Ricean parameter estimation using phase information in low SNR environments

A new Ricean parameter estimator is considered in the context of wireless communications. In comparison to existing methods, the proposed estimator is especially useful in low signal-to-noise environments. It is less reliant on knowledge of the transmitted signal frequency than existing methods, and it performs well in communications environments where the frequency is varying in time.     

A survey of critical success factors in e-Banking: an organisational perspective

We investigate organisational factors critical to the success of e-Banking (EB). Scholars report that a variety of factors are vital to EB success. A shortcoming in the extant EB literature is that much of the research focuses on a small subset of success factors and an overall ranking of factors is still missing. Our aim, therefore, is to synthesise and test the critical success factors (CSFs) identified in the existing literature, thus, substantiating or not the factors purported to be critical. To achieve our aim, we created a survey instrument from a synthesis of CSFs identified from existing EB and e-commerce literature. We draw upon the e-commerce body of knowledge to take in the widest set of CSFs that can affect EB. Data were collected from U.K.-based financial sector organisations that offer EB services. We found the most critical factors for success in EB are: quick responsive products/services, organisational flexibility, services expansion, systems integration and enhanced customer service. Our research shows that organisations need to manage their EB initiative at a strategic level and treat it as business critical rather than simply a technical or operational issue. They need to pay attention to internal integration, which includes channels, technology and business process integration, and improving the overall services to their customers.     

Advanced use of soft computing and eddy current test to evaluate mechanical integrity of metallic plates

The up-to-date structural designing makes by now widely use of high performance numerical codes, mainly in terms of computational powerful, cost and sizing, only available till some time before to limited groups of users. This allowed the experts to focus their attention on a qualifying aspect of the designing, i.e. an use of the materials very close to their limit behavior. Late innovative approaches in material mechanics gave in addition the opportunity to build models very close to the actual behavior but without introducing heavy computational aspects. In this paper, phenomena which relate mechanical stresses with electromagnetic properties of a defined material have been exploited in order to reconstruct electromagnetic maps starting from mechanical quantities by means of support vector regression machines (SVRMs). Purpose of the proposed study is to reconstruct a stress map in strained metallic plates by using electromagnetic measures. Moreover, an heuristic approach is proposed in order to estimate electromagnetic behavior of a stressed plate starting from easily measurable mechanical quantities. It would be very interesting when electrical or mechanical measurements are very hard to realize. The proposed approach could be very useful in such situations as quality controls of civil buildings, without the necessity of applying expensive and time-consuming destructive or non-destructive testing. In this way, it is possible to have a substantially precise idea of mechanical stresses in metallic materials by estimating the local variation of electromagnetic field into the same material using a SVRM-based interpolator.     

The role of solvents in the imbibition of ascorbic acid by zeolites

Ascorbic acid is commonly used as an antioxidant agent in form of a powder. This allows the immediate availability of the molecule but cannot avoid the rapid inactivation of the excess. Sodium zeolites have frequently been proposed as agents for the controlled release of absorbed molecules. In order to prepare controlled release antioxidant agents, we treated sodium X and Y zeolites with ascorbic acid dissolved in organic solvents in order to establish how much acid they were able to retain and understand the retention and release mechanism. We found that the acid: (i) undergoes a dissociation and H⁺/Na⁺ exchange with zeolite; (ii) is retained as sodium salt while the zeolite is protonated; (iii) is released as a function of the sodium salt solubility into the solvent used. Thus, the imbibition was function of the nature of the solvent and, in aqueous-organic solvent mixtures, it was a direct function of the water concentration in the range 0–1% and an inverse function in the range 1–11%. It follows from above that, when sodium zeolite is used as a support for ascorbic acid, water percent in the range 0–11% may control the release as the ascorbate salt into aqueous–organic solvent mixtures.     

Change in major amputation rate in a center dedicated to diabetic foot care during the 1980s: prognostic determinants for major amputation

AIMS: To compare the efficacy of Thio-tepa and Mitomycine C to obviate recurrence; to compare cost-efficacy ratios; to evaluate their facility of use and their complications. METHODS: In a prospective blinded study, 36 patients undergoing surgery for 46 primary and recurrent pterygium were assigned randomly to three groups: group 1 received 0.02 mg/ml of Mitomycine C three times daily for 5 days; group 2 received Thio-tepa four times daily for 6 weeks, group 3 served as a control receiving distilled water three times daily for five days. RESULTS: Recurrence rates were 38%, in group 1; 28% in group 2; 82% in group 3 respectively. Follow-up ranged from 15 to 44 weeks (mean 27.93 +/- 8.9 weeks). Mean delay recurrence time was 6.3 weeks. Topical Mitomycin caused: iritis, conjunctival irritation, excessive lacrymation, photophobia, ocular pain; Thio-tepa caused: photophobia, foreign body sensation, headache. CONCLUSIONS: Mitomycine C appears to be an effective and safe adjunctive treatment for this cost-efficacy and this facility of use comparison.     

A novel analytical framework compounding statistical traffic modeling and aggregate-level service curve disciplines: network performance and efficiency implications

This paper demonstrates that higher network resource efficiency can be achieved by using resource management protocols which consider service disciplines based on service curves together with statistical traffic modeling. To this end, an appropriate analytical framework is introduced which allows calculation of the performance statistically guaranteed to any flow out of an aggregate. This feature enables the analytical framework to be applied to the elements of the core network where aggregates of traffic are considered instead of single flows in order to avoid scalability problems. Given that flows are modeled in the analytical framework through switched batch Bernoulli processes (SBBPs), the whole queueing system is denoted as SBBP/Sc/1/K. The performance is calculated in terms of loss probability and delay distribution. The proposed framework is applied in a significant multinode case study.     

Effect of propionyl-L-carnitine treatment on membrane phospholipid fatty acid turnover in diabetic rat erythrocytes

Multiple pulmonary nodules were found in a patient who had an occupational history of coal mining for eleven years and road construction for fifteen years. An open lung biopsy was performed, because nodules had increased in size compared to previous ones and a trasbronchial biopsy was not diagnostic. The nodules were composed of dense concentric lamellar collagenous structures with a serpentine pattern surrounded by an infiltration of histiocytes, lymphocytes and plasma cells with Russel bodies. These findings are compatible with pulmonary hyalinizing granuloma (PHG) named by Liebow A. A. The etiopathogenetic mechanism and the difference between PHG and silicotic nodule is discussed.     

Composition profiles of CVD platinum and platinum silicide by Auger electron spectroscopy and secondary ion mass spectrometry

Phosphorus, platinum, silicon and oxygen profiles have been studied in thin film Pt formed on Si by chemical vapor deposition (CVD) from Pt(PF₃)₄, and in the platinum silicide formed by interdiffusion at 450° and 625°C. Low voltage sputtered Pt and its silicide have also been studied. Two profiling techniques have been used: inert ion sputtering with sequential Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS).Phosphorus in as-deposited (225°C) Pt formed by chemical vapor deposition (CVD Pt) was found to be non-uniformly distributed, indicating that some diffusion had already occurred even under these mild conditions. There was a high concentration (10–20 at.%) at the surface, decreasing rapidly to the 0.1% range at a depth of about 50 Å. At the interface with the silicon substrate there was a broad peak with a P concentration of about 1 at.%. When platinum silicide was formed, most of the phosphorus from the interior migrated to the surface, resulting in an enhanced P zone now 150–200 Å thick. The phosphorus did not appear to impede silicide formation in any way. The same $\text{Pt}\text{Si}$ ratio was found in platinum silicide formed from CVD Pt at either 450° or 625°C, in silicide from sputtered Pt and in single-crystal PtSi. The composition of the silicide was essentially constant through most of the film. A strong oxygen signal combined with an Si peak shift was present within 100–200 Å of the surface of the silicide. This is the layer of SiO₂ which has been detected by independent methods earlier, and which protects PtSi from attack by the aqua regia used to remove unreacted Pt from insulator areas. The surface silica coincided with the enhanced phosphorus zone when CVD Pt was used, and thus in this case should be considered as a phosphosilicate glass.     

Emergency service systems: The use of the hypercube queueing model in the solution of probabilistic location problems

Probabilistic location problems are surveyed from the perspective of their use in the design of emergency service systems, with special emphasis on emergency medical systems. Pioneering probabilistic models were defined in the 1980s, as a natural extension of deterministic covering models (first generation models) and backup models (second generation). These probabilistic models, however, adopted simplifying assumptions that in many cases do not correspond to real-world situations, where servers usually cooperate and have specific individual workloads . Thus the idea of embedding the hypercube queueing model into these formulations is to make them more adherent to the real world. The hypercube model and its extensions are initially presented in some detail, which is followed by a brief review of exact and approximate methods for its solution. Probabilistic models for the design of emergency service systems are then reviewed. The pioneering models of Daskin and ReVelle and Hogan are extended by embedding the hypercube model into them. Solution methods for these models are surveyed next, with comments on specialized models for the design of emergency medical systems for urban areas and highways.