247 research outputs found

    Rate Control State-of-the-art Survey

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    The majority of Internet traffic use Transmission Control Protocol (TCP) as the transport level protocol. It provides a reliable ordered byte stream for the applications. However, applications such as live video streaming place an emphasis on timeliness over reliability. Also a smooth sending rate can be desirable over sharp changes in the sending rate. For these applications TCP is not necessarily suitable. Rate control attempts to address the demands of these applications. An important design feature in all rate control mechanisms is TCP friendliness. We should not negatively impact TCP performance since it is still the dominant protocol. Rate Control mechanisms are classified into two different mechanisms: window-based mechanisms and rate-based mechanisms. Window-based mechanisms increase their sending rate after a successful transfer of a window of packets similar to TCP. They typically decrease their sending rate sharply after a packet loss. Rate-based solutions control their sending rate in some other way. A large subset of rate-based solutions are called equation-based solutions. Equation-based solutions have a control equation which provides an allowed sending rate. Typically these rate-based solutions react slower to both packet losses and increases in available bandwidth making their sending rate smoother than that of window-based solutions. This report contains a survey of rate control mechanisms and a discussion of their relative strengths and weaknesses. A section is dedicated to a discussion on the enhancements in wireless environments. Another topic in the report is bandwidth estimation. Bandwidth estimation is divided into capacity estimation and available bandwidth estimation. We describe techniques that enable the calculation of a fair sending rate that can be used to create novel rate control mechanisms.Peer reviewe

    FORMALISASI USAHA DAN MODERNISASI INDUSTRI KECIL DAN MENENGAH MAKANAN DAN MINUMAN DI KELURAHAN BATU KOTA KECAMATAN MALALAYANG KOTA MANADO

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    Untuk Mendorong Pertumbuhan Ekonomi Daerah Maka Perlu Fokus Pada Peningkatan Atau Scalling Up Dari Usaha Informal Dan Kecil Di Suatu Wilayah. Untuk Itu Pentingnya Formalisasi Dan Modernisasi Usaha Kecil Dan Menengah Khususnya Yang Berbasis Industri Perlu Didorong Oleh Pemerintah Dan Para Akademisi Agar Bisa Menjadi Maju, Berkembang, Serta Kompetitif. Permasalahan Yang Dihadapi Ditemukan Adalah Masih Rendahnya Usaha IKM Informal Untuk Menjadikan Usaha Mereka Menjadi Usaha Formal Serta Masih Banyak IKM Yang Usahanya Belum Modern Atau Masih Tradisional Dan Menggunakan Teknologi Rendah Serta Minim Inovasi. Tujuan PKM Ini Adalah Untuk Membantu IKM Di Kelurahan Dan Pedesaan Agar Dapat Meningkatkan Usahanya Yaitu Dengan Melegalkan Usahanya Dari Usaha Informal Menjadi Usaha Formal Serta Memodernisasi Usaha IKM Dari Teknologi Tradisional Atau Rendah Menjadi IKM Yang Menggunakan Teknologi Terkini Atau Modern Serta Inovatif. Tahapan Kegiatan Yang Dilakukan Adalah Pengenalan Dan Sosialisasi Formalisasi Usaha Dan Modernisasi IKM Makanan Dan Minuman Di Kelurahan Batu Kota Kecamatan Malalayang Kota Manado. Selanjutnya Adalah Pendampingan Terhadap Formalisasi Usaha Dan Modernisasi IKM.______________________________________________________________________Kata Kunci : formalisasi usaha, modernisasi, IKM, Kelurahan Batu Kota, Malalayang,Manad

    ANALYSIS OF THE IMPACT OF INFLATION REDUCTION ON OUTPUT AND UNEMPLOYMENT IN NIGERIA

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    It has been enunciated that it is possible to reduce the size of the sacrifice ratio in an economy without a corresponding increase in the rate of inflation. Besides, for the Nigerian economy, there are issues relating to the inflation-output relationship, among which is how inflation inertia impacts on output and unemployment. It is therefore apt to ascertain what Nigeria’s sacrifice ratio could be after many successful inflation reductions over the years. Adopting the Instrumental Variables Generalized Method of Moments (IV-GMM) technique and using data from1970-2015, the findings suggest that inflation inertia has a significant negative impact on the actual rate of inflation in Nigeria. It was also revealed that the percentage of a year’s real GDP that must be forgone to reduce inflation by 1 percent in Nigeria is 5.1 while 53.6 percent of output was sacrificed in 1982. Equivalently, a sacrifice of 26.6 percent of cyclical unemployment was made in the same year; while the highest percentage of GDP was sacrificed in 1990 and the lowest in 2007.Keywords: Inflation inertia, sacrifice ratio, output, unemploymentJEL Classification: C22, E61, P4

    An Experimental Study of Home Gateway Characteristics

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    Many residential and small business users connect to the Internet via home gateways, such as DSL and cable modems. The characteristics of these devices heavily influence the quality and performance of the Internet service that these users receive. Anecdotal evidence suggests that an extremely diverse set of behaviors exists in the deployed base, forcing application developers to design for the lowest common denominator. This paper experimentally analyzes some characteristics of a substantial number of different home gateways: binding timeouts, queuing delays, throughput, protocol support and others.Peer reviewe

    Availability and Utilization of Malaria Prevention Strategies in Pregnancy in Eastern India

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    BACKGROUND. Malaria in pregnancy in India, as elsewhere, is responsible for maternal anemia and adverse pregnancy outcomes such as low birth weight and preterm birth. It is not known whether prevention and treatment strategies for malaria in pregnancy (case management, insecticide-treated bednets, intermittent preventive therapy) are widely utilized in India. METHODS. This cross-sectional study was conducted during 2006-2008 in two states of India, Jharkhand and Chhattisgarh, at 7 facilities representing a range of rural and urban populations and areas of more versus less stable malaria transmission. 280 antenatal visits (40/site) were observed by study personnel coupled with exit interviews of pregnant women to assess emphasis upon, availability and utilization of malaria prevention practices by health workers and pregnant women. The facilities were assessed for the availability of antimalarials, lab supplies and bednets. RESULTS. All participating facilities were equipped to perform malaria blood smears; none used rapid diagnostic tests. Chloroquine, endorsed for chemoprophylaxis during pregnancy by the government at the time of the study, was stocked regularly at all facilities although the quantity stocked varied. Availability of alternative antimalarials for use in pregnancy was less consistent. In Jharkhand, no health worker recommended bednet use during the antenatal visit yet over 90% of pregnant women had bednets in their household. In Chhattisgarh, bednets were available at all facilities but only 14.4% of health workers recommended their use. 40% of the pregnant women interviewed had bednets in their household. Only 1.4% of all households owned an insecticide-treated bednet; yet 40% of all women reported their households had been sprayed with insecticide. Antimalarial chemoprophylaxis with chloroquine was prescribed in only 2 (0.7%) and intermittent preventive therapy prescribed in only one (0.4%) of the 280 observed visits. CONCLUSIONS. A disconnect remains between routine antenatal practices in India and known strategies to prevent and treat malaria in pregnancy. Prevention strategies, in particular the use of insecticide-treated bednets, are underutilized. Gaps highlighted by this study combined with recent estimates of the prevalence of malaria during pregnancy in these areas should be used to revise governmental policy and target increased educational efforts among health care workers and pregnant women.United States Agency for International Development/India mission (cooperative agreement GHS-A-00-03-00020-00); National Institute of Allergy and Infectious Disease (R03 HD52167-01); Indian National Institute of Malaria Research; Indo-US Program for Contraception and Reproductive Health Researc

    How large is "large NcN_c" for Nuclear matter?

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    We argue that a so far neglected dimensionless scale, the number of neighbors in a closely packed system, is relevant for the convergence of the large NcN_c expansion at high chemical potential. It is only when the number of colors is large w.r.t. this new scale (\sim \order{10}) that a convergent large NcN_c limit is reached. This provides an explanation as to why the large NcN_c expansion, qualitatively successful in in vacuum QCD, fails to describe high baryo-chemical potential systems, such as nuclear matter. It also means that phenomenological claims about high density matter based on large NcN_c extrapolations should be treated with caution.Comment: Proceedings of CPOD2010 conference, in Dubna. Results based on Phys.Rev.C82, 055202 (2010), http://arxiv.org/abs/1006.247

    Long-term effect of mobile phone use on sleep quality: results from the cohort study of mobile phone use and health (COSMOS)

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    BACKGROUND: Effects of radiofrequency electromagnetic field exposure (RF-EMF) from mobile phone use on sleep quality has mainly been investigated in cross-sectional studies. The few previous prospective cohort studies found no or inconsistent associations, but had limited statistical power and short follow-up. In this large prospective cohort study, our aim was to estimate the effect of RF-EMF from mobile phone use on different sleep outcomes. MATERIALS AND METHODS: The study included Swedish (n = 21,049) and Finnish (n = 3120) participants enrolled in the Cohort Study of Mobile Phone Use and Health (COSMOS) with information about operator-recorded mobile phone use at baseline and sleep outcomes both at baseline and at the 4-year follow-up. Sleep disturbance, sleep adequacy, daytime somnolence, sleep latency, and insomnia were assessed using the Medical Outcome Study (MOS) sleep questionnaire. RESULTS: Operator-recorded mobile phone use at baseline was not associated with most of the sleep outcomes. For insomnia, an odds ratio (OR) of 1.24, 95% CI 1.03-1.51 was observed in the highest decile of mobile phone call-time (>258 min/week). With weights assigned to call-time to account for the lower RF-EMF exposure from Universal Mobile Telecommunications Service (UMTS, 3G) than from Global System for Mobile Communications (GSM, 2G) the OR was 1.09 (95% CI 0.89-1.33) in the highest call-time decile. CONCLUSION: Insomnia was slightly more common among mobile phone users in the highest call-time category, but adjustment for the considerably lower RF-EMF exposure from the UMTS than the GSM network suggests that this association is likely due to other factors associated with mobile phone use than RF-EMF. No association was observed for other sleep outcomes. In conclusion, findings from this study do not support the hypothesis that RF-EMF from mobile phone use has long-term effects on sleep quality

    An international prospective cohort study of mobile phone users and health (COSMOS): Factors affecting validity of self-reported mobile phone use.

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    This study investigates validity of self-reported mobile phone use in a subset of 75 993 adults from the COSMOS cohort study. Agreement between self-reported and operator-derived mobile call frequency and duration for a 3-month period was assessed using Cohen's weighted Kappa (κ). Sensitivity and specificity of both self-reported high (≥10 calls/day or ≥4h/week) and low (≤6 calls/week or <30min/week) mobile phone use were calculated, as compared to operator data. For users of one mobile phone, agreement was fair for call frequency (κ=0.35, 95% CI: 0.35, 0.36) and moderate for call duration (κ=0.50, 95% CI: 0.49, 0.50). Self-reported low call frequency and duration demonstrated high sensitivity (87% and 76% respectively), but for high call frequency and duration sensitivity was lower (38% and 56% respectively), reflecting a tendency for greater underestimation than overestimation. Validity of self-reported mobile phone use was lower in women, younger age groups and those reporting symptoms during/shortly after using a mobile phone. This study highlights the ongoing value of using self-report data to measure mobile phone use. Furthermore, compared to continuous scale estimates used by previous studies, categorical response options used in COSMOS appear to improve validity considerably, most likely by preventing unrealistically high estimates from being reported

    Universality of Phases in QCD and QCD-like Theories

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    We argue that the whole or the part of the phase diagrams of QCD and QCD-like theories should be universal in the large-N_c limit through the orbifold equivalence. The whole phase diagrams, including the chiral phase transitions and the BEC-BCS crossover regions, are identical between SU(N_c) QCD at finite isospin chemical potential and SO(2N_c) and Sp(2N_c) gauge theories at finite baryon chemical potential. Outside the BEC-BCS crossover region in these theories, the phase diagrams are also identical to that of SU(N_c) QCD at finite baryon chemical potential. We give examples of the universality in some solvable cases: (i) QCD and QCD-like theories at asymptotically high density where the controlled weak-coupling calculations are possible, (ii) chiral random matrix theories of different universality classes, which are solvable large-N (large volume) matrix models of QCD. Our results strongly suggest that the chiral phase transition and the QCD critical point at finite baryon chemical potential can be studied using sign-free theories, such as QCD at finite isospin chemical potential, in lattice simulations.Comment: v1: 35 pages, 6 figures; v2: 37 pages, 6 figures, minor improvements, conclusion unchanged; v3: version published in JHE
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