Hybrid Command Issuing in a 2-Dof Servomechanism Operated Under Vision-Based Feedback Control

This paper presents a new method for generating motion commands in a 2 degree-of-freedom (DOF) vision-based position control system. The control system uses a fixed digital camera to direct-observe the multi-dimensional position of a known target displayed on an Liquid Cristal Display (LCD) and determines the position of the tool based on this information. This system, implemented on an XY-stage, was first introduced in Wong [1], and further investigated in Montes & Ziegert [2] and Montes et al. [3]. Previous results demonstrated sensor resolutions on the order of 3 µm; however the resolution of motion commands was constrained to values on the order of hundreds of microns due to the physical characteristics of the LCD picture elements (or pixels). The new method presented here overcomes this constraint and allows generation of motion commands as small as 3 µm. Simulation results are provided

Vision-based tracking of a dynamic target with application to multi-axis position control

Two sub-pixel resolution approaches to measure in-plane displacements and in-plane rotation of a known target, through image processing, are described in this research. A dynamic known target is displayed on a pixel grid, which is attached to one end of the kinematic chain of an XYθZ stage; the latter represents the experimental testbed. At the other end of the kinematic chain, a digital monochrome camera is fixed to the bottom of the stage and provides 3D position information used as the feedback signal to the vision-based control system in charge of the tool’s motion. The illuminated pixels on the display are captured in real time by the digital camera, and the stage motion control system attempts to keep the displayed image in the proper location with respect to the camera image plane. The result is a direct sensing multi-DOF position feedback system. The proposed camera-pixel grid sensing setup eliminates the reliance on the kinematic model and also avoids the need for traditional error compensation techniques, along with their associated cost and complexity. Positioning resolutions on the order of 1/100th of the pixel size on the display are achieved

Deformation machining systems and methods

The present invention relates generally to deformation machining systems and methods that combine, in a single machine tool setup, the machining of thin structures and single point incremental forming (SPIF), such that novel part geometries and enhanced material properties may be obtained that are not achievable using conventional machining or forming systems and methods, individually or collectively. Important to many applications, lighter weight parts may be produced at lower cost using a conventional 3-axis computer numerically controlled (CNC) machine tool or the like, instead of the conventional 5-axis CNC machine tool or the like that is typically required

Dynamic Delegation: Shared, Hierarchical, and Deindividualized Leadership in Extreme Action Teams

This paper examines the leadership of extreme action teams—teams whose highly skilled members cooperate to perform urgent, unpredictable, interdependent, and highly consequential tasks while simultaneously coping with frequent changes in team composition and training their teams\u27 novice members. Our qualitative investigation of the leadership of extreme action medical teams in an emergency trauma center revealed a hierarchical, deindividualized system of shared leadership. At the heart of this system is dynamic delegation: senior leaders\u27 rapid and repeated delegation of the active leadership role to and withdrawal of the active leadership role from more junior leaders of the team. Our findings suggest that dynamic delegation enhances extreme action teams\u27 ability to perform reliably while also building their novice team members\u27 skills. We highlight the contingencies that guide senior leaders\u27 delegation and withdrawal of the active leadership role, as well as the values and structures that motivate and enable the shared, ongoing practice of dynamic delegation. Further, we suggest that extreme action teams and other “improvisational” organizational units may achieve swift coordination and reliable performance by melding hierarchical and bureaucratic role-based structures with flexibility-enhancing processes. The insights emerging from our findings at once extend and challenge prior leadership theory and research, paving the way for further theory development and research on team leadership in dynamic settings

Maintaining families' well-being in everyday life

The aim of this paper is to discuss how everyday life changes for the family in the event of chronic illness or disability. It changes physically due to loss of body function and socially due to time and other constraints related to treatment or lack of mobility. Equally important, there is a psychological impact due to the uncertainty of the future. The article will explore how family participation can help to maintain well-being in everyday life. The family should therefore focus on their own needs as much as on the needs of the family members who are ill. In order to maintain well-being in everyday life, it is crucial for the family to create routines and spend time doing things that they enjoy. By doing this, the family will create a rhythm of well-being regardless of the critical family situation. Family members and professional caregivers also need to come together at the beginning and during the illness or disability event to discuss changes that could be made day-to-day for all those involved, thereby making for an easier transition into care giving

Honeycomb Structures for High Shear Flexure

The present invention provides an improved shear band for use in non-pneumatic tires, pneumatic tires, and other technologies. The improved shear band is uniquely constructed of honeycomb shaped units that can replace the elastomeric continuum materials such as natural or synthetic rubber or polyurethane that are typically used. In particular, honeycomb structures made of high modulus materials such as metals or polycarbonates are used that provide the desired shear strains and shear modulus when subjected to stress. When used in tire construction, improvements in rolling resistance can be obtained because of less mass being deformed and reduced hysteresis provided by these materials. The resulting mass of the shear band is greatly reduced if using low density materials. Higher density materials can be used (such as metals) without increasing mass while utilizing their characteristic low energy loss

Direct Neutron Capture for Magic-Shell Nuclei

In neutron capture for magic--shell nuclei the direct reaction mechanism can be important and may even dominate. As an example we investigated the reaction $^{48}$Ca(n,$\gamma)^{49}$Ca for projectile energies below 250\,keV in a direct capture model using the folding procedure for optical and bound state potentials. The obtained theoretical cross sections are in agreement with the experimental data showing the dominance of the direct reaction mechanism in this case. The above method was also used to calculate the cross section for $^{50}$Ca(n,$\gamma)^{51}$Ca.Comment: REVTeX, 7 pages plus 3 uuencoded figures, the complete uuencoded postscript file is available at ftp://is1.kph.tuwien.ac.at/pub/ohu/calcium.u

Hierarchical multi-class segmentation of glioma images using networks with multi-level activation function

For many segmentation tasks, especially for the biomedical image, the topological prior is vital information which is useful to exploit. The containment/nesting is a typical inter-class geometric relationship. In the MICCAI Brain tumor segmentation challenge, with its three hierarchically nested classes 'whole tumor', 'tumor core', 'active tumor', the nested classes relationship is introduced into the 3D-residual-Unet architecture. The network comprises a context aggregation pathway and a localization pathway, which encodes increasingly abstract representation of the input as going deeper into the network, and then recombines these representations with shallower features to precisely localize the interest domain via a localization path. The nested-class-prior is combined by proposing the multi-class activation function and its corresponding loss function. The model is trained on the training dataset of Brats2018, and 20% of the dataset is regarded as the validation dataset to determine parameters. When the parameters are fixed, we retrain the model on the whole training dataset. The performance achieved on the validation leaderboard is 86%, 77% and 72% Dice scores for the whole tumor, enhancing tumor and tumor core classes without relying on ensembles or complicated post-processing steps. Based on the same start-of-the-art network architecture, the accuracy of nested-class (enhancing tumor) is reasonably improved from 69% to 72% compared with the traditional Softmax-based method which blind to topological prior.Comment: 12pages first versio