3,749 research outputs found

    Foreign exchange reserves in a credit constrained economy

    Get PDF
    We discuss the role of foreign exchange reserves as precautionary savings under an imperfect market framework due to the presence of endogenously determined borrowing constraints. We show that cost of holding reserves is higher in borrowing constrained economies than unconstrained ones as a result of the leverage effect of the debt. We also argue that high global reserve holdings can even be welfare reducing for the world economy where financially constrained developing countries are heavy borrowers in international lending markets

    Foreign Exchange Reserve Demand : An Information Value Approach

    Get PDF
    We perform a statistical analysis to examine the international reserve accumulation of four selected emerging market countries : Argentina, Brazil, Korea and Turkey. We perform Granger causality tests to investigate the information value of key macroeconomic variables on foreign exchange reserves. We use a simple unrestricted vector autoregression analysis to capture a reduced form analysis of the demand for international reserves. Our results suggest that interest rate differentials with the US contain potentially useful information for foreign exchange reserve accumulation for Argentina and Turkey. Similarly, consumption differential with the US and net exports contain information for foreign exchange reserve movements in Korea.Foreign exchange reserves, Vector Autoregression

    Participatory Ecosystem Management Planning at Tuzla Lake (Turkey) Using Fuzzy Cognitive Mapping

    Full text link
    A participatory environmental management plan was prepared for Tuzla Lake, Turkey. Fuzzy cognitive mapping approach was used to obtain stakeholder views and desires. Cognitive maps were prepared with 44 stakeholders (villagers, local decisionmakers, government and non-government organization (NGO) officials). Graph theory indices, statistical methods and "What-if" simulations were used in the analysis. The most mentioned variables were livelihood, agriculture and animal husbandry. The most central variable was agriculture for local people (villagers and local decisionmakers) and education for NGO & Government officials. All the stakeholders agreed that livelihood was increased by agriculture and animal husbandry while hunting decreased birds and wildlife. Although local people focused on their livelihoods, NGO & Government officials focused on conservation of Tuzla Lake and education of local people. Stakeholders indicated that the conservation status of Tuzla Lake should be strengthened to conserve the ecosystem and biodiversity, which may be negatively impacted by agriculture and irrigation. Stakeholders mentioned salt extraction, ecotourism, and carpet weaving as alternative economic activities. Cognitive mapping provided an effective tool for the inclusion of the stakeholders' views and ensured initial participation in environmental planning and policy making.Comment: 43 pages, 4 figure

    Six-fold in-plane magnetic anisotropy in Co-implanted ZnO (0001)

    Full text link
    Magnetic anisotropies of Co-implanted ZnO (0001) films grown on single-crystalline Al2O3 (11-20) substrates have been studied by ferromagnetic resonance (FMR) technique for different cobalt implantation doses. The FMR data show that the easy and hard axes have a periodicity of 60 degrees in the film plane, in agreement with the hexagonal structure of the ZnO films. This six-fold in-plane magnetic anisotropy, which is observed for the first time in ZnO-based diluted magnetic semiconductors, is attributed to the substitution of cobalt on Zn sites in the ZnO structure, and a clear indication for long range ferromagnetic ordering between substitutional cobalt ions in the single-crystalline ZnO films.Comment: 7 pages, 4 figure

    Cross Sections for Neutron–Deuteron Elastic Scattering in the Energy Range 135–250 MeV

    Get PDF
    We report new measurements of the neutron–deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80° to 130°. Cross sections for neutron-proton elastic scattering were also measured with the same experimental setup for normalization purposes. Our nd cross section results are compared with predictions based on Faddeev calculations including three-nucleon forces, and with cross sections measured with charged particle and neutron beams at comparable energies

    Secure key agreement using pure biometrics

    Get PDF
    In this paper, we propose a novel secure key agreement protocol that uses biometrics with unordered set of features. Our protocol enables the user and the server to agree on a symmetric key, which is generated by utilizing only the feature points of the user's biometrics. It means that our protocol does not generate the key randomly or it does not use any random data in the key itself. As a proof of concept, we instantiate our protocol model using fingerprints. In our protocol, we employ a threshold-based quantization mechanism, in order to group the minutiae in a predefined neighborhood. In this way, we increase the chance of user-server agreement on the same set of minutiae. Our protocol works in rounds. In each round, depending on the calculated similarity score on the common set of minutiae, the acceptance/rejection decision is made. Besides, we employ multi-criteria security analyses for our proposed protocol. These security analyses show that the generated keys possess acceptable randomness according to Shannon's entropy. In addition, the keys, which are generated after each protocol run, are indistinguishable from each other, as measured by the Hamming distance metric. Our protocol is also robust against brute-force, replay and impersonation attacks, proven by high attack complexity and low equal error rates

    Differential cross section for neutron-proton bremsstrahlung

    Get PDF
    The neutron-proton bremsstrahlung process (npnpγ)(np \to np\gamma) is known to be sensitive to meson exchange currents in the nucleon-nucleon interaction. The triply differential cross section for this reaction has been measured for the first time at the Los Alamos Neutron Science Center, using an intense, pulsed beam of up to 700 MeV neutrons to bombard a liquid hydrogen target. Scattered neutrons were observed at six angles between 12^\circ and 32^\circ, and the recoil protons were observed in coincidence at 12^\circ, 20^\circ, and 28^\circ on the opposite side of the beam. Measurement of the neutron and proton energies at known angles allows full kinematic reconstruction of each event. The data are compared with predictions of two theoretical calculations, based on relativistic soft-photon and non-relativistic potential models.Comment: 5 pages, 3 figure

    Size-dependent spin-reorientation transition in Nd2Fe14B nanoparticles

    Full text link
    Nd2Fe14B magnetic nanoparticles have been successfully produced using a surfactant-assisted ball milling technique. The nanoparticles with different size about 6, 20 and 300 nm were obtained by a size-selection process. Spin-reorientation transition temperature of the NdFeB nanoparticles was then determined by measuring the temperature dependence of DC and AC magnetic susceptibility. It was found that the spin-reorientation transition temperature (Tsr) of the nanoparticles is strongly size dependent, i.e., Tsr of the 300 nm particles is lower than that of raw materials and a significant decrease was observed in the 20 nm particles
    corecore