The friction and wear properties of polyamide 66 (PA66), polyphenylene sulfide (PPS) and polytetrafluoroethylene (PTFE) sliding against hemselves under dry sliding and oil-lubricated conditions were studied by using a pin-on-disc tribometer. The effect of applied load and sliding peed on tribological behaviors of the polymer–polymer sliding combinations under dry sliding and oil-lubricated cond...

This paper presents the dynamic modeling and fuzzy sliding mode control for rigid-flexible multibody systems. To investigate the dynamic stiffening of rigid-flexible systems, a firstorder approximate model of a flexible spacecraft system is formulated by using Hamilton’s principles and assumed mode method, taking into account the second-order term of the coupling deformation field. For highly f...

area display a striking variety. Ignoring many important differences among Western countries, Soviet orthodoxy reduces the variation to a crude dichotomy between "capitalist" and "socialist" political systems. Taking the United States as a paradigm, it indicts "capitalist" states as the home of malpractice suits and (so far as I know) completely disregards statutory schemes for review of compla...

In fact, we suspect that much more is true: we conjecture that this relative density does not change after restriction to any set of primes defined by a Cebatorevstyle Frobenius condition; that is, we expect that the sets (0.1) yield sets of primes of positive density which are quite different from those sets determined by Galois theoretic conditions. See Conjecture 1.2 for a precise statement....

We explore cosmology of intersecting braneworlds with induced gravity on the branes. We find the cosmological equations that control the evolution of a moving codimension one brane and a codimension two brane that sits at the intersection. We study the Friedmann equation at the intersection, finding new contributions from the six dimensional bulk. These higher dimensional contributions allow us...

We present a new application of Boundary String Field Theory: calculating the induced-gravity action on a D-brane. Using a simple quadratic tachyon potential to model a D-brane fluctuating in the flat target space we derive the effective action in terms of the extrinsic curvature to all orders in α′. We identify both the Born-Infeld structure as well as the Einstein-Hilbert term at order α′. Th...

measuring field gravity in sea due to the accelerations introduced via waves and movements to the gravity measuring systems has a low accuracy since according to einstein's equalent principle, gravimeter isn't able to separate the gravity acceleration from another acceleration. ship borne gravimetery observations by means of like oscillations and accelerations of the ship motion, and ...

The advent of highly efficient and superior digital devices and fast microprocessors for control application has opened the field of discrete time controller design. This paper presents an exciting application of magnetic levitation system using discrete sliding mode control. There is a limited volume of literature available for discrete sliding mode control as applied to magnetic levitation sy...

We present a formula that computes the output of an R-controllable, regular, single-input linear timeinvariant implicit system in such a way that it has prescribed relative degree and zeros. The formula is inspired on different generalizations of Ackermann’s formula. A possible application is in the context of sliding-mode control of implicit systems where, as the first step, one can use the pr...

The paper proposes a framework for engineering a coherent society-oriented system using the concept of sliding-mode control from systems theory. The agents are coordinated through local control laws using a switching logic related to the sliding manifolds. The sliding manifolds stand for sub-plans and therefore they are updated every time a change in planning is required. The agents have the ab...