3,432 research outputs found

    Multi-tier Network Performance Analysis using a Shotgun Cellular System

    Full text link
    This paper studies the carrier-to-interference ratio (CIR) and carrier-to-interference-plus-noise ratio (CINR) performance at the mobile station (MS) within a multi-tier network composed of M tiers of wireless networks, with each tier modeled as the homogeneous n-dimensional (n-D, n=1,2, and 3) shotgun cellular system, where the base station (BS) distribution is given by the homogeneous Poisson point process in n-D. The CIR and CINR at the MS in a single tier network are thoroughly analyzed to simplify the analysis of the multi-tier network. For the multi-tier network with given system parameters, the following are the main results of this paper: (1) semi-analytical expressions for the tail probabilities of CIR and CINR; (2) a closed form expression for the tail probability of CIR in the range [1,Infinity); (3) a closed form expression for the tail probability of an approximation to CIR in the entire range [0,Infinity); (4) a lookup table based approach for obtaining the tail probability of CINR, and (5) the study of the effect of shadow fading and BSs with ideal sectorized antennas on the CIR and CINR. Based on these results, it is shown that, in a practical cellular system, the installation of additional wireless networks (microcells, picocells and femtocells) with low power BSs over the already existing macrocell network will always improve the CINR performance at the MS.Comment: 6 pages, 3 figures, accepted at IEEE Globecom 201

    Agribusiness Capstone Courses Design: Objectives and Strategies

    Get PDF
    This paper discusses the benefits of using strategic management principles as the cornerstone for building the agribusiness capstone experience. The necessity for agribusiness firms to create and implement strategies that build a sustainable competitive advantage in turn necessitates the development of strategic management skills in the leaders/managers of the future. As such, the objectives of a capstone course lean heavily toward the integrative development of strategic decision-making competence. This has a number of implications for the capstone professor in terms of course content, pedagogies, and subsequent measurement of student performance.Agribusiness, Teaching/Communication/Extension/Profession,

    Stochastic Ordering based Carrier-to-Interference Ratio Analysis for the Shotgun Cellular Systems

    Full text link
    A simple analytical tool based on stochastic ordering is developed to compare the distributions of carrier-to-interference ratio at the mobile station of two cellular systems where the base stations are distributed randomly according to certain non-homogeneous Poisson point processes. The comparison is conveniently done by studying only the base station densities without having to solve for the distributions of the carrier-to-interference ratio, that are often hard to obtain.Comment: 10 pages, 0 figures, submitted for review to IEEE Wireless Communications Letters on October 11, 201

    Functionalising the azobenzene motif delivers a light-responsive membrane-interactive compound with the potential for photodynamic therapy applications

    Get PDF
    When adorned with n-octyl chains azobenzene is able to disrupt a variety of calcein-loaded phospholipid liposomes. The levels of lysis observed are dependent both on the lipid headgroup and the conformation of the azobenzene compound. In all cases studied, it has been shown that the cis-conformer is more membrane-interactive than the trans-conformer, suggesting that this class of molecule could be optimised for photo-dynamic therapy applications against infectious pathogens

    Atmospheric trace metal concentrations, solubility and deposition fluxes in remote marine air over the south-east Atlantic

    Get PDF
    Total and soluble trace metal concentrations were determined in atmospheric aerosol and rainwater samples collected during seven cruises in the south-east Atlantic. Back trajectories indicated the samples all represented remote marine air masses, consistent with climatological expectations. Aerosol trace metal loadings were similar to previous measurements in clean, marine air masses. Median total Fe, Al, Mn, V, Co and Zn concentrations were 206, 346, 5, 3, 0.7 and 11 pmol m-3 respectively. Solubility was operationally defined as the fraction extractable using a pH4.7 ammonium acetate leach. Median soluble Fe, Al, Mn, V, Co, Zn, Cu, Ni, Cd and Pb concentrations were 6, 55, 1, 0.7, 0.06, 24, 2, 1, 0.05 and 0.3 pmol m-3 respectively. Large ranges in fractional solubility were observed for all elements except Co; median solubility values for Fe, Al and Mn were below 20% while the median for Zn was 74%. Volume weighted mean rainwater concentrations were 704, 792, 32, 10, 3, 686, 25, 0.02, 0.3 and 10 nmol L-1 for Fe, Al, Mn, V, Co, Zn, Cu, Ni, Cd and Pb respectively (n = 6). Wet deposition fluxes calculated from these values suggest rain makes a significant contribution to total deposition in the study area for all elements except perhaps Ni

    Principles of forensic group therapy

    Get PDF
    Long-term monitoring of distributed, multiple plots is the key to quantify macroecological patterns and changes. Here we examine the evidence for concerted changes in the structure, dynamics and composition of old-growth Amazonian forests in the late twentieth century. In the 1980s and 1990s, mature forests gained biomass and underwent accelerated growth and dynamics, all consistent with a widespread, long-acting stimulation of growth. Because growth on average exceeded mortality, intact Amazonian forests have been a carbon sink. In the late twentieth century, biomass of trees of more than 10cm diameter increased by 0.62±0.23 t C ha-1yr-1 averaged across the basin. This implies a carbon sink in Neotropical old-growth forest of at least 0.49±0.18 Pg C yr-1. If other biomass and necromass components are also increased proportionally, then the old-growth forest sink here has been 0.79±0.29 Pg C yr-1, even before allowing for any gains in soil carbon stocks. This is approximately equal to the carbon emissions to the atmosphere by Amazon deforestation. There is also evidence for recent changes in Amazon biodiversity. In the future, the growth response of remaining old-growth mature Amazon forests will saturate, and these ecosystems may switch from sink to source driven by higher respiration (temperature), higher mortality (as outputs equilibrate to the growth inputs and periodic drought) or compositional change (disturbances). Any switch from carbon sink to source would have profound implications for global climate, biodiversity and human welfare, while the documented acceleration of tree growth and mortality may already be affecting the interactions among millions of species. © 2008 The Royal Society

    Chadha and the Public Lands: Is FLPMA Affected?

    Get PDF

    Truth in Fiction

    Get PDF
    According to literary tradition and genre classification, fiction has often been regarded as writing that lacks a foundation of truth. However, this does not necessarily mean that fiction contains no elements of truth. In this thesis, Timothy Baker argues that fiction contains traces of truth - truths that may not be fundamentally based on facts, yet can still be recognized as embodying the deep-seated essence of truth. These “essential truths”, though largely shunned from the nonfiction genre, can be utilized to establish the groundwork of fiction - making the genre a reflection of reality itself - instead of a captured moment of reality. Fiction that contains essential truths, though not based on actual events, can still be recognized as realistic and existentially valuable. This thesis includes three short works of creative writing by Timothy Baker: “Letters from Llea" a creative essay, "Perfection," a short story, and "Desperate Desires," also a short story all of which, he argues in the introduction, contain essential truths.SUNY BrockportEnglishMaster of Arts (MA)English Master’s These

    Increasing biomass in Amazonian forest plots

    Get PDF
    A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 ± 0.43 Mg per hectare per year (ha-1 yr-1), where 1 ha = 104 m2), or 0.98 ± 0.38 Mg ha-1 yr-1 if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades
    corecore