ANDES: efficient evaluation of NOT-twig queries in relational databases

Despite a large body of work on XPath query processing in relational environment, systematic study of queries containing not-predicates have received little attention in the literature. Particularly, several xml supports of industrial-strength commercial rdbms fail to efficiently evaluate such queries. In this paper, we present an efficient and novel strategy to evaluate not -twig queries in a tree-unaware relational environment. not -twig queries are XPath queries with ancestor–descendant and parent–child axis and contain one or more not-predicates. We propose a novel Dewey-based encoding scheme called Andes (ANcestor Dewey-based Encoding Scheme), which enables us to efficiently filter out elements satisfying a not-predicate by comparing their ancestor group identifiers. In this approach, a set of elements under the same common ancestor at a specific level in the xml tree is assigned same ancestor group identifier. Based on this scheme, we propose a novel sql translation algorithm for not-twig query evaluation. Experiments carried out confirm that our proposed approach built on top of an off-the-shelf commercial rdbms significantly outperforms state-of-the-art relational and native approaches. We also explore the query plans selected by a commercial relational optimizer to evaluate our translated queries in different input cardinality. Such exploration further validates the performance benefits of Andes.     

Soluble Prokaryotic Overexpression and Purification of Human GM-CSF Using the Protein Disulfide Isomerase b′a′ Domain

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a member of the colony-stimulating factor (CSF) family, which functions to enhance the proliferation and differentiation of hematopoietic stem cells and other hematopoietic lineages such as neutrophils, dendritic cells, or macrophages. These proteins have thus generated considerable interest in clinical therapy research. A current obstacle to the prokaryotic production of human GM-CSF (hGM-CSF) is its low solubility when overexpressed and subsequent complex refolding processes. In our present study, the solubility of hGM-CSF was examined when combined with three N-terminal fusion tags in five E. coli strains at three different expression temperatures. In the five E. coli strains BL21 (DE3), ClearColi BL21 (DE3), LOBSTR, SHuffle T7 and Origami2 (DE3), the hexahistidine-tagged hGM-CSF showed the best expression but was insoluble in all cases at each examined temperature. Tagging with the maltose-binding protein (MBP) and the b′a′ domain of protein disulfide isomerase (PDIb′a′) greatly improved the soluble overexpression of hGM-CSF at 30 °C and 18 °C. The solubility was not improved using the Origami2 (DE3) and SHuffle T7 strains that have been engineered for disulfide bond formation. Two conventional chromatographic steps were used to purify hGM-CSF from the overexpressed PDIb′a′-hGM-CSF produced in ClearColi BL21 (DE3). In the experiment, 0.65 mg of hGM-CSF was isolated from a 0.5 L flask culture of these E. coli and showed a 98% purity by SDS-PAGE analysis and silver staining. The bioactivity of this purified hGM-CSF was measured at an EC₅₀ of 16.4 ± 2 pM by a CCK8 assay in TF-1 human erythroleukemia cells.     

Enhanced Dynamic Authentication Scheme (EDAS)

With non-stop growth in network environments, communication security is necessary. A strong protocol guarantees that users and service providers are secure against many kinds of attacks, such as impersonation and replay attack. Sood et al. proposed an authentication scheme based on dynamic identity to prevent transactions from being intercepted by malicious users. Although they claimed that their scheme has advantages over previous schemes with the same approach, we prove that their scheme is vulnerable to impersonation attack and stolen verification attack, and can be affected by clock synchronization. Therefore we propose a novel authentication scheme to enhance security and overcome limitations existing in Sood’s scheme. Our security analysis shows that our proposed method can efficiently resist known types of attacks. Experimental results also show that the method can be implemented and processed in real-time thus applicable for not only regular computers but also mobile devices.     

Effect of physical aging on the fracture behavior of crosslinked epoxies

The effect of physical aging on the fracture behavior, crack opening displacement, and plastic deformation zone of unmodified and rubber-modified epoxies was determined at two aging temperatures and different displacement rates. The strain energy release rate decreases to between 40 and 50% (for rubber modified and unmodified samples, respectively) of the unaged values after 35 days aging. Systematic dependence of the decrease in fracture toughness by aging on the rubber content is not apparent. The increased yield stress after physical aging is the main factor contributing to the reduction in fracture toughness, crack opening displacement, and plastic deformation zone. Physical aging suppresses the crack blunting mechanisms in epoxies.     

Interfacial tension of demixed polymer solutions near the critical temperature: polystyrene + methylcyclohexane

Interfacial tension between demixed solutions of polystyrene + methylcyclohexane has been measured near the critical temperature as a function of temperature using polystyrenes with molecular weights 9000 ～ 1.26 × 10⁶. The critical exponent for the interfacial tension was determined to be about 1.30 for the lower molecular weight systems. However, for higher molecular weights the exponent could not be obtained because the system departed from critical behaviour. Magnitudes of the interfacial tension were proportional to about N^?0.44, where N is the polymerization index. Experimental results were compared with the recently-proposed theories and found to be in qualitative agreement. The tricritical theory of polymer solutions was also compared with the experimental results.     

Application of Fuzzy Moving Sliding Surface Approach for Container Cranes

International Journal of Control, Automation and Systems - In this paper, we consider the fuzzy moving sliding surface anti-sway control problem for container cranes. We first introduce the dynamic...     

Perceptual evaluation of backchannel strategies for artificial listeners

Artificial listeners are virtual agents that can listen attentively to a human speaker in a dialog. In this paper, we present two experiments where we investigate the perception of rule-based backchannel strategies for artificial listeners. In both, we collect subjective judgements of humans who observe a video of a speaker together with a corresponding animation of an artificial listener. In the first experiment, we evaluate six rule-based strategies that differ in the types of features (e.g. prosody, gaze) they consider. The ratings are given at the level of a speech turn and can be considered a measure for how human-like the generated listening behavior is perceived. In the second experiment, we systematically investigate the effect of the quantity, type and timing of backchannels within the discourse of the speaker. Additionally, we asked human observers to press a button whenever they thought a generated backchannel occurrence was inappropriate. Both experiments together give insights in the factors, both from an observation and generation point-of-view, that influence the perception of backchannel strategies for artificial listeners.     

Chemical reaction optimization with greedy strategy for the 0–1 knapsack problem

The 0–1 knapsack problem (KP01) is a well-known combinatorial optimization problem. It is an NP-hard problem which plays important roles in computing theory and in many real life applications. Chemical reaction optimization (CRO) is a new optimization framework, inspired by the nature of chemical reactions. CRO has demonstrated excellent performance in solving many engineering problems such as the quadratic assignment problem, neural network training, multimodal continuous problems, etc. This paper proposes a new chemical reaction optimization with greedy strategy algorithm (CROG) to solve KP01. The paper also explains the operator design and parameter turning methods for CROG. A new repair function integrating a greedy strategy and random selection is used to repair the infeasible solutions. The experimental results have proven the superior performance of CROG compared to genetic algorithm (GA), ant colony optimization (ACO) and quantum-inspired evolutionary algorithm (QEA).     

Attuning speech-enabled interfaces to user and context for inclusive design: technology, methodology and practice

This paper presents a methodology to apply speech technology for compensating sensory, motor, cognitive and affective usage difficulties. It distinguishes (1) an analysis of accessibility and technological issues for the identification of context-dependent user needs and corresponding opportunities to include speech in multimodal user interfaces, and (2) an iterative generate-and-test process to refine the interface prototype and its design rationale. Best practices show that such inclusion of speech technology, although still imperfect in itself, can enhance both the functional and affective information and communication technology-experiences of specific user groups, such as persons with reading difficulties, hearing-impaired, intellectually disabled, children and older adults.