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1.
Analyzes the relationships between impulsivity and antisocial behavior in a noninstitutionalized sample, taking into account the multidimensional nature of impulsivity and the diversity of types of antisocial behavior. Data were obtained in 1989 and 1990 from 1,226 adolescents aged 12–18 yrs as part of a longitudinal study of risk factors for drug abuse and delinquency. The patterns of stability or change of the various dimensions of antisocial behavior (rule breaking, vandalism, theft, aggression, and drug taking) in relation to impulsivity were investigated. The results support that self-report measures of impulsivity are closely correlated with antisocial behavior among adolescents. The longitudinally-oriented analysis of this work also shows that impulsivity is associated with a future increase in antisocial behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
BACKGROUND: We studied availability to mammography among Spanish women aged 40 to 70 years, variation in use of the mammography by autonomous community, and the situation and importance of breast cancer screening programs among other factors, in the access to mammography. SUBJECTS AND METHODS: A cross-sectional population survey was conducted in 1994 in a sample of 3,218 women. A questionnaire was used to collect data on the variable access (receipt of at least one mammogram in the last 2 years) as well as different access-related variables. Information on breast cancer screening programs was collected by contacting the responsible institutions. We considered that a program had total coverage if it included all the municipalities in the province and partial if it did not include all municipalities. RESULTS: Twenty-eight percent of women had performed a mammogram. This proportion varied among autonomous communities (AACC) from 11.5 to 73.8%. Breast cancer screening programs existed in 8 AACC. The multivariant analysis revealed an association between access to mammography and the existence of a screening program, especially when the later had total coverage (OR = 7.64; 95% CI = 5.24-11.10). An association was also found between access to mammography and physician-related factors, place of residence and attitudes of women toward mammography. CONCLUSIONS: Less than one third of women aged 40-70 have performed a mammography in the last 2 years, and this proportion varies among AACC. Gynecologist visits and the existence of breast cancer screening programs are fundamental factors in the access to mammography in Spain.  相似文献   
3.
Fuzzy rule-based classification systems (FRBCSs) are known due to their ability to treat with low quality data and obtain good results in these scenarios. However, their application in problems with missing data are uncommon while in real-life data, information is frequently incomplete in data mining, caused by the presence of missing values in attributes. Several schemes have been studied to overcome the drawbacks produced by missing values in data mining tasks; one of the most well known is based on preprocessing, formerly known as imputation. In this work, we focus on FRBCSs considering 14 different approaches to missing attribute values treatment that are presented and analyzed. The analysis involves three different methods, in which we distinguish between Mamdani and TSK models. From the obtained results, the convenience of using imputation methods for FRBCSs with missing values is stated. The analysis suggests that each type behaves differently while the use of determined missing values imputation methods could improve the accuracy obtained for these methods. Thus, the use of particular imputation methods conditioned to the type of FRBCSs is required.  相似文献   
4.
In the classification framework there are problems in which the number of examples per class is not equitably distributed, formerly known as imbalanced data sets. This situation is a handicap when trying to identify the minority classes, as the learning algorithms are not usually adapted to such characteristics. An usual approach to deal with the problem of imbalanced data sets is the use of a preprocessing step. In this paper we analyze the usefulness of the data complexity measures in order to evaluate the behavior of undersampling and oversampling methods. Two classical learning methods, C4.5 and PART, are considered over a wide range of imbalanced data sets built from real data. Specifically, oversampling techniques and an evolutionary undersampling one have been selected for the study. We extract behavior patterns from the results in the data complexity space defined by the measures, coding them as intervals. Then, we derive rules from the intervals that describe both good or bad behaviors of C4.5 and PART for the different preprocessing approaches, thus obtaining a complete characterization of the data sets and the differences between the oversampling and undersampling results.  相似文献   
5.
In this paper, we focus on the experimental analysis on the performance in artificial neural networks with the use of statistical tests on the classification task. Particularly, we have studied whether the sample of results from multiple trials obtained by conventional artificial neural networks and support vector machines checks the necessary conditions for being analyzed through parametrical tests. The study is conducted by considering three possibilities on classification experiments: random variation in the selection of test data, the selection of training data and internal randomness in the learning algorithm.The results obtained state that the fulfillment of these conditions are problem-dependent and indefinite, which justifies the need of using non-parametric statistics in the experimental analysis.  相似文献   
6.
This paper describes LPS, a Language Prototyping System that facilitates the modular development of interpreters from semantic building blocks. The system is based on the integration of ideas from Modular Monadic Semantics and Generic Programming.To define a new programming language, the abstract syntax is described as the fixpoint of non-recursive pattern functors. For each functor an algebra is defined whose carrier is the computational monad obtained from the application of several monad transformers to a base monad. The interpreter is automatically generated by a catamorphism or, in some special cases, a monadic catamorphism.The system has been implemented as a domain-specific language embedded in Haskell and we have also implemented an interactive framework for language testing.  相似文献   
7.
Detailed measurements of the specific heat jump C at the superconducting transition temperatureT c as a function ofT c are reported for several (La, Th)Ce systems. The measurements document the continuous demagnetization of the Ce impurity ions which proceeds with increasing Th concentration, and provide a critical test of a theory recently developed by Müller-Hartmann and Zittartz for the superconducting behavior of matrix-impurity systems which simultaneously exhibit both superconductivity and the Kondo effect.Research supported by the U.S. Air Force Office of Scientific Research, Grant No. AF-AFOSR-71-2073.Research supported by the University of Chile-University of California Cooperative Program sponsored by the Ford Foundation.  相似文献   
8.
概述了文化景观在近期及可见未来的热点议题。在《保护世界文化和自然遗产公约》40周年庆典之际,突出强调了景观真实性和完整性、可持续景观管理议题,阐述了《全球景观公约》采纳的必要性,分析了联合国教科文组织近期通过的《关于城市历史景观的建议书》及其引发的争论,表述了对传统乡村景观、自然和人为因素威胁下的景观等议题的高度关注,指出针对热点景观议题亟须发展新战略、新政策,亟须国内、国际各个层面的通力协调与合作。  相似文献   
9.
A water-dissolvable film was developed to topically deliver adenosine for a localized anti-wrinkle effect. The polymers used to produce the film were cellulose derivatives. An aqueous mixture of the film components was made, coated on a liner, and then dried to form a solid film. No preservatives were added and the film was shown to be stable over time. The film quickly dissolves in water to form a uniform layer at the surface of the skin, as shown by scanning electron microscopy. The film layer can still be visualized on the wrinkle 6 h after being applied on the skin. A randomized, placebo-controlled, investigator-blind study was conducted in female volunteers to assess the efficacy of the 1% adenosine-containing dissolvable film. After 3 weeks and 8 weeks, a twice daily application led to a significant decrease in the skin roughness parameters as observed using fast optical in vivo topometry (FOITS). These results demonstrate that water-dissolvable films may be used as novel, preservative-free, cosmetic delivery systems.  相似文献   
10.
A characterization study of coal ash samples from Southern Brazil (Charqueadas, Candiota and Leão Butiá) and from the U.S.A. (Pennsylvania bituminous, Illinois sub-bituminous and North Dakota lignite) has been performed with X-ray photoelectron spectroscopy (ESCA). Qualitative as well as quantitative data are presented. the technique also gives information on the oxidation state of several elements detected. the results are in agreement with existing data. The methodology used to extend ESCA, usually considered a surface/semisurface technique, to the analysis of bulk samples is given in some detail.  相似文献   
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