A Framework for Average Case Analysis of Conjunctive Learning Algorithms

We present an approach to modeling the average case behavior of learning algorithms. Our motivation is to predict the expected accuracy of learning algorithms as a function of the number of training examples. We apply this framework to a purely empirical learning algorithm, (the one-sided algorithm for pure conjunctive concepts), and to an algorithm that combines empirical and explanation-based learning. The model is used to gain insight into the behavior of these algorithms on a series of problems. Finally, we evaluate how well the average case model performs when the training examples violate the assumptions of the model.     

Habit and intention in everyday life: The multiple processes by which past behavior predicts future behavior.

Past behavior guides future responses through 2 processes. Well-practiced behaviors in constant contexts recur because the processing that initiates and controls their performance becomes automatic. Frequency of past behavior then reflects habit strength and has a direct effect on future performance. Alternately, when behaviors are not well learned or when they are performed in unstable or difficult contexts, conscious decision making is likely to be necessary to initiate and carry out the behavior. Under these conditions, past behavior (along with attitudes and subjective norms) may contribute to intentions, and behavior is guided by intentions. These relations between past behavior and future behavior are substantiated in a meta-analytic synthesis of prior research on behavior prediction and in a primary research investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute public health consequences associated with hazardous substances released during transit, 1993-2000

Massive quantities of hazardous substances are transported each day throughout the United States. While most arrive safely at their destination, uncontrolled releases of substances in transit do occur and have the potential of causing acute public health consequences for those individuals at or near the release. Data from 16 state health departments participating in the Agency for Toxic Substances and Disease Registry's (ATSDR) Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to determine the public health consequences that occurred from actual releases in transit. Of the 9392 transportation events analyzed, 9.1% resulted in 2008 victims, including 115 deaths. The population groups injured most often were employees and the general public. The most common injury sustained was respiratory irritation. Evacuations were ordered in 5.5% of events effecting at least 63,686 people. Human error and equipment failure were the most common factors leading to events. These findings underscore the importance of job safety training, community planning, and effective emergency response to prevent adverse public health consequences from occurring or lessen their effect on the public.     

Laser-driven formation of a high-pressure phase in amorphous silica

Because of its simple composition, vast availability in pure form and ease of processing, vitreous silica is often used as a model to study the physics of amorphous solids. Research in amorphous silica is also motivated by its ubiquity in modern technology, a prominent example being as bulk material in transmissive and diffractive optics for high-power laser applications such as inertial confinement fusion (ICF). In these applications, stability under high-fluence laser irradiation is a key requirement, with optical breakdown occurring when the fluence of the beam is higher than the laser-induced damage threshold (LIDT) of the material. The optical strength of polished fused silica transmissive optics is limited by their surface LIDT. Surface optical breakdown is accompanied by densification, formation of point defects, cratering, material ejection, melting and cracking. Through a combination of electron diffraction and infrared reflectance measurements we show here that synthetic vitreous silica transforms partially into a defective form of the high-pressure stishovite phase under high-intensity (GW cm(-2)) laser irradiation. This phase transformation offers one suitable mechanism by which laser-induced damage grows catastrophically once initiated, thereby dramatically shortening the service lifetime of optics used for high-power photonics.     

Use of a 13C tracer to quantify the plasma appearance of a physiological dose of lutein in humans

Increased intake of lutein from vegetables promotes increased density of the macular pigment and therefore may protect against age-related macular degeneration. Our objective was to use a ¹³C tracer and high-precision gas chromatography-combustion interfaced-isotope ratio mass spectrometry (GC-C-IRMS) to investigate metabolism of a lutein dose equivalent to that absorbed from vegetables. Biosynthetic per-labeled (>99% ¹³C) lutein was purified from a commercially available extract of algal biomass. Subjects (n=4) ingested 3 mg of [¹³C]lutein with a standardized low-carotenoid breakfast. Blood samples were collected at baseline and then hourly for 12 h; additional blood samples were drawn at 16, 24, 48, 72, 96, 192, 360, and 528 h. To produce perhydro-β-carotene suitable for analysis by GC-C-IRMS, the plasma lutein fraction was hydrogenated on palladium-on-carbon catalyst with acid-catalyzed hydrogenolysis. The stable carbon isotope (¹³C/¹²C) ratio measured by GC-C-IRMS was used to calculate the plasma concentration of [¹³C]lutein. There was a rapid increase in [¹³C]lutein in plasma until peak enrichment at 16 h followed by a decline to the next measurement at 24 h. At 528 h, small changes in ¹³C enrichment from baseline could still be measured in plasma lutein. High-precision GC-C-IRMS enables complete definition of the appearance and disappearance of [¹³C]lutein in plasma after ingestion of a dose similar to that absorbed from foods.     

Evaluative pressure in mothers: Effects of situation, maternal, and child characteristics on autonomy supportive versus controlling behavior.

This study examined the effects of situational pressure and maternal characteristics (social contingent self-worth, controlling parenting attitudes) on mothers' autonomy support versus control in the social domain. Sixty 4th-grade children and their mothers worked on a laboratory task in preparation for meeting new children, with mothers in either an evaluation (mothers told their child would be evaluated by other children) or no-evaluation (no mention of evaluation) condition. Mothers in the evaluation condition spent more time giving answers to their children. Mothers with controlling parenting attitudes exhibited more controlling behavior. Further, mothers with high social contingent self-worth in the evaluation condition were most controlling. Results suggest the importance of interactions between situations and maternal characteristics in determining levels of mothers' autonomy support versus control and have implications for helping parents support children's autonomy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimizing XML queries: Bitmapped materialized views vs. indexes

Optimizing queries using materialized views has not been addressed adequately in the context of XML due to the many limitations associated with the definition and usability of materialized views in traditional XML query evaluation models.     

From majority to minority and vice versa: The asymmetrical effects of losing and gaining majority position within a group.

Two studies examined the effects of stable, partially changed, and completely changed majority and minority positions within a group on perception and evaluation of the group. It was hypothesized that loss of majority position (majority-to-minority change) would have stronger effects than gain of majority position (minority-to-majority change). The hypothesized asymmetrical effect was demonstrated in that loss of majority position decreased perception of group—self similarity, group attraction, and expectations for positive interactions with the group, whereas a corresponding gain of position did not increase them. Thus immediately following changes, the group is especially fragile because disintegrative forces created by the loss of majority position are stronger than integrative forces created by the gain of majority position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of platinum salt concentration on the electrospinning of polyacrylonitrile/platinum acetylacetonate solution

The preparation and characterization of electrospun polyacrylonitrile (PAN)/platinum(II) acetylacetonate composite nanofibers were investigated. The solution properties, such as viscosity, surface tension, and conductivity, of Pt‐acetylacetonate‐added PAN solutions in N,N‐dimethylformamide were measured, and their influences on the resulting fiber structure were also determined. At low Pt salt concentrations, the addition of Pt salt increased the fiber diameter but did not change the fiber diameter distribution. However, the fiber diameter decreased, and the fiber diameter distribution became broader when the Pt salt concentration went beyond a critical value. The structure of the electrospun fibers was determined by the formation of polymer–salt– solvent interactions, which changed the balance among the viscosity, surface tension, and conductivity of the solutions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010