The borders of mobile handset ecosystems: Is coopetition inevitable?

Today, the mobile phone industry witnesses important changes, shifting from a value chain to a burgeoning business ecosystem. This paper deals with the relationships that are at the very core of mobile OS ecosystems for IMTs (smartphones and PDA): Microsoft-OS, Symbian-OS, Palm-OS and RIM-OS over the period 1998–2006. Our study confirms that an ecosystem’s borders are unclear. More than half of our sample’ relationships are shared by at least two different ecosystems. The ecosystems we studied do not differ in terms of exclusive relationship which suggests that coopetitive strategies are particularly relevant in mobile platforms war.     

A surrogate model to assess the whole body SAR induced by multiple plane waves at 2.4?GHz

The assessment of the exposure to electromagnetic waves is nowadays a key question. Dealing with the relationship between exposure and incident field, most of previous investigations have been performed with a single plane wave. Realistic exposure in the far field can be modeled as multiple plane waves with random direction of arrival, random amplitude, and random phase. This paper, based on numerical investigations, studies the whole body specific absorption rate (SAR) linked to the exposure induced by five random plane waves having uniformly distributed angles of arrival in the horizontal plane, log-normal distributed amplitudes, and uniformly distributed phases. A first result shows that this random heterogeneous exposure generates maximal variations of ??25% for the whole body specific absorption. An important observation is that the exposure to a single plane wave arriving face to the body, used for the guidelines, does not constitute the worst case. We propose a surrogate model to assess the distribution of the whole body SAR in the case of an exposure to multiple plane waves. For a sample of 30 values of whole body SAR induced by five plane waves at 2.4?GHz, this simple approach, considering the resulting SAR as the sum of the SAR induced by each isolated plane wave, leads to an estimated distribution of whole body SAR following the real distribution with a p value of 76% according to the Kolmogorov statistical test.     

Early Stages of Recrystallization in Equal-Channel Angular Pressing (ECAP)-Deformed AA3104 Alloy Investigated Using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) Orientation Mappings

Early stages of recrystallization in alloys containing complex structure of second phase particles are of considerable practical interest. They were observed for the AA3104 alloy in which large particles occur against the background of randomly distributed dispersoids. The samples were deformed by equal channel angular pressing and then slightly annealed to obtain the state of partial recrystallization. The highly deformed alloy contained a structure of flat grains with the spacing between high-angle grain boundaries ranging from 100 nm to 1 ??m. On annealing, the structure coarsened and got transformed into nearly equiaxed grains by both discontinuous and continuous recrystallization. The nucleation of new grains was observed in statically recrystallized bulk samples using scanning electron microscopy, and during in-situ recrystallization in a transmission electron microscope. Special attention was paid to the nucleation of new grains in areas close to large second phase particles, where a relatively high stored energy was expected to stimulate nucleation. A particular role in the rise of nuclei is attributed to migration of low angle boundaries. During recrystallization at 623 K (350?°C), in most of the observed cases, the growth of grains occurred by coalescence of neighbouring cells and by migration of high-angle grain boundaries. These processes led to nearly equiaxed grains of similar size. Orientation mappings showed that although orientations of new grains were widely scattered, they were not completely random.     

Nanometric Scale Investigation of Phase Transformations in Advanced Steels for Automotive Application

The current trend toward producing lighter vehicles in the automotive industry is driven by the need to conform to the new exhaust emission control regulations. This objective presents a challenge to steel manufacturers. The difficulty lies in designing new alloys with an optimum strength/formability/cost balance for the various components. Here, the key to success lies in controlling the steel microstructure and especially the phase transformations at the smallest possible scale. Among the different alloying elements, light elements such as carbon and boron are of prime importance due to their major effects on the kinetics of phase transformations. Characterization tools combining high spatial and analytical resolution such as secondary ion mass spectrometry (SIMS) and field emission gun-transmission electron microscopy (TEM) were used. In this article, the examples presented are as follows. (1) Boron segregation and precipitation effects to control hardenability in martensitic steels. (2) Local carbon distribution in advanced high-strength steels, with a specific emphasis on martensite tempering. Links have been established between the boron and carbon distribution and the formability.     

The behavior of statically-indeterminate structural members and frames with cracks present

Crack stability is discussed as affected by their presence in statically-indeterminate beams, frames, rings, etc. loaded into the plastic range. The stability of a crack in a section, which has become plastic, is analyzed with the remainder of the structure elastic and with subsequent additional plastic hinges occurring. The reduction of energy absorption characteristics for large deformations is also discussed. The methods of elastic-plastic tearing instability are incorporated to show that in many cases the fully plastic collapse mechanism must occur for complete failure.     

Effect of Oral and Parenteral N Nutrition vs N-Free Nutrition on the Endogenous Amino Acid Flow at the Ileum of the Pig*

Two methods were tested for suppressing the depressive effect of N-free diets on the digestive secretions in pigs: the blood perfusion of amino acids (AA) or the peptide alimentation method. In the latter, enzymically hydrolysed casein (EHC), composed of oligopeptides and free AA, was used as the source of nitrogen. The unabsorbed dietary N molecules were discarded from the ileal digesta by ultrafiltration or gel filtration, assuming that the endogenous fraction did not contain significant amounts of small molecules. The AA supply by blood perfusion had no effect on the ileal endogenous AA losses (8·0 g AA kg⁻¹ DM intake) in growing pigs (±50 kg), compared with the N-free diet alone (8·3 g), whereas the EHC supplementation significantly increased them (18·0 g). The increase was due to both endogenous and dietary N. The presence of unabsorbed dietary AA in the ileal digesta was confirmed by the AA profile of the soluble molecules with a very low molecular mass (<3 kDa), which was close to that of EHC. Both ultrafiltration (cut-offs of 3 or 10 kDa) and gel filtration methods, utilised to discard the remaining dietary molecules, also eliminated a significant proportion of endogenous AA.     

Adapting an ultrasonic image threshold method to eddy current images and defining a validation domain of the thresholding method

This paper presents a generalization to eddy current images of a thresholding method developed for ultrasonic imaging. It is also shown how to improve the thresholding strength through the definition of a cooperation rule between two threshold assessment measures. This rule is also used to reduce time of calculus. These measures are calculated from the image cooccurrence matrix. The aim is to build a thresholding method that gives a threshold value but also an indicator which allows the operator to know if the methodology applies to the processed image. Examples of results are presented.     

Electrodes based on nano-tree-like vanadium nitride and carbon nanotubes for micro-supercapacitors

Vanadium nitride(VN) was deposited by DC-sputtering on a vertically aligned carbon nanotube(CNTs)template for the purpose of nano-structuration. This led to the fabrication of hierarchically composite electrodes consisting of porous and nanostructured VN grown on vertically aligned CNTs in a nano-treelike configuration for micro-supercapacitor application. The electrodes show excellent performance with an areal capacitance as high as 37.5 m F cm~(-2) at a scan rate of 2 mV s~(-1) in a 0.5 MK_2SO_4 mild electrolyte solution. Furthermore, the capacitance decay was only 15% after 20,000 consecutive cycles. Moreover,the capacitance was found to increase with VN deposit thickness. The X-ray photoelectron spectroscopy analyses of the electrodes before and after cycling suggest that the oxide layers that form at the VN surface is the responsible for the redox energy storage in this material. Such electrodes can compete with other transition metal nitride based electrodes for micro-supercapacitors.