333 research outputs found

    Optimized image processing and clustering to mitigate security threats in mobile ad hoc network

    Get PDF
    Since there are provisions of many attributes that are not possible or difficult to follow by networks conventionally, mobile ad-hoc networks are extensively deployed. This application starts through the defense sectors, the sensory node presents in the hostile territories down to the gadgets for congestion communication in traffic by general transportation when travelling for adequate provision of infrastructure during disaster recovery. As a lot of importance related to (mobile ad hoc network) MANET application, one important factor in ad-hoc networks is security. Using image processing for securing MANET is the area of focus of this research. Therefore, in this article, the security threats are assessed and representative proposals are summarized in ad-hoc network’s context. The study reviewed the current situation of the art for original to security provision called mobile ad hoc network for wireless networking. The threats to security are recognized while the present solution is observed. The study additionally summarized education erudite, talks on general issues and future instructions are recognized. Also, in this study, the forecast weighted clustering algorithm (FWCA) is employed as a cluster head over weighted clustering algorithm (WCA) is examined as quality in cluster-based routing, service is highly significant with MANET

    Plasma oxylipins and unesterified precursor fatty acids are altered by DHA supplementation in pregnancy: Can they help predict risk of preterm birth?

    Get PDF
    Oxidized lipids derived from omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids, collectively known as oxylipins, are bioactive signaling molecules that play diverse roles in human health and disease. Supplementation with n-3 docosahexaenoic acid (DHA) during pregnancy has been reported to decrease the risk of preterm birth in singleton pregnancies, which may be due to effects of DHA supplementation on oxylipins or their precursor n-6 and n-3 fatty acids. There is only limited understanding of the levels and trajectory of changes in plasma oxylipins during pregnancy, effects of DHA supplementation on oxylipins and unesterified fatty acids, and whether and how oxylipins and their unesterified precursor fatty acids influence preterm birth. In the present study we used liquid chromatography-tandem mass spectrometry to profile oxylipins and their precursor fatty acids in the unesterified pool using plasma samples collected from a subset of pregnant Australian women who participated in the ORIP (Omega-3 fats to Reduce the Incidence of Prematurity) study. ORIP is a large randomized controlled trial testing whether daily supplementation with n-3 DHA can reduce the incidence of early preterm birth compared to control. Plasma was collected at study entry (≈pregnancy week 14) and again at ≈week 24, in a subgroup of 48 ORIP participants-12 cases with spontaneous preterm (<37 weeks) birth and 36 matched controls with spontaneous term (≥40 weeks) birth. In the combined preterm and term pregnancies, we observed that in the control group without DHA supplementation unesterified AA and AA-derived oxylipins 12-HETE, 15-HETE and TXB2 declined between weeks 14-24 of pregnancy. Compared to control, DHA supplementation increased unesterified DHA, EPA, and AA, DHA-derived 4-HDHA, 10-HDHA and 19,20-EpDPA, and AA-derived 12-HETE at 24 weeks. In exploratory analysis independent of DHA supplementation, participants with concentrations above the median for 5-lipoxygenase derivatives of AA (5-HETE, Odds Ratio (OR) 8.2; p = 0.014) or DHA (4-HDHA, OR 8.0; p = 0.015) at 14 weeks, or unesterified AA (OR 5.1; p = 0.038) at 24 weeks had higher risk of spontaneous preterm birth. The hypothesis that 5-lipoxygenase-derived oxylipins and unesterified AA could serve as mechanism-based biomarkers predicting spontaneous preterm birth should be evaluated in larger, adequately powered studies

    Natural Regeneration of Severely Degraded Terrestrial Arid Ecosystems Needs More Than Just Removing the Cause of the Degradation

    Get PDF
    Rangelands cover over 75% of Kuwait’s total land area. Most of these rangelands are severely degraded because of overgrazing, poor anthropic utilization, and mismanagement. Restoring natural rangelands is a way to increase forage productivity, enhance biodiversity, and achieve sustainable development. When degradation has not reached the point of irreversibility, natural restoration through resting is one of the best low-cost restoration techniques. This study evaluated the effect of natural restoration on vegetation cover and species richness in the desert rangelands of Kuwait. The studied rangeland was a completely fenced area of 1 km2. The percent of vegetation was measured using the line- intercept method. The cover of perennial species was the same in fenced and unfenced areas (0%), but annual species cover was 19.67% in fenced areas and 6% in unfenced areas. There was no significant difference in the contribution to the total cover of the dominant invasive species Stipa capensis between fenced (90%) and unfenced areas (83%). All recorded species are therophytes, which raises the disturbance index to 100%. This therophytization demonstrates an imbalance in the rangeland ecosystem and desertification due to the high anthropozoogene pressure. Under such a severely degraded ecosystem, natural restoration cannot restore vegetation. Reintroducing native species including Helianthemum lipii, Haloxylon salicornicum, Rhanterium epapposum, and Calligonum comosum, is required to restore the ecosystem, facilitate the growth of annual palatable species, and enhance the flora diversity

    PERANCANGAN MODEL MINIATUR GAS COMPRESSOR AFTERCOOLER PADA STASIUN KOMPRESOR PAGARDEWA PT.PGN AOSS BERBASIS MIKROKONTROLER ATMEGA2560

    Get PDF
    Implementasi metode redundant pada motor AC didalam sistem Gas Compressor Aftercooler pada Stasiun Kompresor Pagardewa PT.PGN AOSS mempunyai dampak perbedaan jadwal maintenance kedua motor AC serta rentang kerja motor yang tidak spesifik. Pada penelitian ini diimplementasikan motor DC dengan metode compact sebagai sistem kerja menggunakan Kontroler Proporsional Integral Difrensial (PID) berbasis mikrokontroler ATMEGA2560. Pertimbangan penggunaan motor DC dan kontroler PID adalah dapat menyelaraskan kecepatan rotasi permenit (rpm) serta mempunyai rentang kerja yang spesifik, sehingga diharapkan akan meningkatkan efisiensi dan menyelaraskan jadwal maintenance motor DC. Berdasarkan metode root-locus dengan pole s = —2.78 didapatkan nilai parameter Kp = 14.19, Ki = 20, dan Kd = 2.59. Sistem dapat mencapai setpoint 125oF dengan settling time sebesar 140 sekon pada temperatur ambient sebesar 77oF dan 144 sekon pada temperatur ambient sebesar 95oF. Sistem dapat menjaga temperatur pada rentang 115oF hingga 135oF dengan recovery time antara 63 dan 75 sekon ketika diberi gangguan berupa peningkatan temperatur sebesar 15oF.Kata kunci— Gas Compressor Aftercooler, manifold, PWM, RPM, kontroler PID, metode root-locus

    The influence of geometrical shapes of stenosis on the blood flow in stenosed artery

    Get PDF
    The present work was carried out to investigate the blood flow behavior and the severity of blockage caused in the arterial passage due to the different geometries such as elliptical, trapezium and triangular shapes of stenosis. The study was conducted with respect to various sizes of stenosis in terms of 70%, 80% and 90% area blockage of the arterial blood flow. The study was carried out numerically with the help of advance computational fluid dynamic software. It was found that the shape of the stenosis plays an important role in overall pressure drop across the blockage region of artery. The highest level of pressure drop was observed for trapezoidal shape of stenosis followed by elliptical and then by triangular shaped stenosis. The wall shear stress across the stenosis is great for trapezoidal shape followed by triangular and elliptical stenosis for same blockage area in the artery

    Processing Traffic Jam in Al-Sadrain Intersection in the Holy City of Najaf

    Get PDF
    Modern metropolitan cities worldwide suffer from heavy congestion due to high daily commutes for various purposes. Intersections are the most congested component of the network and represent the sites of accidents. At the same time, the intersection (Al-Sadrien) in Al- Najaf Al-Ashraf city is regarded as one of the major important intersections. Typically, this intersection increases the volume of traffic during rush hours, which raises traffic congestion, Therefor, the problem with this article is that unclear how the distribution of the surrounding areas affects traffic accidents and junction congestion. Our hypothesis to solve the problem is that an important relationship must be clear between the intersection and its surrounding areas. In this study, analysis the current service of intersection as field survey adopting the analytical approach using simulation by HCS2010 and VISSIM software, based on GIS that showed: the eastern approach (coming from Al- Kufa) was (F) (3.18.97), the result of the western approach (coming from Najaf) (F) (3.45.49), and the result of the northern approach (coming from the College of Administration and Economics) (D) (1.38). 83) and the result of the southern approach (coming from Al- Rawan Street) (E) (1.14.13). When the times of delay to the level of service intersection, as adopted by the capacity of roads on the program (HCS 2010), amounted to more than (800) seconds/vehicle at peak times. So, the classification of service at this intersection is in level (E). Through the traffic intersection analysis, recommendations and proposals must be taken before any decisions regarding land use , which has effects on the city

    Application of the Jaya algorithm to solve the optimal reliability allocation for reduction oxygen supply system of a spacecraft

    Get PDF
    In this paper the reliability of reduction oxygen supply system (ROSS) of a spacecraft which was calculated as a complex system using minimal cut method. The reliability of each component of system was calculated as well as the reliability importance of the system. The cost of each component of the system was possible approaches of the allocation values of reliability based the minimization of the overall cost in this system. The advantage of this algorithm can be used to allocate the optimization of reliability for simple or complex system. This optimization is achieved using the Jaya algorithm. The proposed technique is based on the notion that a conclusion reached on a particular problem should pass near the best results and avoid the worst outcomes. The original findings of this paper are: I) the system used in this paper is a spacecraft's reduced oxygen supply system with the logarithmic cost function; and ii) the results obtained were by using the Jaya algorithm to solve specific system reliability optimization problems
    • …
    corecore