• Publications
  • Influence
Inferences of Multivalued Dependencies in Fixed and Undetermined Universes
  • J. Biskup
  • Computer Science, Mathematics
  • Theor. Comput. Sci.
  • 1980
TLDR
A new inference rule is introduced, the subset rule, and using this rule it is proved that a certain system is complete, and the role of the so-called complementation rule is clarified. Expand
A formal view integration method
TLDR
This paper carefully develops a formal model, clarifying many notions and concepts, related to the view integration method, that serves as a theoretical basis of the integration approach that uses equivalence preserving, local scheme transformations as the main integration operations. Expand
Lying versus refusal for known potential secrets
TLDR
It is proved formally that, in general, lying and refusal are incomparable in many respects, but, under fairly natural assumptions, lies and refusals lead to surprisingly similar behaviors and convey exactly the same information to the user. Expand
The Güttingen study of psychoanalytic therapy: First results
TLDR
Results of a naturalistic study of the effectiveness of psychoanalytic therapy are reported, finding improvements proved to be stable or even increased in symptoms, interpersonal problems, quality of life, well‐being, and target problems. Expand
Controlled query evaluation for enforcing confidentiality in complete information systems
  • J. Biskup, P. Bonatti
  • Computer Science
  • International Journal of Information Security
  • 1 October 2004
TLDR
This work comprehensively treats and compares 12 cases of confidentiality policies based on potential secrets or secrecies, user awareness of the policy instance, and enforcement methods applying either lying or refusal, or a combination thereof. Expand
Synthesizing independent database schemas
TLDR
This work shows that this goal can easily be achieved by an extension of the well-known synthetic approach of Bernstein and others to database design, and how to use the method to synthesize minimal independent third normal form schemas. Expand
A Formal Approach to Null Values in Database Relations
  • J. Biskup
  • Mathematics, Computer Science
  • Advances in Data Base Theory
  • 1979
TLDR
The view that tuples denote statements of predicate logic about database relations is adopted, which means that a null value of the first kind and the second kind corresponds to an existentially quantified variable, respectively universally quantified variables. Expand
For unknown secrecies refusal is better than lying
  • J. Biskup
  • Computer Science
  • Data Knowl. Eng.
  • 1 April 2000
TLDR
The assessment shows that for unknown secrecies refusal is better than lying, and while preserving the same secrets refusal can provide more useful answers. Expand
On the complementation rule for multivalued dependencies in database relations
  • J. Biskup
  • Mathematics, Computer Science
  • Acta Informatica
  • 1 September 1978
TLDR
It is proved that there is a trade-off between the complementation rule and the augmentation rule, and the derivability of inference rules for Boolean operations on the right side of multivalued dependencies. Expand
Keeping secrets in incomplete databases
TLDR
This work introduces a framework in which CQE can be analyzed wrt. Expand
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