V-REP & ROS Testbed for Design, Test, and Tuning of a Quadrotor Vision Based Fuzzy Control System for Autonomous Landing

in Porceedings of The International Micro Air Vehicle Conference and Competition 2014 (2014, August)

This paper focuses on the use of the Virtual Robotics Experimental Platform (V-REP) and the Robotics Operative System (ROS) working in parallel for design, test, and tuning of a vision based control ... [more ▼]

This paper focuses on the use of the Virtual Robotics Experimental Platform (V-REP) and the Robotics Operative System (ROS) working in parallel for design, test, and tuning of a vision based control system to command an Unmanned Aerial Vehicle (UAV). Here, is presented how to configure the V-REP, and ROS to work in parallel, and how to use the developed packages in ROS for the pose estimation based on vision and for the design and use of a fuzzy logic control system. It is also shown in this paper a novel vision based fuzzy control approach for the autonomous landing task on a static and on a moving platform. The control system is based on four fuzzy logic controllers (FLC) working in parallel on an external control loop based on the visual information. All the controllers were designed and tuned to command the vertical, longitudinal, lateral, and heading velocities of the UAV. [less ▲]

V76D mutation in a conserved gD-crystallin region leads to dominant cataracts in mice.

in Mammalian Genome (2002), 13(8), 452-5

During a large-scale ENU mutagenesis screen, a mouse mutant with a dominant cataract was detected and referred to as Aey4. Aim of this study was the morphological description of the mutant, the mapping of ... [more ▼]

During a large-scale ENU mutagenesis screen, a mouse mutant with a dominant cataract was detected and referred to as Aey4. Aim of this study was the morphological description of the mutant, the mapping of the mutation, and the characterization of the underlying molecular lesion. The slit-lamp examination revealed a strong nuclear cataract surrounded by a homogeneous milky opacity in the inner cortex. The histological analysis demonstrated remnants of cell nuclei throughout the entire lens. The mutation was mapped to Chromosome 1 by a genome-wide linkage making the six gamma-crystallin encoding genes and the closely linked betaA2-crystallin encoding gene to relevant candidate genes. Finally, a T-->A exchange in exon 2 of the gammaD-crystallin encoding gene (symbol: Crygd) was demonstrated to be causative for the cataract phenotype; this particular mutation is, therefore, referred to Crygo(Aey4). The alteration in codon 76 leads to an amino acid exchange of Val-->Asp. Val at this position is highly conserved; it is found in all mouse and rat gammaD/E/F-crystallins as well as in the human gammaA- and gammaD-crystallins. It may be replaced solely by Ile, which is present in all bovine gamma-crystallins, in the rat and mouse gammaA/B/C-crystallins, as well as in the human gammaB/C-crystallins. It is predicted that the exchange of a hydrophobic side chain by a polar and acidic one might influence the microenvironment by a dramatic decrease of the isoelectric point by 1.5 pH units in the 10 amino acids surrounding position 76. The Crygd(Aey4) additionally demonstrates the importance of the integrity of the Cryg gene cluster for lens transparency. [less ▲]

Vacationing in the Cold War: Foreign Tourists to Socialist Romania and Francoist Spain, 1960s-1970s

Doctoral thesis (2016)

Vacuum-Healing of Grain Boundaries in Sodium-Doped CuInSe2 Solar Cell Absorbers

in Advanced Energy Materials (2023), 2204183

Vagally mediated heart rate variability is a predictor for the occurrence of the thermal grill-induced pain illusion

Poster (2014, October)

Aim: Unpleasantness and negative affect accompany the sensory experience of pain. Both components of pain are heavily influenced by cognitive and emotional processes. In this framework, alterations in ... [more ▼]

Aim: Unpleasantness and negative affect accompany the sensory experience of pain. Both components of pain are heavily influenced by cognitive and emotional processes. In this framework, alterations in baroreceptor reactivity and concomitant changes in cardiac rhythm and blood pressure related to these processes contribute to the modulation of pain sensitivity. Furthermore, self-regulatory capacity has been shown to play a major role in the regulation of cognitive, affective, and behavioural reactions to adverse contexts. These regulatory mechanisms include adjustment of cardiovascular activity and heavily depend on prefrontal cortical processing. Vagally mediated heart rate variability (HRV) at rest is an indicator of the prefrontally modulated vagal activation and has been used as a psychophysiological marker for self-regulatory capacity. The present study investigated the predictive value of the trait self-regulation in the triggering of the thermal grill-induced pain illusion (TGI). We hypothesized inter-individual differences in paradoxical pain perception to be predicted by self-regulatory capacity in a way that participants displaying lower levels of self-regulation should be more likely to perceive the painful grill illusion than subjects with relatively higher self-regulation ability. Methods: A total of 54 healthy participants were recruited among university students and staff. A custom-built, water-bath driven thermal grill device, with interlaced cold and warm glass tubes, was used for the induction of the TGI. A pre-set temperature combination of 15°C and 41°C was applied to the palm of the dominant hand with stimulus durations of 1 min. Subsequent control conditions consisted in the interlaced combination of a baseline temperature of 32°C with one of the stimulus temperatures mentioned above. The procedure was repeated three times. The volunteers used numerical rating scales ranging from 0-100 to rate sensory and affective pain perceptions in intervals of 15 seconds. Vagally mediated HRV at rest was assessed prior to the thermal stimulation protocols. Results: Time-domain components of HRV used as graded indicators of parasympathetic activity and of the extent of self-regulation significantly predicted the possibility of an occurrence of pain and unpleasantness sensations in response to thermal grill stimulation (p <.05). Participants characterized in this way were more likely to express paradoxical pain than subjects not displaying similar levels of HRV. Conclusion: The present results support previous findings indicating an impact of several psychological traits on the individual disposition to paradoxical pain perceptions. Self-regulation ability, operationalized as vagally mediated heart rate variability, can partially explain the probability of perceived pain in response to non-noxious thermal grill stimulation. [less ▲]

Vaguely mediated heart rate variability promotes the perception of paradoxical pain

in Journal of Psychophysiology (2016)

Self-regulation mechanisms are governed by prefrontal inhibitory processes and play a crucial role in the modulation of pain. In the present study the thermal grill paradigm was used to investigate the ... [more ▼]

Self-regulation mechanisms are governed by prefrontal inhibitory processes and play a crucial role in the modulation of pain. In the present study the thermal grill paradigm was used to investigate the association of vagally mediated resting heart rate variability, a psychophysiological marker of trait self-regulatory capacity, with paradoxical pain sensations induced by non-noxious stimulation. This thermal grill illusion is only perceived by part of the tested individuals. The mechanisms underlying the observed inter-individual differences in paradoxical pain sensitivity are largely unknown. During the experimental task, a temperature combination of 15° C and 41° C was set at the glass tubes of the thermal grill. The fifty-two healthy participants placed their dominant hand on the grill for a duration of one minute. The magnitude of sensory and affective pain sensations perceived during stimulation was assessed with numerical rating scales. Before stimulation, a short-term electrocardiogram was recorded to compute vagally mediated heart rate variability at rest. Logistic regression analyses revealed that participants with higher vagal tone were significantly more likely to perceive the thermal grill illusion than subjects displaying lower resting heart rate variability. Paradoxical pain sensations were primarily predicted by normalized respiratory sinus arrhythmia. Our results confirm that the magnitude of vagally mediated resting heart rate variability is associated with the individual disposition to illusive pain perceptions. Since the latter is considered to be a marker of trait self-regulation ability, the present findings may corroborate and complement previous evidence for an impact of psychological characteristics on paradoxical pain sensitivity. [less ▲]

Valence and Motivation as Predictors of Student Time Use in Everyday Life: An Experience Sampling Study

in FRONTIERS IN PSYCHOLOGY (2019), 10

Popular descriptions of studying frequency show remarkable discrepancies: students complain about their workload, and alumni describe freedom and pleasure. Unfortunately, empirical evidence on student ... [more ▼]

Popular descriptions of studying frequency show remarkable discrepancies: students complain about their workload, and alumni describe freedom and pleasure. Unfortunately, empirical evidence on student time use is sparse. To investigate time use and reveal contributing psychological factors, we conducted an e-diary study. One hundred fifty-four students reported their time use and valence hourly over 7 days, both at the start of the semester and during their examination period. Motivational problems, social support and self-control were assessed once via questionnaires. Whereas the mean academic time use was in the expected range, the between-subject differences were substantial. We used multilevel modeling to separately analyze the within- and between-subject associations of valence as within factor and time use and social support, self-control, and motivation as between factors and time use. The analyses revealed the importance of affective factors on a within-subject level. Before studying, valence was already low, and it deteriorated further during studying. As expected at the between-subject level, motivational problems were related to less time studying, whereas surprisingly, self-control had no effect. The findings at the start of the semester were replicated in the examination period. [less ▲]

Valenzbeurteilung und Persongedächtnis: Effekte der Urteilsqualität und des Verarbeitungsziels auf den Abruf von Personinformation.

Scientific Conference (2001, September)

Valery Larbaud et le journal de voyage intime

in Echappées littéraires en francophonie (2016)

Der Valfish. Jiddische Naturkunde im 19. Jahrhundert.

in Judaica: Beiträge zum Verstehen des Judentums (2010), 66