11,848 research outputs found
Bridging the gap? Corruption, knowledge and foreign ownership
We argue that in addition to host corruption per se, as accounted for by the existing
literature, an explanation of inter-country variation in FDI needs to account for the distance between the host and home corruption, which we call relative corruption. We use a large matched home-host firm-level panel data-set for 1998-2006 from CEE transition countries. Year-specific selectivity corrected estimates suggest that, ceteris paribus, higher relative
âgrandâ corruption lowers foreign ownership as the returns to investment tends to be lower in more corrupt environment. However, after controlling for the selectivity bias,
knowledge-intensive parent firms are found to hold controlling ownership, as the difficulty of successful joint venture looms large in more corrupt environment. Results are robust to alternative specifications.Financial support from the ESRC under RES-062-23-0986 is acknowledge
Destabilizing attack and robust defense for inverter-based microgrids by adversarial deep reinforcement learning
The droop controllers of inverter-based resources (IBRs) can be adjustable by grid operators to facilitate regulation services. Considering the increasing integration of IBRs at power distribution level systems like microgrids, cyber security is becoming a major concern. This paper investigates the data-driven destabilizing attack and robust defense strategy based on adversarial deep reinforcement learning for inverter-based microgrids. Firstly, the full-order high-fidelity model and reduced-order small-signal model of typical inverter-based microgrids are recapitulated. Then the destabilizing attack on the droop control gains is analyzed, which reveals its impact on system small-signal stability. Finally, the attack and defense problems are formulated as Markov decision process (MDP) and adversarial MDP (AMDP). The problems are solved by twin delayed deep deterministic policy gradient (TD3) algorithm to find the least effort attack path of the system and obtain the corresponding robust defense strategy. The simulation studies are conducted in an inverter-based microgrid system with 4 IBRs and IEEE 123-bus system with 10 IBRs to evaluate the proposed method
Determination of cosmological parameters: an introduction for non-specialists
I start by defining the cosmological parameters and
. Then I show how the age of the universe depends on them,
followed by the evolution of the scale parameter of the universe for various
values of the density parameters. Then I define strategies for measuring them,
and show the results for the recent determination of these parameters from
measurements on supernovas of type 1a. Implications for particle physics is
briefly discussed at the end.Comment: 12 pages, Latex with epsf.sty. Invited talk at the ``Discussion
meeting on Recent Developments in Neutrino Physics'', held at the Physical
Research Laboratory, Ahmedabad, February 2--4, 199
Tripartite thermal correlations in an inhomogeneous spin-star system
We exploit the tripartite negativity to study the thermal correlations in a
tripartite system, that is the three outer spins interacting with the central
one in a spin-star system. We analyze the dependence of such correlations on
the homogeneity of the interactions, starting from the case where central-outer
spin interactions are identical and then focusing on the case where the three
coupling constants are different. We single out some important differences
between the negativity and the concurrence.Comment: 8 pages, 9 figure
Scale-Dependent Price Fluctuations for the Indian Stock Market
Classic studies of the probability density of price fluctuations for
stocks and foreign exchanges of several highly developed economies have been
interpreted using a {\it power-law} probability density function with exponent values , which are outside the
L\'evy-stable regime . To test the universality of this
relationship for less highly developed economies, we analyze daily returns for
the period Nov. 1994--June 2002 for the 49 largest stocks of the National Stock
Exchange which has the highest volume of trade in India. We find that
decays as an {\it exponential} function with a
characteristic decay scales for the negative tail and
for the positive tail, which is significantly different
from that observed for developed economies. Thus we conclude that the Indian
stock market may belong to a universality class that differs from those of
developed countries analyzed previously.Comment: 7 pages, 8 figure
Smart control of an electric vehicle for ancillary service in DC microgrid
This article presents a two-stage framework for optimal Electric Vehicle (EV) charging/discharging strategy for DC Microgrid (MG) with Distributed Generators (DGs). A multi-objective optimisation task aimed at minimising system losses and EV battery degradation with Vehicle-to-Grid (V2G) peak shaving service has been realised. This coordinated EV integration into the DCMG was formulated as a directed weighted single source shortest path problem that was solved using a modified Dijkstraâs algorithm. The weights of the edges were obtained using primal-dual interior point method. The proposed framework has been experimentally verified using simulations with a test DCMG system with practical IEEE European low voltage test feeder load profiles. Results show realisation of peak demand shaving leveraging on EV discharge with minimal on-board battery degradation as well as reduced system losses. It is also shown that the proposed two-stage framework reduces the battery state of charge (SOC) sample space requirements in the analysis, thus, reducing the computational burden
Sintering characteristics and kinetics of acidic haematite ore pellets with and without mill scale addition
Haematite ore pellets require very high induration temperature (>1573 K) while, magnetite ore pellets require much lower temperature due to the oxidation of magnetite during induration. Mixing of some magnetite in haematite ore can improve the sintering property of pellets during
induration. Mill scale is a waste material of steel plant which contains mainly FeO and Fe3O4. It can also be blended in haematite ore pellet mix which can enhance diffusion bonding and recrystallisation bonding and facilitate sintering at the lower temperature like magnetite ore. The
extent of improvement in sintering property, sintering mechanism and its kinetics in the presence of mill scale is very imperative to study. In current study, the sintering characteristics of acidic iron ore pellet with 15% mill scale and without mill scale has been studied separately through microstructure observation, apparent porosity measurement and volume change. The volume changes due to heating at varying temperature and time has been measured by mercury displacement method and the data has been exploited for sintering kinetics study, wherein,extent of sintering α has a power relation with time. Several kinetics parameters such as time exponent (n), rate constant (k) and activation energies have been estimated for above two pellets and compared. While acidic pellet without mill scale requires 385 k cal molâ1, acidic pellet with 15% mill scale requires only 310 k cal molâ1 activation energy
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