Search results for "complexi"
showing 10 items of 1116 documents
13C/12C composition, a novel parameter to study the downward migration of paper sludge in soils
2002
δ13C values of crop and forest soils were measured 8 years after disposal of paper sewage sludge. The carbon transfer from paper sludge downward to the first humic layer is evidenced by a 13C-enrichnient of up to + 5.6‰ due to the input of 13C-enriched sludge carbonates. 13C/12C composition is thus a novel, sensitive parameter to follow the downward transfer of paper sludge carbon.
A Comparison between Three Meta-Modeling Optimization Approaches to Design a Tube Hydroforming Process
2012
Computer aided procedures to design and optimize forming processes have become crucial research topics as the industrial interest in cost and time reduction has been increasing. A standalone numerical simulation approach could make the design too time consuming while meta-modeling techniques enables faster approximation of the investigated phenomena, reducing the simulation time. Many researchers are, nowadays, facing such research challenge by using various approaches. Response surface method (RSM) is probably the most known one, since its effectiveness was demonstrated in the past years. The effectiveness of RSM depends both on the definition of the Design of Experiments (DoE) and the acc…
Continuous-Variable Instantaneous Quantum Computing is Hard to Sample
2017
Instantaneous quantum computing is a sub-universal quantum complexity class, whose circuits have proven to be hard to simulate classically in the Discrete-Variable (DV) realm. We extend this proof to the Continuous-Variable (CV) domain by using squeezed states and homodyne detection, and by exploring the properties of post-selected circuits. In order to treat post-selection in CVs we consider finitely-resolved homodyne detectors, corresponding to a realistic scheme based on discrete probability distributions of the measurement outcomes. The unavoidable errors stemming from the use of finitely squeezed states are suppressed through a qubit-into-oscillator GKP encoding of quantum information,…
Optimal Impulse Control Problems and Linear Programming
2009
Optimal impulse control problems are, in general, difficult to solve. A current research goal is to isolate those problems that lead to tractable solutions. In this paper, we identify a special class of optimal impulse control problems which are easy to solve. Easy to solve means that solution algorithms are polynomial in time and therefore suitable to the on-line implementation in real-time problems. We do this by using a paradigm borrowed from the Operations Research field. As main result, we present a solution algorithm that converges to the exact solution in polynomial time. Our approach consists in approximating the optimal impulse control problem via a binary linear programming proble…
A Characterization of Quintic Helices
2005
A polynomial curve of degree 5, @a, is a helix if and only if both @[email protected]^'@? and @[email protected]^'@[email protected]^''@? are polynomial functions.
Exact Voronoi diagram of smooth convex pseudo-circles: General predicates, and implementation for ellipses
2013
International audience; We examine the problem of computing exactly the Voronoi diagram (via the dual Delaunay graph) of a set of, possibly intersecting, smooth convex \pc in the Euclidean plane, given in parametric form. Pseudo-circles are (convex) sites, every pair of which has at most two intersecting points. The Voronoi diagram is constructed incrementally. Our first contribution is to propose robust and efficient algorithms, under the exact computation paradigm, for all required predicates, thus generalizing earlier algorithms for non-intersecting ellipses. Second, we focus on \kcn, which is the hardest predicate, and express it by a simple sparse $5\times 5$ polynomial system, which a…
The use of Markovian metapopulation models: a comparison of three methods reducing the dimensionality of transition matrices.
2001
The use of Markovian models is an established way for deriving the complete distribution of the size of a population and the probability of extinction. However, computationally impractical transition matrices frequently result if this mathematical approach is applied to natural populations. Binning, or aggregating population sizes, has been used to permit a reduction in the dimensionality of matrices. Here, we present three deterministic binning methods and study the errors due to binning for a metapopulation model. Our results indicate that estimation errors of the investigated methods are not consistent and one cannot make generalizations about the quality of a method. For some compared o…
Complejidad social y calidad informativa: hacia un periodismo "glocal"
2013
In the so-called information (and knowledge) society, quality information is, more than ever, an indispensable and inalienable public good for any citizen who wants to exercise his or her civic and political rights. Because of this, we need to have reliable (rigorous and autonomous) communication media, which disseminate relevant and quality information. But journalism does not only depend on structural questions, but also on the conditions and limits (such as simplification, for instance) that mark professional praxis, either of the political or the socioeconomic type. Social complexity requires a treatment of information that might explain reality, which implies taking advantage of the sc…
The Crane Beach Conjecture
2002
A language L over an alphabet A is said to have a neutral letter if there is a letter e/spl isin/A such that inserting or deleting e's from any word in A* does not change its membership (or non-membership) in L. The presence of a neutral letter affects the definability of a language in first-order logic. It was conjectured that it renders all numerical predicates apart from the order predicate useless, i.e., that if a language L with a neutral letter is not definable in first-order logic with linear order then it is not definable in first-order. Logic with any set /spl Nscr/ of numerical predicates. We investigate this conjecture in detail, showing that it fails already for /spl Nscr/={+, *…
On the influence of context-based complexity on information search patterns: An individual perspective
2014
Although context-based complexity measured as the similarity and conflict across alternatives is dependent on individual preference structures, existing studies investigating the influence of context-based complexity on information search patterns have largely ignored that context-based complexity is user- and preference-dependent. Addressing this research gap, this article elicits the individual preferences of decision makers by using the pairwise-comparison-based preference measurement (PCPM) technique and records individuals' search patterns using eye tracking. Our results show that an increased context-based complexity leads to an increase in information acquisition and the use of a mor…