Analysis of the BRIC Countries Technical Efficiency Patterns Using Stochastic Frontier Approach

This study investigates the technical efficiency of BRIC-countries (Brazil, Russia, India, China) at the disaggregated level of six economic activities using stochastic frontier approach. Technical efficiency scores and efficiency externalities effects of international trade and foreign direct investment inflows are estimated based on the panel of sixteen countries - G20 members - over the period from 1995 to 2009. The results suggest that foreign direct investment is a conduit of the positive technological spillovers in all sectors under analysis. Once controlling for the domestic level of the human capital that captures technology absorptive capacity, the positive effect of the international trade is observed in the industrial sector in general and manufacturing in particular, as well as in trade, hotels and restaurants. The positive impact of the human capital on the level of technical efficiency is significant for all sectors, except for the agriculture, and robust for two different measures of human capital

Factors related to the rejection and/or abandonment of AAC devices

More than 3.5 million Americans have such significant communication disability that they cannot rely on their natural speech to meet their communication needs. As a result, these individuals are severely restricted in their participation in all aspects of life, including their education, employment, family, and community. Augmentative and alternative communication strategies offer great potential to enhance the communication of individuals with complex communication needs, and therefore improve their quality of life. Fifty-two ISAAC members that responded to the online survey utilized a 5 point Likert-type scale (strongly agree to strongly disagree) to rate the importance of factors as they relate to the rejection and/or abandonment. The mean values of ratings were calculated to determine which factors were cited as relevant in predicting AAC device rejection and abandonment. Additionally, an independent T-test was utilized to determine if the factors cited varied depending on the role of the person completing the survey. The results of this investigation indicate that it is imperative to consider a complex interaction of factors pertaining to the individuals who use AAC, their conversational partners, settings in which interactions occur, and devices used to interact, when designing an AAC intervention. The statistical analysis revealed no significance difference in how the respondents rated the factors based on their occupation. Based on the results of the study, a checklist of factors that an AAC practitioner might consider addressing in order to foster acceptance of AAC systems initially and later on was constructed

Rate Allocation for Decentralized Detection in Wireless Sensor Networks

We consider the problem of decentralized detection where peripheral nodes make noisy observations of a phenomenon and send quantized information about the phenomenon towards a fusion center over a sum-rate constrained multiple access channel. The fusion center then makes a decision about the state of the phenomenon based on the aggregate received data. Using the Chernoff information as a performance metric, Chamberland and Veeravalli previously studied the structure of optimal rate allocation strategies for this scenario under the assumption of an unlimited number of sensors. Our key contribution is to extend these result to the case where there is a constraint on the maximum number of active sensors. In particular, we find sufficient conditions under which the uniform rate allocation is an optimal strategy, and then numerically verify that these conditions are satisfied for some relevant sensor design rules under a Gaussian observation model.Comment: Accepted at SPAWC 201

Family Watchdog

We consider a distributed detection system under communication constraints, where several peripheral nodes observe a common phenomenon and send their observations to a fusion center via error-free but rate-constrained channels. Using the minimum expected error probability as a design criterion, we propose a cyclic procedure for the design of the peripheral nodes using the person-by-person methodology. It is shown that a fine-grained binning idea together with a method for updating the conditional probabilities of the joint index space at the fusion center, decrease the complexity of the algorithm and make it tractable. Also, unlike previous methods which use dissimilarity measures (e.g., the Bhattacharyya distance), a-prior hypothesis probabilities are allowed to contribute to the design in the proposed method. The performance of the proposed method is comparedto a method due to Longo et al.’s and it is shown that the new method can significantly outperform the previous one at a comparable complexity.QC 20141203</p

Asymptotic Stability of POD based Model Predictive Control for a semilinear parabolic PDE

In this article a stabilizing feedback control is computed for a semilinear parabolic partial differential equation utilizing a nonlinear model predictive (NMPC) method. In each level of the NMPC algorithm the finite time horizon open loop problem is solved by a reduced-order strategy based on proper orthogonal decomposition (POD). A stability analysis is derived for the combined POD-NMPC algorithm so that the lengths of the finite time horizons are chosen in order to ensure the asymptotic stability of the computed feedback controls. The proposed method is successfully tested by numerical examples