. Part of this understanding requires one to view “dread” as implying the possibility of making one's existence one's own, rather than something that must be prevented. In the study of suicide, revolutionary insights can emerge if less emphasis is placed on death as the “enemy” and more attention is placed on “dread” as a potential liberator.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 492
Author(s):  
Valentina Y. Guleva ◽  
Polina O. Andreeva ◽  
Danila A. Vaganov

Finding the building blocks of real-world networks contributes to the understanding of their formation process and related dynamical processes, which is related to prediction and control tasks. We explore different types of social networks, demonstrating high structural variability, and aim to extract and see their minimal building blocks, which are able to reproduce supergraph structural and dynamical properties, so as to be appropriate for diffusion prediction for the whole graph on the base of its small subgraph. For this purpose, we determine topological and functional formal criteria and explore sampling techniques. Using the method that provides the best correspondence to both criteria, we explore the building blocks of interest networks. The best sampling method allows one to extract subgraphs of optimal 30 nodes, which reproduce path lengths, clustering, and degree particularities of an initial graph. The extracted subgraphs are different for the considered interest networks, and provide interesting material for the global dynamics exploration on the mesoscale base.


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