26,661 research outputs found
Bacteria classification using Cyranose 320 electronic nose
Background
An electronic nose (e-nose), the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds.
Method
Linear Principal Component Analysis (PCA) method was able to classify four classes of bacteria out of six classes though in reality other two classes were not better evident from PCA analysis and we got 74% classification accuracy from PCA. An innovative data clustering approach was investigated for these bacteria data by combining the 3-dimensional scatter plot, Fuzzy C Means (FCM) and Self Organizing Map (SOM) network. Using these three data clustering algorithms simultaneously better 'classification' of six eye bacteria classes were represented. Then three supervised classifiers, namely Multi Layer Perceptron (MLP), Probabilistic Neural network (PNN) and Radial basis function network (RBF), were used to classify the six bacteria classes.
Results
A [6 × 1] SOM network gave 96% accuracy for bacteria classification which was best accuracy. A comparative evaluation of the classifiers was conducted for this application. The best results suggest that we are able to predict six classes of bacteria with up to 98% accuracy with the application of the RBF network.
Conclusion
This type of bacteria data analysis and feature extraction is very difficult. But we can conclude that this combined use of three nonlinear methods can solve the feature extraction problem with very complex data and enhance the performance of Cyranose 320
The effects of atmospheric refraction on the accuracy of laser ranging systems
Correction formulas derived by Saastamoinen and Marini, and the ray traces through the refractivity profiles all assume a spherically symmetric refractivity profile. The errors introduced by this assumption were investigated by ray tracing through three-dimensional profiles. The results of this investigation indicate that the difference between ray traces through the spherically symmetric and three-dimensional profiles is approximately three centimeters at 10 deg and decreases to less than one half of a centimeter at 80 deg. If the accuracy desired in future laser ranging systems is less than a few centimeters, Saastamoinen and Marini's formulas must be altered to account for the fact that the refractivity profile is not spherically symmetric
Book Reviews: Poetic Artifice, Levity of Design and On Violence in the Work of J.H. Prynne
Book reviews of the following academic titles: Poetic Artifice: A Theory of Twentieth-Century Poetry by Veronica Forrest-Thomson and Gareth Farmer (ed.), Bristol: Shearsman, 240 pp., 2016. Review by Calum Gardner. Levity of Design: Man and Modernity in the Poetry of J. H. Prynne by Wit Píetrzak, Newcastle upon Tyne: Cambridge Scholars Publishing, 162 pp., 2012. Review by Lisa Jeschke. On Violence in the Work of J. H. Prynne by Matthew Hall, Newcastle upon Tyne: Cambridge Scholars Publishing, 226 pp., 2015. Review by Lisa Jeschke
Evaluation of AIS Data for Agronomic and Rangeland Vegetation: Preliminary Results for August 1984 Flight over Nebraska Sandhills Agricultural Laboratory
Since 1978 scientists from the Center for Agricultural Meteorology and Climatology at the University of Nebraska have been conducting research at the Sandhills Agricultural Laboratory on the effects of water stress on crop growth, development and yield using remote sensing techniques. We have been working to develop techniques, both remote and ground-based, to monitor water stress, phenological development, leaf area, phytomass production and grain yields of corn, soybeans and sorghum. Because of the sandy soils and relatively low rainfall at the site it is an excellent location to study water stress without the necessity of installing expensive rainout shelters. The primary objectives of research with the airborne imaging spectrometer (AIS) data collected during an August 1984 flight over the Sandhills Agricultural Laboratory are to evaluate the potential of using AIS to: (1) discriminate crop type; (2) to detect subtle architectural differences that exist among different cultivars or hybrids of agronomic crops; (3) to detect and quantify, if possible, the level of water stress imposed on the crops; and (4) to evaluate leaf area and biomass differences for different crops
Laboratory studies in ultraviolet solar physics
The research activity comprised the measurement of basic atomic processes and parameters which relate directly to the interpretation of solar ultraviolet observations and to the development of comprehensive models of the component structures of the solar atmosphere. The research was specifically directed towards providing the relevant atomic data needed to perform and to improve solar diagnostic techniques which probe active and quiet portions of the solar chromosphere, the transition zone, the inner corona, and the solar wind acceleration regions of the extended corona. The accuracy with which the physical conditions in these structures can be determined depends directly on the accuracy and completeness of the atomic and molecular data. These laboratory data are used to support the analysis programs of past and current solar observations (e.g., the Orbiting solar Observatories, the Solar Maximum Mission, the Skylab Apollo Telescope Mount, and the Naval Research Laboratory's rocket-borne High Resolution Telescope and Spectrograph). In addition, we attempted to anticipate the needs of future space-borne solar studies such as from the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Our laboratory activities stressed two categories of study: (1) the measurement of absolute rate coefficients for dielectronic recombination and electron impact excitation; and (2) the measurement of atomic transition probabilities for solar density diagnostics. A brief summary of the research activity is provided
Daytime lidar measurements of tidal winds in the mesospheric sodium layer at Urbana, Illinois
For more than 15 years lidar systems have been used to study the chemistry and dynamics of the mesospheric sodium layer. Because the layer is an excellent tracer of atmospheric wave motions, sodium lidar has proven to be particularly useful for studying the influence of gravity waves and tides on mesospheric dynamics. These waves, which originate in the troposphere and stratosphere, propagate through the mesosphere and dissipate their energy near the mesopause making important contributions to the momentum and turbulence budget in this region of the atmosphere. Recently, the sodium lidar was modified for daytime operation so that wave phenomena and chemical effects could be monitored throughout the complete diurnal cycle. The results of continuous 24 hour lidar observations of the sodium layer structure are presented alond with measurement of the semidiurnal tidal winds
The continuous strength method for the design of circular hollow sections
Circular hollow sections (CHS) are widely used in a range of structural engineering applications. Their design is covered by all major design codes, which currently use elastic, perfectly-plastic material models and cross-section classification to determine cross-secti\on compressive and flexural resistances. Experimental data for stocky sections show that this can result in overly conservative estimates of cross-section capacity. The continuous strength method (CSM) has been developed to reflect better the observed behaviour of structural sections of different metallic materials. The method is deformation based and allows for the rational exploitation of strain hardening. In this paper, the CSM is extended to cover the design of non-slender and slender structural steel, stainless steel and aluminium CHS, underpinned by and validated against 342 stub column and bending test results. Comparisons with the test results show that, overall, the CSM on average offers more accurate and less scattered predictions of axial and flexural capacities than existing design methods
How, when and why do young women use nutrition information on food labels? A qualitative analysis
Background. Nutrition information on food packaging offers a public health tool which could be used to promote informed consumer choice and aid consumption of a healthy diet. Research indicates that use of nutrition information can lead to reduced energy intake and lower BMI, but little evidence is available regarding how, when or why people use nutrition information when making everyday food choices. Methods. This qualitative study explored motivations and contexts surrounding the use of nutrition information among 25 UK-based female nutrition information users aged 23-35 years, using semi-structured individual interviews. Verbatim transcripts were analysed using thematic analysis. Results. Six themes were identified: (1) understanding and (2) functions of nutrition information, (3) health versus appearance motives, nutrition information use in (4) affective and (5) symbolic food episodes, and (6) competing point-of-purchase influences. Notable observations included a difficulty in understanding and converting nutrition information into personally meaningful terms, and eschewal of nutrition information in settings where food plays an affective or symbolic role (e.g. food consumption after a stressful day, buying food for a dinner party). Conclusions. We suggest evidence-based directions for future research and offer policy and practice recommendations, including the adoption of clear and consistent nutrition information formats
A Web/Grid Services Approach for Integration of Virtual Clinical & Research Environments
Clinicans have responsibilities for audit and research, often participating in projects with basic scientist colleagues. Our work in a regional teaching hospital setting involves collaboration with the medical school computer services and builds upon work developed in computer science department as part of the Collaborative Orthopaedic Research Environment (CORE) project[1]. This has established a pilot study for proof of concept work. Users are mapped to a personal profile implemented using XML and a service oriented architecture (SOA)[2,3]. This bridges the e-Health and e-Science domains, addressing some of the basic questions of security and uptake
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