I assume that most students have encountered Turing machines before. (Students who have not may want to look at Sipser’s book [3].) A Turing machine is defined by an integer k ≥ 1, a finite set of states Q, an alphabet Γ, and a transition function δ : Q×Γk → Q×Γk−1×{L, S,R}k where: • k is the number of (infinite, one-dimensional) tapes used by the machine. In the general case we have k ≥ 3 and ...

offices of the Wessex Council on Alcoholism, 14 Brunswick Place, Southampton, a group of people meet to discuss the difficulties they encounter in fighting an insidious disease that is threatening to ruin their lives?alcoholism. Any non-alcoholics attending would undoubtedly be surprised by the questions asked by these anxious and often apprehensive addicts. Questions that range from a middle-a...

We consider the problem of implementing general sharedmemory objects on top of write-once bits, which can be changed from 0 to 1 but not back again. In a sequential setting, write-once memory (WOM) codes have been developed that allow simulating memory that support multiple writes, even of large values, setting an average of 1 + o(1) write-once bits per write. We show that similar space efficie...

This is a special conference for the Federal Reserve Bank of Boston, and for me personally. The role of monetary aggregates in monetary policy was intensely controversial when I joined the staff of the Board of Governors in May 1969. I was immediately asked to join the staff of the newly formed FOMC Committee on the Directive. Governor Sherman Maisel chaired that committee; the other two member...

JEDICKE WILL WRITE ONCE REMAINDER OF PAPER IS COMPLETE. Subject headings: Near-Earth Objects; Asteroids, Dynamics

Write-unidirectional memories (WUMs) have been introduced recently. They are binary storage devices having a close relationship to write-once memories (WOMs). When updating the information stored by a WUM the encoder can write 1 's to some positions of the WUM or O's to some positions of the WUM but it is not allowed to do both at the same time. Wolf, Wyner, Ziv and Korner investigated WOMs in ...

Flash memory technology is becoming critical in building embedded systems applications because of its shock-resistant, power economic, and non-volatile nature. Because flash memory is a write-once and bulkerase medium, a translation layer and a garbage collection mechanism is needed to provide applications a transparent storage service. In this paper, we propose a real-time garbage collection m...

I assume that most students have encountered Turing machines before. (Students who have not may want to look at Sipser’s book [3].) A Turing machine is defined by an integer k ≥ 1, a finite set of states Q, an alphabet Γ, and a transition function δ : Q×Γk → Q×Γk−1×{L, S,R}k where: • k is the number of (infinite, one-dimensional) tapes used by the machine. In the general case we have k ≥ 3 and ...

The preparation for DNA replication initiation is tightly linked to cell-cycle progression, ensuring that replication occurs only once per cycle. The time is ripe for a molecular dissection of the links between the two processes.