Towards Enhancement of the Economy of a Thermal Power Generating System through Prediction of Plant Efficiency

The plant ‘Heat Rate’ (HR) is a measure of overall efficiency of a thermal power generating system. It depends on a large number of factors, some of which are non-measurable, while data relating to others are seldom available and recorded. However, coal quality (expressed in terms of ‘effective heat value’ (EHV) as kcal/kg) transpires to be one of the important factors that influences HR values and data on EHV are available in any thermal power generating system. In the present work, we propose a prediction interval of the HR values on the basis of only EHV, keeping in mind that coal quality is one of the important (but not the only) factors that have a pronounced effect on the combustion process and hence on HR. The underlying theory borrows the idea of providing simultaneous confidence interval (SCI) to the coefficients of a p-th p(≥1) order autoregressive model (AR(p)). The theory has been substantiated with the help of real life data from a power utility (after suitable base and scale transformation of the data to maintain the confidentiality of the classified document). Scope for formulating strategies to enhance the economy of a thermal power generating system has also been explored.     

Design and implementation of an integrated production planning system for a pharmaceutical manufacturing concern in India

SmithKline Beecham (SBPI) is a major player in the Indian pharmaceutical industry. Though relatively small in terms of turnover, it has performed Pharmaceuticals (India) exceptionally well in terms ofprofitability and growth rate. The firm has substantial cash reserves. However, the firm operates in 'mass production' mode at present, with the established finished goods inventory norms being in the range of 1 to 1.5 months. Competitive pressure on the firm is now forcing it to move towards world class manufacturing and the application of concepts from MRP II, JIT and OPT is under consideration. This paper describes the considerations that went into the justification, design and implementation of an integrated production planning and control system in this situaion.     

Multistage methodologies for comparing several treatments with a control

We consider the problem of constructing a set of fixed-width simultaneous confidence intervals for the treatment-control differences of means for several independent normal populations with a common unknown variance. Taking c observations from the control population instead of the usual vector-at-a-time approach, purely sequential estimation methodology is developed and asymptotic second-order characteristics are provided. Brief remarks on the accelerated sequential and three-stage methodologies have been added. Next, with the help of simulations, performances of the purely sequential, accelerated sequential and three-stage estimation techniques are compared. Overall, the second-order asymptotics are found to provide useful approximations even for moderate sample sizes.     

On Sharp Jensen's Inequality and Some Unusual Applications

The purpose of this article is two-fold. First, we find it very interesting to explore a kind of notion of optimality of the customary Jensen-bound among all Jensen-type bounds. Without this result, the customary Jensen-bound stood alone simply as just another bound. The proposed notion and the associated optimality are important given that in some situations the Jensen's inequality does leave us empty handed.

When it comes to highlighting Jensen's inequality, unfortunately only a handful of nearly routine applications continues to recycle time after time. Such encounters rarely produce any excitement. This article may change that outlook given its second underlying purpose, which is to introduce a variety of unusual applications of Jensen's inequality. The collection of our important and useful applications and their derivations are new.     

Sequential procedures in identification

In this paper we study the problem of identifying a popula-tion with one of the two populations, with an aim to control both types of errors. We assume that the populations are normal with unknown means, but with unit variance. We have cited examples from anthropological studies where our formulation of the problem fits in quite nicely. We observe that SPRT’s based on the maximal invariant may not terminate with probability one. Simulation studies reported here show a substantial saving in the average number of samples compared to the best invariant fixed sample test.     

Children, spousal love, and happiness: an economic analysis

In this paper we examine how children affect happiness and relationships within a family by analyzing two unique questions in the National Longitudinal Study of Youth’s 1997 cohort. We find that (a) presence of children is associated with a loss of spousal love; (b) loss of spousal love is associated with loss of overall happiness; but (c) presence of children is not associated with significant loss of overall happiness. If children reduce feelings of being loved by the spouse but do not reduce reported happiness even though spousal love induces happiness, then it must be the case that children contribute to parental happiness by providing other benefits. After ruling out some competing compensation mechanisms we infer that loss of spousal love is compensated with altruistic feelings towards children.     

Progesterone: the forgotten hormone in men?

‘Classical’ genomic progesterone receptors appear relatively late in phylogenesis, i.e. it is only in birds and mammals that they are detectable. In the different species, they mediate manifold effects regarding the differentiation of target organ functions, mainly in the reproductive system. Surprisingly, we know little about the physiology, endocrinology, and pharmacology of progesterone and progestins in male gender or men respectively, despite the fact that, as to progesterone secretion and serum progesterone levels, there are no great quantitative differences between men and women (at least outside the luteal phase). In a prospective cohort study of 1026 men with and without cardiovascular disease, we were not able to demonstrate any age-dependent change in serum progesterone concentrations. Progesterone influences spermiogenesis, sperm capacitation/acrosome reaction and testosterone biosynthesis in the Leydig cells. Other progesterone effects in men include those on the central nervous system (CNS) (mainly mediated by 5α-reduced progesterone metabolites as so-called neurosteroids), including blocking of gonadotropin secretion, sleep improvement, and effects on tumors in the CNS (meningioma, fibroma), as well as effects on the immune system, cardiovascular system, kidney function, adipose tissue, behavior, and respiratory system. A progestin may stimulate weight gain and appetite in men as well as in women. The detection of progesterone receptor isoforms would have a highly diagnostic value in prostate pathology (benign prostatic hypertrophy and prostate cancer). The modulation of progesterone effects on typical male targets is connected with a great pharmacodynamic variability. The reason for this is that, in men, some important effects of progesterone are mediated non-genomically through different molecular biological modes of action. Therefore, the precise therapeutic manipulation of progesterone actions in the male requires completely new endocrine-pharmacological approaches.     

Do women value marriage more? The effect of obesity on cohabitation and marriage in the USA

This paper looks into the impact of obesity and other factors on first entry into a marital or cohabiting union, using 1997 cohort data from the national longitudinal survey. Results show obese women are less likely to be accepted into either cohabitation or marriage, while obese men are less likely to be accepted in a cohabitating relation but are not less likely to enter into marriage. Income affects all union and all genders symmetrically, increasing the likelihood of a union. These results suggest that marriage is a special form of union for women, so they are willing to marry obese men because they value other factors related to the marriage choice, such as commitment or the prospect of having children. Men do not appear to value these factors as much, so obese women are less likely to be accepted into either cohabitation or marriage.

When Twenty-Four Hours is not Enough: Time Poverty of Working Parents

Individuals can be money poor, time poor or both. While income is the most used indicator of poverty, broader indexes including non-monetary aspects of deprivation have been proposed and measured. As one such measure, our study focuses on the element of deprivation arising from the time deficit of many working people. The usual poverty threshold is calculated as the amount of income to buy the minimum required goods and services from the market. This minimum required purchase is greater for these people since they have less time than the average person to produce some goods and services for themselves at home. So, they need money to buy these in the market in order to maintain the same consumption. The income standard must be supplemented to adequately measure actual poverty. Time use data make it possible to establish time requirements and time availability and provide a measure of time poverty. Using Canadian GSS 1998 data, and building on the work of Vickery (1977, ‚The time poor: A new look at poverty’, The Journal of Human Resources 12(1), pp. 27-48) and of Douthitt (1993, ‚The inclusion of time availability in Canadian poverty measures’, Time-Use Methodology: Toward Consensus (ISTAT, Roma), pp. 83–91), and our own previous study, we estimate time-adjusted poverty thresholds and rates for single and dual parent Canadian families. As expected, we have found high incidence of time deficit among the employed single parents with children. We make a case for the acceptance of a redefined poverty standard for such time-deprived groups.