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991.
Elaine J. Weyuker Thomas J. Ostrand Robert M. Bell 《Empirical Software Engineering》2010,15(3):277-295
We compare the effectiveness of four modeling methods—negative binomial regression, recursive partitioning, random forests
and Bayesian additive regression trees—for predicting the files likely to contain the most faults for 28 to 35 releases of
three large industrial software systems. Predictor variables included lines of code, file age, faults in the previous release,
changes in the previous two releases, and programming language. To compare the effectiveness of the different models, we use
two metrics—the percent of faults contained in the top 20% of files identified by the model, and a new, more general metric,
the fault-percentile-average. The negative binomial regression and random forests models performed significantly better than recursive partitioning and
Bayesian additive regression trees, as assessed by either of the metrics. For each of the three systems, the negative binomial
and random forests models identified 20% of the files in each release that contained an average of 76% to 94% of the faults. 相似文献
992.
Sung Kyu Park Devin A. Mourey Jeong-In Han John E. Anthony Thomas N. Jackson 《Organic Electronics》2009,10(3):486-490
We report operational and environmental stability of solution-processed organic thin film transistors (OTFTs) using the small molecule organic semiconductor 6,13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene). Typical drop-cast TIPS-pentacene OTFTs show strong molecular ordering and relatively stable characteristics with air and illumination compared to vapor-deposited pentacene OTFTs. For short channel length devices, TIPS-pentacene OTFTs undergo significant degradation with bias-stress, possibly due to operation at large drive currents and large local power dissipation as well as built-in charges in the channel area. 相似文献
993.
Faugloire Elise; Bardy Beno?t G.; Stoffregen Thomas A. 《Canadian Metallurgical Quarterly》2009,35(1):170
The present research examined how learning a new ankle-hip coordination influenced the preexisting postural repertoire. Standing participants learned a new ankle-hip coordination mode (relative phase of 90'). Before and after practice, postural patterns were evaluated in two different tasks. In the required task, specific ankle-hip patterns were requested (12 relative phases in multiples of 30'). In the spontaneous task, participants performed a tracking task in which no instructions about ankle-hip coordination were given. Learning induced changes in both required and spontaneous coordination dynamics. When ankle-hip patterns were required, learning led to improvement and homogenization in performance over the entire postural repertoire. When ankle-hip patterns emerged spontaneously, in-phase and antiphase preexisting patterns destabilized and changed toward the learned pattern of 90'. These findings demonstrate that learning a new coordination pattern can induce modifications of patterns that have not been practiced. The results also suggest that the consequences of learning do not generalize across different types of tasks, even when similar coordination modes are involved. We discuss implications of these findings for the generality of learning mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
994.
Kovacs Attila J.; Mühlbauer Thomas; Shea Charles H. 《Canadian Metallurgical Quarterly》2009,35(2):390
Three experiments utilizing a 14-element arm movement sequence were designed to determine if reinstating the visual–spatial coordinates, which require movements to the same spatial locations utilized during acquisition, results in better effector transfer than reinstating the motor coordinates, which require the same pattern of homologous muscle activation. Results demonstrated better transfer when visual–spatial coordinates were reinstated than when motor coordinates where reinstated regardless of the amount of practice (1, 4, or 12 days; Experiments 1–3, respectively). Transfer (left to right and right to left) was symmetric when visual–spatial coordinates were reinstated but not when motor coordinates were reinstated. When motor coordinates were reinstated after 12 days of practice and vision occluded, transfer was better from right limb to left than vice versa. The data are also consistent with the notion that multiple codes (visual, spatial, and motor) are developed over practice, with each contributing to transfer performance when the respective coordinates are reinstated. Further, the results indicate a disruption of the linkage (concatenation) between subsequences when one or more coordinates are changed on the transfer test. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
995.
Holden Mark P.; Curby Kim M.; Newcombe Nora S.; Shipley Thomas F. 《Canadian Metallurgical Quarterly》2010,36(3):590
Memories for spatial locations often show systematic errors toward the central value of the surrounding region. This bias has been explained using a Bayesian model in which fine-grained and categorical information are combined (Huttenlocher, Hedges, & Duncan, 1991). However, experiments testing this model have largely used locations contained in simple geometric shapes. Use of this paradigm raises 2 issues. First, do results generalize to the complex natural world? Second, what types of information might be used to segment complex spaces into constituent categories? Experiment 1 addressed the 1st question by showing a bias toward prototypical values in memory for spatial locations in complex natural scenes. Experiment 2 addressed the 2nd question by manipulating the availability of basic visual cues (using color negatives) or of semantic information about the scene (using inverted images). Error patterns suggest that both perceptual and conceptual information are involved in segmentation. The possible neurological foundations of location memory of this kind are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
Quantifying Biomediated Ground Improvement by Ureolysis: Large-Scale Biogrout Experiment 总被引:2,自引:0,他引:2
Leon A. van Paassen Ranajit Ghose Thomas J. M. van der Linden Wouter R. L. van der Star Mark C. M. van Loosdrecht 《Canadian Metallurgical Quarterly》2010,136(12):1721-1728
Biogrouting is a biological ground improvement method, in which microorganisms are used to induce carbonate precipitation in the subsurface in order to increase the strength and stiffness of granular soils. In this paper the results of a large-scale experiment (100?m3) are presented, in which the feasibility of biogrouting as a ground improvement method is investigated using techniques and equipment similar to those used in potential applications. In situ geophysical measurements were used to monitor the biogrouting process during treatment and indicated that the stiffness had increased significantly after one day of treatment. The results of unconfined compressive strength tests on samples which were excavated after treatment were used to assess the distribution of mechanical properties throughout the cemented sand body, which correlated quite well with the results of the in situ geophysical measurements. The stiffness increase could be quantified as a function of the injected volume of grouting agents and the distance from the injection points. These results will serve as an important benchmark for future applications of biomediated ground improvement. 相似文献
997.
Hirshfeld-Becker Dina R.; Masek Bruce; Henin Aude; Blakely Lauren Raezer; Pollock-Wurman Rachel A.; McQuade Julia; DePetrillo Lillian; Briesch Jacquelyn; Ollendick Thomas H.; Rosenbaum Jerrold F.; Biederman Joseph 《Canadian Metallurgical Quarterly》2010,78(4):498
Objective: To examine the efficacy of a developmentally appropriate parent–child cognitive behavioral therapy (CBT) protocol for anxiety disorders in children ages 4–7 years. Method: Design: Randomized wait-list controlled trial. Conduct: Sixty-four children (53% female, mean age 5.4 years, 80% European American) with anxiety disorders were randomized to a parent–child CBT intervention (n = 34) or a 6-month wait-list condition (n = 30). Children were assessed by interviewers blind to treatment assignment, using structured diagnostic interviews with parents, laboratory assessments of behavioral inhibition, and parent questionnaires. Analysis: Chi-square analyses of outcome rates and linear and ordinal regression of repeated measures, examining time by intervention interactions. Results: The response rate (much or very much improved on the Clinical Global Impression Scale for Anxiety) among 57 completers was 69% versus 32% (CBT vs. controls), p 相似文献
998.
Adrian K. Clear Thomas Holland Simon Dobson Aaron Quigley Ross Shannon Paddy Nixon 《Pervasive and Mobile Computing》2010,6(5):575-589
Pervasive systems are large-scale systems consisting of many sensors capturing numerous types of information. As this data is highly voluminous and dimensional, data analysis tasks can be extremely cumbersome and time-consuming. Enabling computers to recognise real-world situations is an even more difficult problem, involving not only data analysis, but also consistency checking. Here we present Situvis, an interactive visualisation tool for representing sensor data and creating higher-level abstractions from the data. This paper builds on previous work, Clear et al. (2009) [8] through evolved tool functionality and an evaluation of Situvis. A user-trial consisting of 10 participants shows that Situvis can be used to complete the key tasks in the development process of situation specifications in over 50% less time than an improvised alternative toolset. 相似文献
999.
Amanda N. Elkins Eric R. Muth Adam W. Hoover Alexander D. Walker Thomas L. Carpenter Fred S. Switzer 《Applied ergonomics》2009,40(6):997-1003
Physiological compliance (PC) refers to the correlation between physiological measures of team members over time. The goals of this study were to examine ways of measuring PC in heart rate variability (HRV) data and the relationship between PC and team performance. Teams were tasked with entering both real and simulated rooms and “shooting” individuals with a weapon and identifying individuals without a weapon. The linear correlation and directional agreement PC methods were shown to be the most sensitive to differences in performance, with greater PC being associated with better performance. The correlation method when applied to a measure of respiratory sinus arrhythmia (RSA) revealed a significant difference between high and low performers (t[8] = −2.31, p = 0.03) and the directional agreement applied to inter-beat-intervals and RSA revealed trend-level differences (t[4.62] = −1.86, p = 0.06 and t[8] = −1.68, p = 0.07). These results suggest that PC may have merit for predicting team performance. 相似文献
1000.