Search results for "Grasp"
showing 10 items of 84 documents
Metaheuristic procedures for the lexicographic bottleneck assembly line balancing problem
2015
The goal of this work is to develop an improved procedure for the solution of the lexicographic bottleneck variant of the assembly line balancing problem (LB-ALBP). The objective of the LB-ALBP is to minimize the workload of the most heavily loaded workstation, followed by the workload of the second most heavily loaded workstation and so on. This problem-recently introduced to the literature (Pastor, 2011)-has practical relevance to manufacturing facilities. We design, implement and fine-tune GRASP, tabu search (TS) and scatter search (SS) heuristics for the LB-ALBP and show that our procedures are able to obtain solutions of a quality that outperforms previous approaches. We rely on both s…
GRASP and tabu search for the generalized dispersion problem
2021
Abstract The problem of maximizing dispersion requires the selection of a specific number of elements from a given set, in such a way that the minimum distance between the pairs of selected elements is maximized. In recent years, this problem has received a lot of attention and has been solved with many complex heuristics. However, there is a recent variant in which the selected elements have to satisfy two realistic constraints, a minimum capacity limit and a maximum budget, which in spite of its practical significance in facility location, has received little attention. In this paper, we first propose mathematical models to obtain the optimal solution of small- and medium-size instances, …
Variable neighborhood descent for the incremental graph drawing
2017
Abstract Graphs are used to represent reality in several areas of knowledge. Drawings of graphs have many applications, from project scheduling to software diagrams. The main quality desired for drawings of graphs is readability, and crossing reduction is a fundamental aesthetic criterion for a good representation of a graph. In this paper we target the edge crossing reduction in the context of incremental graph drawing, in which we want to preserve the layout of a graph over successive drawings. We propose a hybrid method based on the GRASP (Greedy Randomized Adaptive Search Procedure) and VND (Variable Neighborhood Descent) methodologies and compare it with previous methods via simulation.
Effects of transcranial random noise stimulation combined with Graded Repetitive Arm Supplementary Program (GRASP) on motor rehabilitation of the upp…
2019
We evaluated the combined use of transcranial random noise stimulation (tRNS) with the Graded Repetitive Arm Supplementary Program (GRASP) in sub-acute ischemic stroke patients suffering from arm impairment. Eighteen ischemic stroke patients with upper limb disability were randomly assigned to either the GRASP + tRNS or GRASP + Sham stimulation group. Fugl-Meyer Assessment-Upper extremity (FMA-UE) was performed to evaluate upper limb impairment before treatment (T0), after the last stimulation (T1) and after 30 days (T2). At T1 and T2, beneficial effects in the tRNS group correlated with better FMA-UE score than sham stimulation group (p < 0.001) and these results did not correlate to st…
Neurostimulation and Reach-to-Grasp Function Recovery Following Acquired Brain Injury: Insight From Pre-clinical Rodent Models and Human Applications.
2020
Reach-to-grasp is an evolutionarily conserved motor function that is adversely impacted following stroke and traumatic brain injury (TBI). Non-invasive brain stimulation (NIBS) methods, such as transcranial magnetic stimulation and transcranial direct current stimulation, are promising tools that could enhance functional recovery of reach-to-grasp post-brain injury. Though the rodent literature provides a causal understanding of post-injury recovery mechanisms, it has had a limited impact on NIBS protocols in human research. The high degree of homology in reach-to-grasp circuitry between humans and rodents further implies that the application of NIBS to brain injury could be better informed…
La saisie esthétique, transformation non narrative de la subjectivité
2017
Abstract Post-Greimassian semiotics has worked toward a return to phenomenology, with the aim of studying the sensorial dimension and the body. Most of this research, however, has all but forgotten Greimas’s last book, De imperfection (1987), in which he proposes an original version of Merleau-Ponty’s philosophy with the notion of the aesthetic grasp. I propose to reconsider this almost abandoned notion, both from a theoretical point of view (a new version of the catharsis of philosophical aesthetics) and from the vantage of textual descriptions (the short story “The Naked Bosom” by Italo Calvino and the movie Ratatouille).
Adventures of Clinical Psychology
2021
Clinical psychology strives to fully grasp the person in his totality and in his individuality, helping him adequately address his own deep internal suffering and discomfort, social uneasiness, and harmonize his own needs, desires and, attachments [...]
Role of the feedforward command and reafferent information in the coordination of a passing prehension task.
1999
The performances of a deafferented patient and five control subjects have been studied during a self-driven passing task in which one hand has to grasp an object transported by the other hand and in a unimanual reach-to-grasp task. The kinematics of the reach and grasp components and the scaling of the grip aperture recorded for the self-driven passing task were very similar in controls and the deafferented subject (GL). In contrast, for the unimanual task when vision was absent, GL's coordination between reaching and grasping was delayed in space and time compared with the control subjects. In addition, frequent reopening of the grip was observed in GL during the final closure phase of the…
Influence of stimulus color on the control of reaching-grasping movements.
2001
This kinematic study aimed to determine whether color is a stimulus property involved in the control of reaching-grasping movements. Subjects reached and grasped a target-object, located either on the right or on the left of the subject's midline. A distractor, placed along the subject's midline, could be randomly presented. The colors, i.e., both chromaticity (red and green stimuli were presented) and lightness, of the target and distractor were varied in experiment 1. Only stimulus lightness and only stimulus chromaticity were varied in experiments 2 and 3, respectively. In experiment 4 subjects matched with their thumb and index finger the size of the target-stimuli presented in experime…
Visual distractors differentially interfere with the reaching and grasping components of prehension movements
1998
In the present study we addressed the issue of how an object is visually isolated from surrounding cues when a reaching-grasping (prehension) movement towards it is planned. Subjects were required to reach and grasp an object presented either alone or with a distractor. In five experiments, different degrees of elaboration of the distractor were induced by varying: (1) the position of the distractor (central or peripheral); (2) the time when the distractor was suppressed (immediately or delayed, with respect to stimulus presentation); and (3) the type of distractor analysis (implicit or explicit). In addition, we tested whether the possible effects of the distractor on reaching-grasping wer…