Comparing with traditional fixed formation for a group of dynamical systems, time-varying formation can produce the following benefits: i) covering the greater part of complex environments; ii) collision avoidance. This paper studies the time-varying formation tracking for multiple manipulator systems (MMSs) under fixed and switching directed graphs with a dynamic leader, whose acceleration can...

Algebraic methods in connection with classical multidimensional geometry have proven to be very efficient in the computation of direct and inverse kinematics of mechanisms as well as the explanation of strange, pathological behavior. In this paper we give an overview of the results achieved within the last years using the algebraic geometric method, geometric preprocessing and numerical analysi...

Two process tracing studies investigated how the information acquisition process in a binary choice task is influenced by the overall level of attractiveness of alternatives, by the magnitude of differences in attractiveness of alternatives, and by the dominance of one alternative. All three factors influenced the subjects’ information selection process regarding the multiattribute choice alter...

This paper deals with the inverse dynamics problem of underactuated mechanical systems subjected to execute partly specified motions. The modeling methodology focuses on a special class of differentially flat systems, represented by a group of relevant technical examples. The governing equations are obtained as index three differential-algebraic equations, and a simple numerical code for their ...

Rock anisotropy plays an important role in engineering behavior of rocks. Slates are anisotropic rocks which have long been used for gable roof, floor tiles, borrow materials, and other purposes. The slates studied in this research are calcareous and have a porphyro-lepidoblastic texture. To determine the role of the anisotropy on the tensile strength and fracture pattern, two variables includi...

offshore pipelines are an effective tool for transportation of oil and gas which are usually assembled by the use of girth welds. since flaws may naturally exist at such welds, fracture assessment of girth welded offshore pipelines is substantial. current fracture assessment procedures like bs 7910 consider identical material properties for the weld and the base metals. however the strength dif...

Whereas considerable interest exists in self-assembly of well-ordered, porous "inverse opal" structures for optical, electronic, and (bio)chemical applications, uncontrolled defect formation has limited the scale-up and practicality of such approaches. Here we demonstrate a new method for assembling highly ordered, crack-free inverse opal films over a centimeter scale. Multilayered composite co...

the inverse problem of identifying an unknown source control param- eter in a semilinear parabolic equation under an integral overdetermina- tion condition is considered. the series pattern solution of the proposed problem is obtained by using the weighted homotopy analysis method (wham). a description of the method for solving the problem and nding the unknown parameter is derived. finally, tw...

We have carried out systematic fracture experiments in a single edge notch geometry over a range of stretch rates on dual crosslink hydrogels made from polyvinyl alcohol chains chemically crosslinked with glutaraldehyde and physically crosslinked with borate ions. If the energy release rate necessary for crack propagation was calculated conventionally, by using the work done to deform the sampl...

INTRODUCTION Given the importance of fracture healing on patient outcome in clinical practice, it is critical to assess fracture healing. AIM The aim of this study was to evaluate the feasibility of the Radiographic Union Score Hip fracture after treatment with intramedullary nail of stable hip fractures. PATIENTS AND METHODS We retrospectively collected the data from the clinical records o...