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Shwetank Lall Seema Jaggi Cini Varghese Arpan Bhowmik 《Journal of Statistical Computation and Simulation》2018,88(6):1191-1199
In this paper, locally D-optimal saturated designs for a logistic model with one and two continuous input variables have been constructed by modifying the famous Fedorov exchange algorithm. A saturated design not only ensures the minimum number of runs in the design but also simplifies the row exchange computation. The basic idea is to exchange a design point with a point from the design space. The algorithm performs the best row exchange between design points and points form a candidate set representing the design space. Naturally, the resultant designs depend on the candidate set. For gain in precision, intuitively a candidate set with a larger number of points and the low discrepancy is desirable, but it increases the computational cost. Apart from the modification in row exchange computation, we propose implementing the algorithm in two stages. Initially, construct a design with a candidate set of affordable size and then later generate a new candidate set around the points of design searched in the former stage. In order to validate the optimality of constructed designs, we have used the general equivalence theorem. Algorithms for the construction of optimal designs have been implemented by developing suitable codes in R. 相似文献
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This study examines the association between pollution disclosures and pollution performance and between pollution disclosures and economic performance for firms in highly polluting industries. An index of pollution disclosures is developed and correlated with indices of pollution performance and economic performance. The results confirm earlier findings that there is no association between pollution disclosures and pollution performance. As far as the association between economic performance and pollution disclosures is concerned, the results show that the subgroup of large firms with poor economic performance provides the most detailed pollution information. For smaller firms there is no association between economic performance and pollution disclosures. 相似文献
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Public relations is evolving in India and the profession is gaining acceptance and recognition. This study is an attempt to measure the extent of professionalism in India and how much consensus, if any, exists regarding professional standards among practitioners in agencies and those in corporations. It also identifies the influence of demographic factors on the standards in the profession. 相似文献
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Randomization of run sequences in factorial experiments may result in large number of changes in factor levels which will make the experimentation expensive, time-consuming and difficult. Experiments in which it is difficult to change the levels of factor(s) use of minimally changed run sequences may often be preferable to a random run sequence. In the present paper, we have developed method for obtaining minimally changed run sequences for factorial experiments. The general expression of factor-wise number of level changes for the developed minimally changed run sequences has also been obtained. A relationship has been established between the time count effect of a lower order factorial with minimally changed run sequences and that of a higher order factorial with minimally changed run sequences obtained through the lower order minimally changed run sequences. For providing a readymade solution to the end users, a SAS macro has also been developed for generating these minimally changed run sequences along with its parameters. 相似文献
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This paper deals with optimality aspects of block designs balanced for interference effects from neighboring units on both sides under a general non additive model along with random block effects. Here, a class of complete, circular block designs strongly balanced for interference effects has been shown to be universally optimal for the estimation of direct effects and interference effects (left and right) of treatments under a non additive mixed effects model. 相似文献
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Paresh Kumar Narayan Seema Narayan Siroos Khademalomoom Dinh Hoang Bach Phan 《Economic inquiry》2018,56(1):547-561
This study examines whether terrorist attacks affect bilateral exchange rates. Using historical 10‐minute exchange rate data for 21 countries' currency vis‐à‐vis the U.S. dollar, we show that exchange rate returns of all countries are statistically significantly affected by terrorist attacks. Some exchange rates appreciate and some depreciate following a terrorist attack, some currencies experience exchange rate reversals while others experience a persistent effect. Generally, the effect declines but persists as terrorist attacks become stale information. (JEL F31, F37) 相似文献
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ABSTRACTThis paper describes some methods of constructing circular neighbor balanced and circular partially neighbor balanced block designs for estimation of direct and neighbor effects of the treatments. A class of circular neighbor balanced block designs with unequal block sizes is also proposed. 相似文献
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Generalized Confounded Row–Column (GCRC) designs for factorial experiments have been introduced and methods of constructing GCRC designs have been discussed. Fractionally replicated GCRC designs have also been constructed. The designs obtained ensure balancing with respect to estimable effects. 相似文献