Fuzzy Weirstrass theorem and convex fuzzy mappings

The convexity and continuity of fuzzy mappings are defined through a linear ordering and a metric on the set of fuzzy numbers. The local-global minimum property of real-valued convex functions is extended to convex fuzzy mappings. It is proved that a strict local minimizer of a quasiconvex fuzzy mapping is also a strict global minimizer. Characterizations for convex fuzzy mappings and quasiconvex fuzzy mappings are given. In addition, the Weirstrass theorem is extended from real-valued functions to fuzzy mappings.     

Nitric oxide reduction at noble metal electrodes: a voltammetric study in acid solution

Features of the electrochemical reduction of nitric oxide on platinum, palladium, rhodium and ruthenium in aqueous perchloric acid solutions (0.33–1.0 M) are compared. The results from voltammetric studies (ie linear potential sweep and rotating disc electrode) using the bulk metal electrodes are described and compared with residual current voltage plots in acid electrolyte alone. In general, three nitric oxide reduction peaks are observed on the metals. The most anodic peak, at ca E = 0.15 V vs sce is attributed to the one-electron reduction of nitric oxide to an adsorbed NOH intermediate on a bare metal surface (ie one free of oxides or adsorbed hydrogen). The other two peaks occur in potential regions where adsorbed hydrogen is present on the metal surface (ca E = 0.0 and −0.20 V, respectively). The co-adsorbed hydrogen complicates the analysis and precludes an unambiguous interpretation of these two peaks. However, they apparently reflect nitric oxide reduction to nitrogen, hydroxylamine and/or ammonia. In a cathodic scan on the rhodium electrode, a current plateau is seen instead of the first (most anodic) peak, a probable consequence of oxide film formation with subsequent chemical complications. On the ruthenium electrode the first two (most anodic) peaks are not observed probably due to a relatively stable oxide layer. Reaction selectivities at metal black gas diffusion cathodes operating in an electrogenerative (ie galvanic) mode with perchloric acid electrolyte are compared with the voltammetric results at the corresponding bulk electrodes. Dinitrogen formation is observed on the platinum and rhodium black electrodes as suggested from voltammetric results. A series-parallel reaction sequence is proposed to explain the results. Limitations of using simple voltammetric techniques for predicting behavior of large scale preparative electrochemical reactors are discussed.     

Differentiating anxiety and depression in older adults with generalized anxiety disorder.

To examine affect and cognition in differentiating anxiety and depression, 83 older participants with generalized anxiety disorder completed the Cognitive Checklist (CCL) and the Positive and Negative Affect Schedule (PANAS). A 3-factor solution was found for the PANAS: positive affect (PA), anxiety and anger (Negative Affect 1 [NA-1]), and guilt and shame (Negative Affect 2 [NA-2]). A 2-factor structure was noted for the CCL. Correlations with anxiety and depression measures suggested that the CCL Depression (CCL-D) subscale showed stronger correlations with depression, whereas the CCL Anxiety subscale did not uniquely correlate with anxiety. The NA-1 subscale correlated positively with measures of depression and anxiety, whereas the PA subscale showed negative correlations. Hierarchical regression suggested that the CCL-D subscale was a significant predictor of self-reported depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implementation of a vector quantization codebook design technique based on a competitive learning artificial neural network

We describe an implementation of a vector quantization codebook design algorithm based on the frequencysensitive competitive learning artificial neural network. The implementation, designed for use on high-performance computers, employs both multitasking and vectorization techniques. A C version of the algorithm tested on a CRAY Y-MP8/864 is discussed. We show how the implementation can be used to perform vector quantization, and demonstrate its use in compressing digital video image data. Two images are used, with various size codebooks, to test the performance of the implementation. The results show that the supercomputer techniques employed have significantly decreased the total execution time without affecting vector quantization performance.This work was supported by a Cray University Research Award and by NASA Lewis research grant number NAG3-1164.     

Mathematical analysis and experimental results of applying enhanced-surface-area packed-bed electrodes in electrogenerative sulfur dioxide oxidation

The results of applying enhanced-surface-area packed-bed (ESAP) electrodes in electrogenerative SO₂/O₂ cells are reported to illustrate their utility and potential applications. Mathematical analysis with parameters pertinent to the experimental conditions shows that all electrocatalyst sites in these electrodes are expected to be uniformly utilized for electrochemical SO₂ oxidation. Experimental results showed that ESAP electrodes (1 mg Pt/cm²) could provide at least 5 times higher SO₂ conversion at given cell voltages than graphite sheet electrodes (1.5 mg Pt/cm²).     

Effects of attachment bereavement and pre-event conditions on subsequent depressive symptoms in older adults.

A sample of 1,411 older adults (age 55+) who had been interviewed both prior to and after bereavement was studied, allowing for pre-event controls. Those who had lost a parent, spouse, or child had the strongest depressive reactions, as predicted by an attachment-bonding hypothesis; however, material losses were also related to depression. Although bereavement/loss events were clearly related to subsequent depression even after pre-event depression, resources, and events were controlled, certain pre-event characteristics were predictive of the bereavement/loss events, including prior undesirable events, age, and urban/rural residency. A further analysis of 1,007 persons with two post-event interviews (at 6-month to 1-year follow-up) revealed an initial depressive reaction to a bereavement/loss event, which then dissipated completely within 1 year's time. Generally, bereavement appeared to have limited etiologic importance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)