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81.
Using an adoption design to collect data on biological and adoptive parents of children adopted at birth, this study explored a possible mechanism through which heritable characteristics of adopted children evoke adoptive parent responses and lead to reciprocal influences between adoptive parent and adopted child behavior. Participants were 25 male and 20 female adoptees, 12-18 years of age, having either a biological parent with substance abuse/dependency or antisocial personality or a biological parent with no such history. The study found that psychiatric disorders of biological parents were significantly related to children's antisocial/hostile behaviors and that biological parents' psychiatric disorders were associated with adoptive parents' behaviors. This genotype-environment association was largely mediated by adoptees' antisocial/hostile behaviors. Results also suggest that the adoptee's antisocial/hostile behavior and adoptive mother's parenting practices affect each other. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
We present a neural network methodology for clustering large data sets into pertinent groups. We applied this methodology to analyze the phytoplankton absorption spectra data gathered by the Laboratoire d'Océanographie de Villefranche. We first partitioned the data into 100 classes by means of a self-organizing map (SOM) and then we clustered these classes into 6 significant groups. We focused our analysis on three POMME campaigns. We were able to interpret the absorption spectra of the samples taken in the first oceanic optical layer during these campaigns, in terms of seasonal variability. We showed that spectra from the PROSOPE Mediterranean campaign, which was conducted in a different region, were strongly similar to those of the POMME-3 campaign. This analysis led us to propose regional empirical relationships, linking phytoplankton absorption spectra to pigment concentrations, that perform better than the previously derived overall relation.  相似文献   
83.
In this paper, a new contribution to the design of quartz crystal oscillators for high-sensitivity microbalance sensors used in liquid media is presented. The oscillation condition for a Miller configuration was studied to work in a wide dynamic range of the resonator losses. The equations relating the values of the active and passive components with the maximum supported damping and mass were obtained. Also, the conditions to obtain a stable frequency according to the resonator damping (R(Q)), the static capacity (Cp) and the filter frequency (f(F)) were found. Under these conditions, the circuit oscillation frequency will be proportional to the resonant series frequency and does not depend on the previous parameters (R(Q), f(F), and Cp). If these conditions cannot be satisfied, the expression of the oscillation frequency is given and the discrimination of these effects is obtained through resonator frequency measurements.  相似文献   
84.
The extent to which positive alcohol expectancies mediated the association between delinquency and alcohol use, as well as whether age, sex, or race moderated this mediational relation, was examined in a population-based sample of Iowa schoolchildren (N = 85,301) from the 6th, 8th, and 11th grades. Positive alcohol expectancies were found to partially mediate the association between delinquency and alcohol use (alcohol use initiation, past-month drinking, and past-month binge drinking) across the full sample and in each age, sex, and racial subgroup. Evidence for moderated mediation was found for age and race but not for sex, which suggests that the magnitude of the relations among delinquency, positive alcohol expectancies, and alcohol involvement is different in younger versus older children and White, African American, Native American, Asian, and Hispanic youths but is similar in boys versus girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
85.
Reports an error in the original article by X. Ge et al (Developmental Psychology, 1996 [Jul], Vol 32[4], 574–589). On page 584, Figure 2, negative signs were mistakenly inserted in front of 2 coefficients. The correct coefficients are given. (The following abstract of this article originally appeared in record 1996-01781-002.). Using an adoption design to collect data on biological and adoptive parents of children adopted at birth, this study explored a possible mechanism through which heritable characteristics of adopted children evoke adoptive parent responses and lead to reciprocal influences between adoptive parent and adopted child behavior. Participants were 25 male and 20 female adoptees, 12–18 years of age, having either a biological parent with substance abuse/dependency or antisocial personality or a biological parent with no such history. The study found that psychiatric disorders of biological parents were significantly related to children's antisocial/hostile behaviors and that biological parents' psychiatric disorders were associated with adoptive parents' behaviors. This genotype-environment association was largely mediated by adoptees' antisocial/hostile behaviors. Results also suggest that the adoptee's antisocial/hostile behavior and adoptive… (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
86.
Neural Networks are relevant statistical methods to extract information from data when physical phenomena are very complicated and cannot be described in terms of theoretical analysis. Scatterometers are active microwave radar which accurately measure the power of the backscatter signal versus incident signal in order to calculate the normalized radar cross section (σ0) of the ocean surface. We use multilayer perceptrons in order to determine the Geophysical Model Function and to estimate the variability of the signal of ERS-1, ERS-2 and NSCAT scatterometers.  相似文献   
87.
We present a new, simple, yet efficient algorithm for triangulating multiply-connected polygons. The algorithm requires sorting only local concave minima (sags). The order in which triangles are created mimics a flooding process of the interior of the polygon. At each stage, the algorithm analyses the positions and neighborhoods of two vertices only, and possibly checks for active sags, so as to determine which of five possible actions to take. Actions are based on a local decomposition of the polygon into monotonic regions, or gorges (raise the water level in the current gorge, spill into an adjacent gorge, jump to the other bank of a filled gorge, divide a gorge into two, and fill a gorge to its top). The implementation is extremely simple and numerically robust for a large class of polygons. It has been tested on millions of cases as a preprocessing step of a walkthrough and inspection program for complex mechanical and architectural scenes. Extensive experimental results indicate that the observed complexity in terms of the number of vertices, remains under in all cases.  相似文献   
88.
Probabilistic self-organizing map and radial basis function networks   总被引:2,自引:0,他引:2  
F. Anouar  F. Badran  S. Thiria   《Neurocomputing》1998,20(1-3):83-96
We propose in this paper a new learning algorithm probabilistic self-organizing map (PRSOM) using a probabilistic formalism for topological maps. This algorithm approximates the density distribution of the input set with a mixture of normal distributions. The unsupervised learning is based on the dynamic clusters principle and optimizes the likelihood function. A supervised version of this algorithm based on radial basis functions (RBF) is proposed. In order to validate the theoretical approach, we achieve regression tasks on simulated and real data using the PRSOM algorithm. Moreover, our results are compared with normalized Gaussian basis functions (NGBF) algorithm.  相似文献   
89.
Some studies found that the removal of middle molecules has a long-term effect on mortality and, even more, is enhanced by high-flux dialysis. In order to enhance middle molecule removal in a low-flux dialyzer, the present study aimed at investigating the combined impact of dialyzer flows and membrane surface area. Blood and dialysate flows were varied within the clinical range 300-500 and 500-800 mL/min, respectively, while the ultrafiltration rate was kept constant at 0.1 L/hr. Single-pass tests were performed in vitro in a single Fresenius F6HPS dialyzer (3 tests) and serially (5 tests) and parallel (3 tests) connected dialyzers. The blood substitution fluid consisted of dialysis fluid in which radioactive-labeled vitamin B12 (molecular weight 1355 Da) was dissolved. Dialyzer clearance as well as whole-body clearance was calculated from radioactivity concentrations of samples taken from the inlet and outlet bloodline. Adding a second dialyzer in series or parallel ameliorated the overall dialyzer and whole-body clearance significantly, except for the highest applied blood flows of 500 mL/min. Better solute removal was also obtained with higher dialysate flows, while the use of higher blood flows seemed advantageous only when using a single dialyzer. Analysis of the ultrafiltration profiles in the different configurations illustrated that enhancing the internal filtration rate ameliorates convective transport of middle molecules. Adequate solute removal results from a number of interactions, as there are blood and dialysate flows, membrane surface area, filtration profile and concentration profiles in the blood and dialysate compartment.  相似文献   
90.
Thermionic power generation is a safe and clean energy source that allows for converting heat into electrical energy using thermionic electrons. The miniaturization is an advantage of this technology that led to the recent development of micro-gap thermionic power generators. In this work, thermal contact resistances between the micro-gap insulators and the emitter as well as between the micro-gap insulators and the collector are measured. A thermal resistance of 48.6 K/W is obtained by downsizing the insulators until 60 × 45 μm2 of contact area with the emitter, demonstrating a high impact for decreasing the micro-gap conduction heat loss density from the emitter to the collector from 28 W/cm2 (theoretical value obtained without considering contact resistances) to 5.6 W/cm2. Downsizing the contact area between the insulators and the emitter from 320 × 300 to 60 × 45 μm2 leads to an increase of the power conversion efficiency from 9.1 × 10?5 until 1.5 × 10?3.  相似文献   
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