The composition of two pattern restricted classes X,Y is the set of all permutation products θφ where θ ∈ X,φ ∈ Y . This set is also defined by pattern restrictions. Examples are given where this set of restrictions is finite and where it is infinite. The composition operation is studied in terms of machines that sort and generate permutations. The theory is then applied to a multistage sorting...

We study one-head machines through symbolic and topological dynamics. In particular, a subshift is associated to the system, and we are interested in its complexity in terms of realtime recognition. We emphasize the class of one-head machines whose subshift can be recognized by a deterministic pushdown automaton. We prove that this class corresponds to particular restrictions on the head moveme...

In the previous lectures, we have introduced the concept of deterministic oracle Turing machines. The concept of non-deterministic oracle Turing machines is just a direct extension of that to the non-deterministic case. To be precise, a non-deterministic oracle Turing machine (sometimes abbreviated to “oracle NTM”) is just like a deterministic oracle TM, but with a non-deterministic transition ...

In power generation and other production settings, technological constraints force restrictions on the number of time-periods that a machine must stay up once activated, and stay down once deactivated. We characterize the polyhedral structure of a model representing these restrictions. We also describe a cutting-plane method for solving integer programs involving such min-up and min-down times ...

Future software and hardware technologies will try to provide improved performance by extracting higher levels of parallelism. However the cost of a main memory access-in terms of missed instruction slots-increases with faster processors and greater issue widths. For this reason latency hiding technology remains one of the most important parts of high performance processor designs. In this pape...

This paper gives operational semantics for a subset of VHDL in terms of abstract machines. Restrictions to the VHDL source code are the niteness of data types, and the absence of quantitative timing infor-mations. The abstract machine of a design unit is built by composition of the abstract machines for its embedded processes and blocks. The kernel process in our model is distributed among the ...