17,133 research outputs found

    A strategic evaluation of the introduction of the East Friesian sheep breed on a North Island hill country farm : a thesis submitted in partial fulfilment of the requirements for the degree of Masters in Applied Science in Agricultural Systems and Management at Massey University

    Get PDF
    New Zealand sheep fanning has changed dramatically over the past 20 years as it has adjusted to a market-led and unsubsidised economy. Despite this, new technology and management practices such as cross breeding offer exciting opportunities for improving sheep industry profitability. The introduction of new genetic material into the sheep flock can provide benefits through improved productivity and product attributes but it may also have negative consequences for industry growth if used incorrectly. The advantages of introducing a new sheep breed to a farm are usually widely published but not necessarily well researched. The East Friesian (EF) was made available to farmers in autumn 1996. It has a reputation for being highly fertile, a good milk producer and heavy-weight-lamb producer. However, no research has been published on how to develop a profitable management strategy for adopting EF's onto a hill country property. The purpose of this study was to test the hypothesis that the EF would improve the productivity and profitability of a lower North Island hill country farm. A case farm analysis using the STOCKPOL farm simulation model was used to compare the productivity and profitability of the current Romney (Rn x Rn) flock with either an East Friesian (EF) x Rn crossbred flock or a purebred EF x EF flock. The STOCKPOL model was calibrated to simulate the existing sheep and beef cattle policy for the 324 ha hill country farm, Tuapaka. Pasture growth rate data were adjusted to sustain the reordered levels of animal production and establish a basis against which the EF x Rn and EF x EF flocks could be compared. The cattle policy was fixed for all options. Ewe numbers, with a 20 % replacement rate, were adjusted for the live weight profiles and production levels of the EF x Rn (67 kg at mating; 148 lambs born: 100 ewes mated) and EF x EF (80 kg at mating; 230 lambs born: 100 ewes mated) breeds until the farm system was just biologically feasible. This indicated 1315 EF x Rn sheep or 909 EF x EF could be farmed compared to 1930 Romneys (52 kg; 117 lambs born: 100 ewes mated). In stock unit terms (SU) the EF x Rn was 1.25 and the EF x EF 1.54 compared to the Rn x Rn ewe (1.00) which consumed 526 kgDM per year. The STOCKPOL outputs were copied into an enterprise margin (EM) format and the profitability of the sheep breeds calculated after adjusting for the cost of capital (CoC) of sheep wintered. The EM's (per ha) were 324,324, 340 and 351fortheRnxRn,EFxRnandEFxEFbreeds,respectively.TheEFxEFwasthepreferredoptionforallriskpreferences.AsheepagestructuremodelwasdevelopedtosimulatedthetransitiontoanEFxRncrossbredflock.Thistooksixyears.Theadditionalnetpresentvalue(NPV)in1998dollarsoftheEFxRnvs.theRnxRnwas351 for the Rn x Rn, EF x Rn and EF x EF breeds, respectively. The EF x EF was the preferred option for all risk preferences. A sheep age structure model was developed to simulated the transition to an EF x Rn crossbred flock. This took six years. The additional net present value (NPV) in 1998 dollars of the EF x Rn vs. the Rn x Rn was 92,133. The transition to a purebred EF flock would take 24 years if a grading up strategy were adopted. An important finding was the breed x pasture production interaction. Annual pasture consumption was 869 t DM for the Rn x Rn flock, 780 t DM for the EF x Rn policy and 647 t DM for the EF x EF flock. Reduced pasture production occurred because of the higher lamb:ewe ratio of the EF sheep contributed to increased pasture senescence and decay in the summer and autumn. Ways to prevent this occurring need to be explored through further modelling studies using STOCKPOL and by evaluating the experience of famers who have adopted EF's. The study confirmed the hypothesis: EF sheep would improve production and profit on the hill country case farm. Recent farmer experience with the East Friesian should now be evaluated against this result. Title: A strategic evaluation of the introduction of the East Friesian sheep breed on a North Island hill country farm. Author: Jesus Romero Martinez Year: 1998 Degree: MApplSc (Agricultural Systems and Management)

    On human motion prediction using recurrent neural networks

    Full text link
    Human motion modelling is a classical problem at the intersection of graphics and computer vision, with applications spanning human-computer interaction, motion synthesis, and motion prediction for virtual and augmented reality. Following the success of deep learning methods in several computer vision tasks, recent work has focused on using deep recurrent neural networks (RNNs) to model human motion, with the goal of learning time-dependent representations that perform tasks such as short-term motion prediction and long-term human motion synthesis. We examine recent work, with a focus on the evaluation methodologies commonly used in the literature, and show that, surprisingly, state-of-the-art performance can be achieved by a simple baseline that does not attempt to model motion at all. We investigate this result, and analyze recent RNN methods by looking at the architectures, loss functions, and training procedures used in state-of-the-art approaches. We propose three changes to the standard RNN models typically used for human motion, which result in a simple and scalable RNN architecture that obtains state-of-the-art performance on human motion prediction.Comment: Accepted at CVPR 1

    Asymptotically Exact Approximations for the Symmetric Difference of Generalized Marcum-Q Functions

    Get PDF
    (c) 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. DOI: 10.1109/TVT.2014.2337263In this paper, we derive two simple and asymptotically exact approximations for the function defined as ΔQm(a, b) =Δ Qm(a, b) - Qm(b, a). The generalized Marcum Q-function Qm(a, b) appears in many scenarios in communications in this particular form and is referred to as the symmetric difference of generalized Marcum Q-functions or the difference of generalized Marcum Q-functions with reversed arguments. We show that the symmetric difference of Marcum Q-functions can be expressed in terms of a single Gaussian Q-function for large and even moderate values of the arguments a and b. A second approximation for ΔQm(a, b) is also given in terms of the exponential function. We illustrate the applicability of these new approximations in different scenarios: 1) statistical characterization of Hoyt fading; 2) performance analysis of communication systems; 3) level crossing statistics of a sampled Rayleigh envelope; and 4) asymptotic approximation of the Rice Ie-function.Universidad de Málaga. Campus de Excelencia Internacional. Andalucía Tech

    A New Framework for the Performance Analysis of Wireless Communications under Hoyt (Nakagami-q) Fading

    Get PDF
    (c) 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. DOI:10.1109/TIT.2017.2655342We present a novel relationship between the distribution of circular and non-circular complex Gaussian random variables. Specifically, we show that the distribution of the squared norm of a non-circular complex Gaussian random variable, usually referred to as the squared Hoyt distribution, can be constructed from a conditional exponential distribution. From this fundamental connection we introduce a new approach, the Hoyt transform method, that allows to analyze the performance of a wireless link under Hoyt (Nakagami-q) fading in a very simple way. We illustrate that many performance metrics for Hoyt fading can be calculated by leveraging well-known results for Rayleigh fading and only performing a finite-range integral. We use this technique to obtain novel results for some information and communication-theoretic metrics in Hoyt fading channels.Universidad de MĂĄlaga. Campus de Execelencia Internacional. AndalucĂ­a Tech

    A study of co-movements between USA and Latin American stock markets: a cross-bicorrelations perspective

    Get PDF
    In this paper we use the Brooks and Hinich cross-bicorrelation test in order to uncover nonlinear dependence periods between USA Standard and Poor 500 (SP500), used as benchmark, and six Latin American stock markets indexes: Mexico (BMV), Brazil (BOVESPA), Chile (IPSA), Colombia (COLCAP), Peru (IGBVL) and Argentina (MERVAL). We have found windows of nonlinear dependence and co-movement between the SP500 and the Latin American stock markets, some of which coincide with periods of crisis, giving way to a possible contagion or interdependence interpretation.Comment: Working paper, 9 page

    Increase of the Energy Necessary to Probe Ultraviolet Theories Due to the Presence of a Strong Magnetic Field

    Full text link
    We use the gauge gravity correspondence to study the renormalization group flow of a double trace fermionic operator in a quark-gluon plasma subject to the influence of a strong magnetic field and compare it with the results for the case at zero temperature and no magnetic field, where the flow between two fixed points is observed. Our results show that the energy necessary to access the physics of the ultraviolet theory increases with the intensity of the magnetic field under which the processes happen. We provide arguments to support that this increase is scheme independent, and to exhibit further evidence we do a very simple calculation showing that the dimensional reduction expected in the gauge theory in this scenario is effective up to an energy scale that grows with the strength of such a background field. We also show that independently of the renormalization scheme, the coupling of the double trace operators in the ultraviolet fixed point increases with the intensity of the background field. These effects combined can change both, the processes that are expected to be involved in a collision experiment at a given energy and the azimuthal anisotropy of the measurements resulting of them.Comment: 23 pages, 10 figures. Added section about renormalization scheme independenc

    Effects of Brief Daily Kundalini Yoga Meditation on Self-Esteem, Mood and Emotional Self-Efficacy: A Randomized Comparison Study

    Get PDF
    This randomized comparison study measured the impact of brief daily use of two types of kundalini yoga meditation from the Yogi Bhajan lineage on self-esteem, regulatory emotional self-efficacy, and positive and negative affect in a non-clinical sample of 46 Spanish-speaking adults residing in Spain. Results of the two meditation types—Kirtan Kriya and Internal Conflict Resolution—are compared. Results showed that both types of meditation had positive impacts on all study variables, though the degree of change and effect size depended on the type of meditation used. Results point to these relevant forms of brief daily meditation as simple and inexpensive tools to improve welfare and support positive personality development in populations without psychological pathologies

    Molecular and computational approach to the link between nutrition and cancer

    Full text link
    Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física Aplicada. Fecha de lectura: 22-11-201
    • 

    corecore