ANALISIS PERBANDINGAN PERFORMANSI SMOOTHED ROUND ROBIN DAN DEFICIT ROUND ROBIN PADA WIMAX

ABSTRAKSI: WiMAX adalah jaringan wireless yang didesain untuk melayani berbagai jenis trafik. Oleh karena itu, WiMAX dibutuhkan untuk memenuhi kebutuhan QoS (Quality of Service) dari beberapa aplikasi dan informasi yang melalui jaringan. Implementasi penjadwalan yang tepat untuk paket yang dibawa pada jaringan WiMAX dapat meningkatkan kualitas QoS.Perbandingan perfomansi algoritma penjadwalan yang berhubungan dengan perfomansi jaringan WiMAX, yaitu Smoothed Round Robin (SRR) dan Deficit Round Robin (DRR). Parameter-parameter yang digunakan antara lain throughput, packetloss dan delay antrian.Penambahan jumlah user mengakibatkan semakin besarnya nilai delay dan packetloss baik pada SRR maupun DRR. Untuk throughput penambahan jumlah user mengakibatkan nilai throughput semakin kecil atau semakin buruk. Untuk scenario perubahan nilai bandwith delay dan packetloss algoritma SRR semakin besar jika nilai bandwith semakin besar,sedangkan untuk algoritma DRR nilai delay tetap atau lebih stabil walaupun besar bandwith diubah-ubah. Untuk algoritma SRR Besarnya throughput pada bandwith 4M,10M,12M adalah 139,236 kbps, 336 kbps, 336 kbps untuk video, untuk algoritma DRR besarnya throughput pada bandwith 4M,10M,12M adalah 336kbps, 336 kbps, 336 kbps untuk video, terlihat bahwa throughput algoritma DRR lebih stabil.Keunggulan algoritma Deficit Round Robin (DRR) adalah kemampuan menangani antrian data yang memiliki prioritas yang paling utama. Pada WiMAX algoritma DRR mampu menangani tipe layanan Unsolicited Grant Service (UGS) dengan baik contohnya VoIPKata Kunci : Schedulling, Smoothed Round Robin, Deficit Round Robin, NS2ABSTRACT: WiMAX is a wireless network designed to serve various types of traffic. Therefore, WiMAX is needed to meet the needs of QoS (Quality of Service) from multiple applications and information through the network. Proper implementation for packet scheduling that brought on the WiMAX network to improve the quality QoS.Comparative performance of scheduling algorithm associated with the performance of WiMAX networks, which is Smoothed Round Robin (SRR) and Deficit Round Robin (DRR). The parameters used include throughput, packetloss and queuing delay.The addition of increasingly large number of users resulting in delay and packetloss good value at SRR and DRR. To increase the number of user throughput resulting throughput value smaller or worse. For the scenario changes in the value of delay and bandwidth greater packetloss SRR algorithm if the value of the greater bandwidth, while for the DRR algorithm delay value is fixed or more stable, although large bandwidth changed. The SRR algorithm for bandwidth throughput of 4M, 10M, 12M is 139.236 kbps, 336 kbps, 336 kbps for video, for the DRR algorithm, the throughput in bandwidth 4M, 10M, 12M is 336kbps, 336 kbps, 336 kbps for video, we see that the throughput DRR algorithm is more stableAdvantages Deficit Round Robin algorithm (DRR) is the ability to handle the data queue that has the ultimate priority. At WiMAX DRR algorithm capable of handling the type of service Unsolicited Grant Service (UGS) with a good example VoIP.Keyword: Schedulling, smoothed Round Robin, Deficit Round Rob

Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier

Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow

Commercial Nucleic-Acid Amplification Tests for Diagnosis of Pulmonary Tuberculosis in Respiratory Specimens: Meta-Analysis and Meta-Regression

BACKGROUND: Hundreds of studies have evaluated the diagnostic accuracy of nucleic-acid amplification tests (NAATs) for tuberculosis (TB). Commercial tests have been shown to give more consistent results than in-house assays. Previous meta-analyses have found high specificity but low and highly variable estimates of sensitivity. However, reasons for variability in study results have not been adequately explored. We performed a meta-analysis on the accuracy of commercial NAATs to diagnose pulmonary TB and meta-regression to identify factors that are associated with higher accuracy. METHODOLOGY/PRINCIPAL FINDINGS: We identified 2948 citations from searching the literature. We found 402 articles that met our eligibility criteria. In the final analysis, 125 separate studies from 105 articles that reported NAAT results from respiratory specimens were included. The pooled sensitivity was 0.85 (range 0.36-1.00) and the pooled specificity was 0.97 (range 0.54-1.00). However, both measures were significantly heterogeneous (p<.001). We performed subgroup and meta-regression analyses to identify sources of heterogeneity. Even after stratifying by type of commercial test, we could not account for the variability. In the meta-regression, the threshold effect was significant (p = .01) and the use of other respiratory specimens besides sputum was associated with higher accuracy. CONCLUSIONS/SIGNIFICANCE: The sensitivity and specificity estimates for commercial NAATs in respiratory specimens were highly variable, with sensitivity lower and more inconsistent than specificity. Thus, summary measures of diagnostic accuracy are not clinically meaningful. The use of different cut-off values and the use of specimens other than sputum could explain some of the observed heterogeneity. Based on these observations, commercial NAATs alone cannot be recommended to replace conventional tests for diagnosing pulmonary TB. Improvements in diagnostic accuracy, particularly sensitivity, need to be made in order for this expensive technology to be worthwhile and beneficial in low-resource countries

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)