scholarly journals Wireless Rechargeable Sensor Network Fault Modeling and Stability Analysis

2021 ◽  
Vol 3 (1) ◽  
pp. 47-54
Author(s):  
Mugunthan S. R.
Keyword(s):  
Optimal Strategies ◽  
Reproductive Value ◽  
Control Group ◽  
Defense Strategies ◽  
Security Issues ◽  
Proposed Model ◽  
The Stability ◽  
Wireless Rechargeable Sensor Network ◽  
Global And Local ◽  
Network Fault

Wide attention has been acquired by the field of wireless rechargeable sensor networks (WRSNs ) across the globe due to its rapid developments. Addressing the security issues in the WRSNs is a crucial task. The process of reinfection, charging and removal in WRSN is performed with a low-energy infected susceptible epidemic model presented in this paper. A basic reproductive value is attained after which the epidemic equilibrium and disease-free points of global and local stabilities are simulated and analyzed. Relationship between the reproductive value and rate of charging as well as the stability is a unique characteristic exhibited by the proposed model observed from the simulations. The WRSN and malware are built with ideal attack-defense strategies. When the reproductive value is not equal to one, the accumulated cost and non-optimal control group are compared in the sensor node evolution and the optimal strategies are validated and verified.

scholarly journals A Novel Epidemic Model for Wireless Rechargeable Sensor Network Security

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 123
Author(s):  
Guiyun Liu ◽  
Baihao Peng ◽  
Xiaojing Zhong
Keyword(s):  
Epidemic Model ◽  
Equilibrium Points ◽  
Optimal Strategies ◽  
Sensor Nodes ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Control Group ◽  
Security Issues ◽  
Sensor Network Security ◽  
Wireless Rechargeable Sensor Network

With the development of wireless rechargeable sensor networks (WRSNs ), security issues of WRSNs have attracted more attention from scholars around the world. In this paper, a novel epidemic model, SILS(Susceptible, Infected, Low-energy, Susceptible), considering the removal, charging and reinfection process of WRSNs is proposed. Subsequently, the local and global stabilities of disease-free and epidemic equilibrium points are analyzed and simulated after obtaining the basic reproductive number R0. Detailedly, the simulations further reveal the unique characteristics of SILS when it tends to being stable, and the relationship between the charging rate and R0. Furthermore, the attack-defense game between malware and WRSNs is constructed and the optimal strategies of both players are obtained. Consequently, in the case of R0<1 and R0>1, the validity of the optimal strategies is verified by comparing with the non-optimal control group in the evolution of sensor nodes and accumulated cost.

scholarly journals A Novel Attack-and-Defense Signaling Game for Optimal Deceptive Defense Strategy Choice

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yongjin Hu ◽  
Han Zhang ◽  
Yuanbo Guo ◽  
Tao Li ◽  
Jun Ma
Keyword(s):  
Traditional Approach ◽  
Optimal Strategies ◽  
Signaling Game ◽  
Game Model ◽  
Defense Strategies ◽  
Defense Strategy ◽  
Bayesian Equilibrium ◽  
Proposed Model ◽  
Improved Model ◽  
Attack And Defense

Increasingly, more administrators (defenders) are using defense strategies with deception such as honeypots to improve the IoT network security in response to attacks. Using game theory, the signaling game is leveraged to describe the confrontation between attacks and defenses. However, the traditional approach focuses only on the defender; the analysis from the attacker side is ignored. Moreover, insufficient analysis has been conducted on the optimal defense strategy with deception when the model is established with the signaling game. In our work, the signaling game model is extended to a novel two-way signaling game model to describe the game from the perspectives of both the defender and the attacker. First, the improved model is formally defined, and an algorithm is proposed for identifying the refined Bayesian equilibrium. Then, according to the calculated benefits, optimal strategies choice for both the attacker and the defender in the game are analyzed. Last, a simulation is conducted to evaluate the performance of the proposed model and to demonstrate that the defense strategy with deception is optimal for the defender.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

scholarly journals Stability and ocular biodistribution of topically administered PLGA nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sean Swetledge ◽  
Renee Carter ◽  
Rhett Stout ◽  
Carlos E. Astete ◽  
Jangwook P. Jung ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Exposure ◽  
Polymeric Nanoparticles ◽  
Plga Nanoparticles ◽  
Eye Disease ◽  
Control Group ◽  
Eye Tissues ◽  
Nanoparticle Morphology ◽  
The Stability

AbstractPolymeric nanoparticles have been investigated as potential delivery systems for therapeutic compounds to address many ailments including eye disease. The stability and spatiotemporal distribution of polymeric nanoparticles in the eye are important regarding the practical applicability and efficacy of the delivery system in treating eye disease. We selected poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with lutein, a carotenoid antioxidant associated with eye health, as our model ophthalmic nanodelivery system and evaluated its stability when suspended in various conditions involving temperature and light exposure. We also assessed the ocular biodistribution of the fluorescently labeled nanoparticle vehicle when administered topically. Lutein-loaded nanoparticles were stable in suspension when stored at 4 °C with only 26% lutein release and no significant lutein decay or changes in nanoparticle morphology. When stored at 25 °C and 37 °C, these NPs showed signs of bulk degradation, had significant lutein decay compared to 4 °C, and released over 40% lutein after 5 weeks in suspension. Lutein-loaded nanoparticles were also more resistant to photodegradation compared to free lutein when exposed to ultraviolet (UV) light, decaying approximately 5 times slower. When applied topically in vivo, Cy5-labled nanoparticles showed high uptake in exterior eye tissues including the cornea, episcleral tissue, and sclera. The choroid was the only inner eye tissue that was significantly higher than the control group. Decreased fluorescence in all exterior eye tissues and the choroid at 1 h compared to 30 min indicated rapid elimination of nanoparticles from the eye.

scholarly journals The Bone Buttress Theory: The Effect of the Mechanical Loading of Bone on the Osseointegration of Dental Implants

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
David Chavarri-Prado ◽  
Aritza Brizuela-Velasco ◽  
Ángel Álvarez-Arenal ◽  
Markel Dieguez-Pereira ◽  
Esteban Pérez-Pevida ◽  
...  
Keyword(s):  
Dental Implants ◽  
Mechanical Loading ◽  
Bone Growth ◽  
Bone Matrix ◽  
Test Group ◽  
Control Group ◽  
Group A ◽  
Bone To Implant Contact ◽  
The Stability ◽  
Group B

Objectives: To determine the effect of mechanical loading of bone on the stability and histomorphometric variables of the osseointegration of dental implants using an experimental test in an animal model. Materials and Methods: A total of 4 human implants were placed in both tibiae of 10 New Zealand rabbits (n = 40). A 6-week osseointegration was considered, and the rabbits were randomly assigned to two groups: Group A (Test group) included 5 rabbits that ran on a treadmill for 20 min daily during the osseointegration period; Group B (Controls) included the other 5 that were housed conventionally. The monitored variables were related to the primary and secondary stability of the dental implants (implant stability quotient—ISQ), vertical bone growth, bone to implant contact (BIC), area of regenerated bone and the percentage of immature matrix. Results: The results of the study show a greater vertical bone growth (Group A 1.26 ± 0.48 mm, Group B 0.32 ± 0.47 mm, p < 0.001), higher ISQ values (Group A 11.25 ± 6.10 ISQ, 15.73%; Group B 5.80 ± 5.97 ISQ, 7.99%, p = 0.006) and a higher BIC (Group A 19.37%, Group B 23.60%, p = 0.0058) for implants in the test group, with statistically significant differences. A higher percentage of immature bone matrix was observed for implants in the control group (20.68 ± 9.53) than those in the test group (15.38 ± 8.84) (p = 0.108). A larger area of regenerated bone was also observed for the test implants (Group A 280.50 ± 125.40 mm2, Group B 228.00 ± 141.40 mm2), but it was not statistically significant (p = 0.121). Conclusions: The mechanical loading of bone improves the stability and the histomorphometric variables of the osseointegration of dental implants.

Light-Induced Metastable Defects in a-Si:H: Towards an Understanding

1985 ◽  
Vol 49 ◽  
Author(s):  
Martin Stutzmann ◽  
Warren B. Jackson ◽  
Chuang Chuang Tsai
Keyword(s):  
Amorphous Silicon ◽  
Mechanical Stress ◽  
Hydrogenated Amorphous Silicon ◽  
Material Parameters ◽  
Kinetic Behaviour ◽  
Proposed Model ◽  
Special Cases ◽  
The Stability ◽  
Hydrogenated Amorphous

AbstractThe dependence of the creation and the annealing of metastable dangling bonds in hydrogenated amorphous silicon on various material parameters will be discussed in the context of a recently proposed model. After a brief review of the kinetic behaviour governing defect creation and annealing in undoped a- Si:H, a number of special cases will be analyzed: the influence of alloying with O, N, C, and Ge, changes introduced by doping and compensation, and the role of mechanical stress. Finally, possibilities to increase the stability of a-Si:H based devices will be examined.

Analysis of Acoustic-Structure Interaction Using a High-Order Doubly Asymptotic Approximation

2016 ◽  
Vol 24 (01) ◽  
pp. 1550021 ◽  
Author(s):  
Heekyu Woo ◽  
Young S. Shin
Keyword(s):  
Order Approximation ◽  
Stable Model ◽  
Approximation Model ◽  
Third Order ◽  
Acoustic Structure ◽  
Structure Interaction ◽  
Proposed Model ◽  
The Stability ◽  
Third Order Approximation ◽  
Interaction Problem

In this paper, a new third-order approximation model for an acoustic-structure interaction problem is introduced. The new approximation model is designed to be an accurate and a stable model for predicting the response of a submerged structure. The proposed model is obtained by combining two lower order approximation models instead of using an operator matching method. The stability of this model is checked by a modal analysis. Finally, the approximation model is coupled to the spherical shell structure, and its performance is checked by a shock analysis.

An extended optimal velocity difference model in a cooperative driving system

2015 ◽  
Vol 26 (05) ◽  
pp. 1550054
Author(s):  
Jinliang Cao ◽  
Zhongke Shi ◽  
Jie Zhou
Keyword(s):  
Traffic Flow ◽  
Linear Stability Theory ◽  
Difference Model ◽  
Optimal Velocity ◽  
Driving System ◽  
Cooperative Driving ◽  
Proposed Model ◽  
De Vries ◽  
The Stability ◽  
Theoretical Results

An extended optimal velocity (OV) difference model is proposed in a cooperative driving system by considering multiple OV differences. The stability condition of the proposed model is obtained by applying the linear stability theory. The results show that the increase in number of cars that precede and their OV differences lead to the more stable traffic flow. The Burgers, Korteweg–de Vries (KdV) and modified Korteweg–de Vries (mKdV) equations are derived to describe the density waves in the stable, metastable and unstable regions, respectively. To verify these theoretical results, the numerical simulation is carried out. The theoretical and numerical results show that the stabilization of traffic flow is enhanced by considering multiple OV differences. The traffic jams can be suppressed by taking more information of cars ahead.

A model of Fe3+-kaolinite, Al3+-goethite, Al3+-hematite equilibria in laterites

Clay Minerals ◽  
1989 ◽  
Vol 24 (1) ◽  
pp. 1-21 ◽  
Author(s):  
F. Trolard ◽  
Y. Tardy
Keyword(s):  
Stability Field ◽  
Equilibrium Conditions ◽  
Dissolved Silica ◽  
Silica Activity ◽  
Proposed Model ◽  
Coexisting Phases ◽  
Activity Temperature ◽  
The Stability ◽  
Fe Substitution ◽  
Mineral Constituents

AbstractThe distribution of Fe3+-kaolinite, Al-goethite and Al-hematite and their contents of Fe and Al in bauxites and ferricretes are controlled by water activity, dissolved silica activity, temperature and particle size. The proposed model, based on ideal solid-solution equilibria in the Fe2O3-Al2O3-SiO2-H2O system, takes into account water and silica activities. By using the same considerations as those previously developed for the Fe2O3-Al2O3-H2O system, the model calculates the amounts of coexisting phases, Al or Fe substitution ratios in goethite, hematite or kaolinite, and the stability field distributions of the minerals under various conditions. Thermodynamic equilibrium conditions and element distributions within the mineral constituents are shown to be dependent on the parameters cited above. The model yields results compatible with natural observations on lateritic profiles.

scholarly journals PRACTICAL IMPLEMENTATION OF THE MODEL OF FORMATION OF CADETS' READINESS TO ENSURE INFORMATION SECURITY IN PROFESSIONAL ACTIVITIES

2021 ◽  
Vol 1 ◽  
pp. 119-129
Author(s):  
Dmitry Dvoretsky ◽  
Natalia Kolesnikova ◽  
Oksana Makarkina ◽  
Kira Lagvilava
Keyword(s):  
Information Systems ◽  
Information Security ◽  
Information Technologies ◽  
The State ◽  
Practical Implementation ◽  
Positive Trend ◽  
Pedagogical Tools ◽  
Professional Activities ◽  
Security Issues ◽  
The Stability

The mass introduction of information technologies in the activities of state structures has made it possible to transfer the efficiency of their functioning to a qualitatively new level. Unfortunately, as a means of action, they have characteristic vulnerabilities and can be used not only for good, but also for harm. For the state, as a guarantor of the stability of a civilized society, the issue of ensuring the security of information processing is particularly important. Despite the automation of many information processes, the most vulnerable link in the work of information systems remains a person. A person acts as an operator of information systems and a consumer of information. The entire service process depends on the competence of the operator and the quality of his perception. There are areas of government activity where the cost of error is particularly high. These include ensuring the life and health of citizens, protecting public order and the state system, and ensuring territorial integrity. The specifics of the spheres must be taken into account when ensuring the security of information. This study concerns official activities that are provided by paramilitary groups. Currently, there is a discrepancy in the level of competence of new personnel in the first months of service. The author traces the shortcomings of general and special professional qualities in the field of information security. The purpose of the study is to substantiate certain pedagogical means of forming cadets ' readiness to ensure information security. As forms of theoretical knowledge, we will use the traditional hypothesis and model, as well as functionally distinguishable judgments – problem, assumption, idea and principle. Empirical forms of knowledge will be observation (experimental method) and fixation of facts. To evaluate the effectiveness of the developed pedagogical tools, we use statistical methods: observation (documented and interrogated) and calculation of generalizing indicators. To formulate conclusions, we will use logical methods: building conclusions and argumentation. The approbation of certain pedagogical tools described in this article showed a significant positive trend in terms of competence in information security issues.

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