Cross sectional efficient estimation of stochastic volatility short rate models

We consider the problem of estimation of term structure of interest rates. Filtering theory approach is very natural here with the underlying setup being non-linear and non-Gaussian. Earlier works make use of Extended Kalman Filter (EKF). However, the EKF in this situation leads to inconsistent estimation of parameters, though without high bias. One way to avoid this is to use methods like Efficient Method of Moments or Indirect Inference Method. These methods, however, are numerically very demanding. We use Kitagawa type scheme for nonlinear filtering problem, which solves the inconsistency problem without being numerically so demanding. \u

On solving discrete optimization problems with one random element under general regret functions

In this paper we consider the class of stochastic discrete optimization problems in which the feasibility of a solution does not depend on the particular values the random elements in the problem take. Given a regret function, we introduce the concept of the risk associated with a solution, and define an optimal solution as one having the least possible risk. We show that for discrete optimization problems with one random element and with min-sum objective functions a least risk solution for the stochastic problem can be obtained by solving a non-stochastic counterpart where the latter is constructed by replacing the random element of the former with a suitable parameter. We show that the above surrogate is the mean if the stochastic problem has only one symmetrically distributed random element. We obtain bounds for this parameter for certain classes of asymmetric distributions and study the limiting behavior of this parameter in details under two asymptotic frameworks. \u

On solving discrete optimization problems with multiple random elements under general regret functions

In this paper we attempt to find least risk solutions for stochastic discrete optimization problems (SDOP) with multiple random elements, where the feasibility of a solution does not depend on the particular values the random elements in the problem take. While the optimal solution, for a linear regret function, can be obtained by solving an auxiliary (non-stochastic) discrete optimization problem (DOP), the situation is complex under general regret. We characterize a finite number of solutions which will include the optimal solution. We establish through various examples that the results from Ghosh, Mandal and Das (2005) can be extended only partially for SDOPs with additional characteristics. We present a result where in selected cases, a complex SDOP may be decomposed into simpler ones facilitating the job of finding an optimal solution to the complex problem. We also propose numerical local search algorithms for obtaining an optimal solution. \u

A new approach to particle based smoothed marginal MAP

We present here a new method of finding the MAP state estimator from the weighted particles representation of marginal smoother distribution. This is in contrast to the usual practice, where the particle with the highest weight is selected as the MAP, although the latter is not necessarily the most probable state estimate. The method developed here uses only particles with corresponding filtering and smoothing weights. We apply this estimator for finding the unknown initial state of a dynamical system and addressing the parameter estimation problem

A User’s Perspective on the Database of Services Sector in Indian Economy

Measuring the contribution of services to the Indian economy is a challenging task because it presents problems not encountered in the primary and secondary sectors. The authors discuss problems found particularly in quantifying the contribution of the banking and software sectors and suggest ways of overcoming these problems.database; services sector; banking; software sector; India

Qualitative analysis of interspecific hybrids of oil palm for bunch components and fatty acid composition

Elaeis oleifera or the American oil palm produces more liquid oil due to higher unsaturated fatty acid content compared to the commercial species Elaeis guineensis. However, due to erratic and poor yield, E. oleifera is not cultivated commercially. Interspecific hybrids are having the potentiality of combining yield and quality in the oil. Seven interspecific crosses were made involving six E. guineensis and five E. oleifera palms. These were evaluated for their bunch component and oil quality in terms of fatty acid composition along with control E. guineensis tenera (D X P) hybrids and E. oleifera parental palms. Bunch component analysis showed intermediate values for bunch weight as well as bunch related parameters including proportion of parthenocarpic fruits. However, the oil/mesocarp and oil/bunch were lower than those of the parents. Fatty acid composition showed intermediate value between the two parental species for all the fatty acids. Wide variability in fatty acid composition was found in progenies of two specific interspecific crosses. No correlation was observed between any two fatty acids. Out of seven interspecific crosses, three were found to be on par with the better performing E. oleifera parental palms with respect to fatty acids. Since performance of each palm is different, individual interspecific hybrid palm was assessed based on total unsaturated fatty acids and oleic acid content and 20 superior palms were selected, which could be employed for further back crossing programme to combine the quality of palm oil and yield

Vitamin D receptor expression levels determine the severity and complexity of disease progression among leprosy reaction patients

AbstractWe studied the roles of vitamin D and its receptor, VDR, in the progression of leprosy. The majority of individuals with leprosy from Kolkata, India, with a type 1 or type 2 reaction have low levels of vitamin D3 in serum samples. Interestingly, individuals with a type 2 reaction associated with neuritis/erythema nodosum leprosum had very low VDR mRNA expression levels, ranging from 5% to 10%, compared to that of healthy control subjects; these patients also had a high bacilli index, ranging from 3+ to 5+. This is the first report to indicate that VDR expression levels may determine the complexity and severity of the progression of leprosy

Use of Crushed and washed overburden for stowing in underground Mines: a case study

This paper throws light on the laboratory studies carried out to investigate the suitability of using overburden rocks produced from opencast mines of Ramagundem area(RG-II and RG – IV) as a stowing material for nearby underground mines of SCCL. This papers also provides a brief overview on the design of flow sheet for the processing of overburden rocks, to produce stowing material of the desired quality