Multi-arm response-adaptive designs for circular responses

A multi-arm response-adaptive allocation design is developed for circular treatment outcomes. Several exact and asymptotic properties of the design are studied. Stage-wise treatment selection procedures based on the proposed response-adaptive design are also suggested to exclude the worse performing treatment(s) at earlier stages. Detailed simulation study is carried out to evaluate the proposed selection procedures. The applicability of the proposed methodologies is illustrated through a real clinical trial data on cataract surgery.     

An Improved Security Requirement for Data Perturbation with Implications for E‐Commerce

With the rapid increase in the ability to store and analyze large amounts of data, organizations are gathering extensive data regarding their customers, vendors, and other entities. There has been a concurrent increase in the demand for preserving the privacy of confidential data that may be collected. The rapid growth of e‐commerce has also increased calls for maintaining privacy and confidentiality of data. For numerical data, data perturbation methods offer an easy yet effective solution to the dilemma of providing access to legitimate users while protecting the data from snoopers (legitimate users who perform illegitimate analysis). In this study, we define a new security requirement that achieves the objective of providing access to legitimate users without an increase in the ability of a snooper to predict confidential information. We also derive the specifications under which perturbation methods can achieve this objective. Numerical examples are provided to show that the use of the new specification achieves the objective of no additional information to the snooper. Implications of the new specification for e‐commerce are discussed.     

An analysis of conservation attitudes and awareness around Kaziranga National Park,Assam, India: implications for conservation and development

Kaziranga National Park and World Heritage Site, Assam, India, situated in a region with a large and diverse human population, was recently expanded due to its global importance for the conservation of many endangered species. Here, we develop detailed demographic and socio-economic profiles of residents around Kaziranga to study conservation attitudes and awareness using a semi-structured survey of 590 households in 37 villages. Results show high variation in attitudes and awareness as a function of ethno-religious group, educational level, and socio-economic and immigration status, indicating more and different needs for economic interventions within some communities than others. We found a high degree of conservation awareness, but most people expressed negative conservation attitudes and almost all lost crops to wildlife. We highlight the complexity of conflict in the area and present a basis for electing a microsite planning approach for conservation and development in areas characterized by high ethnic diversity, high human population densities, and land-dependent large mammals that pose economic risks. The findings imply that highly localized development schemes and participatory approaches to resource management at the village level, coupled with greater efforts at education, are especially needed to achieve conservation and development goals in such cases.     

Revealed Preference Tests of the Cournot Model

The aim of this paper is to develop revealed preference tests for Cournot equilibrium. The tests are akin to the widely used revealed preference tests for consumption, but have to take into account the presence of strategic interaction in a game‐theoretic setting. The tests take the form of linear programs, the solutions to which also allow us to recover cost information on the firms. To check that these nonparametric tests are sufficiently discriminating to reject real data, we apply them to the market for crude oil.     

Perceptions of economic globalization,emerging influence,and international organizations in India

This article presents an exploratory study—based on the emerging economy context of India—which examines the relationships among citizens’ perceptions of economic globalization, their country's “emerging influence”, other key nations, and large international organizations. Demographic and socioeconomic factors influenced respondents’ perceptions of economic globalization and emerging influence. Perceptions of economic globalization influenced emerging influence. Perceptions of international organizations were influenced by views of emerging influence, key nations, and economic globalization. Perceptions of key nations were influenced by views of emerging influence and international organizations. The findings are relevant for extended engagement in global public relations and public diplomacy.     

D-optimal statistical designs with restricted string property

This paper applies Frechet derivatives to derive asymp-totically D-optimal statistical designs where the designmatrix is a (O,l)-matrix having exactly one run [of length at most k(, the number of parameters) of l's in each row. These asymptotic results have been utilized in dealing with the more intractable design problem with a finite number of observations. The problemof E-optimality has also been considered.     

D-optimal designs for covariate models

The problem of finding D-optimal or D-efficient designs in the presence of covariates is considered under a completely randomized design set-up with v treatments, k covariates and N experimental units. In contrast to Lopes Troya [Lopes Troya, J., 1982, Optimal designs for covariates models. Journal of Statistical Planning and Inference, 6, 373–419.], who considered this problem in the equireplicate case, we do not assume that N/v is an integer, and this allows us to study situations where no equireplicate design exists. Even when N/v is an integer, it is seen quite counter-intuitively that there are situations where a non-equireplicate design outperforms the best equireplicate design under the D-criterion.     

Inverse Gaussian Distribution for Modeling Conditional Durations in Finance

The durations between market activities such as trades and quotes provide useful information on the underlying assets while analyzing financial time series. In this article, we propose a stochastic conditional duration model based on the inverse Gaussian distribution. The non-monotonic nature of the failure rate of the inverse Gaussian distribution makes it suitable for modeling the durations in financial time series. The parameters of the proposed model are estimated by an efficient importance sampling method. A simulation experiment is conducted to check the performance of the estimators. These estimates are used to compute estimated hazard functions and to compare with the empirical hazard functions. Finally, a real data analysis is provided to illustrate the practical utility of the models.     

Optimal statistical designs with circular string property

This paper develops an approximate theory for D- and A-optlmal statistical designs with a circular string property. It is shown how the problems of deriving optimal designs can be reduced to non-linear programming problems involving small numbers of decision variables. The results are seen to be helpful in dealing with the exact design problem with a finite number of obser vations.     

Construction of effect-wise orthogonal factorial designs

Generalizing the concept of Kronecker products of designs, two distinct methods have been suggested for the construction of effect-wise orthogonal factorial designs. The methods described ensure desirable properties with respect to main effects, cover almost all cases of factorial designs and require, in most cases, a smaller number of replications than any of the existing methods.