Search results for "COD"
showing 10 items of 2985 documents
Central Polynomials of Algebras and Their Growth
2020
A polynomial in noncommutative variables taking central values in an algebra A is called a central polynomial of A. For instance the algebra of k × k matrices has central polynomials. For general algebras the existence of central polynomials is not granted. Nevertheless if an algebra has such polynomials, how can one measure how many are there?
Trace identities and almost polynomial growth
2021
In this paper we study algebras with trace and their trace polynomial identities over a field of characteristic 0. We consider two commutative matrix algebras: $D_2$, the algebra of $2\times 2$ diagonal matrices and $C_2$, the algebra of $2 \times 2$ matrices generated by $e_{11}+e_{22}$ and $e_{12}$. We describe all possible traces on these algebras and we study the corresponding trace codimensions. Moreover we characterize the varieties with trace of polynomial growth generated by a finite dimensional algebra. As a consequence, we see that the growth of a variety with trace is either polynomial or exponential.
Varieties of special Jordan algebras of almost polynomial growth
2019
Abstract Let J be a special Jordan algebra and let c n ( J ) be its corresponding codimension sequence. The aim of this paper is to prove that in case J is finite dimensional, such a sequence is polynomially bounded if and only if the variety generated by J does not contain U J 2 , the special Jordan algebra of 2 × 2 upper triangular matrices. As an immediate consequence, we prove that U J 2 is the only finite dimensional special Jordan algebra that generates a variety of almost polynomial growth.
Symbolic Worst Case Execution Times
2011
In immediate or hard real-time systems the correctness of an operation depends not only upon its logical correctness, but also on the time in which it is computed. In such systems, it is imperative that operations are performed within a given deadline because missing this deadline constitutes the failure of the complete system. Such systems include medical systems, flight control systems and other systems whose failure in responding punctually results in a high economical loss or even in the loss of human lives. These systems are usually analyzed in a sequence of steps in which first, a socalled control flow graph (CFG) is constructed that represents possible program flows. Furthermore, bou…
Disparate movement behavior and feeding ecology in sympatric ecotypes of Atlantic cod
2021
Abstract Coexistence of ecotypes, genetically divergent population units, is a widespread phenomenon, potentially affecting ecosystem functioning and local food web stability. In coastal Skagerrak, Atlantic cod (Gadus morhua) occur as two such coexisting ecotypes. We applied a combination of acoustic telemetry, genotyping, and stable isotope analysis to 72 individuals to investigate movement ecology and food niche of putative local “Fjord” and putative oceanic “North Sea” ecotypes—thus named based on previous molecular studies. Genotyping and individual origin assignment suggested 41 individuals were Fjord and 31 were North Sea ecotypes. Both ecotypes were found throughout the fjord. Seven …
La definizione della possessio nel Festo Farnesiano fra tradizione manoscritta, edizioni e interpretazione storiografica
2016
La comprensione della definizione di possesso fornita da Elio Gallo (ap. Fest., p. 260-262 L.) dipende dalla ricostruzione del testo tramandato nel Codice Farnesiano (Napoli, Biblioteca Nazionale, Neap. IV A 3). Una nuova analisi della tradizione manoscritta compiuta in una più ampia prospettiva consente di verificare se e in quale misura la circolarità ermeneutica ha condizionato le edizioni a stampa su cui sono basate le varie interpretazioni di tale definizione. The understanding of the definition of possession by Aelius Gallus (ap. Fest., p. 260-262 L.) depends on the reconstruction of the text preserved in the Codex Farnesianus (Napoli, Biblioteca Nazionale, Neap. IV A 3). A new analys…
Intra-specific variability and biological relevance of P3N-PIPO protein length in potyviruses
2013
Background:Pipo was recently described as a new ORF encoded within the genome of the Potyviridae family members (PNAS 105:5897-5902, 2008). It is embedded within the P3 cistron and is translated in the +2 reading frame relative to the potyviral long ORF as the P3N-PIPO fusion protein. In this work, we first collected pipo nucleotide sequences available for different isolates of 48 Potyvirus species. Second, to determine the biological implications of variation in pipo length, we measured infectivity, viral accumulation, cell-to-cell and systemic movements for two Turnip mosaic virus (TuMV) variants with pipo alleles of different length in three different susceptible host species, and tested…
The analysis of poverty in Italy. A fuzzy dynamic approach
2004
The commonly used criterion to sharply separate the poor from the non poor on the basis of a poverty threshold appears to be too severe in comparison with the nature of poverty. The latter is multidimensional in its components (domain) and continue in its states (codomain). Moreover an income-based poverty line allows for a remarkable number of spurious transitions below and over that line, which do not correspond to true variations in household’s standard of living. This study starts from the analysis of common (with crisp states) transition matrices; then a fuzzy multidimensional poverty indicator is built. In conclusion, fuzzy states transition matrices synthesize interpretative content …
Symptoms and the body: Taking the inferential leap
2017
The relationship between the conscious experience of physical symptoms and indicators of objective physiological dysfunction is highly variable and depends on characteristics of the person, the context and their interaction. This relationship often breaks down entirely in the case of "medically unexplained" or functional somatic symptoms, violating the basic assumption in medicine that physical symptoms have physiological causes. In this paper, we describe the prevailing theoretical approach to this problem and review the evidence pertaining to it. We then use the framework of predictive coding to propose a new and more comprehensive model of the body-symptom relationship that integrates ex…
Context-dependent minimisation of prediction errors involves temporal-frontal activation
2020
According to the predictive coding model of perception, the brain constantly generates predictions of the upcoming sensory inputs. Perception is realised through a hierarchical generative model which aims at minimising the discrepancy between predictions and the incoming sensory inputs (i.e., prediction errors). Notably, prediction errors are weighted depending on precision of prior information. However, it remains unclear whether and how the brain monitors prior precision when minimising prediction errors in different contexts. The current study used magnetoencephalography (MEG) to address this question. We presented participants with repetition of two non-predicted probes embedded in cont…