1,509 research outputs found
Characterization of preclones by matrix collections
Preclones are described as the closed classes of the Galois connection
induced by a preservation relation between operations and matrix collections.
The Galois closed classes of matrix collections are also described by explicit
closure conditions.Comment: 11 page
Stochastic memory: memory enhancement due to noise
There are certain classes of resistors, capacitors and inductors that, when
subject to a periodic input of appropriate frequency, develop hysteresis loops
in their characteristic response. Here, we show that the hysteresis of such
memory elements can also be induced by white noise of appropriate intensity
even at very low frequencies of the external driving field. We illustrate this
phenomenon using a physical model of memory resistor realized by
thin films sandwiched between metallic electrodes, and discuss
under which conditions this effect can be observed experimentally. We also
discuss its implications on existing memory systems described in the literature
and the role of colored noise.Comment: 5 pages, 4 figure
Market implications of FMD epidemics in the Finnish pig sector: Does market structure matter?
This paper examines the role of market coordination and market distortions caused by a hypothetical FMD outbreak in the Finnish pig sector. By using stochastic dynamic programming, it simulates the consequences of two outbreak scenarios (large vs. small) under two distinct market regimes (competitive market vs. monopoly in the domestic supply). Simulated losses depend on the magnitude of outbreak and expected duration of possible turndown of meat exports, whereas market regime has a limited impact.Foreign trade, livestock epidemics, dynamic programming, Livestock Production/Industries,
The Impacts of Alternative Policy Scenarios on Multifunctionality
This paper provides first results of the sector model approach to analyze the effects of alternative policy scenarios on the multifunctional role of Finnish agriculture. In terms of environmental non-commodity outputs we focus on nutrient runoffs, landscape diversity and biodiversity. As regards to socio-economic outputs our focus is on direct and indirect agricultural labour force. The results suggest that while partial de-coupling agricultural supports from production is not likely to result in any drastic decline of agricultural production the amount of green fallow will increase considerably. As a result, the agricultural land will become biologically richer. The agricultural labour force is likely to decrease substantially irrespective of agricultural policy.agricultural policy, multifunctionality, sector model, Agricultural and Food Policy, Q18, Q21,
Clones with finitely many relative R-classes
For each clone C on a set A there is an associated equivalence relation
analogous to Green's R-relation, which relates two operations on A iff each one
is a substitution instance of the other using operations from C. We study the
clones for which there are only finitely many relative R-classes.Comment: 41 pages; proofs improved, examples adde
On the homomorphism order of labeled posets
Partially ordered sets labeled with k labels (k-posets) and their
homomorphisms are examined. We give a representation of directed graphs by
k-posets; this provides a new proof of the universality of the homomorphism
order of k-posets. This universal order is a distributive lattice. We
investigate some other properties, namely the infinite distributivity, the
computation of infinite suprema and infima, and the complexity of certain
decision problems involving the homomorphism order of k-posets. Sublattices are
also examined.Comment: 14 page
Pedagogies of inclusion: a critical exploration of small-group teaching practice in higher education
This paper provides a critical examination of inclusion as a pedagogic principle through a practice-based interrogation of contemporary ‘good practice’ strategies for encouraging inclusion in small-group teaching. It reflects on our experiences of delivering four classroom exercises that are frequently proposed as strategies for increasing inclusion, and borrows insight from critical intersectional feminist pedagogy to interrogate normative discourses of inclusion in HE. We argue that both the terms of inclusion, and the assumption that (verbal) participation is itself a measure of improving inclusion in classroom spaces, require interrogation. This article thus responds to the proliferation of inclusion discourses in contemporary UK HE, by identifying some of the potential pitfalls of measuring inclusion through the limited scope of participatio
Where do people direct their attention while cycling? : A comparison of adults and children
Cycling in urban environments requires the ability to distinguish between relevant and irrelevant targets quickly and reliably, so that potential hazards can be anticipated and avoided. In two experiments, we investigated where adults and children direct their attention when viewing videos filmed from a cyclist's perspective. We wanted to see if there were any differences in the responses given by experienced adult cyclists, inexperienced adult cyclists, and child cyclists. In Experiment 1,16 adults (19-33 years) were asked to watch ten videos and to point out things they would pay attention to by tapping a touchscreen (pointed out locations). Afterwards, they were asked to explain their answers. In Experiment 2, 17 adults (19-34 years) and 17 children (11-12 years) performed the same task with the same ten videos, but they were not asked to explain their answers afterwards. The data sets from these two experiments were pooled, creating three groups: ten experienced adult cyclists, 23 inexperienced adult cyclists and 17 children. A total of 23 clearly visible, traffic-relevant targets (pre-specified targets) had previously been identified in the videos. We investigated whether the participants' pointed-out locations matched these targets (and if so, how fast they responded in pointing them out). We also investigated the number and vertical/horizontal dispersion of these pointed-out locations on the touchscreen. Adults pointed out more locations than children, especially pedestrians and cyclists. This result suggests that, while children focussed as well as adults on cars (arguably the most salient hazard), they were less able to identify other hazards (such as pedestrians or other cyclists). The children had also a larger vertical dispersion and a larger between-participant variation than the adults. Adults were faster at tapping the pre-specified targets and they missed them less often. Overall, the results suggest that 11-12 year old-cyclists have worse situation awareness in traffic than adults. (C) 2018 Published by Elsevier Ltd.Peer reviewe
Differential Expression Of Gap Junction mRNAs And Proteins In The Developing Murine Kidney And In Experimentally Induced Nephric Mesenchymes
The expression of three gap junction (GJ) proteins, alpha-1 (Cx43), beta-1 (Cx32), and beta-2 (Cx26), and their transcripts were examined during the ontogeny of the mouse and rat kidney. These proteins were expressed in two non-overlapping patterns. The alpha-1 GJ protein was first observed in mesenchymal cells in the 12-day mouse kidney. By day 14 and thereafter, the ai protein was detected in the transient S-shaped bodies, but not in the podocytes of the maturing glomeruli. After birth the antigen was retained in a small subset of secretory tubules.The beta-1 and beta-2 GJ proteins were similar in their developmental patterns. They were first detected in a small subset of secretory tubules in the subcortical zone of day 17 embryos. These tubules were identified by immunohistochemical markers to be proximal. At birth, practically all proximal tubules expressed the two antigens.This analysis of GJ proteins was consistent with the results of S1 nuclease protection assays showing that, while the alpha-1 mRNA appeared early during kidney development and declined around birth, the two beta mRNAs appeared later and became intensified during the last days of intrauterine development.In experimentally induced metanephric mesenchymes, a transient expression of the alpha-1 GJ protein was seen during the segregation of the tubular anlagen. beta-1 and beta-2 GJ proteins were not detected in such induced mesenchymes cultivated up to 7 days.These observations provide evidence for the cell-specific utilization of different GJ genes during different stages of kidney organogenesis. The alpha-1 gene is activated during the early segregation of the secretory tubule and might contribute to its compartmentalization, while the beta-1 and beta-2 gene products are not detected until advanced stages of development. The latter gene products might be correlated with the physiological activity of the proximal tubules in vivo, as they are not expressed in experimentally induced tubules detectable with markers for proximal tubules
Euklidiset renkaat
Tiivistelmä. Tutkielmaa varten lukijalla on hyvä olla peruskäsitys kongruenssista ja algebrallisista ryhmärakenteista sekä niiden operaatioista. Alussa käsitelään renkaiden ja niiden ideaalien määritelmiä ja ominaisuuksia ja laajennetaan siitä kokonaisalueen määritelmään, jossa kahden renkaan nolla-alkiosta eroavien alkioiden kertolaskuoperaation tulos ei voi olla renkaan nolla-alkio, millään alkioilla. Tutkielmassa käydään myös läpi kuntien ja polynomirenkaiden määritelmä, sillä niistä on hyödynnettävissä muutama esimerkki ja lause tutkielman loppua varten.
Kokonaisalueen määritelmää käyttäen käsitellään euklidisen renkaan määritelmä, jossa kokonaisalueelle määritellään astefunktio ja tämän astefunktion avulla määriteltävä jakoalgoritmi. Tämän jälkeen käsitellään euklidisten renkaiden ominaisuuksia kuten, että jokainen euklidinen rengas on pääideaalirengas sekä yleisen jakajan määritelmä. Lopuksi tutkielma päätetään näiden ominaisuuksien ja muutaman apulemman avulla päästävään Fermat’n kahden neliön lauseeseen, jonka mukaan pariton alkuluku p≡1 mod 4 jos ja vain jos on olemassa kokonaisluvut a ja b siten, että alkuluku p voidaan esittää lukujen a ja b neliöiden summana
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