SQL-99 allows for nested subqueries at nearly all places within a query. From a user’s point of view, nested queries can greatly simplify the formulation of complex queries. However, nested queries that are correlated with the outer queries frequently lead to dependent joins with nested loops evaluations and thus poor performance. Existing systems therefore use a number of heuristics to unnest ...

Energy saving is becoming one of the major design issues in processor architectures with multiple functional units (FUs). Nested loops are usually the most critical part in multimedia and high-performance DSP systems. There is a tradeoff between power saving and performance, such as timing constraint and code size requirement, of nested loops. This paper studies how to minimize the total energy...

The statistics of nested spiral self–avoiding loops, which is closely related to the partition of integers into decreasing parts, has been studied on the square and triangular lattices. The number of configurations with N steps is cN ≃ ( √ 2/24)N−3/2 exp(π √ 2 3 N1/2) and their average sizeXN ≃ (1/2π) √ 3 2 N1/2 lnN to leading order on the square lattice while the corresponding values for the t...

The paper shows t h a t t he s t a t e of a r t i n a r t i f i c i a l i n t e l l i g e n c e r e q u i r e s development of a s e m i o t i c system theory wh i ch shou ld p l a y i n t h i s f i e l d t he same r o l e t h a t was p l ayed by f o r m a l systems a t i t s i n i t i a l s t a g e s . Basic problems of s e m i o t i c model and systems t heo ry are d i scussed . I l l u s t r...

The classical certificate systems are computationally inefficient, since they use signature operations based on public key cryptosystems. The nested certificates (A. Levi, Design and performance evaluation of the nested certification scheme and its applications in public key infrastructures, Ph.D. Thesis, Department of Computer Engineering, Boğaziçi University, Istanbul, Turkey) are proposed to...

Based on the improvement of Open L-system, this paper presents a four-layer model of plant growth visualization. Take Radix Isatidis for example, the paper carries on morphologic model of its base leaves growing period and eco-physiological model about temperature and growth rate. The prototype system design and development are also discussed on the base of this four-layer model. The results sh...

In this paper we focus on proof methods and theorem proving for normal conditional logics, by describing nested sequent calculi as well as a theorem prover for them. Nested sequent calculi are a useful generalization of ordinary sequent calculi, where sequents are allowed to occur within sequents. Nested sequent calculi have been profitably employed in the area of (multi)-modal logic to obtain ...

We study languages of nested trees—structures obtained by augmenting trees with sets of nested jump-edges. These graphs can naturally model branching behaviors of pushdown programs, so that the problem of branching-time software model checking may be phrased as a membership question for such languages. We define finite-state automata accepting such languages—these automata can pass states along...

Ecologists are fascinated by the prevalence of nestedness in biogeographic and community data, where it is thought to promote biodiversity in mutualistic systems. Traditionally, nestedness has been treated in a binary sense: species and their interactions are either present or absent, neglecting information on abundances and interaction frequencies. Extending nestedness to quantitative data fac...