Introduction: One of the major causes of image non-uniformity in MRI is due to the existence of  non-homogeneity in RF receive and transmit. This can be the most effective source of error in  quantitative  studies  in  MRI  imaging.  Part  of  this  non-homogeneity  demonstrates  the  characteristics of RF coil and part of it is due to the interaction of RF field with the material being  imaged...

It is proved that no region of a homogeneous locally compact, locally connected metric space can be cut by an Fσ-subset of a “smaller” dimension. The result applies to different finite or infinite topological dimensions of metrizable spaces. The classical Hurewicz-Menger-Tumarkin theorem in dimension theory says that connected topological n-manifolds (with or without boundary) are Cantor manifo...

Abstract The structural stability of ausferrite in thin-walled Austempered Ductile Iron (ADI) castings with 5 mm wall thickness is compared to a reference casting 25 thickness. and were first austenitized between 850 925 °C, then austempered 250 380 °C. X-ray diffraction (XRD) investigations changing temperature performed − 260 up + 450 °C investigate the change phase fraction, lattice paramete...

Statistically homogeneous flows obey exact kinematic relations. The Betchov homogeneity constraints (Betchov, J. Fluid Mech. , vol. 1, 1956, pp. 497–504) for the average principal invariants of velocity gradient are among most well-known and extensively employed These relations have far-reaching implications coupled dynamics strain vorticity, as well turbulent energy cascade. Whether only possi...

We present a consistent, geometric notion of homogeneity, for vector elds (diierential equations and control systems), functions, diierential forms and endomorphisms. The fundamental observation is that homogeneity is an intrinsic, geometric property. Accordingly, a coordinate-free characterization is given, and shown to yield the desired/expected results. This also addresses: \When do there ex...

The notion of geometric homogeneity is extended for differential inclusions. This kind of homogeneity provides the most advanced coordinate-free framework for analysis and synthesis of nonlinear discontinuous systems. The main qualitative properties of continuous homogeneous systems are extended to the discontinuous setting: the equivalence of the global asymptotic stability and the existence o...

Sufficient as well as necessary conditions are studied for a dendrite or a dendroid to be homogeneous with respect to monotone mappings. The obtained results extend ones due to H. Kato and the first named author. A number of open problems are asked.

background: heat stress is a common and usual problem in industries. several indices, including wet bulb globe temperature (wbgt), are used to evaluate heat stress. however, wbgt index has limitations such as high cost and response time. it is not thus suitable as a screening tool. heat strain scoring index (hssi) is also an observational-judgmental technique that has been developed for primary...

Jarik Nešetřil suggested to the first author the investigation of notions of homogeneity for relational structures, where “isomorphism” is replaced by “homomorphism” in the definition. Here we look in detail at what happens for posets. For the strict order, all five generalisations of homogeneity coincide, and we give a characterisation of the countable structures that arise. For the non-strict...

Many medical studies are carried out to investigate the size of some effect, for example the treatment effect in a controlled clinical trial or the risk of exposure to some substance in an observational study. To this end it is usual to compare groups of subjects, such as those receiving active treatment with those getting placebo or those exposed with those not exposed. The comparison is often...