Middle-Tier Extensible Data Management

Current data management solutions are largely optimized for intra-enterprise, client–server applications. They depend on predictability, predefined structure, and universal administrative control, and cannot easily cope with change and lack of structure. However, modern e-commerce applications are dynamic, unpredictable, organic, and decentralized, and require adaptability. eXtensible Data Management (XDM) is a new approach that enables rapid development and deployment of networked, data-intensive services by providing semantically-rich, high-performance middle-tier data management, and allows heterogeneous data from different sources to be accessed in a uniform manner. Here, we discuss how middle tier extensible data management can benefit an enterprise, and present technical details and examples from the Index Fabric, an XDM engine we have implemented.     

Structure of operating domains of loop reactors

A loop reactor (LR), composed as an N-unit loop with step-wise shifted inlet and outlet ports, is one of suggested technological solutions for low-concentration volatile organic compounds (VOC) combustion. Such a scheme ensures a sufficiently high temperature with autothermal behavior and nearly uniform catalytic utilization. The main drawback of the LR is a very narrow window of switching velocities that sustain a stable “frozen” solution that exists if the switching and the pulse velocity are synchronized. In the present work we show the existence of many “finger”-like domains of complex frequency-locked solutions that allow to significantly extend the operation domain, rendering the LR scheme more attractive for practical implementation. A brief comparison with the other heat recuperation technologies (reverse flow and circular loop reactors) is presented. © 2008 American Institute of Chemical Engineers AIChE J, 2008     

Dynamic non-Bayesian decision making in multi-agent systems

We consider a group of several non-Bayesian agents that can fully coordinate their activities and share their past experience in order to obtain a joint goal in face of uncertainty. The reward obtained by each agent is a function of the environment state but not of the action taken by other agents in the group. The environment state (controlled by Nature) may change arbitrarily, and the reward function is initially unknown. Two basic feedback structures are considered. In one of them — the perfect monitoring case — the agents are able to observe the previous environment state as part of their feedback, while in the other — the imperfect monitoring case — all that is available to the agents are the rewards obtained. Both of these settings refer to partially observable processes, where the current environment state is unknown. Our study refers to the competitive ratio criterion. It is shown that, for the imperfect monitoring case, there exists an efficient stochastic policy that ensures that the competitive ratio is obtained for all agents at almost all stages with an arbitrarily high probability, where efficiency is measured in terms of rate of convergence. It is also shown that if the agents are restricted only to deterministic policies then such a policy does not exist, even in the perfect monitoring case. This revised version was published online in June 2006 with corrections to the Cover Date.     

Divided attention during encoding and retrieval: Differential control effects?

Previous studies have shown that divided attention (DA) during retrieval has little effect on recall of episodic memories, although DA during encoding has a large detrimental effect. One possible reason for this asymmetry is that stimulus presentation at encoding is under experimenter control, whereas retrieval operations and responses are under participant control. This experiment tested this possibility by presenting paired-associate word lists for learning and recall, either at a fixed 4-s rate or at a rate controlled by the participant. The results showed that the higher recall levels for DA at retrieval than for DA at encoding held under all combinations of experimenter and participant control. The implications of these results for a fuller understanding of encoding and retrieval processes are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distributed Protocols for Networks with Mobile Users — The Mobilizer Approach

This paper introduces a novel approach, called Mobilizer, of operating synchronous communication protocols in cellular mobile environment. First, we present a distributed protocol, called Mobile Propagation of Information (MPI), for broadcasting information in mobile environment. Then, we present the Mobile Propagation of Information with Feedback (MPIF) protocol, which can be used to implement the Mobilizer approach, i.e., enable broadcast-based synchronous protocols run over distributed networks with mobile users. We prove the correctness of the protocols and show that the additional message complexity overhead, induced due to the Mobilizer, is linear with the number of users' movements.     

In‐plane vibrations of shear deformable curved beams

This paper presents the exact dynamic stiffness matrix for a circular beam with a uniform cross‐section. The stiffness matrix is frequency dependent, and the natural frequencies are those that cause the matrix to become singular. Using this matrix the exact natural frequencies of circular beams with various boundary conditions are calculated and compared with available results in the literature. Copyright © 2001 John Wiley & Sons, Ltd.     

Extraction of phenolic compounds from spent blackberry pulp by enhanced-fluidity liquid extraction

This research describes an enhance-fluidity liquid extraction process for extracting total phenolic compounds (TPC) from spent blackberry pulp (SBP) using a modified solvent (CO₂–ethanol mixture). Effects of particle size (from 1,400 to 180 μm), pressure (150–300 bar), and cosolvent (ethanol)-to-solid ratio (64, 128, and 192 mL ethanol/32 g solid) on the extraction of TPC at 40°C were investigated. Experimental data was processed using the Sovova's model to obtain the solubility of TPC in the modified solvent. The Peng–Robinson equation of state was used to correlate the solubility of phenolic compounds at high pressures. Results indicated that particle sizes ranging from 600 to 850 μm and pressure of 300 bar allowed obtaining extracts with higher antioxidant activity (94.71% of inhibition) and TPC content (11.59 mg GA/g SBP). High pressure and the modified solvent increased the solubility up to 3.4 × 10⁻⁴ (mol fraction).     

Sketching the Theory of Copper Oxide High Temperature Superconductivity

The role of the antibonding state in the electron correlations in copper oxide HTSC is analyzed. Then the t-J Hamiltonian is used to establish the formation of the charge stripes in underdoped oxides. It is proposed that these stripes make up the boundaries between the two degenerate antiferromagnetic (AFM) states, and that they are a key factor in switching between these states. We also provide a theoretical expression to the charge driven AFM magnons that have been observed by Neutron scattering experiments. Finally, the double correlation theory is applied to the stripe phase of holes to result in the superconductive gap and in the “pseudogap.”     

Associative deficit in recognition memory in a lifespan sample of healthy adults.

Advanced age is associated with decrements in episodic memory, which are more pronounced in memory for associations than for individual items. The associative deficit hypothesis (ADH) states that age differences in recognition memory reflect difficulty in binding components of a memory episode and retrieving bound units. To date, ADH has received support only in studies of extreme age groups, and the influence of sex, education, and health on age-related associative deficit is unknown. We address those issues using a verbal paired-associate yes–no recognition paradigm on a lifespan sample of 278 healthy, well-educated adults. In accord with the ADH, greater age was associated with lower hit and greater false alarm rates and more liberal response bias on associative recognition tests. Women outperformed men on recognition of items and associations, but among normotensive participants, women outperformed men only on memory for associations and not on item recognition. Thus, although supporting ADH in a large lifespan sample of healthy adults, the findings indicate that the effect may be partially driven by an age-related increase in liberal bias in recognition of associations. Sex differences and health factors may modify the associative deficit regardless of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

GP-Gammon: Genetically Programming Backgammon Players

We apply genetic programming to the evolution of strategies for playing the game of backgammon. We explore two different strategies of learning: using a fixed external opponent as teacher, and letting the individuals play against each other. We conclude that the second approach is better and leads to excellent results: Pitted in a 1000-game tournament against a standard benchmark player—Pubeval—our best evolved program wins 62.4% of the games, the highest result to date. Moreover, several other evolved programs attain win percentages not far behind the champion, evidencing the repeatability of our approach.