E-Consultation for Skincare Products via Intelligent Agent Technology

Intelligent Agent technologies are becoming viable solutions to many problems related to E-commerce technologies that are not as user friendly as they seem. The skincare industry is continuously serving customer through consultation by humans. However, human beings have limited capability in fulfilling one's request. With these being said, this Final Year Project focuses on finding an intelligent agent that provides electronic consultation for the skincare industry. The main objective of this project is to create a flexible consultation environment for skincare's customers. This will result in a higher level of satisfaction and experience just like the current system. The methodology used for this project is the waterfall development-based technique which comprises of requirements analysis and definition, system design, implementation and testing, verification and maintenance. The tools used are Macromedia Dreamweaver MX, Adobe Photoshop, Pandorabots free web hosting, Oddcast Inc.'s VHost™, AIML, Apache Web Server and PHP. Based on the work carried out, it is found that although the usage of agent technology is a natural evolution of e-commerce, to effectively build and deliver an agent technology into an e-commerce websites requires rethinking and re-evaluating the human-computer interaction in the new environment. Second round of surveys were conducted to help determining whether users will be interested in the technology. It is found that the conceptof an Agent Technology might be an interest to users, provided it can assist them in consultation process. Agent Technology will be even easily acceptable if it is able to provide almost the same consultation experience based on the current consultation style, and able to provide an interactive discussion environment to users. Those who disagree prefer to stick to current style or might reject technology changes. Users are very concern with the reliability of the system as this will be the main factor whether the information provided by the agent technology is reliable or not. As a conclusion, more researches are expected to be carried out by technologists to further understand the acceptance on an agent technology and thus implementing it in various industries throughout the world

Effects Of Some Herbicides On Soil Nitrifiers and Nitrification

The herbicides Ioxynil, Bromoxynil, NPH 1320. Totril, Dieamba, Tricamba, Trifluralin, Oxadiazon, Legurame, M and B 9057 and M and B 9555 were tested for their effects on the process of nitrification in soil as well as in pure cultures. An improved version of the perfusion apparatus was developed and the perfusion technique was used as the principal experimental method in the soil studies in which the effects of different herbicides on the rates of nitrification in soils previously enriched with nltrifiers and in fresh soils continuously perfused with the herbicides were estimated. These estimates were made use of in the assessment of the degree of toxicities of the herbicides under consideration, on the metabolic rates per cell of nitrifiers and on their degree of proliferation in soil. An attempt was also made to study the possible differential effects of these herbicides on the two main groups of chemoautotrophic soil nitrifiers and the results obtained revealed that the metabolic activities of Nitrosomonas populations in soil were much less sensitive to the lower concentrations of many of the herbicides tested when compared with the sensitivities shown by the Nitrobacter populations, of the same soils, to the toxic effects of the same herbicides. But the rates of metabolic activities of Nitrosomonas populations were found to be the factor limiting the overall rates of the nitrification process in soils treated with the higher concentrations of most of these herbicides. The nitrification experiments carried out with cell suspensions of pure cultures of Nitrosomonas Euronaea and Nitrobacter Winogradski indicated that the herbicides exerted differential effects on the metabolic activities of these two organisms even in artificial media. The only other method used in studying the effects of herbicides on soil nitrification involved the measurement of the rates of oxygen uptake by samples of enriched soil treated with known concentrations of herbicides, making use of the conventional Warburg respirometrie technique. The qualitative effects of most of the herbicides on the activities of nitrifiers, grown in artificial media and in the natural medium of soil, were found to be essentially similar although the concentrations effective in causing these toxicities in pure cultures were much less than the concentrations needed to cause similar levels of toxicities in soil media. <p

Abundance determinations in HII regions: model fitting versus Te-method

The discrepancy between the oxygen abundances in high-metallicity HII regions determined through the Te-method (and/or through the corresponding "strong lines - oxygen abundance" calibration) and that determined through the model fitting (and/or through the corresponding "strong lines - oxygen abundance" calibration) is discussed. It is suggested to use the interstellar oxygen abundance in the solar vicinity, derived with very high precision from the high-resolution observations of the weak interstellar absorption lines towards the stars, as a "Rosetta stone" to verify the validity of the oxygen abundances derived in HII regions with the Te-method at high abundances. The agreement between the value of the oxygen abundance at the solar galactocentric distance traced by the abundances derived in HII regions through the Te-method and that derived from the interstellar absorption lines towards the stars is strong evidence in favor of that i) the two-zone model for Te seems to be a realistic interpretation of the temperature structure within HII regions, and ii) the classic Te-method provides accurate oxygen abundances in HII regions. It has been concluded that the "strong lines - oxygen abundance" calibrations must be based on the HII regions with the oxygen abundances derived with the Te-method but not on the existing grids of the models for HII regions.Comment: 5 pages, 3 figures, accepted for publication in Astronomy and Astrophysic

The M Dwarf Problem in the Galaxy

We present evidence that there is an M dwarf problem similar to the previously identified G dwarf and K dwarf problems: the number of low-metallicity M dwarfs is not sufficient to match simple closed-box models of local Galactic chemical evolution. We estimated the metallicity of 4141 M dwarf stars with spectra from the Sloan Digital Sky Survey (SDSS) using a molecular band strength versus metallicity calibration developed using high resolution spectra of nearby M dwarfs. Using a sample of M dwarfs with measured magnitudes, parallaxes, and metallicities, we derived a relation that describes the absolute magnitude variation as a function of metallicity. When we examined the metallicity distribution of SDSS stars, after correcting for the different volumes sampled by the magnitude-limited survey, we found that there is an M dwarf problem, with the number of M dwarfs at [Fe/H] ~ -0.5 less than 1% the number at [Fe/H] = 0, where a simple model of Galactic chemical evolution predicts a more gradual drop in star numbers with decreasing metallicity.Comment: To be published in Monthly Notices of the RAS by the Royal Astronomical Society and Blackwell Publishing. 7 pages, 3 figure

Bivariate least squares linear regression: towards a unified analytic formalism

Concerning bivariate least squares linear regression, the classical approach pursued for functional models in earlier attempts is reviewed using a new formalism in terms of deviation (matrix) traces. Within the framework of classical error models, the dependent variable relates to the independent variable according to the usual additive model. Linear models of regression lines are considered in the general case of correlated errors in X and in Y for heteroscedastic data. The special case of (C) generalized orthogonal regression is considered in detail together with well known subcases. In the limit of homoscedastic data, the results determined for functional models are compared with their counterparts related to extreme structural models. While regression line slope and intercept estimators for functional and structural models necessarily coincide, the contrary holds for related variance estimators even if the residuals obey a Gaussian distribution, with a single exception. An example of astronomical application is considered, concerning the [O/H]-[Fe/H] empirical relations deduced from five samples related to different stars and/or different methods of oxygen abundance determination. For selected samples and assigned methods, different regression models yield consistent results within the errors for both heteroscedastic and homoscedastic data. Conversely, samples related to different methods produce discrepant results, due to the presence of (still undetected) systematic errors, which implies no definitive statement can be made at present. A comparison is also made between different expressions of regression line slope and intercept variance estimators, where fractional discrepancies are found to be not exceeding a few percent, which grows up to about 20% in presence of large dispersion data.Comment: 56 pages, 2 tables, and 2 figures. New Astronomy, accepte

S4N: A Spectroscopic Survey of Stars in the Solar Neighborhood

[ABRIDGED] We report the results of a high-resolution spectroscopic survey of all the stars more luminous than Mv = 6.5 mag within 14.5 pc from the Sun. We derive stellar parameters and perform a preliminary abundance and kinematic analysis of the F-G-K stars in the sample. The inferred metallicity ([Fe/H]) distribution is centered at about -0.1 dex, and shows a standard deviation of 0.2 dex. We identify a number of metal-rich K-type stars which appear to be very old, confirming the claims for the existence of such stars in the solar neighborhood. With atmospheric effective temperatures and gravities derived independently of the spectra, we find that our classical LTE model-atmosphere analysis of metal-rich (and mainly K-type) stars provides discrepant abundances from neutral and ionized lines of several metals. Based on transitions of majority species, we discuss abundances of 16 chemical elements. In agreement with earlier studies we find that the abundance ratios to iron of Si, Sc, Ti, Co, and Zn become smaller as the iron abundance increases until approaching the solar values, but the trends reverse for higher iron abundances. At any given metallicity, stars with a `low' galactic rotational velocity tend to have high abundances of Mg, Si, Ca, Sc, Ti, Co, Zn, and Eu, but low abundances of Ba, Ce, and Nd. The Sun appears deficient by roughly 0.1 dex in O, Si, Ca, Sc, Ti, Y, Ce, Nd, and Eu, compared to its immediate neighbors with similar iron abundances.Comment: 24 pages, 19 figures, to appear in A&A; data can be accessed from http://hebe.as.utexas.edu/s4n/ or http://www.astro.uu.se/~s4n

Tracing the vertical composition of disc galaxies through colour gradients

(Abbreviated) Optical observations of a statistically complete sample of edge-on disc galaxies are used to study the intrinsic vertical colour gradients in the galactic discs, to constrain the effects of population gradients, residual dust extinction and gradients in the galaxies' metal abundance. It appears that the intrinsic vertical colour gradients are either non-existent, or small and relatively constant as a function of position along the galaxies' major axes. Our results are consistent with the absence of any vertical colour gradient in the discs of the early-type sample galaxies. In most galaxies small-scale variations in the magnitude and even the direction of the vertical gradient are observed: at larger galactocentric distances they generally display redder colours with increasing z height, whereas the opposite is often observed in and near the galactic centres. For a significant fraction of our sample galaxies another mechanism in addition to the effects of stellar population gradients is required to explain the magnitude of the observed gradients. The non-zero colour gradients in a significant fraction of our sample galaxies are likely (at least) partially due to residual dust extinction at these z heights, as is also evidenced from the sometimes significant differences between the vertical colour gradients measured on either side of the galactic planes. We suggest that initial vertical metallicity gradients, if any, have likely not been accentuated by accretion or merging events over the lifetimes of our sample galaxies. On the other hand, they may have weakened any existing vertical metallicity gradients, although they also may have left the existing correlations unchanged.Comment: 17 pages LaTeX, incl. 5 embedded postscript figures, resubmitted to MNRAS (referee's comments taken into account

Gas Accretion and Star Formation Rates

Cosmological numerical simulations of galaxy evolution show that accretion of metal-poor gas from the cosmic web drives the star formation in galaxy disks. Unfortunately, the observational support for this theoretical prediction is still indirect, and modeling and analysis are required to identify hints as actual signs of star-formation feeding from metal-poor gas accretion. Thus, a meticulous interpretation of the observations is crucial, and this observational review begins with a simple theoretical description of the physical process and the key ingredients it involves, including the properties of the accreted gas and of the star-formation that it induces. A number of observations pointing out the connection between metal-poor gas accretion and star-formation are analyzed, specifically, the short gas consumption time-scale compared to the age of the stellar populations, the fundamental metallicity relationship, the relationship between disk morphology and gas metallicity, the existence of metallicity drops in starbursts of star-forming galaxies, the so-called G dwarf problem, the existence of a minimum metallicity for the star-forming gas in the local universe, the origin of the alpha-enhanced gas forming stars in the local universe, the metallicity of the quiescent BCDs, and the direct measurements of gas accretion onto galaxies. A final section discusses intrinsic difficulties to obtain direct observational evidence, and points out alternative observational pathways to further consolidate the current ideas.Comment: Invited review to appear in Gas Accretion onto Galaxies, Astrophysics and Space Science Library, eds. A. J. Fox & R. Dav\'e, to be published by Springe