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1.
The basic idea behind LBP is that an image is composed of micropatterns. A histogram of these micropatterns contains information about the local features in an image. These micropatterns can be divided into two types: uniform and non-uniform. In standard applications using LBP, only the uniform patterns are used. The non-uniform patterns are considered in only a single bin of the histogram that is used to extract features in the classification stage. Non-uniform patterns have undesirable characteristics: they are of a high dimension, partially correlated, and introduce unwanted noise. To offset these disadvantages, we explore using random subspace, well-known to work well with noise and correlated features, to train features based also on non-uniform patterns. We find that a stand-alone support vector machine performs best with the uniform patterns and random subspace with histograms of 50 bins performs best with the non-uniform patterns. Superior results are obtained when the two are combined. Based on extensive experiments conducted in several domains using several benchmark databases, it is our conclusion that non-uniform patterns improve classifier performance. 相似文献
2.
Tracy J. Evans-Whipp Stephanie M. Plenty John W. Toumbourou Craig Olsson Bosco Rowland Sheryl A. Hemphill 《Accident; analysis and prevention》2013
The purpose of this study was to investigate the influence of exposure to others’ drink driving during adolescence on self-reported driving under the influence (DUI) of alcohol in young adulthood. Data were drawn from 1956 participants with a driving license enrolled in the International Youth Development Study from Victoria, Australia. During 2003 and 2004, adolescents in Grades 7, 9 and 10 (aged 12–17) completed questionnaires examining whether they had ridden in a vehicle with a driver who had been drinking, as well as other demographic, individual, peer and family risk factors for DUI. In 2010, the same participants (aged 18–24) then reported on their own DUI behaviour. 18% of young adults with a driving license reported DUI in the past 12 months. Exposure to others’ drink driving during adolescence was associated with an increased likelihood of DUI as a young adult (OR = 2.13, 95% CI 1.68–2.69). This association remained after accounting for the effects of other potential confounding factors from the individual, peer and family domains (OR = 1.62, 95% CI 1.23–2.13). Observing the drink driving behaviours of others during adolescence may increase the likelihood of DUI as a young adult. Strategies to reduce youth exposure to drink driving are warranted. 相似文献
3.
4.
Eicosapentaenoic acid is primarily responsible for hypotriglyceridemic effect of fish oil in humans 总被引:4,自引:0,他引:4
The aim of this study was to determine whether eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), or both, were responsible
for the triglyceride (TG)-lowering effects of fish oil. EPA (91% pure) and DHA (83% pure), a fish oil concentrate (FOC; 41%
EPA and 23% DHA) and an olive oil (OO) placebo (all ethyl esters) were tested. A total of 49 normolipidemic subjects participated.
Each subject was given placebo for 2–3 wk and one of the n-3 supplements for 3 wk in randomized, blinded trials. The target
n-3 fatty acid (FA) intake was 3 g/day in all studies. Blood samples were drawn twice at the end of each supplementation phase
and analyzed for lipids, lipoproteins, and phospholipid FA composition. In all groups, the phospholipid FA composition changed
to reflect the n-3 FA given. On DHA supplementation, EPA levels increased to a small but significant extent, suggesting that
some retroconversion may have occurred. EPA supplementation did not raise DHA levels, however, FOC and EPA produced significant
decreases in both TG and very low density lipoprotein (VLDL) cholesterol (C) levels (P<0.01) and increases in low density lipoprotein (LDL) cholesterol levels (P<0.05). DHA supplementation did not affect cholesterol, triglyceride, VLDL, LDL, or high density lipoprotein (HDL) levels,
but it did cause a significant increase in the HDL2/HDL3 cholesterol ratio. We conclude that EPA appears to be primarily responsible for TG-lowering (and LDL-C raising) effects of
fish oil. 相似文献
5.
Dong H Onstott TC Deflaun MF Fuller ME Scheibe TD Streger SH Rothmel RK Mailloux BJ 《Environmental science & technology》2002,36(5):891-900
Bacterial transport experiments were conducted using intact sediment cores collected from sites on the Delmarva Peninsula near South Oyster, VA, to delineate the relative importance of physical and chemical heterogeneity in controlling transport of an adhesion-deficient bacterial strain. Electron microscopy revealed that the sediments consisted of quartz and feldspar with a variable amount of clay and iron and aluminum hydroxide coatings on the grains. A nonmotile, gram-negative indigenous groundwater strain, designated as Comamonas sp. DA001, was injected into the cores along with a conservative tracer bromide (Br). DA001 cells were 1.2 x 0.6 microm in size with a hydrophilic surface and a slightly negative surface charge. Bacterial breakthrough preceded that of Br. This differential advection phenomenon can be accounted for by reduction of the effective porosity for the bacteria relative to Br. The distribution of cells remaining in the core as determined by scintillation counting and phosphor imaging techniques was variable, ranging from nearly uniform concentrations throughout the core to exponentially decreasing concentrations with distance from the point of injection. The fraction of bacterial retention in the core was positively correlated with the abundance of the metal hydroxides and negatively correlated with grain size. Because grain size was inversely correlated with the abundance of the metal hydroxide coatings, it was necessary to separate the effects of grain size and mineralogy. The fraction of the bacterial retention accounting for the effect of grain size, the collision efficiency, exhibited no correlation with the abundance of the metal hydroxides, indicating that the bacterial retention was primarily controlled by grain size. Reasons for the lack of influence of mineralogy on bacterial transport include (i) the slightly negatively charged bacterial surfaces; (ii) an insufficient heterogeneity of sediment surface properties; and (iii) the masking of the positive charge of the metal hydroxide surfaces by adsorbed organic carbon (up to 1180 ppm). This study demonstrates that the laboratory-based bacterial transport experiments are effective in delineating physical versus chemical controlling factors and provide an important link to field-based bacterial transport studies. 相似文献
6.
Women are approximately twice as likely as men to develop posttraumatic stress disorder (PTSD), but the cause of this disparity remains unclear. This study evaluated 2 alternative explanations of gender differences in PTSD, one pointing to an intrinsic vulnerability in women and the other emphasizing sexual violence across the life span. To test these competing theories, the authors analyzed National Violence Against Women Survey data from 591 victims of partner aggression. Results suggested that gender, when considered alone, has a small but significant effect on PTSD symptom severity. However, once models factor in sexual victimization history, the latter replaces gender as a key determinant of PTSD symptoms. These findings argue against theories of "feminine vulnerability," instead linking PTSD risk to sexually violent situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
Cohen Sheldon; Krantz David S.; Evans Gary W.; Stokols Daniel; Kelly Sheryl 《Canadian Metallurgical Quarterly》1981,40(2):331
Assessed the impact of noise on attentional strategies, learned helplessness, performance on cognitive tasks, and blood pressure. Third and 4th graders were tested on the same measures twice, with a 1-yr interval between sessions. Longitudinal data were used to determine whether Ss adapted to aircraft noise over the 1-yr period and to assess the effectiveness of noise abatement interventions introduced in a number of noise-impacted classrooms. Additional cross-sectional data are presented to provide further information on the utility of noise abatement. In general, there was little evidence for adaptation to noise over the 1-yr period. Noise abatement had small ameliorative effects on cognitive performance, Ss' ability to hear their teachers, and school achievement. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
Although iron-based permeable reactive barriers are gaining importance for treating groundwater contaminants, little is currently known about the effect of cosolutes on barrier longevity. Because of their corrosion inhibiting properties, dissolved silica species are of particular concern. This research investigates the effect of silica on the reduction of 1,1,1-trichloroethane by granular iron as a function of added silica concentration, pH, and duration of iron exposure to dissolved silica. Batch studies reveal that, at pH 8.5 and above, added silica concentrations as low as 0.17 mM cause a 30% reduction in the reactivity of iron. At higher silica concentrations, reactivity decreases by 65-75%. The inhibitory effect is greater at higher pH: 0.83 mM silica has no apparent adverse effect at pH 7.5, but leads to a 46% decrease in reaction rate at pH 8 and 90% at pH 9. This corresponds to observed trends in silica adsorption onto iron, which is low at pH 7.3 but increases at higher pH. Extending the duration of iron exposure to silica solutions also leads to a more pronounced inhibitory effect. This is in good agreement with the increase in silica coverage on the iron surface as revealed by X-ray photoelectron spectroscopy. 相似文献
9.
In January 1993, we received NSF funding to develop a pre‐graphics course for freshman engineering majors who are weak in 3‐D spatial visualization skills. A text and computer lab exercises utilizing I‐DEAS software were written specifically for this course. The course is 3‐credits (quarter system) with two hours of lecture and two hours of computer lab each week. It was offered at Michigan Technological University (MTU) for the first time during the 1993 Fall term and has been offered each fall since that time. The objective of the course is to provide the prerequisite spatial skills needed by students to succeed in their subsequent engineering graphics courses. Assessment for the course has been continuous. Recently, a six‐year longitudinal study was conducted to determine the overall success of this project. This paper will describe the project and the assessment findings from the longitudinal study. 相似文献
10.
The Personal Attributes Questionnaire (PAQ) is one of the pre-eminent measures of gender-specific personality characteristics. To evaluate the PAQ'S viability 20 yrs after its creation, the authors assessed the dimensionality and psychometric properties of the original PAQ and a French version using samples of 637 English-speaking and French-speaking university administrators. The structure of the English form of the PAQ was supported for both women and men when the data were submitted to confirmatory analyses. Support was not as convincing for the dimensionality of the French form of the PAQ, however. Some evidence for expected differences in mean Instrumentality and Expressivity scores was found between women and men. Findings support the continued use of the English PAQ as a measure of Instrumental and Expressive personality traits. Further study of the French PAQ is recommended. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献