I n valid-time indeterminacy, it is known that an event stored in a temporal database did in fact occur, but it is not known ezactly when the event occurred. W e present an eztension of the tuple-timestamped temporal data model, called the the possible chronons data model, t o support valid-time indetrrtninncy In the possible chronons data model, each event is represented with a set of possible...

Many WWW applications generate HTML or XML documents dynamically. Current tools, however, like languages using DOM or JAVA Server Pages do not allow to check the validity of the generated documents statically. Instead, validity has to be “checked” dynamically by appropriate test runs. This paper addresses this problem by introducing a new distinct class for each element type of a DTD. Each clas...

We consider the problem of generating a lattice-free convex set to find a valid inequality that minimizes the sum of its coefficients for 2-row simplex cuts. Multi-row simplex cuts has been receiving considerable attention recently and we show that a pseudo-polytime generation of a lattice-free convex set is possible. We conclude with a short numerical study.

We describe an algorithm to learn word pronunciations from acoustic data. The algorithm jointly optimizes the pronunciation of a word using (a) the acoustic match of this pronunciation to the observed data, and (b) how “linguistically reasonable” the pronunciation is. Variations of word pronunciations in the recognition dictionary (which was created by linguists), are used to train a model of w...

It is common practice in statistical data analysis to perform data-driven variable selection and derive statistical inference from the resulting model. Such inference enjoys none of the guarantees that classical statistical theory provides for tests and confidence intervals when the model has been chosen a priori. We propose to produce valid “post-selection inference” by reducing the problem to...

islamic traditional medicine (itm) is a holistic system of medicine. saffron (crocus sativus) is one of the most famous plants cultivated in iran and has a wide range of activities such as oxytocic, anti-carcinogenic, exhilarant, anti-depressant, and anti-asthma effects. in addition, saffron can increase the bioavailability and enhance absorption of other drugs. this study comprises a bibliogra...

Information in databases can be imperfect and this imperfection has several forms and causes. In some cases, a single value should be stored, but it is (partially) unknown. The uncertainty about which value to store leads to the aforementioned imperfection. In temporal databases, uncertainty can arise, concerning which temporal notion needs to be stored. Because in temporal databases, temporal ...

Tuples of a temporal relation are equipped with a valid time period. A simple extension of the SPC (SelectionProjection-Cross product) algebra for temporal relations is defined, which conforms to primitives in existing temporal query languages. In particular, temporal projection involves coalescing of time intervals, which results in non-monotonic queries. Also the “select-from-where” normal fo...

Allen Interval Algebra introduces a set of operators, which describe any possible temporal association between two valid time intervals. The requirement of Allen operators for complete temporal knowledge goes against the monotonic knowledge generation sequence, which is witnessed in observation driven fields like stratigraphy. In such cases, incomplete temporal information yields a disjunctive ...