Front and Center

Newsletter providing "a lighter, human interest side of the news" from the Boston University Medical Campus

Front and Center

Newsletter providing "a lighter, human interest side of the news" from the Boston University Medical Campus

Front and Center

Newsletter providing "a lighter, human interest side of the news" from the Boston University Medical Campus

An elementary construction of Anick's fibration

Cohen, Moore, and Neisendorfer's work on the odd primary homotopy theory of spheres and Moore spaces, as well as the first author's work on the secondary suspension, predicted the existence of a p-local fibration S^2n-1 --> T --> \Omega S^2n+1 whose connecting map is degree p^r. In a long and complex monograph, Anick constructed such a fibration for p>= 5 and r>= 1. Using new methods we give a much more conceptual construction which is also valid for p=3 and r>= 1. We go on to establish several properties of the space T.Comment: 30 page

Efficient Solution of Language Equations Using Partitioned Representations

A class of discrete event synthesis problems can be reduced to solving language equations f . X ⊆ S, where F is the fixed component and S the specification. Sequential synthesis deals with FSMs when the automata for F and S are prefix closed, and are naturally represented by multi-level networks with latches. For this special case, we present an efficient computation, using partitioned representations, of the most general prefix-closed solution of the above class of language equations. The transition and the output relations of the FSMs for F and S in their partitioned form are represented by the sets of output and next state functions of the corresponding networks. Experimentally, we show that using partitioned representations is much faster than using monolithic representations, as well as applicable to larger problem instances.Comment: Submitted on behalf of EDAA (http://www.edaa.com/

Front and Center

Newsletter providing "a lighter, human interest side of the news" from the Boston University Medical Campus

A New Formal

The girl stood in the narrow doorway a moment before she went, slowly, into the living-room. She did not speak to her mother who was sitting in the dingy, brown leather chair by the window, did not seem to notice the anxious, gray eyes staring at her through old-fashioned, horn-rimmed glasses. She walked aimlessly about the room, then stopped to peer out of the window. Mother, the girl began, still looking through the window into the cold, December twilight

Solubility and diffusion of oxygen in tantalum

Solubility of oxygen in tantalum determined by resistivity techniqu

The role of expectations in the FRB/US macroeconomic model

In the past year, the staff of the Board of Governors of the Federal Reserve System began using a new macroeconomic model of the U.S. economy referred to as the FRB/US model. This system of mathematical equations, describing interactions among economic measures such as inflation, interest rates, and gross domestic product, is one of the tools used in economic forecasting and the analysis of macroeconomic policy issues at the Board. The FRB/US model replaces the MPS model, which, with periodic revisions, had been used at the Federal Reserve Board since the early 1970s. A key feature of the new model is that expectations of future economic conditions are explicit in many of its equations. Because of this clear delineation of expectations, the FRB/US model can be used to study issues that would be difficult or impossible to study with the MPS model. For example, the new model can show how the economy's response to specific events, such as a reduction in defense spending, may vary considerably with the speed at which the public recognizes that the event has occurred or will occur.Econometric models ; Federal Reserve System ; Forecasting