14 research outputs found

    Evaluation of Mental Workload and Familiarity in Human Computer Interaction with Integrated Development Environments using Single-Channel EEG

    Get PDF
    With modern developments in sensing technology it has become possible to detect and classify brain activity into distinct states such as attention and relaxation using commercially avail- able EEG devices. These devices provide a low-cost and minimally intrusive method to observe a subject’s cognitive load whilst interacting with a computer system, thus providing a basis for deter- mining the overall effectiveness of the design of a computer interface. In this paper, a single-channel dry sensor EEG headset is used to record the mental effort and familiarity data of participants whilst they repeat a task eight times in either the Visual Studio or Eclipse Integrated Development Environments (IDEs). This data is used in conjunction with observed behaviour and perceived difficulties reported by the participants to suggest that human computer interaction with IDEs can be evaluated using mental effort and familiarity data retrieved by an affordable EEG headse

    Biometric verification using gait

    No full text
    The work presented within this document details the development of a novel gait verification system suitable for a variety of applications such as human motion studies, medical analysis and security situations. The human gait is a spatio temporal process involving the coordination and interaction between the nervous, skeletal and muscular systems. Due to inherent variations in the limb lengths, muscle strengths and body mass gait is inherently individual. To develop a suitable feature extraction process a virtual gait laboratory was developed. The virtual laboratory contains virtual character templates articulated with a 32 bone skeleton system using motion capture data. Data was extracted from the character as a series of X, Y and Z translations for pro cessing. The virtual laboratory allows the testing of data extraction processes without the need for direct testing on human subjects. Feature extraction was performed using Principal Component Analysis (PCA). PCA allows data to be compressed and describes as a series of principal scores (PC) containing the weightings of the data. Feature extraction was performed on human subjects with the motions applied to a skeletal system containing individual physical dimensions. A second set of features was created by applying the motions to a single skeletal system. This removed the interpersonal variations from the dataset to explore the difference in classification when these variables have been removed. Overall generic motions are present within the first PC score. Higher PC scores contain unique motion characteristics suitable for classification of the subject s within a database. To verify a subject within the database Linear Discriminant Analysis (LOA) was performed. LOA projects data as a linear combination of features using a t raining data set of known outcomes. A subsequent sample can then be projected into the linear space for classification and verification of the subject within the database.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Solid fraction of separated digestate as soil improver : implications for soil fertility and carbon sequestration

    No full text
    Purpose: This study investigated the C and N mineralisation potential of solid fractions (SFs) from co-digestated pig manure after P-stripping (P-POOR SF) in comparison with P-rich SFs, as a means to estimate their organic matter stability in soil. Compost (COMP) and biochar (BCHR) (made from P-POOR SF) were also included in the study as reference biosolids. Methods: The SFs were incubated in a sandy-loam soil under moist conditions to determine production of CO2 and mineral N. At specified intervals, CO2 evolution in the mixtures was measured via the alkali trap method and titration over a period of 81 days, while mineral N was measured using a flow analyser after KCl extraction over a period of 112 days. Results: The various SFs showed similar patterns of C mineralisation (15\u201326% of added total C in 81 days) that were clearly higher than for COMP and BCHR (6% and 7%, respectively). Temporary N immobilisation was observed in biosolids with a high C/N ratio. The effective organic matter (EOM) of the SFs was calculated based on the C mineralisation data and varied between 130 and 369 kg Mg 121. Conclusions: The SF with a reduced P content had a high EOM/P ratio which is beneficial in areas where P status of the soil is already high. Moreover, the N mineralisation patterns confirm that a high C/N ratio may also reduce risks for N leaching due to temporary N immobilisation

    Environmental Risk Assessment of Sunscreens

    No full text
    22 pagesThe sunscreens are complex products for protecting the skin of UV radiation. These products contain active ingredients organic and inorganic UV filters. The release of some of these components can provoke negative effects to aquatic ecosystems. The UV filters have shown to be present in environmental compartments (freshwater, wastewater, groundwater, seawater, sediment, and sand) and to be ubiquitous, motivated by the use in other applications. To assess the environmental risk of these products implies to know exposure conditions and toxic effects in order to establish the risk quotient. This is calculated as the ratio between predicted environmental concentration (PEC) or measured environmental concentration (MEC) and predicted no-effect concentration (PNEC). The organic compounds that presented higher risk were benzophenone-3, ethylhexyl methoxycinnamate, and 4-methylbenzylidene camphor. Nevertheless, this risk is depending on the location and environmental compartment. The lack of a database concentration of inorganic nanoparticles (TiO2 and ZnO) makes difficult to carry out a realistic assessment of environmental risk, although using modeled data an approach was carried out. The results evidenced that certain risk can be related to the release of these nanomaterials from sunscreens, although a refinement will be necessary to reduce the uncertainties. Finally, some gaps of information have been identified in order to get a more realistic environmental risk assessment. Thus, the toxicity of the mixture of sunscreens compounds under realistic conditions and the improvement of the knowledge of their mode of actions could be the next stepsWe would like to thank to the projects CTM2016-75908-R funding by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) and FEDER funds and the Junta de Andalucía PAIDI, Excellence Research Group RNM306 for their supportPeer reviewe

    Ibuprofen and diclofenac: Effect on freshwater and marine aquatic organisms-Are they at risk?

    No full text
    Pharmaceuticals are included in the group of emergent pollutants due to their characteristics and potential negative effects. They remain mostly unregulated or are undergoing currently some sort of regularization process. Diclofenac, for instance, has been included in a watch list of substances for European Union-wide monitoring and the priority list of the Water Framework Directive (WFD) of the European Union. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a varied and chemically heterogeneous group of mainly anti-inflammatory, analgesic, and antipyretic drugs, reducing symptoms of inflammation, pain, and fever, respectively. They are widely employed and have been detected in freshwater, seawater, and sediment. Nevertheless, they are found as mixture instead of single compounds. In this chapter, we have tried to summarize how to assess the risk due to the occurrence of pharmaceuticals in aquatic ecosystems. We have focused on the mixture of diclofenac and ibuprofen using acute and sublethal toxicity data for different aquatic species. It has been presented new strategies as adverse outcome pathway to improve the understanding of the toxicity of these compounds. Although gaps of the information are pointed out, the risk levels associated with the occurrence of these compounds in aquatic ecosystems will range between no risk or high risk, depending on concentrations and environmental conditions.We would like to thank the projects CTM2016-75908-R and CTM2015-70731-R and the Junta de Andalucía PAIDI Excellence Research Group RNM306 for their support. MH is supported by the Spanish Ramón y Cajal funding scheme (contract reference RYC-2012-12217) of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO)
    corecore