In Clock routing research, such practical considerations as hierarchical buffering, rise-time and overshoot constraints, obstacleand legal location-checking, varying layer parasitics and congestion, and even the underlying design flow are often ignored. This paper explores directions in which traditional formulations can be extended so that the resulting algorithms are more useful in production...

Lexicalized Tree Adjoining Grammars (LTAGs) [6] are tree rewriting systems consisting of a finite set of trees associated with lexical items, so-called elementary trees (etrees). Elementary trees represent extended projections of lexical items that encapsulate all their syntactic/semantic arguments. Due to this property, semantics construction in LTAG can be based on elementary trees as basic u...

This paper presents a new approach to global clock distribution in which traditional tree-driven grids are augmented with onchip inductors to resonate the clock capacitance at the fundamental frequency of the clock node. Rather than being dissipated as heat, the energy of the fundamental resonates between electric and magnetic forms. The clock drivers must only provide the energy necessary to o...

A technique is described to dynamically limit power dissipation in heavily pipelined digital circuits. Stages in the pipeline are clock gated based upon validity of data at that stage. As the pipe approaches a stalled or inactive state, branches of the clock tree are progressively disabled stage by stage. The technique has the additional advantage of removing gaps or “bubbles” in the data strea...

This paper presents an e cient algorithm for bu ered Steiner tree construction with wire sizing. Given a source and n sinks of a signal net, with given positions and a required arrival time associated with each sink, the algorithm nds a Steiner tree with bu er insertion and wire sizing so that the required arrival time (or timing slack) at the source is maximized. The unique contribution of our...

introduction: the utility and discriminatory pattern of the clock face drawing test in adhd is unclear. this study therefore compared clock face drawing test performance in children with adhd and controls. methods: 95 school children with adhd and 191 other children were matched for gender ratio and age. adhd symptoms severities were assessed using dsm-iv adhd checklist and their intellectual f...

A Steiner quadruple system S(v, 4, 3) of order v is a 3-design T (v, 4, 3, λ) with λ = 1. In the previous paper [1] we classified all such Steiner systems S(16, 4, 3) of order 16 with rank 13 or less over F 2. In particular, we have proved that there is can be obtained by the generalized doubling construction, which we give here. Our main result is that there are exactly 684764 non-isomorphic S...

It has remained an open question whether the twins property for weighted tree automata is decidable. This property is crucial for determinizing such an automaton, and it has been argued that determinization improves the output of parsers and translation systems. We show that the twins property for weighted tree automata over extremal semifields is decidable.