Opportunistic Routing with Multi-Channel Cooperative Neighbour Discovery

Due to the scattered nature of the network,data transmission in a dis-tributed Mobile Ad-hoc Network(MANET)consumes more energy resources(ER)than in a centralized network,resulting in a shorter network lifespan(NL).As a result,we build an Enhanced Opportunistic Routing(EORP)protocol architecture in order to address the issues raised before.This proposed routing protocol goal is to manage the routing cost by employing power,load,and delay to manage the routing energy consumption based on theflooding of control pack-ets from the target node.According to the goal of the proposed protocol techni-que,it is possible to manage the routing cost by applying power,load,and delay.The proposed technique also manage the routing energy consumption based on theflooding of control packets from the destination node in order to reduce the routing cost.Control packet exchange between the target and all the nodes,on the other hand,is capable of having an influence on the overall efficiency of the system.The EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adja-cent nodes for each node in the routing route as part of the routing path discovery process,which occurs during control packet transmission.While control packet transmission is taking place during the routing path discovery process,the EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adjacent nodes for each node in the routing.Also included is a simulation of these protocols in order to evaluate their performance across a wide range of packet speeds using Constant Bit Rate(CBR).When the packet rate of the CBR is 20 packets per second,the results reveal that the EORP-MCCND is 0.6 s quicker than the state-of-the-art protocols,according to thefindings.Assuming that the CBR packet rate is 20 packets per second,the EORP-MCCND achieves 0.6 s of End 2 End Delay,0.05 s of Routing Overhead Delay,120 s of Network Lifetime,and 20 J of Energy Consumption efficiency,which is much better than that of the state-of-the-art protocols.

Evolutionary Profile of Opportunistic Infections in People Living with Human Immunodeficiency Virus during Six Months of Dolutegravir Based Antiretroviral Treatment in Kinshasa, Democratic Republic of Congo

Background: Opportunistic infections (OI), which are still a major problem in the care of People Living with HIV (PLHIV), occur in situations of immunosuppression. The AntiRetroViral Treatments (ART) used allow a spectacular reduction in the frequency of Opportunistic Infections. Objective: The objective of this study is to present the evolution of Opportunistic Infections in People Living with HIV under AntiRetroViral Treatment in Kinshasa in the era of Dolutegravir. Methods: The present study is a prospective cohort to present the evolutionary profile of OIs in PLHIV on ART for 6 months in Outpatient Treatment Centers (OTC) in Kinshasa. Sixteen OTCs had been included. The population of the present work was patients over 18 years of age at inclusion, infected with HIV-1 and initiating ART in the selected OTC. Results: On inclusion, 119 patients were included of which 56.3% were women. Malaria (45.4%), tuberculosis (29.4%) and cutaneous pruritus (23.5%) were the most common Opportunistic Infections (OIs). In the third month of ART, 37 patients came for the consultation of which 70.3% were women. Non-specific STIs (97.3%), skin pruritus (37.8%) and malaria (24.3%) were the dominant OIs among patients. At the sixth month of ART, 62 patients came for the medical consultation of which 61.3% were women. Skin pruritus (25.8%), dermatitis (22.6%) and rash (21%) were the most common OIs. Conclusion: The evolutionary profile is marked by the conservation of Opportunistic Infections such as dermatitis (pruritus and rashes) and malaria.

Opportunistic and other intestinal parasites among HIV/AIDS patients attending Gambi higher clinic in Bahir Dar city,North West Ethiopia

Objective:To determine the magnitude of opportunistic and non-opportunistic intestinal parasitic infections among HTV/AIDS patients in Bahir Dar.Methods:Cross-sectional study was conducted among HIV/ AIDS patients attending Gambi higher clinic from Aprill- May 30,2009. Convenient sampling technique was employed to identify the study subjects and hence a total of 248 subjects were included.A pre-tested structured questionnaire was used to collect sociodemographic data of patients.Stool samples were examined by direct saline,iodine wet mount, formol-ether sedimentation concentration and modified Ziehl-Neelsen staining technique. Results:Out of 248 enrolled in the study,171(69.0%)(90 males and 81 females) were infected with one or more intestinal parasites.The highest rate of intestinal parasites were observed among HIV/AIDS patients(80.3%,151/188),and the infection rate of HIV negative individuals was 33.3%(20/60).Cryptosporidum parvum(43.6%),Isospora belli(15.5%) and Blastocystis hominis (10.5%) were opportunistic parasites that were found only in HIV/AIDS patients.Conclusions: Opportunistic parasite infections are common health problem among HIV/ AIDS patients in the study area.Therefore,early detection and treatment of these parasites are important to improve the quality of life of HIV/AIDS patients.

A preventive opportunistic maintenance method for railway traction power supply system based on equipment reliability

Conventional maintenance mode for the traction power supply system(TPSS)is to perform scheduled regular maintenance activities for power supply equipment,while such maintenance mode may result in undue maintenance tasks and low efficiency due to different degradation processes of different sorts of equipment.To address this problem,this paper introduces a preventive opportunistic maintenance(POM)method for TPSS based on equipment reliability.Firstly,a POM model is established by considering the equipment reliability degradation process based on Weibull distribution.Then,by considering the total power outage time in the planned operation cycle of TPSS as the optimization objective,the optimal maintenance scheme of TPSS is formulated by iterative method of maintenance strategies.The proposed method is verified by introducing practical maintenance strategies and fault record data of the traction transformer,circuit breaker and disconnector in an actual TPSS of a railway administration.Results show that the presented method can make full use of the existing fault data to develop a POM scheme for TPSS.It can improve maintenance efficiency and reduce power outage time,providing guidance to formulate scientific maintenance strategies for TPSS.

Polyphase orthogonal sequences design for opportunistic array radar via HGA

Opportunistic array radar （OAR） is a new generation radar system based on the stealth of the platform, which can improve the modern radar performance effectively. Designing the orthogonal code sets with low autocorrelation and cross-correlation is a key issue for OAR. This paper proposes a novel hybrid genetic algorithm （HGA） and designs the polyphase orthogonal code sets with low autocorrelation and cross-correlation properties, which can be used in the OAR system. The novel algorithm combines with simulated annealing （SA） and genetic algorithm （GA）, adds in keeping best individuals and competition in small scope, and introduces grey correlation evaluation to evaluate fitness function. These avoid the premature convergence problem existed in GA and enhance the global searching capability. At last, the genetic results are optimized to obtain the best solution by using greedy algorithm. The simulation results show that the proposed algorithm is effective for the design of orthogonal phase signals used in OAR systems.

Nested case-control study on risk factors for opportunistic infections in patients with inflammatory bowel disease

BACKGROUND When opportunistic infections occur, patients with inflammatory bowel disease(IBD) commonly display a significantly increased rate of morbidity and mortality.With increasing use of immunosuppressive agents and biological agents,opportunistic infections are becoming a hot topic in the perspective of drug safety in IBD patients. Despite the well-established role of opportunistic infections in the prognosis of IBD patients, there are few epidemiological data investigating the incidence of opportunis-tic infections in IBD patients in China. Besides, the risk factors for opportunistic infection in Chinese IBD patients remain unclear.AIM To predict the incidence of opportunistic infections related to IBD in China, and explore the risk factors for opportunistic infections.METHODS A single-center, prospective study of IBD patients was conducted. The patients were followed for up to 12 mo to calculate the incidence of infections. For each infected IBD patient, two non-infected IBD patients were selected as controls. A conditional logistic regression analysis was used to assess associations between putative risk factors and opportunistic infections, which are represented as odds ratios(OR) and 95% confidence intervals(CIs).RESULTS Seventy(28.11%) out of 249 IBD patients developed opportunistic infections.Clostridium difficile infections and respiratory syncytial virus infections were found in 24 and 16 patients, respectively. In a univariate analysis, factors such as the severity of IBD, use of an immunosuppressant or immunosuppressants, high levels of fecal calprotectin, and C-reactive protein or erythrocyte sedimentation rate were individually related to a significantly increased risk of opportunistic infection. Multivariate analysis indicated that the use of any immunosuppressant yielded an OR of 3.247(95%CI: 1.128-9.341), whereas the use of any two immunosuppressants yielded an OR of 6.457(95%CI: 1.726-24.152) for opportunistic infection. Interestingly, when immunosuppressants were used in combination with infliximab(IFX) or 5-aminosalicylic acid, a significantly increased risk of opportunistic infection was also observed. The relative risk of opportunistic infection was greatest in IBD patients with severe disease activity(OR = 9.090; 95%CI: 1.532-53.941, relative to the remission stage). However, the use of IFX alone did not increase the risk of opportunistic infection.CONCLUSION Factors such as severe IBD, elevated levels of fecal calprotectin, and the use of immunosuppressive medications, especially when used in combination, are major risk factors for opportunistic infections in IBD patients. The use of IFX alone does not increase the risk of opportunistic infection.

Opportunistic maintenance for multi-component systems considering structural dependence and economic dependence

Although opportunistic maintenance strategies are widely used for multi-component systems, all opportunistic mainte- nance strategies only consider economic dependence and do not take structural dependence into account. An opportunistic main- tenance strategy is presented for a multi-component system that considers both structural dependence and economic dependence. The cost relation and time relation among components based on structural dependence are developed. The maintenance strategy for each component of a multi-component system involves one of five maintenance actions, namely, no-maintenance, a minimal maintenance action, an imperfect maintenance action, a perfect maintenance action, and a replacement action. The maintenance action is determined by the virtual age of the component, the life expectancy of the component, and the age threshold values. Monte Carlo simulation is designed to obtain the optimal oppor- tunistic maintenance strategy of the system over its lifetime. The simulation result reveals that the minimum maintenance cost with a strategy that considers structural dependence is less than that with a strategy that does not consider structural dependence. The availability with a strategy that considers structural dependence is greater than that with a strategy that does not consider structural dependence under the same conditions.

Effectiveness of gastric cancer screening programs in South Korea:Organized vs opportunistic models

AIM:To investigate the outcome and effectiveness of two screening programs,National Cancer Screening Program(NCSP)and opportunistic screening(OS),for the detection of gastric cancer. METHODS:A total of 45 654 subjects underwent upper endoscopy as part of the NCSP or OS at the Chung-Ang University Healthcare System in Korea between January 2007 and December 2010.The study population was comprised of subjects over the age of 40 years.More specifically,subjects who took part in the NCSP were Medicaid recipients and beneficiaries of the National Health Insurance Corporation.Still photo-graphs from the endoscopies diagnosed as gastric cancer were reviewed by two experienced endoscopists. RESULTS:The mean age of the screened subjects was 55 years for men and 54 years for women.A total of 126 cases(0.28%)of gastric cancer were detected from both screening programs;100 cases(0.3%)from NCSP and in 26 cases(0.2%)from OS.The proportion of early gastric cancer(EGC)detected in NCSP was higher than that in OS(74.0%vs 53.8%,P=0.046). Among the 34 416 screenees in NCSP,6585(19.1%) underwent upper endoscopy every other year as scheduled.Among the 11 238 screenees in OS,3050(27.1%) underwent upper endoscopy at least once every two years during the study period.The detection rate of gastric cancer was found to be significantly higher during irregular follow-up than during regular follow-up in both screening programs(0.3%vs 0.2%,P=0.036).A higher incidence of EGC than advanced gastric cancer was observed during regular follow-up compared with irregular follow-up. CONCLUSION:Compliance to the screening program is more important than the type of screening system used.

Optimal opportunistic maintenance model of multi-unit systems

An opportunistic maintenance model is presented for a continuously deteriorating series system with economical de-pendence. The system consists of two kinds of units, which are respectively subjected to the deterioration failure described by Gamma process and the random failure described by Poisson process. A two-level opportunistic policy defined by three decision parameters is proposed to coordinate the different maintenance actions and minimize the long-run maintenance cost rate of the system. A computable expression of the average cost rate is established by using the renewal property of the stochastic process of the maintained system state. The optimal values of three deci- sion parameters are derived by an iteration approach based on the characteristic of Gamma process. The behavior of the proposed policy is illustrated through a numerical experiment. Comparative study with the widely used corrective maintenance policy demonstrates the advantage of the proposed opportunistic maintenance method in significantly reducing the maintenance cost. Simultane- ously, the applicable area of this opportunistic model is discussed by the sensitivity analysis of the set-up cost and random failure rate.

Prevalence of Opportunistic Pathogens and Diversity of Microbial Communities in the Water System of a Pulmonary Hospital

Objective Our objective was to investigate the occurrence of opportunistic pathogens and characterize the bacterial community structures in the water system of a pulmonary hospital.Methods The water samples were collected from automatic and manual faucets in the consulting room,treatment room,dressing room,respiratory ward,and other non-medical rooms in three buildings of the hospital.Quantitative polymerase chain reaction was used to quantify the load of several waterborne opportunistic pathogens and related microorganisms,including Legionella spp.,Mycobacterium spp.,and M.avium.Illumina sequencing targeting 16 S r RNA genes was performed to profile bacterial communities.Results The occurrence rates of Legionella spp.,Mycobacterium spp.,and M.avium were 100%,100%,and 76%,respectively in all samples.Higher occurrence rates of M.avium were observed in the outpatient service building(building 1,91.7%)and respiration department and wards(building 2,80%)than in the office building(building 3),where no M.avium was found.M.avium were more abundant in automatic faucets(average 2.21×10~4 gene copies/L)than in manual faucets(average 1.03×10~4 gene copies/m L)(P<0.01).Proteobacteria,Actinobacteria,Bacteroidetes,Cyanobacteria,Firmicutes,and Acidobacteria were the dominant bacterial phyla.Disinfectant residuals,nitrate,and temperature were found to be the key environmental factors driving microbial community structure shifts in water systems.Conclusion This study revealed a high level of colonization of water faucets by opportunistic pathogens and provided insight into the characteristics of microbial communities in a hospital water system and approaches to reduce risks of microbial contamination.

Investigation and Analysis on Pathogen Distribution of HIV/AIDS Patients with Opportunistic Infection

Objective: This study aims to understand the distribution of pathogenic bacteria in the region of HIV/AIDS patients with opportunistic infection. Methods: To count the number of the bacterial culture of HIV/AIDS patients in our hospital from October 2011 to December 2014, and observe the distribution of all kinds of pathogenic bacteria. Results: From the 4269 cases of HIV/AIDS patients’ bacteria, 5045 cases were cultured whose main flora distribution wasCandida albicans, 1759 cases. The second one was penicillium, 982 cases. The third one was mycobacteria, 557 cases. And then there are 213 cases ofCryptococcus neoformans, 212 cases of?Klebsiella pneumonia, 209 cases of?E. coli, 157 cases of coagulase-negative staphylococci, 112 cases of?Candida tropicalis, 90 cases of glabrata, 81 cases of?Staphylococcus aureus, 75 cases of?Pseudomonas aeruginosa, 60 cases of Salmonella, 48 cases of Acinetobacter and the distribution of the rest of cultured bacterial was less than 40 cases. Conclusion: There are many kinds of types of Pathogenic bacteria in HIV/AIDS patients with the opportunity to infectious. And the majorities are?Candida albicans,?Penicillium marneffei,?Penicillium,?Mycobacterium,?Cryptococcus neoformans?and so on. The infection sites are widely distributed;respiratory and circulatory are the main infected system. Improving the detection rate and reducing the contamination rate can truly reflect the distribution of pathogenic bacteria, and the distribution can guide the infection work in hospital. At the same time, it’s good to predict and prevent opportunistic infection. Thus, the patients can get immediate treatment.

Opportunistic screening for atrial fibrillation with a single lead device in geriatric patients

Objective To determine the diagnostic yield of repeated screening for atrial fibrillation(AF)among geriatric patients.Methods A pragmatic prospective cohort study into applying opportunistic screening for AF with a handheld single lead ECG device(SLD)in a geriatric cohort.Consecutive patients of 65 years old and older visiting the geriatric outpatient clinic were eligible for inclusion.A 12 lead ECG was performed,followed by measurements with the SLD during every visit to the geriatric outpatient clinic.A frailty index was based on the accumulation of deficits model.Results 478 patients were eligible.Patients were excluded if they did not give informed consent(17 patients),had a pacemaker or implantable cardioverter defibrillator(20 patients),or had incomplete medical files(two patients).After exclusion,439 patients participated in this study.The mean age was 78 years(range 65 to 100 years),54%were female.AF was known in 89 patients(20%),first detected on the baseline ECG in four patients(1%)and first detected with the SLD in 20 patients(5%)during follow up visits.Sensitivity of the SLD was 90.0%,specificity 99.0%,negative predictive value 99.7%,and positive predictive value 73.5%.Most patients(82%)with AF were frail and 53%were severely frail.Conclusion Repeated screening in geriatric patients has a five times higher diagnostic yield than usual care.It was easily combined with usual care.Because of the positive predictive value of 73.5%,it remains necessary to confirm AF with a 12 lead ECG or 24-h Holter monitoring.

Stochastic Learning for Opportunistic Peer-to-Peer Computation Offloading in IoT Edge Computing

Peer-to-peer computation offloading has been a promising approach that enables resourcelimited Internet of Things(IoT)devices to offload their computation-intensive tasks to idle peer devices in proximity.Different from dedicated servers,the spare computation resources offered by peer devices are random and intermittent,which affects the offloading performance.The mutual interference caused by multiple simultaneous offloading requestors that share the same wireless channel further complicates the offloading decisions.In this work,we investigate the opportunistic peer-to-peer task offloading problem by jointly considering the stochastic task arrivals,dynamic interuser interference,and opportunistic availability of peer devices.Each requestor makes decisions on both local computation frequency and offloading transmission power to minimize its own expected long-term cost on tasks completion,which takes into consideration its energy consumption,task delay,and task loss due to buffer overflow.The dynamic decision process among multiple requestors is formulated as a stochastic game.By constructing the post-decision states,a decentralized online offloading algorithm is proposed,where each requestor as an independent learning agent learns to approach the optimal strategies with its local observations.Simulation results under different system parameter configurations demonstrate the proposed online algorithm achieves a better performance compared with some existing algorithms,especially in the scenarios with large task arrival probability or small helper availability probability.

Distribution Characteristics of Drug Susceptibility Test Results of Tuberculosis and Non-Tuberculous Bacilli in Patients with Opportunistic Infections of AIDS

Objective: To understand the distribution of drug susceptibility test results of opportunistic infections of tuberculosis and non-tuberculous bacilli in AIDS patients. Methods: The AIDS patients who were hospitalized in our hospital from January 2016 to June 2019 were collected as the research objects, and patients with opportunistic tuberculosis and non-tuberculous bacilli from AIDS patients were screened for drug susceptibility tests, and the distribution characteristics of drug susceptibility were analyzed. Results: 179 strains of tuberculosis and non-tuberculous mycobacteria were isolated from the specimens of AIDS patients, including 135 cases of tuberculosis mycobacteria and 44 cases of non-tuberculous mycobacteria. In the results of the drug susceptibility test, most strains of Mycobacterium tuberculosis showed sensitivity to commonly used drugs, and a few strains showed resistance;most strains of non-tuberculous mycobacteria showed resistance, and a few strains showed sensitivity. Conclusion: AIDS opportunistic infection of Mycobacterium tuberculosis and non-tuberculous mycobacteria have significant differences in drug sensitivity test results. Timely detection and analysis are of great significance to the diagnosis and treatment of the disease.

Opportunistic-tended life history traits of Siniperca kneri in the Three Gorges Reservoir,China: potential responses to impoundment

Reservoir impoundment changes original fluvial habitats into lentic environments. Fish species adapted to lentic habitats may take the advantage of such habitat changes and show typical life history traits might facilitate the population increase. Siniperca kneri rarely occurred in fishery landing in the Three Gorges Reservoir (TGR) area before its impoundment in 2003, but it is now a dominant species. In this study, a total of 438 females of S . kneri were collected monthly during September 2012 through January 2014 using gill nets in the TGR. The age, growth, and reproductive biology were then investigated, and compared with other S . kneri populations. The standard length at age 1 was 149.9 mm in the TGR, which is larger than the three compared populations (i.e., Sandaohe Reservoir, Xinfengjiang Reservoir, and North River), but smaller than one (the Guishi Reservoir). The youngest mature female in the TGR was age 1, which is younger than that of the two compared populations (i.e., Xinfengjiang Reservoir and the North River). The relative fecundity in the TGR was 140 eggs/g, which is higher than that of the only available compared population (Xinfengjiang Reservoir, 96 eggs/g). Our results demonstrated that S . kneri in the TGR tended to have faster growth in the first year, a younger age at first maturation, and higher reproductive eff ort. We suggest that such opportunistic-tended life history traits might facilitate rapid increase of the population.

User-Oriented Hybrid Opportunistic Network Design

To improve the end-to-end Successful Delivery Probability(SDP) of mobile nodes in opportunistic network,hybrid Opportunistic Network(OppNet) architecture using Fix Infrastructure Nodes(FINs) is proposed.As enhanced OppNet serving for special users,the network planning and design should take user's mobility behavior into account.We adopt collected users' mobility records,analyze users' stay pattern,and establish Message Exchange Points(MEPs) where FINs should be installed.Our solution includes MEPs detection algorithm,Maximum end-to-end Success Delivery Probability(MSDP) detection algorithm,and simulated annealing algorithm.After data preprocessing,MEPs detection algorithm detects feasible locations from users' trajectory records where not more than one user visit frequently.End to end SDPs of these feasible MEPs are evaluated using MSDP detection algorithm.To reduce the computation complexity,a simulated annealing algorithm to select optimal FIN locations in a large number of feasible MEPs is given.The evaluation experiments based on reallife trajectory dataset verify our proposal can achieve better E2 E SDP gain than "most visitors" strategy and "max residence probability" strategy.

Characterization and Identification of Two Opportunistic Human Bacterial Pathogens in Rice

Burkholderia cepacia （Bc） and Pseudomonas aeruginosa （Pa） are both biocontrol agents in agriculture and opportunistic human pathogens in hospitals. Effective management and utilization practice is needed to understand their characteristics and distribution in rice. During the last decade, the two opportunistic human pathogens were detected in 631 samples of rice seed and 117 samples of rice plant in plain, highland and mountainous rice growing areas of China. Bc and Pa were primarily differentiated by common bacteriological characteristics and pathogenic tests and then identified into species by Biolog and FAME tests. However, the genotypes of Bc still could not be distinguished. It has been noted that the Bc and Pa mainly existed in rice root with the highest distribution frequency in plain areas （ 6.1% and 16.1%） and lowest in the mountainous areas （1.0% and 7.8%）.

Opportunistic spectrum sharing in software defined wireless network

Over the past few decades, the world has witnessed a rapid growth in mobile and wireless networks（MWNs） which significantly change human life. However, proliferating mobile demands lead to several intractable challenges that MWN has to face. Software-defined network is expected as a promising way for future network and has captured growing attention. Network virtualization is an essential feature in software-defined wireless network（SDWN）, and it brings two new entities, physical networks and virtual networks. Accordingly, efficiently assigning spectrum resource to virtual networks is one of the fundamental problems in SDWN. Directly orienting towards the spectrum resource allocation problem, firstly, the fluctuation features of virtual network requirements in SDWN are researched, and the opportunistic spectrum sharing method is introduced to SDWN. Then, the problem is proved as NP-hardness. After that, a dynamic programming and graph theory based spectrum sharing algorithm is proposed.Simulations demonstrate that the opportunistic spectrum sharing method conspicuously improves the system performance up to around 20%–30% in SDWN, and the proposed algorithm achieves more efficient performance.

Novel Energy-Efficient Opportunistic Routing Protocol for Marine Wireless Sensor Networks Based on Compressed Sensing and Power Control

In marine wireless sensor networks(MWSNs),an appropriate routing protocol is the key to the collaborative collection and efficient transmission of massive data.However,designing an appropriate routing protocol under the condition of sparse marine node deployment,highly dynamic network topology,and limited node energy is complicated.Moreover,the absence of continuous endto-end connection introduces further difficulties in the design of routing protocols.In this case,we present a novel energy-efficient opportunistic routing(Novel Energy-Efficient Opportunistic Routing,NEOR)protocol for MWSNs that is based on compressed sensing and power control.First,a lightweight time-series prediction method-weighted moving average method is proposed to predict the packet advancement value such that the number of location information that is exchanged among a node and its neighbor nodes can be minimized.Second,an adaptive power control mechanism is presented to determine the optimal transmitting power and candidate nodeset on the basis of node mobility,packet advancement,communication link quality,and remaining node energy.Subsequently,a timer-based scheduling algorithm is utilized to coordinate packet forwarding to avoid packet conflict.Furthermore,we introduce the compressed sensing theory to compress perceptual data at source nodes and reconstruct the original data at sink nodes.Therefore,energy consumption in the MWSNs is greatly reduced due to the decrease in the amount of data perception and transmission.Numerical simulation experiments are carried out in a wide range of marine scenarios to verify the superiority of our approach over selected benchmark algorithms.

A Direction-Based Data Forwarding Algorithm for Opportunistic Networks

In this paper, the forwarding objective and mobility law of nodes in opportunistic networks are first investigated to establish a mathematical model for further analysis, then a gradually accelerated data forwarding algorithm is proposed. In this algorithm, according to the distance between data carriers （nodes） and the destination, some intermediate nodes are selected to relay the data. Especially, the forwarded copies can be increased when the delay reaches a threshold, to guarantee the required delivery ratio. The simulation results show that the proposed algorithm can effectively reduce the storage occupancies of nodes and forwarding delay, and guarantee the delivery ratio simultaneously.