726 research outputs found
FIGURE 2. Aristolochia gurinderii K in Aristolochia gurinderii (Aristolochiaceae): a new species from Great Nicobar Island, India
No full textFIGURE 2. Aristolochia gurinderii K. Ravikumar, Umeshkumar Tiwari and N. Balachandran, sp. nov.: A. Leaf with fruit; B. Inflorescence; C. Flower patterns; D. Close up of Flower; E. Dry Fruits and F. Green Fruit (Type: FRLH).Published as part of Ravikumar, K., Tiwari, Umeshkumar & Balachandran, N., 2014, Aristolochia gurinderii (Aristolochiaceae): a new species from Great Nicobar Island, India, pp. 117-122 in Phytotaxa 172 (2) on page 120, DOI: 10.11646/phytotaxa.172.2.7, http://zenodo.org/record/514244
Ambiguity and communication
No full textThe ambiguity of a nondeterministic finite automaton (NFA) N for input size n is the maximal number of accepting computations of N for an input of size n. For all k, r 2 N we construct languages Lr,k which can be recognized by NFA's with size k poly(r) and ambiguity O(nk), but Lr,k has only NFA's with exponential size, if ambiguity o(nk) is required. In particular, a hierarchy for polynomial ambiguity is obtained, solving a long standing open problem (Ravikumar and Ibarra, 1989, Leung, 1998)
Public Infrastructure Spillovers and Growth: Theory and Time Series Evidence for Australia.
No full textIn this paper, growth of per capita income can be exogenous and/or endogenous due to aggregate public infrastructure spillover. The deterministic Glomm and Ravikumar (1994) model is augmented in this paper to produce a stochastic growth counterpart which has useful time series implications.INCOME ; TIME SERIES ; CAPITAL
Optimal auditing and insurance in a dynamic model of tax compliance
No full textWe study the optimal auditing of a taxpayer’s income in a dynamic principal- agent model of hidden income. Taxpayers in our model initially have low income and stochastically transit to high income that is an absorbing state. A low-income taxpayer who transits to high income can underreport his true income and evade his taxes. With a constant absolute risk-aversion utility function and a costly and imperfect auditing technology, we show that the optimal auditing mechanism in our model consists of cycles. Within each cycle, a low-income taxpayer is initially unaudited, but if the duration of low-income reports exceeds a threshold, then the auditing probability becomes positive. That is, the tax authority guarantees that the taxpayer will not be audited until the threshold duration is reached. We also find that auditing becomes less frequent if the auditing cost is higher or if the variance of income is lower.Tax auditing ; Taxation
On some variations of two-way probabilistic finite automata models
No full textAbstractRabin [M. Rabin, Probabilistic finite automata, Information and Control (1963) 230–245] initiated the study of probabilistic finite automata (pfa). Rabin’s work showed a crucial role of the gap in the error bound (for accepting and non-accepting computations) in the power of the model. Further work resulted in the identification of qualitatively different error models (one-sided error, bounded and unbounded errors, no error etc.) Karpinski and Verbeek [M. Karpinski, R. Verbeek, There is no polynomial deterministic simulation of probabilistic space with two-way random-tape generator, Information and Control 67 (1985) 158–162] and Nisan [N. Nisan, On read-once vs. multiple access to randomness in logspace, in: Proc. of Fifth IEEE Structure in Complexity Theory, Barcelona, Spain, 1990, pp. 179–184] studied a model of probabilistic automaton in which the tape containing random bits can be read by a two-way head. They presented results comparing models with one-way vs. two-way access to randomness. Dwork and Stockmeyer [C. Dwork, L. Stockmeyer, Interactive proof systems with finite state verifiers, IBM Report RJ 6262, 1988] and Condon et al. [A. Condon, et al., On the power of finite automata with both nondeterministic and probabilistic states, SIAM Journal on Computing (1998) 739–762] studied a model of 2-pfa with nondeterministic states (2-npfa). In this paper, we present some results about the above mentioned variations of probabilistic finite automata, as well as a model of 2-pfa augmented with a pebble studied in [B. Ravikumar, Some observations on two-way probabilistic finite automata, in: Proc. of the Foundations of Software Technology and Theoretical Computer Science, 1992, pp. 392–403]. Our observations indicate that these models exhibit subtle variations in their computational power. We also mention many open problems about these models. Complete characterizations of their power will likely provide deeper insights about the role of randomness in space-bounded computations
Evaluation of elastic properties and study on water absorption behavior of alumina filled jute-epoxy composites
No full textElectrochemical studies of aluminium 7075 reinforced with Al2O3/SiCp hybrid composites in acid chloride medium
No full textStochastic Discount Factor Models and the Equity Premium Puzzle
No full textOne view of the equity premium puzzle is that in the standard asset-pricing model with time-separable preferences, the volatility of the stochastic discount factor, for plausible values of risk aversion, is too low to be consistent with consumption and asset return data. We adopt this characterization of the puzzle, due to Hansen and Jagannathan (1991), and establish two results: (i) resolutions of the puzzle based on complete frictionless markets and non-separabilities in preferences are very sensitive to small changes in the consumption data, and (ii) models with frictions avoid this sensitivity problem. Using quarterly data from 1947-97, we calibrate a state non-separable model and a time non-separable model to satisfy the Hansen-Jagannathan volatility bound and show that the two resolutions are not robust. We support our argument via a bootstrap experiment where the models almost always violate the bound. These violations are primarily due to the fact that small changes in consumption growth moments imply changes in the mean of the stochastic discount factor, which render the volatility of the stochastic discount factor to be too low relative to the bound. Asset-pricing models with frictions, however, are much more successful in the bootstrap experiment relative to the case without frictions.Stochastic Discount Factor; Hansen-Jagannathan Bound; Equity Premium;
Influence of radiation on MHD peristaltic blood flow through a tapered channel in presence of slip and joule heating
No full textPeg-solitaire, string rewriting systems and finite automata
No full textAbstractWe consider a class of length-preserving string rewriting systems and show that the set of encodings of pairs of strings 〈s,f〉 such that f can be derived from s using the rewriting rules can be accepted by finite automata. As a consequence, we show the existence of a linear time algorithm for determining the solvability of a given k×n peg-solitaire board, for any fixed k. This result is in contrast to the results of (13) and (1) that the same problem is NP-hard for n×n boards. We look at some related string rewriting systems and find conditions under which the encodings of the pairs 〈s,f〉 where f can be derived from s is regular
- …
