scholarly journals An Energy-Saving Forwarding Mechanism Based on Clustering for Opportunistic Networks

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7427
Author(s):  
Gilmara Santos ◽  
Diogo Soares ◽  
Celso Carvalho ◽  
Edjair Mota

In Opportunistic Networks (OppNets), mobility of and contact between nodes are explored to create communication opportunities and exchange messages and information. A basic premise for a better performance of these networks is a collaboration of the nodes during communication. However, due to energy restriction factors, nodes may eventually fail to collaborate with message exchanges. In this work, we propose a routing mechanism called eGPDMI to improve message probability of delivery while optimizing nodes’ energy consumption. Unlike other algorithms proposed in OppNets literature, eGPDMI groups nodes by energy level and nodes interests using clustering techniques. Our major assumption is that retaining messages in nodes with the highest energy levels can improve network performance, thus overcoming the problem of nodes’ disconnection due to unwillingness to cooperate due to low energy values. Through questionnaire application and factorial design experiments, we characterize the impacts of energy levels in OppNets. Further, we apply performance evaluation of the eGPDMI mechanism in terms of effectiveness using mobility from real-world scenarios. The results show that our mechanism effectively reduces the degradation of the probability of delivery when the minimum energy level used for nodes to cooperate with communication increases.

Author(s):  
Piyush Rawat ◽  
Siddhartha Chauhan

Background and Objective: The functionalities of wireless sensor networks (WSN) are growing in various areas, so to handle the energy consumption of network in an efficient manner is a challenging task. The sensor nodes in the WSN are equipped with limited battery power, so there is a need to utilize the sensor power in an efficient way. The clustering of nodes in the network is one of the ways to handle the limited energy of nodes to enhance the lifetime of the network for its longer working without failure. Methods: The proposed approach is based on forming a cluster of various sensor nodes and then selecting a sensor as cluster head (CH). The heterogeneous sensor nodes are used in the proposed approach in which sensors are provided with different energy levels. The selection of an efficient node as CH can help in enhancing the network lifetime. The threshold function and random function are used for selecting the cluster head among various sensors for selecting the efficient node as CH. Various performance parameters such as network lifespan, packets transferred to the base station (BS) and energy consumption are used to perform the comparison between the proposed technique and previous approaches. Results and Discussion: To validate the working of the proposed technique the simulation is performed in MATLAB simulator. The proposed approach has enhanced the lifetime of the network as compared to the existing approaches. The proposed algorithm is compared with various existing techniques to measure its performance and effectiveness. The sensor nodes are randomly deployed in a 100m*100m area. Conclusion: The simulation results showed that the proposed technique has enhanced the lifespan of the network by utilizing the node’s energy in an efficient manner and reduced the consumption of energy for better network performance.


2017 ◽  
Vol 53 (6) ◽  
pp. 1104-1107 ◽  
Author(s):  
Abdolreza Jahanbekam ◽  
Colin Harthcock ◽  
David Y. Lee

A new method to directly modify the surface structure and energy levels of a porphyrin monolayer was examined with molecular-scale resolution using scanning tunneling microscopy and spectroscopy (STM and STS) and presented in this communication.


2006 ◽  
Vol 06 (02) ◽  
pp. 269-284 ◽  
Author(s):  
SUNNY K. GEORGE ◽  
K. SHANKAR

The distribution of vibrational energy in members of a complex structure with tuned absorbers attached at the joints and subjected to dynamic loading is studied. The concept of power flows through the structure is used to determine the time-averaged energy levels of each member in the structure. The power flows are calculated using the time-averaged product of force and velocity at the input and coupling points (joints) of a general structure made of axially vibrating rods. The receptance approach is used to calculate the coupling forces and velocities in the structure. By balancing the input power against the dissipated powers, the time-averaged energy levels in members are determined. The main criteria studied here is the reduction in the frequency-averaged vibrational energy level of a member when an absorber is attached, expressed as a percentage compared to the case where there are no absorbers. The concept is first illustrated with a simple model of 2 axially vibrating rods with an absorber attached to the joint. Next, a more complex structure comprising 8 rods with arbitrary orientations and several absorbers attached to junctions is studied. The effect of activating absorbers at various locations on reducing the energy levels of certain members is examined. It is possible to estimate the usefulness of the absorber with respect to any member by determining the percentage reduction of energy level for that member.


2007 ◽  
Vol 21 (18n19) ◽  
pp. 3455-3458
Author(s):  
ANPING LIU ◽  
YINFENG WANG ◽  
XUEHENG YANG

The Zr -doped TiN coating, a nanometer (Ti, Zr)N thin film, has been deposited by reactive magnetron sputtering on slides and Al substrates. The crystalline phase and energy band structure have been analyzed by XRD and STS. The results of XRD show that the (Ti, Zr)N film is poly crystalline and consisted of mixed crystal of TiN and ZrN phase. The STS spectra show that Zr -doping didn't change the position and band-gap of energy level, only two new energy levels appeared, Eg = 0.33eV and Eg = 0.42eV. According to the results of measurement, (Ti, Zr)N has higher hardness and better corrosion resistance than TiN by Zr -doping.


2009 ◽  
Vol 38 (5) ◽  
pp. 857-862
Author(s):  
Fernando Guilherme Perazzo Costa ◽  
Janaine Sena da Costa ◽  
Cláudia de Castro Goulart ◽  
Denise Fontana Figueiredo-Lima ◽  
Raul da Cunha Lima Neto ◽  
...  

This study was carried out to evaluate the energy levels in the diet to obtain better performance rates and quality of eggs from laying hens in the second production cycle. One hundred and eighty Bovans Goldline laying hens with 62 weeks of age were used during four 28-day periods. A completely randomized experimental design was used with four metabolizable energy levels (2,650, 2,725, 2,800, 2,875 and 2,950 kcal/kg), each with six replicates of six birds. The energy level of diet did not affect the weight of the egg, yolk, albumen and eggshell, the percentages of yolk, albumen and eggshell, yolk color and egg specific gravity. Feed intake, egg production, egg mass and feed conversion per egg mass and per dozen eggs increased significantly with increasing levels of metabolizable energy. Feed intake decreased linearly as the energy level in the diet increased. The metabolizable energy levels showed a quadratic effect on egg production, egg mass and feed conversion per egg mass and per dozen eggs. The metabolizable energy level of 2,830 kcal/kg was the most appropriate to promote better performance and quality of eggs from laying hens in the second production cycle.


2010 ◽  
Vol 39 (7) ◽  
pp. 1565-1570 ◽  
Author(s):  
Ana Cristina Chacon Lisboa ◽  
Dermeval Araújo Furtado ◽  
Ariosvaldo Nunes de Medeiros ◽  
Roberto Germano Costa ◽  
Rita de Cássia do Egypto Queiroga ◽  
...  

The objective of this work was to evaluate the quantitative characteristics of carcasses of Moxotó and Canindé goats finished in feedlots and fed diets of two levels of energy. It was used 40 castrated young goats, 20 from Moxotó breed and 20 from Canindé breed, each one with an average body weight of 15.2 kg. The animals were fed with diets containing 2.20 and 2.71 (Mcal/kg DM). The experimental period lasted 86 days. There was no difference among the barometric measures of Moxotó and Canindé kids. Canindé goats showed higher final weight, higher weight after fasting and higher hot and cold carcass weights when compared to the Moxotó animals. Animals that consumed diets with higher energy level had higher final weight and conformation as well as higher carcass yield. Considering the percentage values of the commercial meat cuts, no difference among treatments was observed. The diet was the factor that most influenced the non-constituent components of the carcass of Moxotó and Canindé goats. In general, animals belonging to the Canindé breed presented higher quantitative characteristics than the Moxotó breed. Supply of diets with higher energetic level (2.71 Mcal/kg DM) for goats from Moxotó and Canindé breeds, in feedlots, favors the production of carcass with higher yields and heavier commercial meat cuts.


2020 ◽  
Vol 54 (s1) ◽  
pp. 45-52
Author(s):  
Joyce M. Hansen ◽  
Niki Fidopiastis ◽  
Trabue Bryans ◽  
Michelle Luebke ◽  
Terri Rymer

Abstract In the radiation sterilization arena, the question often arises as to whether radiation resistance of microorganisms might be affected by the energy level of the radiation source and the rate of the dose delivered (kGy/time). The basis for the question is if the microbial lethality is affected by the radiation energy level and/or the rate the dose is delivered, then the ability to transfer dose among different radiation sources could be challenged. This study addressed that question by performing a microbial inactivation study using two radiation sources (gamma and electron beam [E-beam]), two microbial challenges (natural product bioburden and biological indicators), and four dose rates delivered by three energy levels (1.17 MeV [gamma], 1.33 MeV [gamma], and 10 MeV [high-energy E-beam]). Based on analysis of the data, no significant differences were seen in the rate of microbial lethality across the range of radiation energies evaluated. In summary, as long as proof exists that the specified dose is delivered, dose is dose.


2014 ◽  
Vol 38 (3) ◽  
pp. 286-294 ◽  
Author(s):  
Rodrigo de Souza ◽  
Claudete Regina Alcalde ◽  
Bruna Hygino ◽  
Bruna Susan de Labio Molina ◽  
Geraldo Tadeu dos Santos ◽  
...  

Peripartum is a critical period for dairy goats, as dry matter intake (DMI) is not enough to supply the energy requirement for foetal growth and subsequent lactation. The objective of this study was to evaluate the use of calcium salts of fatty acids (CSFA) to increase dietary energy level of peripartum dairy goats and its effects on nutritive value of diets and milk quality. Twenty multiparous Saanen goats (body weight 63.5±10.3 kg) were distributed in a completely randomised design in four treatments at the following dietary energy levels: 2.6 Mcal of metabolisable energy per kg of dry matter (Mcal ME/kg DM) - control diet; and 2.7, 2.8, and 2.9 Mcal/kg DM - with added CSFA. Goats were housed in individual stalls and evaluated in the peripartum period, by measuring body weight (BW), DMI, dry matter and nutrient digestibility of diets, blood composition, and milk quality and yield. Increasing dietary energy level to 2.9 Mcal ME/kg DM had no effect on BW and did not limit DMI. CSFA supplementation increased intake of total digestible nutrients and did not affect fibre digestion. Blood triglycerides and cholesterol concentration increased with CSFA addition. The treatments had no effect on milk yield and composition; however, CSFA supplementation changed the fatty acid concentration of milk fat, increasing levels of polyunsaturated and essential fatty acids. In conclusion, peripartum dairy goats supplemented with CSFA to increase dietary energy level up to 2.9 Mcal ME/kg DM had a greater supply of total digestible nutrients and showed altered fatty acid concentration of milk fat.


1983 ◽  
Vol 17 (4) ◽  
pp. 330-335 ◽  
Author(s):  
D. J. Ford ◽  
R. J. Ward

Rats of 3 strains were fed diets of natural ingredients in 4 different laboratories. The diets contained different levels of protein and energy within ranges comparable to those found in existing laboratory diets. Energy level over the range examined appeared to exert greatest influence on bodyweight gain, but had no effect on food intake. The diet with the highest amino acid content was consumed in smaller amounts than the other diets. Food utilization was less efficient in the lower energy diets. Fat deposition was reduced in animals fed the lowest energy diet. It is concluded that energy level of the diet exerts an effect on the rate of bodyweight gain in rats, but that for longer-term studies a reduced energy level may be beneficial by leading to smaller fat deposits with consequent increase in longevity.


Author(s):  
Elisa Peñalvo-López ◽  
Javier Cárcel-Carrasco ◽  
Manuel Valcuende-Paya ◽  
María Carmen Carnero-Moya

The construction segment is an important economic sector in Europe, representing 9% of European gross domestic product (GDP) and providing approximately 18 million direct jobs. Construction activities that include renovation work and energy retrofits add almost twice as much value as the construction of new buildings, and small and medium-sized enterprises (SMEs) contribute more than 70% of the value added in the EU building sector. Furthermore, European legislation obliges member states to establish minimum energy efficiency requirements for buildings to achieve optimum levels of costs versus energy demand reduction. These requirements are reviewed every five years and represent categories of buildings based on their energy levels (demand and generation). This chapter analyzes the legislation associated to nearly zero energy buildings (nZEB) in Spain in order to identify the factors that will leverage their massive implementation.


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