排序方式: 共有73条查询结果,搜索用时 93 毫秒
51.
Starting from the premise that firms are distinct in terms of their capacity to create innovations, this article explores
the rationale for R&D cooperation and the choice between alliances that involve information sharing, cost sharing or both.
Defining innovative capability as the probability of creating an innovation, it examines firm strategy in a duopoly market,
where firms have to decide whether or not to cooperate to acquire a fixed cost R&D infrastructure that would endow each firm
with a firm-specific innovative capability. Furthermore, since emerging industries are often characterized by high technological
uncertainty and diverse firm focus that makes the exploitation of spillovers difficult, this article focuses on a zero spillover
context. It demonstrates that asymmetry has an impact on alliance choice and social welfare, as a function of ex-post market
competition and fixed costs of R&D. With significant asymmetry no alliance may be formed, while with similar firms the cost
sharing alliance is dominant. Finally, it ascertains the settings under which the equilibrium outcome is distinct from that
maximizing social welfare, thereby highlighting some conditions under which public investment in a technology park can be
justified. 相似文献
52.
Education policy favouring ‘inclusion’, together with medical advances, mean that a growing number of pupils in mainstream schools may have health‐related support needs in respect of a chronic illness or physical disability. Data from an empirical research study investigating these needs and carried out between 1996 and 1998 are used to reflect on the position of this group of pupils within policy guidance on special educational needs (SEN) and medical needs. Evidence of confusion and ambiguity, both in the guidance and its interpretation, suggests that the needs of this group remain somewhat hidden. More recent developments in special needs policy guidance are discussed in terms of the prospect for strengthening support for this group of pupils. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
53.
Amitava Mukherjee Uttam Bandyopadhyay 《Journal of statistical planning and inference》2011,141(8):2645-2655
In the present study, we develop two nonparametric partially sequential tests for detecting possible presence of linear trend among the incoming series of observations. We assume that a sample of fixed size is available a priori from some unknown univariate continuous population and there is no sign of trend among these historical observations. Our proposed tests can be viewed as the sequential type tests for monitoring structural changes. We use partial sequential sampling schemes based on usual ranks as well as on sequential ranks. We provide detailed discussion on asymptotic studies related to the proposed tests. We compare the two tests under various situations. We also present some numerical results based on simulation studies. Proposed tests are extremely important in profit making in volatile market through Margin Trading. We illustrate the mechanism with a detailed analysis of a stock price data. 相似文献
54.
Uttam Bandyopadhyay Atanu Biswas Shirsendu Mukherjee 《Journal of the Korean Statistical Society》2011,40(3):245-255
We consider a two-treatment two-period crossover design in the presence of possible carryover effects, where the treatment responses are binary. We provide some simple probability models incorporating the possible carryover effects. Asymptotic distributions of the estimates of the parameters under the proposed models are derived. We carry out tests for treatment difference and carryover effects. Finally we use a data set to illustrate the applicability of the proposed procedures. 相似文献
55.
Atanu Biswas Rahul Bhattacharya Taranga Mukherjee 《Journal of the Korean Statistical Society》2019,48(4):524-536
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. 相似文献
56.
57.
Conan Mukherjee 《Social Choice and Welfare》2014,42(2):289-311
We completely characterize the class of fair and group strategy-proof mechanisms. We consider two notions of fairness, anonymity in welfare and no-envy. Both fairness axioms, when applied with strategy-proofness, imply decision efficiency, and lead to the same class of group strategy-proof mechanisms (where the group size is restricted to two). We find that the only feasible mechanism satisfying a mild zero transfer axiom, in this class, is the Pivotal mechanism. 相似文献
58.
Interval-censored data are very common in the reliability and lifetime data analysis. This paper investigates the performance of different estimation procedures for a special type of interval-censored data, i.e. grouped data, from three widely used lifetime distributions. The approaches considered here include the maximum likelihood estimation, the minimum distance estimation based on chi-square criterion, the moment estimation based on imputation (IM) method and an ad hoc estimation procedure. Although IM-based techniques are extensively used recently, we show that this method is not always effective. It is found that the ad hoc estimation procedure is equivalent to the minimum distance estimation with another distance metric and more effective in the simulation. The procedures of different approaches are presented and their performances are investigated by Monte Carlo simulation for various combinations of sample sizes and parameter settings. The numerical results provide guidelines to analyse grouped data for practitioners when they need to choose a good estimation approach. 相似文献
59.
In cross-over experiments, where different treatments are applied successively to the same experimental unit over a number of time periods, it is often expected that a treatment has a carry-over effect in one or more periods following its period of application. The effect of interaction between the treatments in the successive periods may also affect the response. However, it seems that all systematic studies of the optimality properties of cross-over designs have been done under models where carry-over effects are assumed to persist for only one subsequent period. This paper proposes a model which allows for the possible presence of carry-over effects up to k subsequent periods, together with all the interactions between treatments applied at k + 1 successive periods. This model allows the practitioner to choose k for any experiment according to the requirements of that particular experiment. Under this model, the cross-over designs are studied and the class of optimal designs is obtained. A method of constructing these optimal designs is also given. 相似文献
60.
A general successive substitutions' scheme is developed to estimate parameters in a finite mixture of distributions from the exponential family, based on censored data. It is assumed that the data can be grouped in the first class and the number of observations in each of the remaining classes are known Examples from Poisson Exponential and Normal distributions are given A small simulation exercise has also been carried out for the mixture of two one parameter exponential population. 相似文献