Search results for "tractor"
showing 10 items of 219 documents
Various Approaches to Early Contractor Involvement in Relational Contracts
2021
Abstract The main rationale for involving contractors is to apply collaboration to mitigate risk and to harvest opportunities to reduce cost and to increase the project owner’s value. In the paper we argue in the applied analytical model that there are four levels of early contractor involvement (ECI), which are 1) Preparation of the project (before sparking off competition); 2) During the procurement phase (development of what to build); 3) Project delivery model (before construction contract, but after the contractor and designers are selected); 4) Project delivery model (where involvement also continues in the execution phase). In the paper we argue that category 4 have the largest poten…
Transitive Anosov flows and Axiom-A diffeomorphisms
2009
AbstractLet M be a smooth compact Riemannian manifold without boundary, and ϕ:M×ℝ→M a transitive Anosov flow. We prove that if the time-one map of ϕ is C1-approximated by Axiom-A diffeomorphisms with more than one attractor, then ϕ is topologically equivalent to the suspension of an Anosov diffeomorphism.
On the existence of attractors
2009
On every compact 3-manifold, we build a non-empty open set $\cU$ of $\Diff^1(M)$ such that, for every $r\geq 1$, every $C^r$-generic diffeomorphism $f\in\cU\cap \Diff^r(M)$ has no topological attractors. On higher dimensional manifolds, one may require that $f$ has neither topological attractors nor topological repellers. Our examples have finitely many quasi attractors. For flows, we may require that these quasi attractors contain singular points. Finally we discuss alternative definitions of attractors which may be better adapted to generic dynamics.
Constructional morphology and mode of attachment of the trunk ofCorynosoma cetaceum (Acanthocephala: Polymorphidae)
1999
Dead specimens of Corynosoma cetaceum were used to describe the trunk musculature of this species and to infer the use of the trunk as a secondary holdfast. Inferences were based on trunk muscle arrangement, changes in trunk shape, size and distribution of spines, and geometry of tegument thickness. The foretrunk of C. cetaceum is swollen and forms a spiny disk that is bent ventrally. The disk is flattened by several groups of muscles not described previously, which seem able to finely adjust the disk surface over the substratum. Disk attachment appears to be accomplished by two dorsal neck retractor muscles specialized in pulling the anchored proboscis into the foretrunk. This mechanism ha…
Hidden attractors in dynamical models of phase-locked loop circuits : limitations of simulation in MATLAB and SPICE
2017
During recent years it has been shown that hidden oscillations, whose basin of attraction does not overlap with small neighborhoods of equilibria, may significantly complicate simulation of dynamical models, lead to unreliable results and wrong conclusions, and cause serious damage in drilling systems, aircrafts control systems, electromechanical systems, and other applications. This article provides a survey of various phase-locked loop based circuits (used in satellite navigation systems, optical, and digital communication), where such difficulties take place in MATLAB and SPICE. Considered examples can be used for testing other phase-locked loop based circuits and simulation tools, and m…
Tīmekļa sistēmu lietotāju saskarnes testu automatizācijas ieviešana
2020
Bakalaura darbs apraksta lietotāja saskarnes testu automatizācijas ieviešanas procesu uzņēmumā, kas nodarbojas ar dažādu sistēmu izstrādi, izmantojot GWT-Ext un Angular tīmekļa lietotnes ietvarus. Ieviešanas process sākas ar iniciatīvu un nepieciešamības argumentāciju, tad tiek izvēlēti testi, kas tiks automatizēti un ar kādiem rīkiem tas tiks darīts. Kad šie uzdevumi ir izdarīti, tad sākas implementācijas posms un ieguvumu salīdzināšana pret ieguldītajiem resursiem. Šis darbs apraksta autores pieredzi visos ieviešanas posmos.
Analogical reasoning performance and organization is influenced by the type of semantic distractors : an investigation with adults
2015
International audience; The way participants adapt their search to the specifics of different types of analogies is not fully understood. We compared the effects of two types of semantic distractors. The first were related to C by a semantic relation which had nothing to do with the semantic relation used in the A:B pairs, whereas the second, the so-called "double distractors", were not only related to C but also had a semantic relation similar to the one linking A to B. We used eye-tracking measurements in addition to reaction time and performance indices. We found that performance decreased, and that the solution set was less explored visually with the double distractors than with the for…
Attracting sets in a deterministic discrete traffic model
2001
The fundamental diagram of the Nagel-Schreckenberg traffic model is derived analytically for the deterministic case using methods and concepts from nonlinear dynamics. It is shown that the possible states of the long-term behaviour form a globally attractive subset which can be well characterized. This attractive set of states is composed of coexisting attractors. The attractor concept is applied to a slow-to-start extension of the model. For this example it is shown that the attractive set consists of coexisting attractors with different macroscopic properties, that can be determined analytically.
TRACLAS: a project to improve under canopy tractor safety in case of overturning
2018
Poster Abstract non previsto
Risk exposure to vibration and noise in the use of tracklaying tractors
2014
Human exposure to mechanical vibration may represent a significant risk factor for exposed workers in the agricultural sector, with particular reference to the operators driving tractors. Also noise in agriculture is one of the risk factors to be taken into account for the evaluation of workers health and safety. In particular, one of the major sources of discomfort for the workers operating a tractor is the noise to which they are subjected during work. In Italy, Law Decree 81/2008 has defined the obligations of vibration and noise assessment and risk management.The aim of this study is to evaluate the risk of exposure to whole-body vibration for the operator driving a tracklaying tractor …