Sizing user stories using paired comparisons

Agile estimation approaches usually start by sizing the user stories to be developed by comparing them to one another. Various techniques, with varying degrees of formality, are used to perform the comparisons – plain contrasts, triangulation, planning poker, and voting. This article proposes the use of a modified paired comparison method in which a reduced number of comparisons is selected according to an incomplete cyclic design. Using two sets of data, the authors show that the proposed method produces good estimates, even when the number of comparisons is reduced by half those required by the original formulation of the method.     

Developing Project Duration Models in Software Engineering

Based on the empirical analysis of data contained in the International Software Benchmarking Standards Group （ISBSG） repository, this paper presents software engineering project duration models based on project effort. Duration models are built for the entire dataset and for subsets of projects developed for personal computer, mid-range and mainframe platforms. Duration models are also constructed for projects requiring fewer than 400 person-hours of effort and for projects requiring more than 400 person-hours of effort. The usefulness of adding the maximum number of assigned resources as a second independent variable to explain duration is also analyzed. The opportunity to build duration models directly from project functional size in function points is investigated as well.     

A ψ–ω finite element formulations for the Navier-Stokes equations

A new method of solving the two-dimensional Navier–Stokes equations by using the finite element method is proposed. The flow is represented by the stream function–vorticity formulation and the no-slip boundary conditions are explicitly introduced in the nonlinear equations. This formulation coupled with the Newton-Raphson method enables the study of stationary flows for high Reynolds number, without any convergence problem. A number of flow problems are analysed in order to demonstrate the efficiency of the present formulation.     

Characterization of quaternary ammonium oligomers by paired-ion reversed-phase liquid chromatography-mass spectrometry

The separation of novel permanently charged oligomers was studied using paired-ion reversed-phase liquid chromatography. The polyionene studied is less than 5 kDa in size, but contains three oligomer series with different end-group chemistries. The complexity of this polyionene makes development of a single-dimension separation quite challenging. Separation under critical conditions was employed to fractionate the end-group conformations and then the chain length of the oligomers in each series was confirmed by LC-MS. The oligomers were then used to optimize a single-dimension HPLC separation. Precise modulation of the hydrophobicity of the ion-pair reagent and the stationary-phase chemistry yielded very high resolution one-dimensional separations.     

Pharmacokinetics of single intravenous and oral doses of dolasetron mesylate in healthy elderly volunteers

Dolasetron mesylate (MDL 73,147EF, Anzemet; Hoechst Marion Roussel, Laval, Canada) is a 5-HT3 receptor antagonist undergoing clinical evaluation for use as an antiemetic agent. The pharmacokinetics of dolasetron and its reduced metabolite (MDL 74,156) were studied after administration of single intravenous and oral doses of dolasetron mesylate 2.4 mg/kg in 18 healthy elderly subjects. Expressed as the dolasetron base, this dose was 1.8 mg/kg. Dolasetron was rapidly metabolized to the reduced metabolite, which appeared in plasma within 10 minutes after intravenous or oral administration. The mean half-life (t1/2) of dolasetron was 0.24 hours after intravenous administration and 0.50 hours after oral administration. The pharmacokinetic parameters of the reduced metabolite were similar after intravenous and oral administration. The apparent absolute bioavailability of the reduced metabolite was 89%, and it had an elimination t1/2 of approximately 7 hours and an apparent volume of distribution (Vd beta) of 4.69 L/kg. Dolasetron was not detected in urine. Metabolites were excreted in urine almost completely within 24 hours of administration. The primary metabolite detected in urine was the (+)-enantiomer of the reduced metabolite, which accounted for 25.35% (+/- 7.79%) and 18.88% (+/- 7.65%) of the intravenous and oral doses, respectively. Hydroxylated metabolites accounted for 5% or less of the total dose via either route. The pharmacokinetics of the reduced metabolite after single intravenous or oral doses in elderly volunteers were consistent with pharmacokinetics observed in both young healthy men and cancer patients receiving high-dose cisplatin chemotherapy. Dosage adjustments of dolasetron mesylate on the basis of age do not appear to be necessary.     

Fatal and hospitalized injuries resulting from the 1994 Northridge earthquake

BACKGROUND: The Northridge earthquake struck Los Angeles on 17 January 1994, originating from a previously unknown thrust fault. The earthquake measured 6.7 on the Richter scale and caused extensive damage to buildings, utilities and roadways. This report describes injuries occurring in the Northridge earthquake which resulted in death or hospital admission. METHODS: Earthquake-related deaths were identified by the Los Angeles Department of the Coroner. All 78 hospitals in Los Angeles County were screened for earthquake-related admissions and were found in 16 of them. Coroner's records and medical records from the 16 hospitals were individually reviewed to identify earthquake-related injuries and to obtain information about the injury. RESULTS: A total of 171 earthquake-related injuries was identified in Los Angeles County, 33 were fatal and 138 required hospital admission. Injury rates were approximately equal by gender and increased significantly with increasing age. Most of the fatalities were due to building collapse, and most of the hospital-admitted injuries were caused by falls or being hit by objects. Motor vehicle injuries and burns were also common causes of injury. Head and chest injuries were common among fatalities, and extremity injuries were the most common among those admitted to a hospital. CONCLUSION: Earthquakes cause injuries through many mechanisms, and a clearer understanding of these pathways can help focus prevention strategies. Research combining comprehensive surveillance with risk factor assessment can help identify behaviours and circumstances increasing the risk of injury in an earthquake.     

étude psychometrique du questionnaire de dépression de Beck auprès d'un échantillon d'étudiants universitaires francophones.

Validated a French version of the Beck Depression Inventory (BDI) with 498 French speaking university students. The internal-consistency reliability measure showed a coefficient of .92 for the standard 21-item form and .90 for the short 13-item form. The test–retest procedure indicated adequate stability over a 4-mo period. The norms correspond to those obtained with American college students. The factor analysis of the questionnaire items yielded 3 factors accounting for 75.8% of the variance. Results reveal that both the standard and short form of the French version of the BDI are valid instruments for use in the college population. (English abstract) (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methane/propane mixture oxidation at high pressures and at high, intermediate and low temperatures

The oxidation of methane/propane mixtures in “air” has been studied for blends containing 90% CH₄/10% C₃H₈ and 70% CH₄/30% C₃H₈ in the temperature range 740-1550 K, at compressed gas pressures of 10, 20 and 30 atm, and at varying equivalence ratios of 0.3, 0.5, 1.0, 2.0 and 3.0 in a high-pressure shock tube and in a rapid compression machine. These data are consistent with other experiments presented in the literature for other alkane fuels in that, when ignition delay times are plotted as a function of temperature, a characteristic negative coefficient behavior is observed, particularly for mixtures containing 30% propane. In addition, the results were simulated using a detailed chemical kinetic model. It was found that qualitatively, the model reproduces correctly the effect of change in equivalence ratio and pressure, predicting that fuel-rich, high-pressure mixtures ignite fastest while fuel-lean, low-pressure mixtures ignite slowest. Moreover, the reactivity as a function of temperature is well captured with the model predicting negative temperature coefficient behavior similar to the experiments. Quantitatively the model is faster than experiment for all mixtures at the lowest temperatures (740-950 K) and is also faster than experiment throughout the entire temperature range for fuel rich mixtures.