Neurocognitive dynamics of translating information from a spatial map into action

EEG correlates of spatial orientation in the human retrosplenial complex

Considering the crucial role of morality in shaping one's reputation, exploring factors that modulate people's decision to share morally salient news is important. Previous studies suggested that self-expression and socializing are 2 key factors for news-sharing behaviors, suggesting the key role of anonymity in such decisions. Using functional magnetic resonance imaging (fMRI) and transcranial direct current stimulation (tDCS), the present study focused on how anonymity modulates the sharing of morally salient information, as well as its neural mechanisms. Results showed that compared to moral news, people were more reluctant to share immoral news, especially when they share it with their real names shown. On the neural level, we found that this effect was associated with the activity of the left temporoparietal junction (TPJ), as well as its functional connection to its right counterpart. Dynamic causal modeling analysis revealed the moral valence of news and the anonymity of sharing modulated the effective connectivity between the left TPJ and the middle frontal gyrus as well as the medial frontal gyrus. There was no significant difference when sharing news anonymously. Further, a followed-up tDCS experiment supported the causal role of the left TPJ in this behavioral effect. Taken together, these results suggested that people concern more about social repercussion, when they share the news with their real-names shown, especially when sharing immoral news, and this effect is associated with stronger neural activation in the left TPJ, as well as changes in its functional connectivity with other brain regions.

Differences in behavioral and cortical indices in pianists and non-musicians during a non-musical motor planning task: An event-related potential study

The rotational properties of a light beam are controlled by its spin and orbital angular momentum (SAM and OAM). The q-plate, a liquid crystal device that can give rise to a coupling of these two quantities, was introduced a few years ago, leading to several applications in classical and quantum photonics. Very recently, in particular, a specific kind of q-plate was used to generate rotational-invariant states of single photons, which were then employed for performing a demonstration of quantum key distribution without the need for establishing a common reference frame between the transmitting and the receiving units. This result may find applications in future satellite-based quantum communication. By a similar approach, photonic states having a strongly enhanced rotational sensitivity, as opposed to rotational invariance, can be generated by using q-plates with very high topological charge. Photons in these states can be obtained starting from light having a uniform linear polarization and, after a physical rotation, can be converted back into light having uniformly linear polarization. As a result, one obtains linearly polarized light whose polarization plane rotates by an angle that is proportional to the angle of physical rotation between the generation and detection stages, with a very large proportionality constant. This effect of rotational amplification, which we named “photonic gear”, leads to a sort of “super-resolved Malus’ law”, potentially useful for measuring mechanical angles with very high precision.

PurposeThe purpose of this paper is to investigate the use of a laser tracker, a laser interferometer system and a telescopic ballbar for assessing the positioning performance of a six‐axis industrial serial robot. The paper also aims to illustrate the limitations of these three metrology instruments for the assessment of robot positioning performance and to demonstrate the inadequacy of simplistic performance tests.Design/methodology/approachSpecific test methods in the case of the laser interferometer system and the telescopic ballbar are proposed. Measurements are analyzed in accordance to the ISO 9283 norm.FindingsIt is found that, in static conditions and after a relatively short warm‐up, the unidirectional position repeatability of the non‐calibrated industrial robot under study (an ABB IRB 1600) is better than 37 μm, the unidirectional orientation repeatability is at worst 87 μrad, the linear position accuracy is better than 650 μm, and the rotation accuracy is at worst 2.8 mrad (mainly because of the sixth robot axis). It was also found that the dynamic (radial) errors due to vibrations can be up to approximately ±250 μm along a small circular path at TCP speed of 700 mm/s.Practical implicationsIt is pointed out that the use of a laser tracker (or any other large range portable 3D measurement system) is questionable for assessing – let alone analyzing in depth – the unidirectional position repeatability of some of today's industrial robots. It is also demonstrated that the laser interferometer system can be used for measuring linear errors along a linear path of motion as well as angular errors about axes orthogonal to the path of motion. Finally, it is shown that the telescopic ballbar is an excellent, comparably low‐cost, high‐precision tool for assessing the static and dynamic positioning performance of industrial robots and its use in robotics should be further developed.Originality/valueThis work is the first to detail the use of three metrology equipments for assessing the positioning performance of an industrial robot. Experimental results are presented and discussed. Some guidelines for optimizing the positioning performance of an industrial robot are provided.

Extending arterial stiffness assessment along the circumference using beam-steered ARFI and wave-tracking: A proof-of-principle study in phantoms and ex vivo

Revisiting the computation of the critical points of the Keplerian distance Authors: Giovanni F. Gronchi, Giulio Baù, Clara Grassi We consider the Keplerian distance d in the case of two elliptic orbits, i.e., the distance between one point on the first ellipse and one point on the second one, assuming they have a common focus. The absolute minimum d_min of this function, called MOID or orbit distance in the literature, is relevant to detect possible impacts between two objects following approximately these elliptic trajectories. We revisit and compare two different approaches to compute the critical points of d^2, where we squared the distance d to include crossing points among the critical ones. One approach uses trigonometric polynomials, and the other uses ordinary polynomials. A new way to test the reliability of the computation of d_min is introduced, based on optimal estimates that can be found in the literature. The planar case is also discussed: in this case, we present an estimate for the maximal number of critical points of d^2, together with a conjecture supported by numerical tests. Mars orientation and rotation angles Authors: Marie Yseboodt, Rose-Marie Baland, Sébastien Le Maistre The rotation and orientation of Mars is commonly described using two different sets of angles, namely (1) the Euler angles with respect to the Mars orbit plane and (2) the right ascension, declination, and prime meridian location angles with respect to the Earth equator at J2000 (as adopted by the IAU). We propose a formulation for both these sets of angles, which consists of the sum of a second degree polynomial and of periodic and Poisson series. Such a formulation is shown here to enable accurate (and physically sound) transformation from one set of angles to the other. The transformation formulas are provided and discussed in this paper. In particular, we point that the quadratic and Poisson terms are key ingredients to reach a transformation precision of 0.1 mas, even 30 years away from the reference epoch of the rotation model (e.g., J2000). Such a precision is required to accurately determine the smaller and smaller geophysical signals observed in the high-accuracy data acquired from the surface of Mars. In addition, we present good practices to build an accurate Martian rotation model over a long time span (30 years around J2000) or over a shorter one (e.g., lifetime of a space mission). We recommend to consider the J2000 mean orbit of Mars as the reference plane for Euler angles. An accurate rotation model should make use of up-to-date models for the rigid (this study) and liquid (Le Maistre et al., 2023) nutations, relativistic corrections in rotation (Baland et al. 2023), and polar motion induced by the external torque (this study). Our transformation model and recommendations can be used to define the future IAU solution for the rotation and orientation of Mars using right ascension, declination, and prime meridian location. In particular, thanks to its quadratic terms, our transformation model does not introduce arbitrary and non-physical terms of very long period and large amplitudes, thus providing unbiased values of the rates and epoch values of the angles.

The dynamic model of a spatial flexible manipulator is challenging to establish accurately and is susceptible to disturbances from uncertainties, which negatively impact system control. To mitigate the effects of uncertainties and improve control precision, this paper develops the dynamic model of a spatial flexible manipulator system using the Lagrange principle and the assumed mode method. Additionally, to address the chattering issue in sliding mode control, a super-twisting algorithm sliding mode control strategy is proposed, which utilizes an RBF neural network to compensate for system uncertainties. By incorporating the concept of higher-order sliding mode, the super-twisting algorithm sliding mode is integrated with non-singular terminal sliding mode to design the sliding surface and control law, ensuring the stable and rapid convergence of the system state while reducing chattering. The simulation results demonstrate that the proposed strategy reduces fluctuations in rotation angle and angular velocity errors at both the input and output ends, enhances trajectory tracking performance, and achieves effective chattering suppression.

Summary In multi-component seismic exploration projects that use ocean bottom nodes as recording instrument, the attitude correction of nodes is a crucial step. The process can be roughly described as recording the deviation angles of nodes in three mutually perpendicular directions (Pitch, Roll, Azimuth), and then apply this angle to the node data to complete the correction. The traditional correction method uses Euler Angle for data rotation, but this method has its own limitations in the algorithm and there is room for optimization of the operation efficiency. Based on the theoretical analysis of the traditional Euler Angle method, this essay introduces the feasibility of applying the quaternion method to the rotation of multi-component seismic data, and further compares the effects of these two methods in effect, algorithm efficiency and rotation accuracy, and finally summarizes the application prospect of the quaternion method in the future.

Common neural activations of creativity and exploration: A meta-analysis of task-based fMRI studies.

Complex virtual reality (VR) tasks, like 3D solid modelling, are challenging with standard input controllers. We propose exploiting the affordances and input capabilities when using a 3D-tracked multi-touch tablet in an immersive VR environment. Observations gained during semi-structured interviews with general users, and those experienced with 3D software, are used to define a set of design dimensions and guidelines. These are used to develop a vocabulary of interaction techniques to demonstrate how a tablet's precise touch input capability, physical shape, metaphorical associations, and natural compatibility with barehand mid-air input can be used in VR. For example, transforming objects with touch input, "cutting" objects by using the tablet as a physical "knife", navigating in 3D by using the tablet as a viewport, and triggering commands by interleaving bare-hand input around the tablet. Key aspects of the vocabulary are evaluated with users, with results validating the approach.

Background Setting the angle of tip rotation is of utmost importance in achieving satisfactory results in rhinoplasty. Conventionally the upward rotation of the tip requires shortening of the septum by caudal resection and shortening of the lateral walls by cephalic trim of the alar cartilages. The results are usually assessed subjectively. We describe the use of objective parameters to ensure accuracy of nasal tip rotation in patients operated with “cock-up” alar cartilage flaps, a modification of the cephalic trim. Methods Fifteen patients with a long nose having adequate width of lateral crura, desiring a shorter nose with upward tip rotation, were included in the study. Values of preoperative and desired nasolabial angle (from morphed images), and the derived columellar–labial angle were documented. Nasal tip rotation was set to the derived angle and maintained using cock-up alar cartilage flaps. The outcome was evaluated by digital measurements of the nasolabial angle and patients’ feedback by Rhinoplasty Outcome Evaluation (ROE) score. Results Satisfactory tip rotation and an aesthetic supratip area could be achieved. The difference in preoperative and postoperative nasolabial angles was statistically significant (p value < 0.0001). The difference in desired and the obtained nasolabial angle was not significant (p value 0.085). The results were maintained on subsequent follow-up. Conclusion Application of angles in practice and use of K-wire template helps us achieve accurate and consistent results. Cock-up flap is an effective technique—to obtain an open nasolabial angle and a desirable supratip region by making use of tissues otherwise discarded.

Functional and radiological outcomes of computer-assisted and handheld robotic total knee arthroplasty: A prospective randomised study.

Validation of 3D surface reconstruction of vertebrae and spinal column using 3D ultrasound data – A pilot study

Error analyses of Euler angle transformations arise in the design of precision pointing systems, guidance systems and other systems containing gimbals. The generalized problem, including nonorthogonality of nominally orthogonal coordinate axes as well as errors in the Euler angles, is treated. The usual approach by tedious matrix techniques is simplified to yield a vector solution by application of a similarity transformation to the skew- symmetric error matrices. A vector solution is obtained directly by invoking the vector property of infinitesimal rotations. Piograms, symbolic representations of Euler angle transformations, are used to formulate the problem and to develop the vector solution. EQUENCES of angular rotations are universally used in the analysis of rigid-body dynamics. Examples can be widely found in analysis of precision pointing systems and aircraft, missiles, and space vehicles. As shown by Euler, a minimum of three rotations are required to specify the relative orientation of two orthogonal coordinate systems with arbitrary attitudes. Any physical realization of coordinate transformations, as with gimbals, for example, will introduce angular errors so that each coordinate axis is perturbed from its idealized position. The most general error analysis of an Euler angle sequence must include the effects of nonorthogonal ity of the nominally orthogonal coordinate axes as well as errors in the angles of rotation. An example problem is presented to illustrate the various approaches available for error analysis of an Euler angle sequence. The usual but tedious solution by matrix techniques is given, A vector solution is obtained by applying a similarity transformation to the matrix solution. In a second approach a vector solution to the problem is obtained directly by invoking the vector property of infinitesimal rotations. Piograms, symbolic representations of rotational coordinate transformations,1'2 are used to define the problem and are shown to give the vector solution in a particularly compact way. Three different Euler angle sequences are commonly used in the literature. One of these three is used as the example problem in this paper. The method of solution presented in the paper is applicable to any of the twelve possible three-angle Euler sequences. The method is applicable to rotational sequences of any length by an obvious extension of the technique.