A study of methods for textual satisfaction assessment

Software projects requiring satisfaction assessment are often large scale systems containing hundreds of requirements and design elements. These projects may exist within a high assurance domain where human lives and millions of dollars are at stake. Satisfaction assessment can help identify unsatisfied requirements early in the software development lifecycle, when issues can be corrected with less impact and lower cost. Manual satisfaction assessment is expensive both in terms of human effort and project cost. Automated satisfaction assessment assists requirements analysts during the satisfaction assessment process to more quickly determine satisfied requirements and to reduce the satisfaction assessment search space. This paper introduces two new automated satisfaction assessment techniques and empirically demonstrates their effectiveness, as well as validates two previously existing automated satisfaction assessment techniques. Validation shows that automatically generated satisfaction assessments have high accuracy, thus reducing the workload of the analyst in the satisfaction assessment process.     

Designs on objects: imaginative practice,aesthetic categorisation,and the design of multimedia archiving support

This paper discusses the collaborative evolution of a digital system to provide support for landscape architects and other design professionals in storing, encountering and retrieving large bodies of 'inspirational objects', mostly in the form of images. The system combines visual 'weak indexing' of objects through placing them in a visual environment, with easy-to-use methods for allocating keywords to objects on a variety of dimensions. The system design is informed by ethnographic observations of landscape architects' work, and by experience gained with earlier prototypes. The features of the system are described, and illustrated with a scenario of use in landscape architectural work.     

An Activity to Encourage Writing in Mathematics

Abstract

This article discusses an activity designed to encourage writing to learn in mathematics. There were three stages of data collection. An assessment, requiring basic algebra only, was completed by118 undergraduates from statistics and calculus courses. Students were given summaries of all participant responses, along with the correct answers. After discussing the results, 25 students wrote about the underlying concepts needed to answer the questions correctly and 38 gave reasons someone might answer the questions incorrectly. The written responses were easy to evaluate and revealed much about misunderstandings. A follow-up survey was given to students to elicit their attitudes.     

The combinatorics of neurite self-avoidance

During neural development in Drosophila, the ability of neurite branches to recognize whether they are from the same or different neurons depends crucially on the molecule Dscam1. In particular, this recognition depends on the stochastic acquisition of a unique combination of Dscam1 isoforms out of a large set of possible isoforms. To properly interpret these findings, it is crucial to understand the combinatorics involved, which has previously been attempted only using stochastic simulations for some specific parameter combinations. Here we present closed-form solutions for the general case. These reveal the relationships among the key variables and how these constrain possible biological scenarios.     

Microwave-assisted proteomics

State-of-the-art proteomic analysis has recently undergone a rapid evolution; with more high-throughput analytical instrumentation and informatic tools available, sample preparation is becoming one of the rate-limiting steps in protein characterization workflows. Recently several protocols have appeared in the literature that employ microwave irradiation as a tool for the preparation of biological samples for subsequent mass spectrometric characterization. Techniques for microwave-assisted bio-catalyzed reactions (including sample reduction and alkylation, enzymatic and chemical digestion, removal and analysis of post-translational modifications and characterization of enzymes and protein-interaction sites) are described. This review summarizes the various approaches undertaken, instrumentation employed, and reduction in overall experimental time observed when microwave assistance is applied.     

A comparative study of manganese and lead levels in human umbilical cords and maternal blood from two urban centers exposed to different gasoline additives

Manganese (Mn) and lead (Pb) are two neurotoxic chemicals and experimental evidence suggests that they can cross the placental barrier. Tetraethyl lead was still in use as an antiknock agent in Paris during the sampling period of the study, while it has been replaced by methylcyclopentadienyl manganese tricarbonyl (MMT) in Canada since 1977. By 1990, MMT was in 100% of gasoline in Canada. In a study of 160 pairs of mothers-neonates in Montreal and 206 pairs in Paris, we compared levels of Mn and Pb in the umbilical cord and in maternal blood. Neonates and mothers had significantly higher Pb levels in Paris where lead additives were still used in gasoline. Geometric mean maternal blood Pb levels were 5.4 microg/dl compared to 2.1 microg/dl in Montreal and cord blood Pb levels were 3.2 microg/dl in Parisian mothers compared to 1.7 microg/dl in Montreal. The prevalence of Paris Pb values superior to the 95th percentile of the Montreal distribution was highly elevated in all media studied. The prevalence of high Mn levels in umbilical cord blood was also significantly higher in Montreal. Surveillance programs are important to limit Pb overexposure and associated neurological effects in neonates where tetraethyl Pb is still in use as a gasoline additive. Since Mn is an essential element and dietary Mn intake may differ between Montreal and Paris, the difference observed with regard to high Mn values between Montreal and Paris cannot, at this time, be attributed to MMT in Montreal's gasoline. Further studies are needed to infer an association between Mn emissions from MMT and prenatal exposure to Mn.     

Cryptosporidium parvum oocyst inactivation in field soil and its relation to soil characteristics: analyses using the geographic information systems

The need exists to understand the environmental parameters that affect inactivation of Cryptosporidium parvum oocysts in soil under field conditions. The inactivation of C. parvum oocysts placed in the natural environment was studied at a dairy farm in western New York State, USA. Seventy sampling points were arranged in a grid with points 150 m apart using the Geographic Information System. The sampling points were distributed among three distinct areas: woodland, corn field and pasture. Purified oocysts were inoculated into chambers filled with soil from each sampling point, and buried in the surface of each respective sampling point. To compare C. parvum oocyst survival with another organism known to survive environmental stresses, Ascaris suum eggs were also placed in soil contained in chambers and buried at the same sampling points as the oocysts. As controls oocysts and eggs in distilled water were also placed at each sampling point. Oocyst and egg viability, soil pH and percent gravimetric water content were measured at all sampling points at 0, 60 and 120 day sampling periods. Soil organic content was determined for each sampling point. At 120 days after placement, mean viability of C. parvum oocysts was 10% although at a few sampling points, 30% of oocysts were still potentially infective; whereas 90% of A. suum eggs were viable at all sampling points. Statistically significant differences were not observed among the three different sampling areas, and no statistically significant predictors were found by regression analysis. Results exemplified the heterogeneity of soil parameters and oocyst viability across a landscape; such results make predictive models for C. parvum inactivation problematical. The long-term survival of C. parvum oocysts in soil under field conditions, as this study demonstrated, emphasizes their potential as a risk to contaminate surface waters.     

Trends in Grain Boundary Mobility: Survey of Motion Mechanisms

Grain boundary (GB) motion in polycrystalline materials is expected and observed to be dominated by thermally activated processes. This has important implications for properties influenced by the presence of GBs. Here, the GB motions of a catalog of 388 simulated nickel boundaries reveal a rich set of behaviors, which demonstrate that the temperature dependencies of GB mobility are far more complex than originally believed. In the set of 388 boundaries, four different general classes were observed with the following percentages: (I) ~57% exhibited traditional thermally activated mobility; (II) ~20% exhibited non-thermally activated mobility, where mobility was either independent of temperature or mobility decreased with increasing temperature (i.e., not thermally activated); (III) ~14% exhibited mixed modes of mobility, where different trends were exhibited over different temperature regimes (e.g., thermally activated at low temperature and non-thermally activated at high temperature); and (IV) ~9% exhibited unclassifiable mobility trends or were immobile over the studied temperature range. Thus, although the studied set of boundaries is not statistically representative of all GBs, it indicates that we must expand our preconceived notions to include new and interesting phenomena.     

Texture transformations in Ag thin films

A thickness-dependent texture transformation during annealing of initially (1 1 1) fiber-textured face-centered-cubic metal thin films is phenomenologically well known: sufficiently thin films retain the (1 1 1) texture, while sufficiently thick films transform to a (1 0 0) fiber texture. This transformation has been explained based on minimization of strain and interface energies, but recent work calls into question the roles of both of these driving forces. A high-throughput experimental method for the study of this texture transformation has been developed and applied to thin silver films with and without Ti adhesion layers. More than 150 individual samples spanning a range of thicknesses and interface conditions were prepared in a single deposition run. The texture evolution of these samples was characterized using X-ray diffraction as a function of time and temperature during annealing. The transformation proceeds despite the fact that the stresses are too low according to the strain/interface energy model. For films with Ti adhesion layers, the transformation kinetics and extent of transformation depend on the film thickness in a surprising way with intermediate thickness films showing initially fast transformations and stable mixed textures, while thicker films show an incubation time but transform fully. The results are consistent with reduction in defect energy (e.g. dislocations or point defects) as the driving force for secondary grain growth in an environment in which only (1 0 0) recrystallization nuclei can form. The driving force increases with film thickness so the nonmonotonic variation in transformation rate implies that the density of (1 0 0) nuclei decreases with thickness.