We characterize all pairs of connected graphs {X,Y } such that each 3-connected {X,Y }-free graph is pancyclic. In particular, we show that if each of the graphs in such a pair {X,Y } has at least four vertices, then one of them is the claw K1,3, while the other is a subgraph of one of six specified graphs.

A circular-arc model (C,A) is a circle C together with a collection A of arcs of C. If A satisfies the Helly Property then (C,A) is a Helly circular-arc model. A (Helly) circular-arc graph is the intersection graph of a (Helly) circular-arc model. Circular-arc graphs and their subclasses have been the object of a great deal of attention, in the literature. Linear time recognition algorithm have...

We discuss the use of K-terminal networks to represent arbitrary clutters. A given clutter has many di¤erent representations, and there does not seem to be any set of simple transformations that can be used to transform one representation of a clutter into any other. We observe that for t 2 the class of clutters that can be represented using no more than t terminals is closed under minors, and ...

A generalized Davenport-Schinzel sequence is one over a finite alphabet that contains no subsequences isomorphic to a fixed forbidden subsequence. One of the fundamental problems in this area is bounding (asymptotically) the maximum length of such sequences. Following Klazar, let Ex(σ, n) be the maximum length of a sequence over an alphabet of size n avoiding subsequences isomorphic to σ. It ha...

Reservoir characterization This paper gives an overview of the activities in geostatistics for the Petroleum industry in the domain of reservoir characterization. This description has been simplified in order to emphasize the original techniques involved. The main steps of a study consist in successively building: • the reservoir architecture where the geometry of the units is established, • th...

This paper characterizes revenue maximizing auctions for a …nite horizon version of the standard IV P model of Myerson (1981) for a seller who cannot commit not to propose a new mechanism, if previously chosen ones fail to allocate the object. We show that a revenue maximizing mechanism in the …rst period assigns the good to the buyer with the highest virtual valuation, provided that it is abov...

An overview is provided of materials and processes research currently being conducted in support of MEMS device design at MIT. Underpinning research is being conducted in five areas: room temperature strength characterization, elevated temperature strength characterization, processing of Si/SiC hybrid structures, modeling of wafer bonding processes and development of high temperature fluid inte...

The states of penile erection have not been quantified to establish their relationship to intracorporal fluid pressure and to soft tissue constraint. Computer-based circumferential rigidity sensing during erectile cycles now permits circumferential size and rigidity characterization. Measurements during dynamic infusion cavernometry and cavernosography relate intracorporal pressure and axial ri...