and error compensation

Top PDF and error compensation:

Compliance error compensation in robotic-based milling

Compliance error compensation in robotic-based milling

It should be noted that the part of the trajectory while machining tool is engaging into the workpiece does not have effect on the quality of final product (surface). Dur- ing this stage the contact area between the tool and the workpiece is increasing pro- gressively. Hence, at each instant of processing the cutter corrects the machining pro- file and eliminates trajectory errors produced during all previous instants. On the con- trary, during the stage of machining with the fully engaged tool the trajectory in x,y- directions define directly the final machining profile and this part of trajectory is ana- lyzed here (Fig. 15). Comparison results presented in Fig. 13 and Fig. 15 are summa- rized in Table 2. So after applying error compensation technique the static deviation in y direction has been reduced from 0.058 mm to 0.00014 mm (99.8%). Maximum defilation in the machining profile has been reduced from 0.063 mm to 0.0047 mm (92.6%). Low frequency remained the same for both cases.
En savoir plus

19 En savoir plus

Compliance error compensation technique for parallel robots composed of non-perfect serial chains

Compliance error compensation technique for parallel robots composed of non-perfect serial chains

For the geometrical errors, relevant compensation techniques are already well developed. A comprehensive review of related works is given in [2, 9, 17]. Here, if the main error sources are concentrated in the link length or in the joint offsets, the compensation is reduced to straightforward modification of the manipulator parameters in the robot controller. Otherwise, if there are any geometrical error sources that are not presented in the nominal inverse/direct kinematics, relevant modification of the controller input is required. In this case, it is possible to use (in off-line mode) either extended geometrical model with additional parameters or simply a non-linear function that describes the error distribution throughout the workspace. Examples of such a function are given in [18, 19] where the neural network technique is employed. In this framework , it is assumed that the geometrical errors are less essential compared to the non-geometrical ones caused by the interaction between the machining tool and workpiece. So, the main attention will be paid to the compliance errors and their compensation techniques.
En savoir plus

13 En savoir plus

Pose error compensation for performance-oriented view planning

Pose error compensation for performance-oriented view planning

Copyright 2004 by National Research Council of Canada Permission is granted to quote short excerpts and to reproduce figures and tables from this report, provided that the source of such[r]

15 En savoir plus

Compensation in Collaborative Editing

Compensation in Collaborative Editing

Abstract: In order to support users to recover from erroneous changes or to explore previously executed modifications, editing systems require an undo mechanism. In collaborative editors, users are allowed to revert any changes performed by any user, anytime. Operational transformation has been devised as a suitable mechanism for maintaining consistency in collaborative editing systems. Therefore, in this paper we present a novel undo approach in the context of operational trans- formation mechanism. Our approach is based on the notion of compensation used in databases where compensating operations semantically undo other operations. Moreover, our compensation mechanism is less restraining than any undo approaches and is generic in the sense that it can be used in association with any existing operational transformation algorithm.
En savoir plus

21 En savoir plus

Réparer le vivant : éthique de la compensation

Réparer le vivant : éthique de la compensation

L’expérience démontre que la réussite d’un projet d’aménagement tient à son acceptabilité sociale locale 33 . Le lien spatial entre les mesures compensatoires et le site endommagé invite à développer une approche territoriale, qui pourrait notamment trouver place au sein des documents de planification locaux 34 . Les populations impactées doivent connaître les pertes que l’infrastructure va occasionner (en termes de paysage, de milieux naturels, de surfaces arables…) et quels gains leur sont promis en retour 35 . Des auteurs parlent d’un « contrat compensatoire » 36 qui embrasserait le système territorial dans ses multiples composantes. Ainsi la compensation ne serait pas l’affaire de quelques uns (administration, techniciens de l’environnement, de l’agriculture…), mais de tous les acteurs du territoire (collectivités, conservatoires, SAFER, syndicats professionnels, associations, Direction départementale des territoires…), tenus de s’entendre et de coopérer 37 . Cette approche intégrée et négociée peut sembler manquer de rigueur scientifique. Elle est pourtant, sur un plan démocratique, la seule qui permette de dépasser l’opposition stérile entre nature et culture, entre développement et conservation.
En savoir plus

8 En savoir plus

Pollution, décès prématuré et compensation

Pollution, décès prématuré et compensation

L’objectif de cette étude est d’analyser la compensation des victimes de la pollution. Comme cela a été discuté antérieurement (Fleurbaey et Pon- thiere 2013, Fleurbaey et al 2014a), la compensation des personnes disparues prématurément semble, à première vue, impossible. Ex ante, il est di¢ cile d’identi…er les personnes qui connaitront un décès prématuré, tandis qu’ex post (une fois la durée de vie révélée), il est trop tard pour les compenser. Malgré ces di¢ cultés, ces travaux ont montré qu’il était possible de minimiser les écarts de bien-être entre les individus à vie courte et à vie longue. A cette …n, l’optimum égalitarien ex post implique des pro…ls de consommation décroissants avec l’âge, voire un report de l’âge de départ à la retraite (Fleurbaey et al 2014b).
En savoir plus

17 En savoir plus

COMPENSATION MEASURES IN BULGARIA

COMPENSATION MEASURES IN BULGARIA

In other case (Decision No. 11209 of 13 September 2012) concerning the authorization of investment project in the extraction industry of gold the SEEC has provided its positive opinion on the report of assessment on the effects on the environment which has been followed by the Ministry of Environment and the Water. This decision has been brought in action by a coalition of NGOs with scope of activity in the field of the environment. The latter have pretended that the decision approving the report has not been grounded and as a result has to be declared null and void. As regards of the compensation measures proposed and described in the report the SAC has found out that they are proportionate vis-à-vis the potential risks for the environment. Nevertheless in its analysis the SAC underlined that the administrative body in charge has operational independence when adopting the report and it has the discretionary power as regards to its considerations. This suggests certain legal uncertaintyfor investors and applicants when the administrative body assesses the compensation measures. This would not be such an issue but at present there are no official guidelines issued by the government on how the compensation measures should be applied and whether they meet the environmental criteria.
En savoir plus

17 En savoir plus

La compensation obligatoire des dérivés CDS

La compensation obligatoire des dérivés CDS

En théorie, l’architecture idéale pour un réseau de chambres de compensation serait un réseau en étoile, où une chambre de compensation unique viendrait compenser toutes les transactions. Cette structure permettrait en effet d’intégrer au mieux les avantages d’une chambre de compensation unique, notamment les économies d’échelle dans l’analyse du risque et un meilleur calcul du collatéral par une connaissance exhaustive des positions de ses membres. Les études théoriques, dans leur calcul sur le nombre idéal de chambres de compensation, laissent cependant de côté les modalités de fonctionnement d’une chambre de compensation. Dans la pratique, même lorsqu’une grande chambre de compensation semble être en position dominante, elle segmente ses marchés, c’est-à-dire qu’elle sépare ses activités sur les différents actifs ou dérivés. Ainsi, les obligations « fixed income » et les CDS adossés seront compensés dans des départements différents de la chambre. Ainsi, alors que l’on mettait en avant le netting des portefeuilles pour économiser du collatéral, il y a très peu de chance de le voir se généraliser. En effet, les modèles de calcul des risques seraient alors trop complexes et ils ne peuvent en pratique pas prendre en compte toutes les corrélations d’un portefeuille. A cela s’ajoute également un intérêt partagé par la plupart des acteurs du marché pour le cloisonnement, ayant pour but d’éviter la contagion entre des acteurs et actifs tout à fait hétérogènes.
En savoir plus

45 En savoir plus

Two routes toward compensation: An investigation into the mechanisms of compensation for high- and low-status groups

Two routes toward compensation: An investigation into the mechanisms of compensation for high- and low-status groups

SD=1.32) condition, F(1,44)=69.79, p<.0001, ŋ p 2 =.61. In sum, and in line with our hypothesis, the manipulation of affirmation only affected the judgments expressed by low-status groups and essentially on the warmth dimension. Although our experimental approach lead us to cast our predictions at the level of the means, we also wanted to explore patterns of compensation at the correlational level. Building upon earlier compensation work (Judd et al., 2005, Yzerbyt et al., 2005), we conjectured that compensation would manifest itself with a negative correlation between ingroup favoritism on competence and ingroup favoritism on warmth. We thus hoped to find this pattern of compensation for high-status group members as well as for low-status group members in the no-affirmation condition. In the affirmation, low-status, condition, we expected no correlation between the two kinds of favoritism. As a matter of fact, and corroborating the analyses on the mean ratings in a somewhat different way, a significant negative correlation confirmed the presence of compensation in all conditions (all rs>-.45) except for low-status groups who had the possibility to self-affirm (r=-.18, ns).
En savoir plus

44 En savoir plus

Direct and apparent compensation in plant-herbivore interactions

Direct and apparent compensation in plant-herbivore interactions

4.2. Phase plane diagrams To illustrate the dynamical behaviour produced by model (8) in the “Direct compensa- tion” and in the “Direct compensation and Resistance” cases, we computed typical phase plane diagrams in two specific cases producing bi-stable patterns (Figure 6). Bi-stability indicates that the long-term behaviour of the model is determined by a critical relationship between plants and herbivores densities at the onset of herbivory. Phase plane analysis helps to determine the conditions leading to one or the other long term behaviour. Figure 6 was obtained from fairly standard phase plane analysis methods that are not detailed any further. Figure 6 (a) figures case (iii), in which both the herbivore-free equilibrium and an over- compensation equilibrium are asymptotically stable, as simulated from the “Direct compen- sation” version of model (8). Other cases relevant to this model, ensuring either the existence and stability of the herbivore-free equilibrium alone (case (ii)) or of an undercompensation one (case (i)), are easily interpreted and thus do not require phase plane analyses. As for case (iii), Figure 6 (a) shows that if the initial herbivore density is large enough, it can trigger a sufficiently strong positive response of the plants, which can sustain a herbivore population in the long term and leads to plant-herbivore co-existence at an overcompensation equilib- rium (mutualistic interaction). If, however, the initial herbivore density is too small, the positive response of the plants is not strong enough to make it possible for the herbivores to survive; the latter are then doomed to extinction because of starvation.
En savoir plus

40 En savoir plus

Compensation génétique en pathologie humaine

Compensation génétique en pathologie humaine

rapporté par un groupe de cytogénéti- ciens français [3] . Le père d’une fillette atteinte de 22q11 DS, phénotypiquement normal, était porteur d’un double rema- niement : délétion 22q11 sur l’un de ses chromosomes 22 et duplication de la même région sur l’autre. Le phénotype normal s’explique par une compensation génétique qui a pu être prouvée par l’ex- pression - par PCR transcriptase inverse - de chacun des deux gènes TBX, visibles en FISH côte à côte sur le même chro- mosome 22 sur les mitoses et dans les noyaux en interphase. Cette observation atteste d’un mécanisme de compensa- tion génique dans une maladie humaine ; effet compensatoire qui a d’ailleurs été préalablement démontré dans un modèle murin sur la région homologue à 22q11.2
En savoir plus

1 En savoir plus

Which compensation for whom ?

Which compensation for whom ?

To reach our goal, we propose a simple model of an economy with two goods, a composite good and a natural resource. In this model, we determine which type of com- pensation the decision-maker may enforce the polluter to implement given the magnitude of the damage, the number and the characteristics of the prejudiced agents, and the cost associated with each compensation scheme. Since we do not introduce any incentives in our model (prevention, mitigation), we focus on accidental or unanticipated damages. Moreover, our model refers to marginal damages in the sense that they do not alter the agents’ preferences. For instance, these damages could be either an accidental release of hazardous-substance into the environment (soil or river) or unanticipated temporary damages to verges and footpaths due to road building processes. In these cases, ecological compensation could consist in replanting plants or restoring fish streams. To determine the optimal compensation scheme, the decision-maker pursues three goals:
En savoir plus

30 En savoir plus

Introduction : Entre compensation et accessibilité

Introduction : Entre compensation et accessibilité

Nous vivons ainsi comme le souligne Michel Serres une invention nouvelle, une nouvelle ère avec des changements de pratiques, voire de rapport aux savoirs, aussi conséquente que la découverte de l'imprimerie (Serres, 2012). Amadieu et Tricot soulignent également ce point de vue en indiquant que cette révolution est sans doute aussi importante que l'invention de l'écriture et celle de l'imprimerie. Comme ces deux précédentes inventions, l'informatique modifie profondément la façon dont nous diffusons, partageons et recherchons des informations, voire des connaissances (Amadieu et Tricot, 2014). Pour autant, s'il est évident que les outils numériques ont envahi le monde actuel quel que soit l'âge des usagers, il est peu fréquent de questionner, au delà des dimensions ingénieriques, l'effet de l'usage et l'intérêt d'une telle utilisation technologique. Les questions d’accessibilité et/ou de compensation pour les publics à besoins spécifiques, qu'ils soient jeunes ou âgés, sont quant à elles étudiées mais peu diffusées en dehors de la sphère scientifique. Nous voyons chez les âgés des plans d'équipement qui émanent des collectivités territoriales locales (une communauté de commune par exemple) permettant de les doter de tablettes, parfois de robots de téléprésence, ou encore d'outils d'assistance en ligne, sans pour autant questionner les domaines de savoir qu'ils sont supposés rendre plus accessibles. En fait l'entrée se fait généralement par la compensation des troubles d'autonomie ou d'apprentissage, pour les plus jeunes comme chez les personnes âgées, en faisant l'hypothèse qu'ils vont résoudre les problèmes d'activités ou les troubles cognitifs.
En savoir plus

7 En savoir plus

Error estimate and unfolding for periodic homogenization

Error estimate and unfolding for periodic homogenization

1. Introduction The error estimate in periodic homogenization problems was presented for the first time in Bensoussan, Lions and Papanicolaou [2]. It can also be found in Oleinik, Shamaev and Yosifian [8], and more recently in Cioranescu and Donato [5]. In all these books, the result is proved under the assumption that the correctors belong to W 1,∞ (Y ) (Y =]0, 1[ n being the reference cell). The estimate is of order ε 1/2 . The additional

16 En savoir plus

Registration and error estimation in correlated multimodal imaging

Registration and error estimation in correlated multimodal imaging

Guillaume Potier, L’unité de recherche de l’institut du thorax guillaume.potier@univ-nantes.fr 1. L'institut du thorax, INSERM, Nantes, France ; 2. Laboratoire de Mathématiques Jean Leray, Nantes, France ; 3. MicroPICell , SFR Santé Bonamy, Nantes, France Registration and error estimation in correlated multimodal imaging

2 En savoir plus

Minimal Observability and Privacy Preserving Compensation for Transactional Services

Minimal Observability and Privacy Preserving Compensation for Transactional Services

Making the graph a system is a little more involved. We use the graph G from Fig. 1. It then suffices to create a balanced binary tree of transitions with root s i , such that there are |E| leaves. This tree has O(2|E|) nodes, that we add to the system S we built from (V, E). The root of the tree is the unique initial node, and every leaf is connected to a node (e 1 ) e∈E through a copy of graph G. The same is done for nodes (e 2 ) e∈E connected through copies of G to a balanced binary tree with root s f (the unique final node). This system has O(|V | + |E|) nodes, is acyclic and of total degree 3. Now, it is easy to show that if the minimal vertex cover has k vertices, then the minimal compensable set of transitions is of size k + 4|E|. Indeed, there are 2|E| copies of the graph G each of which requires 2 visible transitions. Once these transitions have been deleted, the two balanced trees are totally disconnected from each other and from the first system we had built (since every path from the initial to the final node of the graph G uses one of the two visible transitions), and hence we need exactly k more transitions to be visible. Note that connecting directly the tree with S without using G would not work since it would potentially connect s 0 , s f through two different paths s 0 −→ e
En savoir plus

28 En savoir plus

Coherent multi-photon interference and compensation of polarization dispersion

Coherent multi-photon interference and compensation of polarization dispersion

The current theoretical understanding of the quantum interferometer is quite so- phisticated. It includes methods of representing states and visualizing the transfor- mations such as given in [87]. It is clear that the authors of these papers understood that quantum states can in principle display complex, qualitatively non-classical dy- namics. However, examples in the real world are hard to come by, due in part to decoherence e ects that we discuss in Chapters 4 and 6. The community has come to think of things semiclassically, so that now the suggestion of any e ect that is not semiclassical is seen as being very counter-intuitive. The untraditional perspec- tives that we discuss in this thesis try to present an intuitive way of understanding problems outside of the semiclassical regime. It remains to be seen whether these perspectives will ful ll their potential for uncovering new possibilities in real systems. The brief background that we have given above give some of the basic context of our problem. In Appendix A we outline some interesting related problems that may help motivate and clarify the scope of this research.
En savoir plus

233 En savoir plus

Cryptographic error correction

Cryptographic error correction

In our cryptographic construction of a coding scheme, the sender keeps a secret key, maintains some local state between each encoding, and the channel is assumed t[r]

71 En savoir plus

C language mechanism for error handling and deferred cleanup

C language mechanism for error handling and deferred cleanup

streams ( fopen , freopen ). Improper resource management and error handling frequently results in software vulnerabilities. They can result in denial-of- service (DoS) attacks which seek to prevent legitimate users from being able to access information systems, devices, or other network resources [ 3 ]. For example, if an attacker can identify an external action that causes memory to be allocated but not freed, memory can eventually be exhausted. Once memory is exhausted, additional allocations fail, and the application is unable to process valid user requests. Another variant of such erroneous resource management can be exploited in multi-threaded programs that use mutexes. By default, most systems have no provisions to cope with a mutex that is locked by a thread that exits. Other threads that try to access that same mutex will block, eventually causing a deadlock of the whole execution.
En savoir plus

4 En savoir plus

2019 — Nonlinear control and perturbation compensation in UAV quadrotor

2019 — Nonlinear control and perturbation compensation in UAV quadrotor

control (Kurode & Dixit, 2013; J. Mu et al., 2017; Slotine & Li, 1991; Xia et al., 2010; Youcef- Toumi & Ito, 1988), which is one of the most attractive control techniques, suffers from hard nonlinearities, unmodelled dynamics and external disturbance could reduce the performance. In (B. Mu, Zhang, & Shi, 2017) disturbance and uncertainties are reduced by an integral sliding mode flight controller incorporating reference angular signals and desired position information. Although it avoids output sensor noise and sensor accuracy problems, it does not incorporate the real states with control. In (Antonelli et al., 2017; Yoshimura, 2008), the robustness of the adaptive control is implemented to reduce external disturbance and uncertainty. In (Jia et al., 2017) an integral backstepping combined with sliding mode control is built to provide robustness to external disturbances. Nonlinear control systems, such as sliding mode control and backstepping are robust enough to reduce the effect of disturbances. However, they lack estimation and compensation of disturbances, mainly when disturbances are high. In our proposed system, an auxiliary approach is used to support the control by estimating and compensating all disturbances in order to provide higher rejection to disturbances and uncertainty. Furthermore, disturbance can be eliminated regardless of the control system used. In another approach (Yang, Cheng, Xia, & Yuan, 2017), a disturbance observer is used in a quadrotor system with a linear PD controller used in the outer loop, similar to (Zhou, Deng, Shi, & Zhong, 2017) where a cascade PID with a compensator is utilized. Anyway, a linear control applied to highly nonlinear system like the quadrotor does not guarantee robustness in all flying conditions. In (Jun Wang, Xin, & Zhang, 2017) a fuzzy logic controller FLC is designed to study the behavior of quadrotor subject to external disturbances. In spite of the advantages of FLC, it is still not robust to large disturbances variation.
En savoir plus

200 En savoir plus

Show all 10000 documents...