Video compression using spatiotemporal regularity flow.

We propose a new framework in wavelet video coding to improve the compression rate by exploiting the spatiotemporal regularity of the data. A sequence of images creates a spatiotemporal volume. This volume is said to be regular along the directions in which the pixels vary the least, hence the entropy is the lowest. The wavelet decomposition of regularized data results in a fewer number of significant coefficients, thus yielding a higher compression rate. The directions of regularity of an image sequence depend on both its motion content and spatial structure. We propose the representation of these directions by a 3-D vector field, which we refer to as the spatiotemporal regularity flow (SPREF). SPREF uses splines to approximate the directions of regularity. The compactness of the spline representation results in a low storage overhead for SPREF, which is a desired property in compression applications. Once SPREF directions are known, they can be converted into actual paths along which the data is regular. Directional decomposition of the data along these paths can be further improved by using a special class of wavelet basis called the 3-D orthonormal bandelet basis. SPREF -based video compression not only removes the temporal redundancy, but it also compensates for the spatial redundancy. Our experiments on several standard video sequences demonstrate that the proposed method results in higher compression rates as compared to the standard wavelet based compression.     

Multi-objective rule mining using a chaotic particle swarm optimization algorithm

In this paper, classification rule mining which is one of the most studied tasks in data mining community has been modeled as a multi-objective optimization problem with predictive accuracy and comprehensibility objectives. A multi-objective chaotic particle swarm optimization (PSO) method has been introduced as a search strategy to mine classification rules within datasets. The used extension to PSO uses similarity measure for neighborhood and far-neighborhood search to store the global best particles found in multi-objective manner. For the bi-objective problem of rule mining of high accuracy/comprehensibility, the multi-objective approach is intended to allow the PSO algorithm to return an approximation to the upper accuracy/comprehensibility border, containing solutions that are spread across the border. The experimental results show the efficiency of the algorithm.     

Wear characteristics of commercial gas turbine components

Wear is one of the common degradations in a commercial gas turbine. A stainless steel grade 304 (SS 304) fuel nozzle and its collar made of nickel-based superalloy (Hastelloy X) are two vital components that normally suffer from rapid wear. During an installation, the fuel nozzle is slotted into the collar of the combustion liner. In operation, these two surfaces are subjected to high pressure from the fuel combustion, hence continuously rubbing against each other causes vibrations. During the start–stop operation, these surfaces had undergone a large relative motion. The vibration is the main cause of the wear occurrence on the surfaces. Physical properties of the worn surfaces were obtained through visual observations: wear measurement, hardness and microstructure examination. Through visual observations, fretting wear was mainly suspected as the dominant wear mode, particularly after 8,000 of running hours at high temperature and vibration. In short, this paper discusses the preliminary findings of wear on the fuel nozzle and its collar. It also discusses the changes in the mechanical properties before and after the operation. Solutions for mitigating the problem were discussed.     

Molecular attributes of an effective steric agent: Yield stress of dispersions in the presence of pure enantiomeric and racemate malic acids

The effects of pH on the yield stress and zeta potential behaviour of α-Al₂O₃ dispersions with addition of d-, l- and racemate (DL) malic acids were evaluated. Conformational structures and intramolecular hydrogen bonding of the adsorbed malic acids obtained via MM2 modeling were used to explain the surface forces operating in the dispersions. We found that the yield stress-pH behaviour is almost identical for d-, l- and racemate malic acids. At low surface coverage of adsorbed malic acid, the maximum yield stress was reduced by as much as 55%. At complete surface coverage the reduction decreased to ～40%. MM2 modeling showed the presence of intramolecular hydrogen bonding between the hydroxyl and the (free) charged carboxylate group within the malic acid molecule. Intra-molecular hydrogen bonding and the high number of strongly bound water molecules (hydration number of malic di-ionic species) were likely responsible for the di-ionic malic acid species acting as a very effective steric agent. At complete surface coverage, the inter-molecular hydrogen bond formed between the layers of adsorbed malic acid, is responsible for the small rise in the maximum yield stress. Racemate malic acid produced a smaller maximum yield stress at complete surface coverage compared to the pure enantiomers. This may be related to the two different types of hydrogen bonds found in the racemate. Only one type is found in the pure enantiomers.     

Tectonic and radioactivity impacts of 238U on groundwater-based drinking water at Gosa and Lugbe areas of Abuja,North Central Nigeria

Tectonic contribution of activity level of ²³⁸U in groundwater-based drinking water in Gosa and Lugbe areas of Abuja was measured using inductively coupled plasma mass spectrometry (ICP-MS). The highest activity level of 2736 µBq L^?1 reported in Lugbe borehole, whereas the lowest value of 443 µBq L^?1 reported at Gosa borehole. The inhabitants permanently used water from the boreholes for daily consumption. The group receives 5.55 × 10^?5 mSv of the annual collective effective dose due to ²³⁸U in drinking water. The radiological risks of ²³⁸U in the water samples were found to be low, typically in magnitude of 10^?7 with cancer mortality value of 1.03 × 10^?7 and morbidity value of 1.57 × 10^?7. The chemical toxicity risk of ²³⁸U in drinking water over a lifetime consumption has a mean value of 4.0 × 10^?3 μg kg^?1 day^?1. It could be that the human risk due to ²³⁸U content in groundwater supplies from ingestion may likely be the chemical toxicity of ²³⁸U as a heavy metal rather than radiological risk. Significantly, Lugbe subsurface may have developed some fractions of granitic strata that contributed to the distribution of radioactive of ²³⁸U in tectonically weak zones.     

Preparation and characterization of gelatin mediated silver nanoparticles by laser ablation

We successfully prepared colloidal silver nanoparticles (Ag-NPs) using a nanosecond pulsed Nd:YAG laser, λ = 532 nm, with laser fluence of approximately about 0.6 J/pulse, in an aqueous gelatin solution. The size and optical absorption properties of samples were studied as a function of the laser repetition rates. The results from the UV-vis spectroscopy demonstrated that the mean diameter of Ag-NPs increase with the laser repetition rate increases. The Ag-NPs have mean diameters ranging from approximately 9 nm to 15 nm. Compared with other preparation methods, this work is clean, rapid, and simple to use.     

Surface force arising from adsorbed graphene oxide in alumina suspensions with different shape and size

The effects of graphene oxide (GO) on the yield stress‐pH of α‐Al₂O₃ (alumina) suspensions were investigated. For micron‐sized platelet alumina suspensions, micron‐sized GO additive increased the maximum yield stress by as much as six‐folds. This was attributed to GO‐mediated bridging interactions between the platelet particles. This type of bridging interactions was much less effective with submicron‐sized, spherical, and irregular shape alumina. Adsorption of the anionic GO reflected by the shift of pH of zero zeta potential to a lower pH is particularly high for platelet alumina. The 1.0 dwb % GO concentration added is sufficient to reinforce each platelet particle–particle bond, assisted by a directed GO–platelet interaction configuration. This is, however, not true with submicron‐sized particles as the particle concentration increases sharply with the inverse of the particle diameter to power of 3. Moreover, a GO sheet can adsorb several submicron‐sized particles and this does not produce the right interaction configuration. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3633–3641, 2013     

Customers perspectives on adoption of cloud computing in banking sector

The advent of cloud computing has transformed the role of the Internet in many businesses and organizations. Currently, banks are increasingly adopting cloud technologies to fulfil their varied purposes and to create a flexible and agile banking environment that can quickly respond to new business needs. However, past studies tend to focus more on the adoption issues of cloud computing from the organizational perspective with little attention paid on the users’ view of these cloud-based services. Therefore, this paper attempts to investigate the factors influencing cloud computing adoption in the banking sector from the customers’ perspective and to propose an adoption model for this purpose. The model is mainly developed based on the TAM-diffusion theory model (TAM-DTM) with the introduction of three new constructs namely trust, cost, and security and privacy. Questionnaires were randomly distributed to 162 bank customers in Malaysia. Survey data were analyzed using the partial least squares (PLS) method while SmartPLS was used to test the hypotheses and to validate the proposed model. The results suggest that trust, cost, and security and privacy can be successfully integrated within the TAM-TDM. The security and privacy constructs exhibited strong positive influence on perceived ease of use, perceived usefulness, and trust. The study concludes that perceived usefulness, perceived ease of use, cost, attitudes toward cloud and trust significantly influence users’ behavioral intention to adopt cloud computing. Thus, the finding of this study will enable banks to focus more on customer perspectives on cloud-based applications and identify their attitude towards their adoption.     

A novel chemistry based metaheuristic optimization method for mining of classification rules

When investigated carefully, chemical reactions possess efficient objects, states, process, and events that can be designed as a computational method en bloc. In this study, a novel computational method, which is robust and have less parameters than that of used in the literature, is intended to be developed inspiring from types and occurring of chemical reactions. The proposed method is named as artificial chemical reaction optimization algorithm, ACROA. In this study, one of the first applications of this method has been performed in classification rule discovery field of data mining and efficiency has been demonstrated.     

Progression of excess embryos to the blastocyst stage predicts pregnancy and implantation rates after intracytoplasmic sperm injection

In the spherical cells of Escherichia coli rodA mutants, division is initiated at a single point, from which a furrow extends progressively around the cell. Using "giant" rodA ftsA cells, we confirmed that each new division furrow is initiated at the midpoint of the previous division plane and runs perpendicular to it.