101 research outputs found

    On-demand Bandwidth and Stability Based Unicast Routing in Mobile Adhoc Networks

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    Characteristics of mobile ad hoc networks (MANETs) such as lack of central coordination, dynamic topology and limited resources pose a challenging problem in quality of service (QoS) routing. Providing an efficient, robust and low overhead QoS unicast route from source to destination is a critical issue. Bandwidth and route stability are the major important QoS parameters for applications where long duration connections are required with stringent bandwidth requirements for multimedia applications. This paper proposes an On-demand Bandwidth and Stability based Unicast Routing scheme (OBSUR) in MANET by adding additional QoS features to existing Dynamic Source Routing (DSR) protocol. The objective of the OBSUR is to provide QoS satisfied, reliable and robust route for communicating nodes. The scheme works in following steps. (1) Each node in the network periodically (small regular intervals) estimates bandwidth availability, node and link stability, buffer availability, and stability factor between nodes. (2) Construction of neighbor stability and QoS database at every node which is used in route establishment process. (3) The unicast path is constructed by using route request and route reply packets with the help of route information cache, and (4) route maintenance in case of node mobility and route failures. Simulation results show that there is an improvement in terms of traffic admission ratio, control overhead, packet delivery ratio, end to end delay and throughput as compared to Route Stability Based QoS Routing (RSQR) in MANETs.

    A novel key management protocol for vehicular cloud security

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    Vehicular cloud computing (VCC) is a new hybrid technology which has become an outstanding area of research. VCC combines salient features of cloud computing and wireless communication technology to help drivers in network connectivity, storage space availability and applications. VCC is formed by dynamic cloud formation by moving vehicles. Security plays an important role in VCC communication. Key management is one of the important tasks for security of VCC. This paper proposes a novel key management protocol for VCC security. Proposed scheme is based on Elliptical Curve Cryptography (ECC). The simulation results demonstrated that the proposed protocol is efficient compared to existing key management algorithms in terms of key generation time, memory usage and cpu utilization

    The study of causes, mode of delivery in intrauterine fetal death and associated complications

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    Background: Intra uterine fetal death (IUFD) is defined as the baby born with no signs of life at or after 28 weeks of gestation. It is important to diagnose the cause in order to avoid further recurrence and to treat any maternal associated factors. The aim of the present study was to calculate incidence of IUFD in our hospital and know the causes, mode of delivery, associated complications. So we can take measures to prevent them in future.Methods: The retrospective study was conducted in the department of Obstetrics and Gynecology in Kanachur Medical College, Mangalore from January 2017 to January 2020. The women with confirmed diagnosis of IUFD on Ultrasound and beyond 28 weeks of gestation were included in the study.Results: In the study period, total 2026 patients delivered, of which 40 cases were IUFD, hence our incidence rate was 19.74 per 1000 population. 62.5% cases were multigravida. 15% had previous history of abortions while 5% previously had IUFD. In 37.5% cases, the cause was unknown, followed by 22.5% having pregnancy induced hypertension. Anemia contributed to 17.5% and placental causes in 12.5%. 10% of the women had PPH. One patient had sepsis, followed by acute renal failure and later died of multi organ failure.Conclusions: All the causes are not preventable, many of them can be identified early in pregnancy and thus IUFD can be prevented. All the high risk pregnancies should undergo antenatal fetal surveillance and should have frequent ante natal visits to reduce IUFD rates

    Design and Development of Miniature Dual Antenna GPS-GLONASS Receiver for Uninterrupted and Accurate Navigation, Journal of Telecommunications and Information Technology, 2014, nr 4

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    Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), and GPS-GLONASS receivers are commonly used for navigation. However, there are some applications where a single antenna interface to a GPS or GPS-GLONASS receiver will not suffice. For example, an airborne platform such as an Unmanned Aerial Vehicles (UAV) will need multiple antennae during maneuvering. Also, some applications will need redundancy of antenna connectivity to prevent loss of positioning if a link to satellite fails. The scope of this work is to design a dual antenna GPS-GLONASS navigation receiver and implement it in a very small form-factor to serve multiple needs such as: provide redundancy when a link fails, and provide uninterrupted navigation even under maneuvering, also provide improved performance by combining data from both signal paths. Both hardware and software architectures are analyzed before implementation. A set of objectives are identified for the receiver which will serve as the benchmarks against which the receiver will be validated. Both analysis and objectives are highlighted in this paper. The results from the tests conducted on such a dual antenna GPS-GLONASS receiver have given positive results on several counts that promise a wider target audience for such a solution

    Neural Underpinnings of Decoupled Ethical Behavior in Adolescents as an Interaction of Peer and Personal Values

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    In the present study, we are trying to understand how peer unethical behavior stimulates the decoupling of emotions in adolescents. We have simulated an interactive game-based environment in order to stimulate participants to make decisions that are found to be correlated with their virtual partner decisions. The responses given by participants were also recorded as neural signals using an EEG to study neurophysiological correlates of different decision-making behavioral patterns. There was an active correlation between personality values and decision-making. Preliminary analysis was focused on studying the differences in lower brain frequencies (0.1-4Hz) when the participants developed frustration, in contrast to when they experienced gratitude. The study presents three case studies in which delta frequencies increased in cases when frustration was experienced and decreased when gratitude was experienced. The study focused on understanding the neural underpinnings of corresponding modified behavior in adolescents. The findings highlight an increase in delta frequencies when apparent frustration was developed in adolescents due to their peer unethical behavior. The delta frequencies lowered when participants were tested for ethical behavior. The results concluded that based on personality value types, adolescents tend to develop frustration toward perceived unethical behavior and carry it over to other unrelated peers. This study is highly explorative in nature, with preliminary analysis using only three case studies, having a small sample size. However, the novelty of this study brings about new dimensions to social cognition and personality studies.Comment: 8 Pages, 6 Figure

    Production of Antibiotics from Soil-Isolated Actinomycetes and Evaluation of their Antimicrobial Activities

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    Purpose: To investigate the production of antibiotic from actinomycetes isolated from soil and evaluate its antimicrobial activities. Methods: In a medium formulation study, A-4 and A-4 actinomycete mutant strains (out of the six strains selected from the nine actinomycetes that were screened) were evaluated for maximum antibiotic production using various carbon and nitrogen sources. Zone of inhibition and packed cellvolume were the parameters used for the evaluation. Various fermentation conditions such as pH, temperature and dissolved oxygen were also optimized for maximal production of antibiotic from both A-4 and A-4 mutant. Results: Some actinomycetes strains showed promising antimicrobial activity against different strains of bacteria and fungi. Out of the six strains selected, one strain, designated A-4, showed maximum antimicrobial property against Gram positive and Gram negative strains as well as against various fungi. Conclusion: Findings from this investigation reveal that strain A-4 and A-4 mutant strains, in that order, exhibited superior antimicrobial activities to other soil isolates of actinomycetes.Keywords:  Actinomycete, Antibiotic, MIC, fermentation

    Isolation and morphological characterization of antibiotic producing actinomycetes

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    Purpose: To isolate and characterize antibiotic producing actinomycetes from soil samples in Belgaum, Karnataka, India. Methods: Crowded plate technique was used for the isolation of actinomycetes in media such assoybean – casein digest medium and actinomycetes isolation agar. The morphological and cultural characterization of one of the selected strains, designated A-4, was performed as per International Streptomycete Project (ISP). Results: Morphological and cultural studies showed that A-4 belonged to the Actinomycete genus. The morphological and cultural characteristics of the A-4 mutant showed cellular and aerial growth as well as soluble pigment formation in various ISP media. Conclusion: Findings from this investigation revealed that the selected strain, A-4, is an actinomycete.Keywords: Actinomycete, Antibiotic, MIC, Crowded plate technique, Morpholog

    Modified PSO Based Channel Allocation Scheme for Interference Management in 5G Wireless Mesh Networks, Journal of Telecommunications and Information Technology, 2022, nr 2

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    Efficient channel management is a challenge that next-generation wireless networks need to meet in order to satisfy increasing bandwidth demand and transmission rate requirements. Non-orthogonal multiple access (NOMA) is one of such efficient channel allocation methods used in 5G backhaul wireless mesh networks. In this paper, we propose a power demand-based channel allocation method for 5G backhaul wireless mesh networks by employing NOMA and considering traffic demands in small cells, thereby improving channel utility. In this scheme, we work with physical layer transmission. The foremost aim is to mutually optimize the uplink/downlink NOMA channel assignment in order to increase user fairness. The approach concerned may be divided into two steps. First, initial channel allocation is performed by employing the traveling salesman problem (TSP), due to its similarity to many-to-many double-side user-channel allocation. Second, the modified particle swarm optimization (PSO) method is applied for allocation updates, by introducing a decreasing coefficient which may have the form of a standard stochastic estimate algorithm. To enhance exploration capacity of modified the PSO, a random velocity is included to optimize the convergence rate and exploration behavior. The performance of the designed scheme is estimated through simulation, taking into account such parameters as through put, spectral efficiency, sum-rate, outage probability, signal to-interference plus noise ratio (SINR), and fairness. The proposed scheme maximizes network capacity and improves fairness between the individual stations. Experimental results show that the proposed technique performs better than existing solutions
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