673 research outputs found
Agame-theoretical approach to network capacity planning under competition
The paper discusses the dimensioning strategies of two network providers (operators) that supply channels to the same population of users in a competitive environment. Usersare assumed to compete for best service (lowest blocking probability of new request), while operators wishto maximize their profits. This setting gives rise to two interconnected, noncooperative games: a) a users game, in which the partition of primary traffic between operators is determined by the operators' channel capacities and by the users' blocking-avoidance strategy; and b) a network dimensioning game between operators in which the players alternate dimensioning decisions thatmaximize their profit rate under the current channel capacity of his/her opponent. At least for two plausible users' blocking avoidance strategies discussed in the paper, the users game will always reach some algorithmic equilibrium. In the operators' game, the player strategies are given by their numbers of deployed chanels, limited by their available infrastructure resources. If the infrastrucutre is under-dimensioned with respect to the traffic rate, the operators game willreach a Nash equilibrium when both players reach full use of their available infrastructures. Otherweise, a Nash equilibrium may also arise if both operators incur the same deployment costs. If costs are asymmetric, though, the alternating game may enter a loop. If the asymmetry is modest, both players may then try to achieve a competitive monopoly in which the opponent is forced to leave the game or operate with a loss (negative profit). However, if the asymmetry is high enough, only the player with the lower costs can force his opponent to leave the game while still holding a profitable operation. --network dimensioning,game theory,duopoly,Nash equilibrium,circuit switching,blocking probability
The Partnership Of EDGAR Online And XBRL - Should Compustat Care?
Until EDGAR Online began operational, Compustat was (arguably) the only provider of financial statement information with accompanying database development capabilities. While EDGAR Online has received relatively little attention in the literature to date, we posit that the use of Edgar Online could flourish given the recent XBRL (eXtensible Business Reporting Language) reporting mandate of the SEC (Securities and Exchange Commission). In this regard, we identify the differences between Compustat and EDGAR Online in terms of data presentation as well as database development capabilities and product pricing. Our results suggest that differences exist between data presentation, database development capabilities as well as product pricing. In turn, we believe that such differences may facilitate EDGAR Online's competitive position with respect to Compustat
Comparative evaluation of different methods to quantify proteinuria in preeclampsia
Background: Worsening of condition in preeclampsia is indicated by progressive proteinuria, hence its quantification helps in decision making and plan treatment accordingly. The present study was undertaken to compare different methods of estimation of proteinuria to find best method for quantification.Methods: It was a hospital based prospective study conducted on a group of 100 pregnant women diagnosed as preeclampsia after 20 weeks of gestation, they were subjected to different methods of quantification of proteinuria after admission in department of obstetrics and gynaecology, Narayana medical college and hospital, Nellore over a period of one year.Results: Present study showed strong positive strength of association of SSA test was higher compared to the spot urinary PCR and spot urinary dipstick. To assess the predictability of three methods compared against 24-hour urine protein estimation by ROC curve. The AUC of the SSA test and spot urinary PCR was stronger than the urinary dipstick. Study showed a significant better method as SSA>>Urinary PCR>>dipstick with accuracy of 96.04%, 95.0% and 54% respectively.Conclusions: This study concluded that spot urine SSA and urine PCR are reliable investigations compared to dipstick method. So, spot urine SSA and urine PCR can be used for detection of proteinuria in pregnant women with pre-eclampsia with high accuracy, which is more rapid than time consuming 24-hour urine protein estimation. Thus, this quick method with high accuracy is very useful to prevent feto-maternal morbidity and mortality in India
Semantic Web-based Turmeric Expert System using IWD Algorithm
Semantic web is a structured way of re-usable data representation that can be used for inferring new knowledge. It provides a common data format for data representation. And it also provides semantics through structured information. Agriculture involves a vast variety of unstructured information. Normally agricultural experts, with their vast experience, provide critical advice in their farming activity. Machine learning algorithms acquire knowledge in the same manner as that of a human expert acquires knowledge with experience. In the present paper, an expert advisory system is simulated using machine learning algorithm for providing expert advice to the end users. A critical study is conducted for understanding the semantic web stack and an attempt has been made to design and develop an expert system namely, "Semantic Web-based Turmeric Expert System using IWD Algorithm". The proposed system has two modules namely, expert advice module and information system module. The Advisory system takes certain details from the end users, regarding their crop and provides the suitable advice. In the present paper, only yield assessment module was considered. Yield estimation system uses Intelligent Water Drops (IWD) algorithm to estimate the yield for each crop variety. Information system provides information about Turmeric crop varieties, parts, pests, pesticides, symptoms and diseases. Protégé is used to develop Ontology. JENA framework is used to retrieve information from Ontology. SWRL rules are implemented to infer rules from the data
Training spatial hearing skills in virtual reality through a sound-reaching task
Sound localization is crucial for interacting with the surrounding world. This ability can be learned across time and improved by multisensory and motor cues. In the last decade, studying the contributions of multisensory and motor cues has been facilitated by the increased adoption of virtual reality (VR). In a recent study, sound localization had been trained through a task where the visual stimuli were rendered through a VR headset, and the auditory ones through a loudspeaker moved around by the experimenter. Physically reaching to sound sources reduced sound localization errors faster and to a greater extent if compared to naming sourcesâ positions. Interestingly, training efficacy extended also to hearing-impaired people. Yet, this approach is unfeasible for rehabilitation at home. Fullyvirtual approaches have been used to study spatial hearing learning processes, performing headphones-rendered acoustic simulations. In the present study, we investigate whether the effects of our reaching-based training can be observed when taking advantage of such simulations, showing that the improvement is comparable between the full-VR and blended VR conditions. This validates the use of training paradigms that are completely based on portable equipment and donât require an external operator, opening new perspectives in the field of remote rehabilitation
Qualitative and quantitative phytochemical screening and in vitro anti oxidant and anti microbial activities of Elephantopus scaber Linn.
Preliminary phytochemical analysis and quantification of total phenols, In-vitro antioxidant and anti microbial activities of the different fractions (hydro alcoholic, hexane, ethyl acetate and methanol) of Elephantopus scaber were carried out against five selected pathogenic bacteria and three fungal species. The plant fraction possesses steroids, triterpinoids, saponins, flavonoides, carbohydrates, glycosides and oils. For total phenolic content gallic acid was taken as a standard, the ethyl acetate fraction contains rich phenolic content than other fractions and the methanol fraction shows more DPPH, superoxide and hydroxyl radical scavenging activity. In Anti-microbial activity study all fractions showed good inhibition zone against three organisms i.e., Escherichia coli, Staphylococcus aureus Klebsiella pneumonia among the other test organisms along with Candida spp (fungal organism)
GREEN SYNTHESIS OF NANOSTRUCTURED ZINC PARTICLES USING AQUEOUS LEAF EXTRACT OF SCHREBERA SWIETENIOIDES ROXB. AND THEIR CATALYTIC APPLICATION IN DEGRADATION OF METHYL ORANGE, CRYSTAL VIOLET DYES AND CHROMIUM METAL
Objective: The present work was aimed to synthesized the zinc nanoparticles (ZnO NPs) using aqueous leaf extract of Schrebera swietenioides Roxb., and further, the green-synthesized ZnO NPs were studied for its efficacy in the degradation of hazardous dyes like methyl orange, crystal violet and hazardous metal such as chromium.
Methods: The ZnO NPs were synthesized using aqueous leaf extract of S. swietenioides Roxb., as a green reducing agent and 0.1 M Zinc acetate as metal source and the NPs synthesis was completed within a short period of 6 h. The ZnO NPs synthesized were characterized using SEM, TEM, EDS, XRD, FT-IR and UV-visible spectrophotometer. Further, the synthesized NPs were applied for reduction of pollutant days such as methyl orange, crystal violet and pollutant metal chromium.
Results: The synthesis of NPs was monitored by observing the color change in the reaction mixture and UV visible spectral analysis. The UV spectral analysis shows a characteristic absorption wavelength at 379 nm. The synthesized NPs were hexagonal wurtzite form crystals having a spherical shape with rough surfaces with an average size of 68 nm and having 73.7 % of zinc content. At a NPs dose of 1.0 g/l the photocatalytic reduction was observed as 85.33±0.02 %, 86.82±0.095 % and 86.73±0.104 % for crystal violet dye, methyl orange dye and chromium metal, respectively. The NPs shows a high % photocatalytic reduction of chromium metal, crystal violet dye and methyl orange dye with less contact time confirms that the synthesized ZnO NPs were effectively catalyzed the degradation of methyl orange, crystal violet dyes and chromium metal. The NPs were observed to be recyclable and can shows high reduction activity after the completion of three cycles of degradation.
Conclusion: Hence it can be concluded that synthesized greener nanocatalyst was efficient for pollutant treatment and demonstrated the power of green biosynthesis for metallic nanoparticles
A VALIDATED STABILITY INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS DETERMINTION OF ATORVASTATIN CALCIUM AND EZETIMIBE HYDROCHLORIDE IN BULK AND TABLET DOSAGE FORM
Objective: To develop a simple, selective and precise stability indicating reverse-phase high performance liquid chromatography method for the simultaneous estimation of atorvastatin calcium and ezetimibe hydrochloride in bulk and tablet dosage form.Methods: The chromatographic separation was performed by Agilent Zorbax column (250Ăâ4.6 mm, 5 Ă”m) using methanol: 0.1 % v/v orthophosphoric acid in water (65:35) as mobile phase at flow rate of 1.0 ml/min with injection volume 20 Ă”l and the detection was carried out using UV detector at 240 nm. The method was validated as per ICH guidelines.Results: The retention time for atorvastatin calcium (ATV) and ezetimibe hydrochloride (EZT) was found to be 6.81 min and 4.96 min respectively. The linear regression analysis data for the calibration plots showed good linear relationship in the concentration range of 5-50 Ă”g/ml for both ATV and EZT. The percentage recoveries of ATV and EZT in the marketed dosage form were found to be 100.82 and 94.27 respectively. The correlation coefficients for ATV and EZT were 0.9983 and 0.998 respectively. The percentage degradation at different stress conditions like acid, alkaline, oxidative and photolytic for atorvastatin calcium were found to be 14.91, 8.26, 8.02 and 2.65 respectively and for ezetimibe hydrochloride, found to be 9.70, 32.18, 2.51 and 0.16 respectively.Conclusion: The developed method was successfully validated as per ICH guidelines. This method is simple, selective, linear, precise, accurate and sensitive, and can be used for routine analysis of tablet dosage forms containing both the drugs.Keywords: Atorvastatin calcium, Ezetimibe hydrochloride, RP-HPLC, Stress degradatio
Objective structured practical examination as a formative assessment tool for IInd MBBS microbiology students
Background: Assessment drives learning. It is well known that conventional or Traditional Practical Examination (TPE) has several limitations, especially in terms of subjectivity. In OSPE the procedures are standardized, so objectivity is ensured and also reliability maximized. Objectives of the study were to compare TPE & OSPE examination in formative assessment for IInd MBBS microbiology students on the topic culture media and to obtain feedback from students attending OSPE, and faculty.Methods: 76 students were taught about culture media and simultaneously were sensitized about OSPE and TPE, which followed the next week. Informed consent was taken. All students were randomly divided into 2 batches (TPE and OSPE) based on roll call. 71 students were tested, 33 for OSPE and 38 for TPE. Eight OSPE stations were set up with 8 culture media, plus a rest station after station 4. TPE students went for viva-voce to one examiner for same eight culture media. Both OSPE and TPE students were evaluated for a score of 20. OSPE students and the faculty were given a pre-validated questionnaire for feedback.Results: Mean scores, standard deviation (SD) and âpâ values were calculated using the T-test from the scores obtained. The mean scores for OSPE and TPE were found to be statistically significant- p-value <0.01. Feedback from OSPE students & faculty was also evaluated.Conclusions: OSPE is more structured and eliminates examiner bias better, and should be practiced in formative assessments and also be introduced in summative assessments
Open Cluster Characterization via Cross-Correlation with Spectral Library
We present a characterization method based on spectral cross-correlation to
obtain the physical parameters of the controversial stellar aggregate
ESO442-SC04. The data used was obtained with GMOS at Gemini-South telescope
including 17 stars in the central region of the ob ject and 6 standard-stars.
FXCOR was used in an iterative process to obtain self-consistent radial
velocities for the standard-stars and averaged radial velocities for the
science spectra. Spectral types, effective temperature, suface gravity and
metallicities parameters were determined using FXCOR to correlate cluster
spectra with ELODIE spectral library and selecting the best correlation matches
using the Tonry and Davis Ratio (TDR). Analysis of the results suggests that
the stars in ESO442-SC04 are not bound and therefore they do not constitute a
physical system.Comment: 4-page paper from IAU symposium 266. Contains 3 eps figures and IAU
document class file 'iau.cls
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