Search results for " space"
showing 10 items of 4562 documents
Span Programs and Quantum Algorithms for st-Connectivity and Claw Detection
2012
We introduce a span program that decides st-connectivity, and generalize the span program to develop quantum algorithms for several graph problems. First, we give an algorithm for st-connectivity that uses O(n d^{1/2}) quantum queries to the n x n adjacency matrix to decide if vertices s and t are connected, under the promise that they either are connected by a path of length at most d, or are disconnected. We also show that if T is a path, a star with two subdivided legs, or a subdivision of a claw, its presence as a subgraph in the input graph G can be detected with O(n) quantum queries to the adjacency matrix. Under the promise that G either contains T as a subgraph or does not contain T…
Spazi aperti di comunità in ambito climatico Mediterraneo. Il caso di Hassan Fathy in Egitto
2022
The complexity of the relationship between architecture and the Mediterranean climate, in energy regimes and resource scarcity, requires special attention. Specifically, the article aims to explore how community spaces can become design subjects, intervening in climatic, environmental, social, and cultural features. Hassan Fathy’s architecture, in particular the two schools in New Gourna and Fares, offer a different key to understanding man, climate, culture, technology, and education. A relationship that is still evolving today, calling architecture back toits educational and social focus.
Differential properties of the Moreau envelope
2014
International audience; In a vector space endowed with a uniformly Gâteaux differentiable norm, it is proved that the Moreau envelope enjoys many remarkable differential properties and that its subdifferential can be completely described through a certain approximate proximal mapping. This description shows in particular that the Moreau envelope is essentially directionally smooth. New differential properties are derived for the distance function associated with a closed set. Moreover, the analysis, when applied to the investigation of the convexity of Tchebyshev sets, allows us to recover several known results in the literature and to provide some new ones.
Managers’ and consumers’ representations of the closeness to a store : a contribution to retailer strategy
2013
Getting close to the consumer is one major concern in retailing. This research tries to understand the rehabilitation of small food stores in the French retailing context and explores the notion of closeness in all in its dimensions from a retailer as well as a consumer perspective. The research involves data collection from both retail companies and consumers. The qualitative and quantitative analysis show that creating closeness with the customer can be defined as the management of the spatial, temporal, functional and social distance that links a store to its customers. Seven dimensions can be identified: the access closeness, the functional closeness, the process closeness, the relation…
A study on recovering the cloud top-height from infra-red video sequences
2004
In this paper we present some preliminary results on an opticalfow based technique aimed at recovering the cloud-top height from infra-red image sequences. The recovery of the cloud-top height from satellite infra-red images is an important topic in meteorological studies, and is traditionally based on the analysis of the temperature maps. In this work we explore the feasibility for this problem of a technique based on a robust multi-resolution opticalfow algorithm. The robustness is achieved adopting a Least Median of Squares paradigm. The algorithm has been tested on semi-synthetic data (i.e. real data that have been synthetically warped in order to have a reliable ground truth for the mo…
A reappraisal of the Pleurotus eryngii complex – New species and taxonomic combinations based on the application of a polyphasic approach, and an ide…
2014
The Pleurotus eryngii species-complex comprises choice edible mushrooms growing on roots and lower stem residues of Apiaceae (umbellifers) plants. Material deriving from extensive sampling was studied by mating compatibility, morphological and ecological criteria, and through analysis of ITS1-5.8S-ITS2 and IGS1 rRNA sequences. Results revealed that P. eryngii sensu stricto forms a diverse and widely distributed aggregate composed of varieties elaeoselini, eryngii, ferulae, thapsiae, and tingitanus. Pleurotus eryngii subsp. tuoliensis comb. nov. is a phylogenetically sister group to the former growing only on various Ferula species in Asia. The existence of Pleurotus nebrodensis outside of S…
The Coble Quadric
2023
Given a smooth genus three curve $C$, the moduli space of rank two stable vector bundles on C with trivial determinant embeds in $\mathbb{P}^8$ as a hypersurface whose singular locus is the Kummer threefold of $C$; this hypersurface is the Coble quartic. Gruson, Sam and Weyman realized that this quartic could be constructed from a general skew-symmetric fourform in eight variables. Using the lines contained in the quartic, we prove that a similar construction allows to recover SU$_C(2, L)$, the moduli space of rank two stable vector bundles on C with fixed determinant of odd degree L, as a subvariety of $G(2, 8)$. In fact, each point $p \in C$ defines a natural embedding of SU$_C(2, \mathca…
A cognitive architecture for artificial vision
1997
Abstract A new cognitive architecture for artificial vision is proposed. The architecture, aimed at an autonomous intelligent system, is cognitive in the sense that several cognitive hypotheses have been postulated as guidelines for its design. The first one is the existence of a conceptual representation level between the subsymbolic level, that processes sensory data, and the linguistic level, that describes scenes by means of a high level language. The conceptual level plays the role of the interpretation domain for the symbols at the linguistic levels. A second cognitive hypothesis concerns the active role of a focus of attention mechanism in the link between the conceptual and the ling…
Panel Summary: Knowledge Model Representations
1997
Following the usual classifications of cognitive psychologists, we can say that the problem of representation spans three domains: the environment, the brain, and cognitive processes, which are usually studied by different scientists: the physicists, the neurobiologists and the psychologists. With the development of computer science and artificial intelligence new approaches have been introduced, which make possible simulation and implementation of cognitive processes through neural networks and symbolic systems. But the contribution of new methods is not limited to simulation, because they try to provide new models which consider cognitive process as information processing, not as reaction…
Panel Summary: Symbolism and Connectionism Paradigms
1999
The aim of this chapter is to report the panel discussion on symbolism and connectionism paradigms. In particular, the following hot point are analysed: what cognitive phenomena are most difficult for connectionists to explain? what cognitive phenomena are most naturally explained in connectionist terms? is symbolic deduction a central kind of human thinking? How do people make deductions? is nondeductive reasoning done in accord with the laws of probability? what areas of knowledge do you have that are easily described in terms of symbolic rules? concepts reduced to rules, concepts reduced to networks; symbolic and connectionist mechanisms of analogy; planning, decision, explanation, learn…