Search results for "selection"
showing 10 items of 1940 documents
Entanglement generation and protection by detuning modulation
2006
We introduce a protocol for steady-state entanglement generation and protection based on detuning modulation in the dissipative interaction between a two-qubit system and a bosonic mode. The protocol is a global-addressing scheme which only requires control over the system as a whole. We describe a postselection procedure to project the register state onto a subspace of maximally entangled states. We also outline how our proposal can be implemented in a circuit-quantum electrodynamics setup.
Sexual selection on male body size and assortative pairing in Gammarus pulex (Crustacea: Amphipoda): field surveys and laboratory experiments
2004
Variation in size-assortative pairing was studied in relation to sexual selection on male body size in the amphipod Gammarus pulex, using both transverse and longitudinal surveys of natural populations. In addition, the influence of male–male competition on size-assortative pairing was tested in the laboratory. In both surveys, the intensity of sexual selection was positive and significant for male body size but not for females, and size-assortative pairing was positive and significant. The magnitude of size-assortative pairing, however, varied significantly between populations. The magnitude of size-assortative pairing was positively correlated with the intensity of sexual selection on mal…
A Comparative Study on Feature Selection for Retinal Vessel Segmentation Using FABC
2009
This paper presents a comparative study on five feature selection heuristics applied to a retinal image database called DRIVE. Features are chosen from a feature vector (encoding local information, but as well information from structures and shapes available in the image) constructed for each pixel in the field of view (FOV) of the image. After selecting the most discriminatory features, an AdaBoost classifier is applied for training. The results of classifications are used to compare the effectiveness of the five feature selection methods.
De la literatura anglesa a la catalana : un canvi de circuit lector en el relat per a adolescents
2013
The article analyses the links between the stories written for teens in an English culture and their translation into Catalan. Our starting point is the analysis of three key stories in the history of reading, and we complete this analysis with the investigation of circuit readers in Catalan that deal with translations of the accounts. The main aim of this research is to analyse how do they adapt to a new and different society, what is the context where they operate and what changes do they produce into the target culture. The conclu- sions show to what extend these translated stories represent a model of liter - ary communication once they enter the Catalan circuit readers and how do they …
VARIANTS OF A SELECTION PRINCIPLE FOR SEQUENCES OF REGULATED AND NON-REGULATED FUNCTIONS
2008
Let $T$ be a nonempty subset of $\RB$, $X$ a metric space with metric $d$ and $X^T$ the set of all functions mapping $T$ into $X$. Given $\vep>0$ and $f\in X^T$, we denote by $N(\vep,f,T)$ the least upper bound of those $n\in\NB$, for which there exist numbers $s_1,\dots,s_n,t_1,\dots,t_n$ from $T$ such that $s_1\vep$ for all $i=1,\dots,n$ ($N(\vep,f,T)=0$ if there are no such $n$'s). The following pointwise selection principle is proved: {\em If a sequence of functions\/ $\{f_j\}_{j=1}^\infty\subset X^T$ is such that the closure in $X$ of the sequence\/ $\{f_j(t)\}_{j=1}^\infty$ is compact for each $t\in T$ and\/ $\limsup_{j\to\infty}N(\vep,f_j,T)0$, then\/ $\{f_j\}_{j=1}^\infty$ contains …
A pointwise selection principle for metric semigroup valued functions
2008
Abstract Let ∅ ≠ T ⊂ R , ( X , d , + ) be an additive commutative semigroup with metric d satisfying d ( x + z , y + z ) = d ( x , y ) for all x , y , z ∈ X , and X T the set of all functions from T into X . If n ∈ N and f , g ∈ X T , we set ν ( n , f , g , T ) = sup ∑ i = 1 n d ( f ( t i ) + g ( s i ) , g ( t i ) + f ( s i ) ) , where the supremum is taken over all numbers s 1 , … , s n , t 1 , … , t n from T such that s 1 ⩽ t 1 ⩽ s 2 ⩽ t 2 ⩽ ⋯ ⩽ s n ⩽ t n . We prove the following pointwise selection theorem: If a sequence of functions { f j } j ∈ N ⊂ X T is such that the closure in X of the set { f j ( t ) } j ∈ N is compact for each t ∈ T , and lim n → ∞ ( 1 n lim N → ∞ sup j , k ⩾ N , j…
Party leadership in Poland in comparative perspective
2016
The aim of this paper is to analyse leadership in Polish political parties in comparative perspective. In the further parts of this paper, the methods of leader selections, their competitiveness, as well as reasons for their stepping down are discussed. Similarly to the western political parties, the Polish ones have been changing their methods of leadership selection. So far each time it has consisted in a formal increase in the inclusiveness of the selection. The reasons for transferring the rights relating to the leadership selection to party members were brought closer to the premises typical for Westminster democracies rather than the consensual ones. The analysis of the Polish case sh…
Analysing the efficiency of wastewater treatment plants: The problem of the definition of desirable outputs and its solution
2020
Abstract Evaluating the efficiency of wastewater treatment plants (WWTPs) is highly relevant to improve their performance from an economic and environmental perspective. The issue is even more critical in countries where WWTPs are benchmarked to regulate water companies and define WWTPs’ economic and environmental objectives. Despite the large number of previous studies on this topic, none has considered that the amount of outputs produced by the WWTPs is restricted by the concentration of pollutants in the effluent. To overcome this limitation, the study’s main objective was to propose a new variant of the Weighted Russell Directional Distance Model (WRDDM) that would solve problems regard…
Molecular Clustering of Phenylurea Herbicides: Comparison with Sulphonylureas, Pesticides and Persistent Organic Pollutants
2014
Chromatographic retention times of phenylurea herbicides are modelled by structure–property relationships. Properties are hydration free energy and dipole. Bioplastic evolution is an evolutionary perspective conjugating the effect of acquired characters and relations that emerge among evolutionary indeterminacy, morphological determination and natural selection principles. Classification algorithms are proposed based on information entropy and production. Phenylureas are classified by Cl2, O2 and N2 presence; their different behaviour depends on the number of Cl atoms. When applying procedures to moderate-sized sets, excessive results appear compatible with data and suffer a combinatorial e…
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,…