A formal framework for evaluating heuristic programs

We address the question of how one evaluates the usefulness of a heuristic program on a particular input. If theoretical tools do not allow us to decide for every instance whether a particular heuristic is fast enough, might we at least write a simple, fast companion program that makes this decision on some inputs of interest? We call such a companion program a timer for the heuristic. Timers are related to program checkers, as defined by Blum (1993), in the following sense: Checkers are companion programs that check the correctness of the output produced by (unproven but bounded‐time) programs on particular instances; timers, on the other hand, are companion programs that attempt to bound the running time on particular instances of correct programs whose running times have not been fully analyzed. This paper provides a family of definitions that formalize the notion of a timer and some preliminary results that demonstrate the utility of these definitions.     

Preface by the section editors

The papers in this special section present a sample of recent approaches to modeling and verification of software-based systems. This research was initially presented at the 4th International Conference on Verification, Model Checking, and Abstract Interpretation (VMCAI 03). The choice of papers for the issue was based on their merit as well as on the fact that, as a group, they represent the main current research areas in the field of software-based systems.     

Computer‐vision determination of 3‐D geometric parameters of LDL particles via cryogenic transmission electron microscopy

Abstract— Previous research has shown that the size of the LDL macromolecules can have an effect on cardiovascular health and that LDL macromolecules may be non‐spherical in shape. Some of these studies, however, used methods that are not conducive to automatic determination of the 3‐D parameters of the particles. In particular, the prior methods used for determination of geometric‐parameter determination were either centrifugal separations or manual determination of parameters from cryogenic transmission electron micrographs. An application of computer‐vision techniques to automatically determine the 3‐D parameters from cryogenic transmission electron microscopy (CTEM) images will be described. Correlation of computer‐generated geometric models to the orthonormal projection CTEM imagery were investigated to determine the applicability of finding the pertinent geometric parameters of the expected discoid shape of the LDL particles. The processing showed that the discoid shape can be verified using small‐angle rotations that are more amenable to the limitations of CTEM imaging.     

The relationships of self-efficacy for the Holland themes to gender, occupational group membership, and vocational interests.

The studies presented in this article resulted in the findings that gender differences in self-efficacy for the Holland themes are consistent with previous findings regarding gender differences in Holland interest patterns, although the gender differences are less pronounced in employed adults than in college students. Within occupational group, the self-efficacy profiles of women and men were very similar and closely corresponded to the Holland interest code of the occupation. Confidence for and interest in a theme were moderately correlated, and recommendations for the counseling use of joint combinations of interests and self-efficacy are made. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Susceptibility and precipitating factors in depression: Sex differences and similarities.

Argues that the well-documented sex difference in depression may be due to a sex difference in susceptibility, in precipitating factors, or in both. Data from a large mental health survey (2,515 White over-18 residents of 2 cities) were used to study precipitating factors. It was found that women were exposed more often to more of the factors that relate to depression; with a few exceptions, the factors related to depression similarly for men and women. Matching on these factors did not eliminate the sex difference in depression. This suggests that there may be a sex difference in susceptibility. Current theories of depression are incorporated into a sequential model of how learned factors might contribute both to susceptibility and to the sex difference. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Everyday memory failure: Age differences in appraisal and attribution.

A person perception paradigm was used to test 86 young and 84 older Ss for evidence of a double standard in appraising everyday memory failures of young and older targets. Vignettes were judged on separate Likert scales for possible attributions for the failure (ability, effort, task difficulty, chance, and 2 measures of attention), signs of mental difficulty, need for memory training, and indications of need for professional evaluation. Results confirmed a double standard used by young and old: The failures of older targets were judged as signifying greater mental difficulty and greater need for memory training than were the identical failures of young targets. Older Ss were more lenient overall than young Ss in their appraisals. Young Ss judged target persons' memory failures as signifying more mental difficulty, and they more readily recommended professional evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)