7,150 research outputs found
Measuring Spillovers from Alternative Forms of Foreign Investment
Much of the endogenous growth literature has dwelled on evaluating the spillover effects of trade on growth, but much less efforts have been directed towards tracing and quantifying the spillover effects of foreign investments. This paper, in incorporating the effects of various types of foreign investments, namely foreign direct investment (FDI), foreign portfolio investment (FPI) and other foreign investment (OFI) fills this gap in the literature. Adopting the stochastic frontier approach, this paper constructs an OECD frontier based on a panel dataset of 20 OECD countries over the 1981-2000 period. Spillover effects of FDI, FPI, OFI and trade are gauged by their respective contributions towards reducing technical inefficiencies, which are represented by the distance of each country from the constructed frontier. Results from the multiple models examined in the paper indicate that inflows of foreign investment and trade have been instrumental in reducing inefficiencies across OECD countries, whereas outflows of foreign investment exacerbate inefficiencies. The study also confirms some previous findings that the spillover effects of FDI inflows are larger than that of trade but does not find evidence in favour of the view that the spillover effects of trade are overestimated when FDI flows are excluded from the analysis. Moreover, the impact of FDI inflows is larger than those of FPI and OFI inflows. The importance of absorptive capacities of host economies in capturing spillover gains from FDI inflows is also examined. Amongst the various measures of absorptive capacity considered, only human capital was found to be importantforeign direct, portfolio and other investment; spillovers; stochastic production frontier; OECD;
Thermal analysis, optimization and design of a Martian oxygen production plant
The objective is to optimally design the thermal components of a system that uses carbon dioxide (CO2) from the Martian atmosphere to produce oxygen (O2) for spacecraft propulsion and/or life-support. Carbon dioxide is thermally decomposed into carbon monoxide (CO) and O2 followed by the electrochemical separation of O2. The design of the overall system and its various individual components depends on, among other things, the fraction of the stoichiometric yield of O2 that can be realized in the system and the temperature of operation of the electrochemical separation membrane. The analysis indicates that a substantial reduction could be obtained in the mass and power requirements of the system if the unreacted CO2 were to be recycled. The concepts of an optimum temperature of the zirconia cell and impracticality of plant operation at low cell efficiencies are also discussed. The design of the thermal equipment is such that the mass and power requirements of the individual components and of the overall system are optimized
Analog-digital simulation of transient-induced logic errors and upset susceptibility of an advanced control system
A simulation study is described which predicts the susceptibility of an advanced control system to electrical transients resulting in logic errors, latched errors, error propagation, and digital upset. The system is based on a custom-designed microprocessor and it incorporates fault-tolerant techniques. The system under test and the method to perform the transient injection experiment are described. Results for 2100 transient injections are analyzed and classified according to charge level, type of error, and location of injection
CO2 lidar system for atmospheric studies
A lidar facility using a TEA CO2 laser source is being developed at the ENEA Laboratories for Atmospheric Studies. The different subsystems and the proposed experimental activities are described
Material growth and characterization for solid state devices
Manganese was used as the dopant for p-type InGaAs layers grown on semi-insulating (Fe-doped) and n-type (Sn-doped) InP substrates. Optical, electrical (Hall) and SIMS measurements were used to characterize the layers. Mn-diffusion into the substrate (during the growth of In GaAs) was observed only when Fe-doped substrates were used. Quaternary layers of two compositions corresponding to wavelengths (energy gaps) of approximated 1.52 micrometers were successfully grown at a constant temperature of 640 C and InP was grown in the temperature range of 640 C to 655 C. A study of the effect of pulses on the growth velocity of InP indicated no significant change as long as the average applied current was kept constant. A system for depositing films of Al2O3 by the pyrolysis of aluminum isopropoxide was designed and built. Deposited layers on Si were characterized with an ellipsometer and exhibited indices of refraction between 1.582 and 1.622 for films on the order of 3000 A thick. Undoped and p-type (Mn-doped) InGaAs epitaxial layers were also grown on Fe-doped InP substrates through windows in sputtered SiO2 (3200 A thick) layers
Ferromagnetic feature from Mn near room temperature in the fine particles of GdMn2Ge2 and TbMn2Ge2
The magnetization behaviors of GdMn2Ge2 and TbMn2Ge2 in the bulk and in the
fine particles obtained by high-energy ball-milling are compared. Pronounced
modificayions in the spontaneous, remnent and high-field magnetization in the
fine particle form, attributable to Mn are observed. The results indicate that
the antiferromagnetism of Mn sub-lattice known for the bulk form in the range
100-300 K gets weakened in favor of ferromagnetism in the fine particles. On
the basis of this observation, we infer that there are other factors like size
(and possibly defects) also play a role to decide the exact nature of magnetic
ordering of Mn in this ternary family of compounds, contrasting the
traditionally held view that the basal plane Mn-Mn distance is the crucial
controlling parameter.Comment: Communicated for publication on 2nd January 201
The Role of Trust in the Intention to Use Feedback from Reputation Systems
Online reputation systems have evolved to increase our knowledge of sellers, products, services, and other individuals in the electronic setting of the Internet. Evidence from prior studies suggests that the feedback individuals provide through reputation systems in the form of numerical ratings, a given number of stars, and text commentary should alleviate an element of uncertainty when interacting in the online environment. However, the user of the feedback must believe that the feedback is trustworthy. To our knowledge, no studies exist which examine the role of trust with regard to the consumer’s intention to use feedback from reputation systems. As online interactions increase, mechanisms for reputation in this context continue to grow in importance. This study will endeavor to address a significant gap in current literature to examine how trust impacts the user’s intention to use feedback from online reputation systems
Non-magnetic left-handed material
We develop a new approach to build a material with negative refraction index.
In contrast to conventional designs which make use of a resonant behavior to
achieve a non-zero magnetic response, our material is intrinsically
non-magnetic and relies on an anisotropic dielectric constant to provide a
left-handed response in waveguide geometry. We demonstrate that the proposed
material can support surface (polariton) waves, and show the connection between
polaritons and the enhancement of evanescent fields, also referred to as
super-lensing
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