Adaptive Forwarding Scheme for Bounded Time Constraint in Delay Tolerant Networks

© 2017, Springer Science+Business Media New York. In parallel with lots of research to improve message delivery rate in Delay Tolerant Networks (DTN), additional application specific requirements are demanded to deploy them in the real world. Among many requirements, we focus on desired delivery ratio within required deadline in DTN. To achieve this, we propose an adaptive forwarding algorithm primarily based on well-known DTN algorithm, Spray and Wait. Unlike conventional static forwarding schemes, the number of message copies and forwarding algorithm are dynamically adjusted according to the difference between current service level and given requirement in the proposed scheme. Furthermore, analytical model and recorded history on a node are used sequentially depending on availability of parameters to meet application specific requirement. Finally, simulation results demonstrate that our proposed algorithm can meet given requirement with lower resources consumption than existing protocols in varying network conditions

Fuzzy logic-based guaranteed lifetime protocol for real-time wireless sensor networks

© 2015 by the authors; licensee MDPI, Basel, Switzerland. Few techniques for guaranteeing a network lifetime have been proposed despite its great impact on network management. Moreover, since the existing schemes are mostly dependent on the combination of disparate parameters, they do not provide additional services, such as real-time communications and balanced energy consumption among sensor nodes; thus, the adaptability problems remain unresolved among nodes in wireless sensor networks (WSNs). To solve these problems, we propose a novel fuzzy logic model to provide real-time communication in a guaranteed WSN lifetime. The proposed fuzzy logic controller accepts the input descriptors energy, time and velocity to determine each node’s role for the next duration and the next hop relay node for real-time packets. Through the simulation results, we verified that both the guaranteed network’s lifetime and real-time delivery are efficiently ensured by the new fuzzy logic model. In more detail, the above-mentioned two performance metrics are improved up to 8%, as compared to our previous work, and 14% compared to existing schemes, respectively

Interference aware real-time flows scheduling in cluster based wireless sensor networks

© TAETI. For the real-time scheduling in wireless sensor networks, Time Division Multiple Access (TDMA) under cluster architecture is usually considered as reasonable as well as scalable approach. Under this architecture, several type of inferences should be taken into account to allocate time slot. For this goal, we have already proposed a new real-time scheduling algorithm. But, it has several assumptions and constraints so their deployment is limited to some specific real scenarios. In this paper, we additionally concern the interference of a node which belongs to two clusters concurrently. Token based scheduling algorithm between two cluster heads is proposed to solve this problem. Token is given to each cluster head consequently so order of slot allocation is achieved automatically. Finally, simulation results are given to prove that more flows are delivered within the deadline than previous work due to avoidance of inter-cluster interference in efficient way

Guaranteed lifetime protocol for IoT based wireless sensor networks with multiple constraints

© 2020 Elsevier B.V. Over the past two decades, the subject of extension of the lifetime of Wireless Sensor Networks (WSN) based on the Internet of Things (IoT) has been thoroughly investigated by researcher. As WSN, and its new form based on IoT, are increasingly being deployed in time-critical applications, users require certain network lifetime guarantees to satisfy application requirements. Few research efforts in the past have focused on guaranteeing the IoT-based network lifetime. Most such efforts pay little or no attention to other network performance indicators such as sensing coverage and network connectivity. To address this challenge, this work proposes a new centralized approach that analyzes a network\u27s energy consumption to optimize node duty cycles. In the proposed scheme, the sink node periodically assigns an active/sleep role to each node for the next network cycle by coupling the residual energy, total active time, and possible coverage area to guarantee their lifetimes. We show through extensive simulation that the proposed guaranteed lifetime protocol achieves less average end-to-end delay and better packet delivery ratio when compared to its best rival protocols formulated in past research, i.e., the CERACC, A-Mac, and Coverage Preserving protocols

Study of fungicidal properties of colloidal silver nanoparticles (AgNPs) on trout egg pathogen, Saprolegnia sp.

Silver nanoparticles (AgNPs) are known to have bactericidal and fungicidal effects. Since, there is few information available on the interaction of colloidal nanosilver with fish pathogens. Hence, the current study investigated the effects of colloidal AgNPs on the in vitro growth of the fish pathogen Saprolegnia sp.. Before the experiments, various important properties of AgNPs were well-characterized. The antifungal activity of AgNPs was then evaluated by determining the minimum inhibitory concentrations (MICs) using two-fold serial dilutions of colloidal nanosilver in a glucose yeast extract agar at 22ºC. The growth of Saprolegnia sp. on the AgNPs agar treatments was compared to that of nanosilver-free agar as controls. The results showed that AgNPs have an inhibitory effect on the in vitro growth of the tested fungi. The MIC of AgNPs for Saprolegnia sp. was calculated at 1800 mg/L, which is equal to 0.18 percent. It seems that AgNPs could be a proper replacement for teratogenic and toxic agents, such as malachite green. In addition, the indirect use of AgNPs could be a useful method for providing new antifungal activity in aquaculture systems

Delay and energy based message delivery in delay tolerant networks

© 2019 IEEE. Routing in delay tolerant network (DTN) is one of the most challenging problems in addressing the application specific requirements. This paper presents a routing algorithm in DTN that achieves the delivery ratio within the given deadline requirements by evaluating the capability of a node to deliver a message to its destination on the basis of destination-dependent and destination-independent attributes of the encountered node. The protocol dynamically adjusts the number of message copies based on our previous works [13] and chooses the most suitable relay node by taking the delivery probability to the destination and the remaining energy level of nodes into account. Simulation results demonstrate that our proposed algorithm achieves better performance compared to the counterpart and is adaptive to varying network conditions

Nutritional and ameliorative effects of dietary curcumin and its nano-silica and nano-zeolite encapsulated forms on growth, biochemical and fatty acid profile of common carp (Cyprinus carpio)

The present study aimed to examine individual nutritional and ameliorative effects of silica nanoparticles (SiO(2)NPs) and natural zeolite nanoparticles (ZeNPs) and their potential role as carriers to alter the bioavailability of curcumin. Common carps (Cyprinus carpio) were fed during 60 days with a control diet, and curcumin, turmeric, SiO(2)NPs, curcumin-loaded SiO(2)NPs, ZeNPs, and curcumin-loaded ZeNPs each at 1, 50, 6.15, 7.15, 39, and 40 g/kg diet, respectively. The highest weight gain (WG) and specific growth rate (SGR) were observed in fish fed with turmeric (P < 0.05). Moreover, dietary curcumin and ZeNPs increased the content of monounsaturated fatty acids (P < 0.05). After exposure to silver nanoparticles (AgNPs), the lowest amount of aspartate aminotransferase (AST) was obtained in fish fed with curcumin (P < 0.05). In addition, alanine aminotransferase (ALT) decreased significantly in the negative control, curcumin, and curcumin-loaded SiO(2)NPs treatments in comparison to the positive control group (P < 0.05). The lowest silver accumulation was observed in the negative control and SiO(2)NPs groups (P < 0.05). This experiment demonstrated that while the nanoencapsulation of curcumin on SiO(2)NPs and ZeNPs did not enhanced the impact of curcumin on the growth and biochemical factors of carps, it can still be considered a potential dietary supplement for enhancing growth and antioxidant indices when added individually to the diet.GRC97-06503-1info:eu-repo/semantics/publishedVersio

Stability Analysis of a Vector-Borne Disease with Variable Human Population

A mathematical model of a vector-borne disease involving variable human population is analyzed. The varying population size includes a term for disease-related deaths. Equilibria and stability are determined for the system of ordinary differential equations. If R0≤1, the disease-“free” equilibrium is globally asymptotically stable and the disease always dies out. If R0>1, a unique “endemic” equilibrium is globally asymptotically stable in the interior of feasible region and the disease persists at the “endemic” level. Our theoretical results are sustained by numerical simulations

Mathematical Analysis of a Malaria Model with Partial Immunity to Reinfection

A deterministic model with variable human population for the transmission dynamics of malaria disease, which allows transmission by the recovered humans, is first developed and rigorously analyzed. The model reveals the presence of the phenomenon of backward bifurcation, where a stable disease-free equilibrium coexists with one or more stable endemic equilibria when the associated reproduction number is less than unity. This phenomenon may arise due to the reinfection of host individuals who recovered from the disease. The model in an asymptotical constant population is also investigated. This results in a model with mass action incidence. A complete global analysis of the model with mass action incidence is given, which reveals that the global dynamics of malaria disease with reinfection is completely determined by the associated reproduction number. Moreover, it is shown that the phenomenon of backward bifurcation can be removed by replacing the standard incidence function with a mass action incidence. Graphical representations are provided to study the effect of reinfection rate and to qualitatively support the analytical results on the transmission dynamics of malaria