Compressing High-Dimensional Data Spaces Using Non-Differential Augmented Vector Quantization

query processing times and space requirements. Database compression has been discovered to alleviate the I/O bottleneck, reduce disk space, improve disk access speed, speed up query, reduce overall retrieval time and increase the effective I/O bandwidth. However, random access to individual tuples in a compressed database is very difficult to achieve with most available compression techniques. We propose a lossless compression technique called non-differential augmented vector quantization, a close variant of the novel augmented vector quantization. The technique is applicable to a collection of tuples and especially effective for tuples with many low to medium cardinality fields. In addition, the technique supports standard database operations, permits very fast random access and atomic decompression of tuples in large collections. The technique maps a database relation into a static bitmap index cached access structure. Consequently, we were able to achieve substantial savings in space by storing each database tuple as a bit value in the computer memory. Important distinguishing characteristics of our technique is that individual tuples can be compressed and decompressed, rather than a full page or entire relation at a time, (b) the information needed for tuple compression and decompression can reside in the memory or at worst in a single page. Promising application domains include decision support systems, statistical databases and life databases with low cardinality fields and possibly no text field

Investigating Concrete Steel Rebar Degradation Using Some Selected Inhibitors in Marine and Microbial Media

Potential monitoring investigations were conducted on concrete steel rebar samples premixed with selected inhibitors accompanied by fixed amount of sodium chloride salt and partially immersed in sulphuric acid and sodium chloride solution. Varying concentration of potassium dichromate, potassium chromate and sodium nitrite inhibitors were used individually and synergistically in this study. The potential readings were taken in accordance with ASTM C 876 through the open circuit potential corrosion monitoring technique. Suppressive quality and dependability of the inhibitor was then assessed by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and forecast the most effective inhibitor concentration in each media. Inhibitor effect on the compressive strengths of the reinforced concrete samples was also examined and reported. Results showed that 0.15M potassium chromate inhibitor had the best overall and individual performance in its inhibiting ability in the H2SO4 medium, while 0.68M sodium nitrite admixture was predicted as showing the lowest probability of corrosion risk in NaCl medium. Also, the best synergistic performance was shown by sample admixed with 0.06M K2Cr2O7, 0.15M K2CrO4 and 0.27M NaNO2 partially immersed in the NaCl medium. The compressive strength of concrete sample admixed with 0.03M K2Cr2O7 and 0.10M K2CrO4 was the highest amongst samples admixed with inhibitor in both media, though the control sample partially immersed in the NaCl medium had the highest overall compressive strength value

Efimov physics in bosonic atom-trimer scattering

Bosonic atom-trimer scattering is studied in the unitary limit using momentum-space equations for four-particle transition operators. The impact of the Efimov effect on the atom-trimer scattering observables is explored and a number of universal relations is established. Positions and widths of tetramer resonances are determined. Trimer relaxation rate constant is calculated.Comment: Added results for the trimer relaxation rate constan

Aniline effect on concrete steel rebar degradation in saline and sulfate media

Electrochemical potential monitoring experiments were performed on mild steel rebars embedded in concrete admixed with aniline inhibitor and fixed amount of sodium chloride salt partially immersed in sulfuric acid and sodium chloride solution. The open circuit potential corrosion monitoring technique was employed and the potential readings were taken in accordance with ASTM C 876. Repressive attribute and consistency of the inhibitor was then estimated by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and to predict the most efficient inhibitor concentration in each media. Aniline effect on the compressive strengths of the reinforced concrete samples was also investigated and reported. Varying concentrations of the inhibitor were used and its performance improved as concentration changed in NaCl medium, while no particular order of performance was noted in sulfuric medium. In the statistically analyzed experimental results for each of the inhibitor concentrations employed, 0.34 and 0.41 M aniline admixed samples were identified as exhibiting the best inhibiting quality in sodium chloride while 0.14 M aniline was predicted as showing the lowest probability of corrosion risk in sulfuric acid medium. The overall effective inhibitive performance in sulfuric acid was less when compared to the sodium chloride medium. Concrete sample admixed with 0.41 M aniline had the highest improvement in compressive strength in both media

Occupational mobility in engineering profession (craftman and artisan) in Oyo State, Nigeria.

This paper evaluate occupational mobility in engineering professional in Oyo State of Nigeria with the goal assessing causes and readiness of the professionals to return to the profession when the hindering factors are removed as well as sufficiency of the survey instrument in addressing the research problems. The study was conducted using a well structured questionnaire administered in 20 local government of Oyo State, Nigeria representing the sample space of 0.424. The Cronbach’s alpha of the reliability test of 0.453 was returned for the scale mean statistics of 11516.83 and variance of 0.0000007 showing that the survey instrument was sufficient and could be relied upon. The result of the socio economic analysis showed that 80% of the respondents were married while (15%) were single and the rest (5%) were divorced. The age distribution of the respondents ranged between greater than 50 years groups (12%) and 30 -39 years group (39%).The result of the analysis of job characteristics of the respondents showed that the longer the year of graduation, the lesser the number of graduates still in the business. The cross table analysis of the socio-economic indices with the job status of the respondents showed that marital status and level of education does not have significant effects on the job status of the respondents (whether still practicing or not) because 1.454 and 5.223 returned for both marital status and level of education are not significant (P<0.05). Also, the contingency table analysis of the effects of the skill acquisition methods showed that more of the respondents who acquired their skill via Technical School (70%) are willing to go back to the professions. However, for those who acquired their skill through Learning/artisanship, less than average (32%) of the respondents are ready to return to the profession. Lastly, the establishment of the regression model for the relationship between the proportion of the people wishing to go back to the profession and year of practicing the profession provide a necessary impetus for addressing the Job mobility problem faced by the profession

Endpoint Mobility Ratios for Vertical and Horizontal Wells with Incidence of Scale Deposition

One of the most difficult and profit hurting problems found in the oil field is the build-up of scale deposits in the well bore, production string, flow lines and even in storage tanks. These deposits act as a restriction during build-up in the wellbore causing a gradual decrease in production and, in many cases, as a solid barrier for wellbore fluid flow. This paper presents an analytical model based on the existing thermodynamic model showing the endpoint mobility ratios for both vertical and horizontal wells with the incidence of scale precipitation and deposition at the near wellbore region during water flooding. The results revealed that Endpoint mobility ratio for a vertical well with radial flow approaches unity “1” faster than for the horizontal well with elliptical flow. And horizontal wells are good candidates for managing scale precipitation and deposition during waterflooding

Phytochemical Screening and in vivo antioxidant activity of Ethanolic extract of caesalpinia bondus (L.) Roxb

Phytochemical screening, antioxidant activity in vivo and lipid peroxidation of 75 % ethanolic extract of young twigs and leaves of Caesalpinia bonduc were carried out by chemical test, and assessment of catalase and peroxidase activities and lipid peroxidation in Wistar rats after oral administration of different concentrations of the plant extract for ten days. Phytochemical screening of the extract revealed the presence of all major classes of phytochemicals: tannins, flavonoids, saponin, steroids, terpenoids, cardiac glycosides, glycosides, except phlobatannins. There were significant (p<0.05) graded increase in catalase and peroxidase activities and decrease in TBARS concentrations in the extract tested rats in comparison with normal control, Vitamin C and amodiaquine tested rats. The various pharmacological activities of C. bonduc may be due to its antioxidant activity

Investigating the Acid Failure of Aluminium Alloy in 2 M Hydrochloric Acid Using Vernonia amygdalina

The acid failure of aluminium alloy in 2 M hydrochloric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Aluminium alloy coupons of dimension 4 cm by 1 cm were immersed in test solutions of free acid and also those containing extract volumes of 2, 3, 4 and 5 cm3 at ambient temperature for 30 minutes. The volumes of hydrogen gas evolved as a result of the rate of reaction were recorded and analyzed. Analysis revealed that maximum inhibitor efficiency which corresponds to the lowest corrosion rate was obtained at optimum inhibitor volumes of 5 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volumes. Adsorption study revealed that Temkin isotherm best described the metal surface interaction with the extract phytochemicals, with 12 minutes becoming the best exposure time for the phytochemicals to adsorb to the metal surface at all volumes. Statistical modelling of the corrosion rate yielded an important relationship suitable for estimating corrosion rate values once volumes of the extract is known. Microstructural studies, showed an indirect relationship between crack growth rates and extract volumes, while consistency of the irregular intermetallic phases increases with increasing extract volumes

New nonlocal effective action

We suggest a new method for the calculation of the nonlocal part of the effective action. It is based on resummation of perturbation series for the heat kernel and its functional trace at large values of the proper time parameter. We derive a new, essentially nonperturbative, nonlocal contribution to the effective action in spacetimes with dimensions $d>2$.Comment: 28 pages, latex, no figures, typos are corrected, presentation improve