For a given family of groups B, we define an elementary class E(B) as the smallest class of groups, that contains B and is closed under the passing to subgroups, quotients, and taking extensions and direct limits. The properties of these classes are considered. The proposed theory has close connections with the theory of elementary amenable groups as well as of Kuroš – Černikov classes.

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This paper presents the key steps involved in the design, calibration and error modelling of a low cost odometry system capable of achieving high accuracy dead-reckoning. A consistent error model for estimating position and orientation errors has been developed. Previous work on propagating odometry error covariance relies on incrementally updating the covariance matrix in small time steps. The...

We developed a faster search algorithm that avoids the use of the N-Best paradigm until after more powerful knowledge sources have been used. We found, however, that there was little or no decrease in word errors. We then showed that the use of the N-Best paradigm is still essential for the use of still more powerful knowledge sources, and for several other purposes that are outlined in the pap...

A report of a patient with Lazarus phenomenon (the return of spontaneous circulation after cardiopulmonary resuscitation) following cardiac arrest (myocardium ischemia) is presented. A 65 year patient was found unconscious at home. He taken to the emergency department On arrival he was unconscious, his pupils fixed and dilated bilaterally. Resuscitation proceeded for 55 minutes. He was then pro...

Converting to an electronic medical record (EMR) has been the health care system's collective goal for decades. Hundreds of EMRs have been developed during the last 30 years, but the likelihood of a patient having a largely electronic medical record in the near future remains slim. Adoption has been slow, and the physician time required to enter data is still daunting. And related technologies,...

Biological molecules, like organisms themselves, are subject to genetic drift and may even become "extinct". Molecules that are no longer extant in living systems are of high interest for several reasons including insight into how existing life forms evolved and the possibility that they may have new and useful properties no longer available in currently functioning molecules. Predicting the se...

The paper evaluates the e ectiveness of learning for speeding up the solution of constraint satisfaction problems. It extends previous work (Dechter 1990) by introducing a new and powerful variant of learning and by presenting an extensive empirical study on much larger and more di cult problem instances. Our results show that learning can speed up backjumping when using either a xed or dynamic...

Is Inflation Dead? I n the past few years the United States has enjoyed the unique economic duet of very low unemployment and declining price inflation. For decades, we have come to associate tight labor markets with accelerating wages and prices. But in 1997, the unemployment rate sank below 5 percent and neither wage nor price inflation became a problem. Have our inflation processes fundament...

Mark Twain once remarked that the reports of his death were greatly exaggerated. So too, the death of virology. In certain quarters, it is now fashionable to declare the passing of virology. “Viruses are retro,” a faculty colleague once told me, deadly serious. We have heard this before. In 1967, the U.S. Surgeon General allegedly proclaimed, “The time has come to close the book on infectious d...