Given a hypergraph and a set of embedded functional dependencies, we investigate the problem of determining the conditions under which we can efficiently generate redundancy-free XML storage structures with as few scheme trees as possible. Redundancy-free XML structures guarantee both economy in storage space and the absence of update anomalies, and having the least number of scheme trees requi...

This paper discusses normalization of relations when the candidate keys of a relation have missing information represented by nulls. The paper shows that when the missing information is of the type " not applicable " or " does not exist, " problems and confusion can arise in normalizing relations. Candidate keys with missing information commonly are found in relations that represent information...

A common approach in designing relational databases is to start with a universal relation schema, which is then decomposed into multiple subschemas. A good choice of subschemas can be determined using integrity constraints defined on the schema, such as functional, multivalued or join dependencies. In this paper we propose and analyze a new normal form based on the idea of minimizing overall st...

Normal forms play a central role in the design of relational databases. Several normal forms for temporal relational databases have been proposed. These definitions are particular to specific temporal data models, which are numerous and incompatible. This paper attempts to rectify this situation. We define a consistent framework of temporal equivalents of the important conventional database des...

Short wavelength FELS using the SLAC linac H. Winick a,*, K. Bane a, R. Boyce a, J. Cobb a, G. Loew a, P. Morton a, H.-D. Ntihn a, J. Paterson a, P. Pianetta a, T. Raubenheimer a, J. Seeman a, R. Tatchyn a, V. Vylet a, C. Pellegrini J. Rosenzweig b, G. Travish b, D. Prosnitz c, E.T . Scharlemann °, K. Halbach d , KA. Kim d, R. Schlueter d, M. Xie d, R. Bonifacio e, L. De Salvo e, P. Pierini e '...

This paper considers a dynamic common agency model of natural resource harvest quota regulation in which both conservationists and harvesters vie to influence the regulator’s quota allocations as well as the choice of regulator. Conservationists tend to benefit from the adoption of regulation since the regulator will reduce the aggregate harvest quota relative to the unregulated equilibrium. Ha...