A systematic method is developed for the type synthesis of 4-DOF nonoverconstrained parallel mechanisms with three translations and one rotation inspired by the design of H-4. First, the motion requirements of primary platform and secondary platform of the 4-DOF nonoverconstrained parallel mechanisms are analyzed, and the conflict between the number of actuators and the constraint system for no...

Depth of field (DOF) is defined as the distance range within which objects are perceived as sharp. Previous research has focused on blur discrimination in artificial stimuli and natural photographs. The discrimination of DOF, however, has received less attention. Since DOF introduces blur which is related to distance in depth, many levels of blur are simultaneously present. As a consequence, it...

PURPOSE To investigate repositioning accuracy in particle radiotherapy in 6 degrees of freedom (DOF) and intensity-modulated radiotherapy (IMRT, 3 DOF) for two immobilization devices (Scotchcast masks vs thermoplastic head masks) currently in use at our institution for fractionated radiation therapy in head and neck cancer patients. METHODS AND MATERIALS Position verifications in patients tre...

In this paper a new procedure for type synthesis of low-DoF parallel robots based on screw theory is presented. The motivation of these work is that for many industrial applications, in particular in the machine-tool field, less than 6 degree of freedom (6-DoF) may be needed to complete the task. For example, for milling operation in the machine-tool domain, the rotation of the platform around ...

At ANSYS Workbench 11.0, the ANSYS Rigid Dynamics add-on module enables users to define joint connections in complex kinematic assemblies. This ability to model rigid and flexible parts in ANSYS Workbench Simulation via joints is beneficial since the rigid parts are modeled with mass and rigid links (that is, rigid contact elements), thus providing load transfer capabilities and allowing users ...

In this paper, dynamic equations of motion of a 5 DoF robot manipulator including mechanical arms with revolute joints and their electrical actuators are considered. The application of integrator backstepping technique for trajectory tracking in presence of parameters of uncertainty and disturbance is studied. The advantage of this control technique is that it imposes the desired properties of ...

Purpose: To measure the subjective depth of focus (DOF) in keratoconic eyes andcompare it to that of normal eyes. Methods: We measured the subjective DOF in two groups of subjects with a dual-Badal-channel optical system. The first group consisted of 10 normal subjects and the secondgroup consisted of 5 keratoconic subjects. We measured DOF of the normal subjectsunder conditions...

Important applications of single-particle tracking (SPT) aim at deciphering the diffusion properties single fluorescent nanoparticles immersed in heterogeneous environments, such as multi-cellular biological tissues. To maximize particle localization precision complex high numerical aperture objectives are often required, which intrinsically restrict depth-of-focus (DOF) to less than a micromet...

Application of haptic devices expanded to fields like virtual manufacturing, virtual assembly or medical simulations. Advances in development of haptic devices have resulted in a wide distribution of assymetric 6/3-DOF haptic devices. However, current haptic rendering algorithms work correctly only for symmetric devices. This thesis analyzes 3-DOF and 6-DOF haptic rendering algorithms and propo...