881 resultados para representational theory of measurement
Resumo:
In the past few years a great deal of attention has been given to the electrodeposition of alloys. For the main part, this investigation has been of scientific interest only; but in a few instances, such work has attained commercial importance.
Resumo:
Because of the important morbidity and mortality associated with osteoporosis, it is essential to detect subjects at risk by screening methods, such as bone quantitative ultrasounds (QUSs). Several studies showed that QUS could predict fractures. None, however, compared prospectively different QUS devices, and few data of quality controls (QCs) have been published. The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk is a prospective multicenter study that compared three QUSs for the assessment of hip fracture risk in a population of 7609 women age >/=70 yr. Because the inclusion phase lasted 20 mo, and because 10 centers participated in this study, QC became a major issue. We therefore developed a QC procedure to assess the stability and precision of the devices, and for their cross-calibration. Our study focuses on the two heel QUSs. The water bath system (Achilles+) had a higher precision than the dry system (Sahara). The QC results were highly dependent on temperature. QUS stability was acceptable, but Sahara must be calibrated regularly. A sufficient homogeneity among all the Sahara devices could be demonstrated, whereas significant differences were found among the Achilles+ devices. For speed of sound, 52% of the differences among the Achilles+ was explained by the water s temperature. However, for broadband ultrasound attenuation, a maximal difference of 23% persisted after adjustment for temperature. Because such differences could influence measurements in vivo, it is crucial to develop standardized phantoms to be used in prospective multicenter studies.
Resumo:
The IDA model of cognition is a fully integrated artificial cognitive system reaching across the full spectrum of cognition, from low-level perception/action to high-level reasoning. Extensively based on empirical data, it accurately reflects the full range of cognitive processes found in natural cognitive systems. As a source of plausible explanations for very many cognitive processes, the IDA model provides an ideal tool to think with about how minds work. This online tutorial offers a reasonably full account of the IDA conceptual model, including background material. It also provides a high-level account of the underlying computational “mechanisms of mind” that constitute the IDA computational model.
Resumo:
A model of theoretical science is set forth to guide the formulation of general theories around abstract concepts and processes. Such theories permit explanatory application to many phenomena that are not ostensibly alike, and in so doing encompass socially disapproved violence, making special theories of violence unnecessary. Though none is completely adequate for the explanatory job, at least seven examples of general theories that help account for deviance make up the contemporary theoretical repertoire. From them, we can identify abstractions built around features of offenses, aspects of individuals, the nature of social relationships, and different social processes. Although further development of general theories may be hampered by potential indeterminacy of the subject matter and by the possibility of human agency, maneuvers to deal with such obstacles are available.