Evaluating correlated outcomes and sources of new information

This paper considers the difficulties associated with evaluating the expected value of additional information when the outcomes of various decision alternatives may be correlated. Such correlation is explained in terms of dependence of outcomes on common exogenous factors and it is argued that decisions regarding what, if any, additional information to collect should take such dependencies into account. A model-based ‘fixed-parameter’ approach to evaluating EVPI in such a context is developed and compared to the traditional ‘fixed-correlation’ approach. The results suggest that different assumptions about the issue of correlation can produce different, sometimes contradictory, conclusions about the expected value of additional information and bence, should be explicitly stated as part of any pre-posterior analysis. A hybrid model encompassing both approaches and rooted in the theory of psychology of inference is then proposed and illustrated.     

基于NURBS方法的转子表面造型技术

采用双三次NURBS方法对某型号转子进行几何造型,对造型过程中出现的曲面延伸、求交和裁剪等问题进行了研究.根据叶片的形状特征,以曲线的几何形式为基础,提出了一种简单实用的曲线曲面延伸方法,实现了切矢量连续的叶片型面的延伸.对于两相交面分别为自由曲面和解析曲面的求交问题,提出了一种简化的跟踪算法,实现了转子叶片型面和圆台面的准确求交和裁剪,从而实现转子精确的几何造型.     

Minimum contrast estimation of random processes based on information of second and third orders

This paper presents the results on consistency and asymptotic normality of a class of minimum contrast estimators for random processes with short- or long-range dependence based on the second- and third-order cumulant spectra. Asymptotic properties of sample spectral functionals of second and third orders, which are of independent interest in view of their possible use for nonparametric estimation of processes with short- or long-range dependence, are also provided.     

Integrating Theory and Research on the Institutional Determinants of Fertility

This article links recent conceptual theories regarding the determinants of fertility with research designs appropriate for testing those theories. The most important causal factors in these theories--typically social or cultural institutions, occasionally emergent properties of the collective behavior of individuals--are properly conceptualized at the macro level. Research designs must therefore feature variation at this level and are at a minimum comparative. Noncomparative micro-level research designs will be misspecified from the standpoint of theory. A case is also made for continuing to incorporate the observation of individual-level behavior into any comprehensive research design. A focus on macro determinants of fertility does not imply that fertility outcomes are determined at the institutional level. Instead, there remains some process whereby systemic properties are translated into individual behaviors. Recommendations for comparative community-level studies are discussed. The multilevel analysis framework is reviewed as a paradigm for the conceptual features of cross-contextual analysis.     

How NASA moved from R & D to operations

This paper investigates the initial planning process for the transition of an organization from a R & D environment to an Operations environment. Using a developed transition life cycle model, the paper demonstrates a four step analysis of the management of the transition. Further, the paper suggests the utilization of existing methods for achieving a smooth transformation under various levels of technical, political, cultural, managerial, and economic uncertainties. Finally, the paper lists possible courses of action and considerations for the transition once the initial planning stage is completed. The concepts herein were used to begin planning the change, from R & D to Operations, of the Space Shuttle Program at NASA.     

Evaluating Application Service Provisioning Using System Dynamics Methodology

Despite the hype surrounding the value‐added potential of e‐business for contemporary firms, the recent technology downturn was marked by poor customer satisfaction from investment in e‐business initiatives. An apparent mismatch between customer expectations and vendor offerings suggested a lack of appropriate methods and techniques for evaluating e‐business. This article draws from a longitudinal research study on the deployment, hosting and integration of application service provisioning (ASP), an e‐business model targeted mainly at small and medium‐sized businesses (SMBs). Using system dynamics as a methodology that addresses the inherent complexity of the ASP model, the article demonstrates how a series of complex inter‐relationships between key performance indicators (KPIs) will impact the business value for customers from ASP vendor products and services. The lessons from this research will be particularly relevant for existing and future ASP vendors and customers.     

A BETA-OPTIMAL TEST OF THE EQUICORRELATION COEFFICIENT

This paper considers the problem of testing for nonzero values of the equicorrelation coefficient of a standard symmetric multivariate normal distribution. Recently, SenGupta (1987) proposed a locally best test. We construct a beta-optimal test and present selected one and five percent critical values. An empirical power comparison of SenGupta's test with two versions of the beta-optimal test and the power envelope shows the relative strengths of the three tests. It also allows us to assess and confirm Efron's (1975) rule of when to question the use of a locally best test, at least for this testing problem. On the basis of these results, we argue that the two beta-optimal tests can be considered as approximately uniformly most powerful tests, at least at the five percent significance level.     

The acquisition of tacts,mands, and intraverbals by individuals with traumatic brain injury

Two individuals who sustained traumatic brain injuries from motorcycle accidents were taught several verbal responses by using tact, mand, and intraverbal training procedures. The rate of acquisition for each operant and the transfer to untrained verbal operants involving the same response topography were measured. The results showed that tacts and intraverbals were acquired quickest, and training on the tact produced the greatest amount of transfer to the untrained verbal operants. Intraverbal training also resulted in transfer for both subjects, but to varying degrees. Direct mand training proved to be the least efficient way to generate a mand repertoire, and when acquired showed least amount of transfer to the untrained operants. These results seem to be in contrast with the findings of similar research with developmentally disabled individuals, and may have implications for methods of language instruction for the brain injured population.

     

Propensity to adopt innovative housing: Development of knowledge indexes

The process by which energy efficient housing alternatives is diffused through society in relation to the information flow is relatively unknown. The major purpose of this study was to validate a continuum of the propensity to adopt alternative housing (passive and active solar, earth sheltered and retrofitted) based on knowledge level. Findings indicate knowledge indices are valid predictors of consumer acceptance of energy efficient housing alternatives. A greater level of knowledge was correlated with respondents willing to adopt an alternative housing type.