A Comparison of Quantitative and Qualitative Data from a Formative Usability Evaluation of an Augmented Reality Learning Scenario

The proliferation of augmented reality (AR) technologies creates opportunities for the devel-opment of new learning scenarios. More recently, the advances in the design and implementation of desktop AR systems make it possible the deployment of such scenarios in primary and secondary schools. Usability evaluation is a precondition for the pedagogical effectiveness of these new technologies and requires a systematic approach for finding and fixing usability problems. In this paper we present an approach to a formative usability evaluation based on heuristic evaluation and user testing. The basic idea is to compare and integrate quantitative and qualitative measures in order to increase confidence in results and enhance the descriptive power of the usability evaluation report.augmented reality, multimodal interaction, e-learning, formative usability evaluation, user testing, heuristic evaluation

Analyzing the Impact of Airborne Particulate Matter on Urban Contamination with the Help of Hybrid Neural Networks

In this study, particulate matter (PM), total suspended particulate (TSP), PM10, and PM2.5 fractions) concentrations were recorded in various cities from south of Romania to build the corresponding time series for various intervals. First, the time series of each pollutant were used as inputs in various configurations of feed-forward neural networks (FANN) to find the most suitable network architecture to the PM specificity. The outputs were evaluated using mean absolute error (MAE), mean absolute percentage error (MAPE), root mean square error (RMSE), and Pearson correlation coefficient (r) between observed series and output series. Second, each time series was decomposed using Daubechies wavelets of third order into its corresponding components. Each decomposed component of a PM time series was used as input in the optimal feed-forward neural networks (FANN) architecture established in the first step. The output of each component was re-included to form the modeled series of the original pollutant time series

Exploring the Usage of Social Networking Websites: Perceptions and Opinions of Romanian University Students

Social networking websites (SNWs) have become a popular virtual meeting place allowing users to voluntarily post personal information, send and receive message, stay connected online with their offline friends and new online friends, or share photos, videos, bookmarks, blogs, private messages and join groups. People are spending ample amount of time on social networking websites such as You Tube, Facebook, Google+, LinkedIn, Facebook, Twitter, Hi5 etc., and this high usage has also brought changes in the way people behave. These social networking websites present a variety of features for their users to facilitate socialization. This paper presents the results of a study aiming to identify the Romanian student opinions regarding SNWs. The main findings of this study are: the most frequently visited and most popular social networks among Romanian student are You Tube and Facebook; the majority of the respondents use social networking websites a few times a day; only a small part of the respondents know how social networking websites use published and other type of information; the usage of SNWs is related with the usage of computers and internet. Also the most important functions of SNWs for Romanian student are: communication (including communication in interest groups), learning and exchanging information, exchanging photo, video, friend search and texting

Exploring the Usability of Municipal Web Sites: A Comparison Based on Expert Evaluation Results from Four Case Studies

The usability of public administration web sites is a key quality attribute for the successful implementation of the Information Society. Formative usability evaluation aims at finding and reporting usability problems as early as possible in the development process. The objective of this paper is to present and comparatively analyze the results of an expert usability evaluation of 4 municipality web sites. In order to document usability problems an extended set of heuristics was used that is based on two sources: usability heuristics and ergonomic criteria. The explanatory power of heuristics was supplemented with a set of usability guidelines. The evaluation results revealed that a set of specific tasks with clearly defined goals helps to identify many severe usability problems that occur frequently in the municipality web sites. A typical issue for this category of web sites is the lack of information support for the user.Formative Usability Evaluation, User Testing, Expert Evaluation, Heuristic Evaluation, Ergonomic Criteria, Usability Problem, Municipal Web Sites

Propagation of uncertainty in atmospheric parameters to hyperspectral unmixing

Atmospheric correction (AC) is important in pre-processing of airborne hyperspectral imagery. AC requires knowledge on the atmospheric state expressed by atmospheric condition parameters. Their values are affected by uncertainties that propagate to the application level. This study investigates the propagation of uncertainty from column water vapor (CWV) and aerosol optical depth (AOD) towards abundance maps obtained by means of spectral unmixing. Both Fully Constrained Least Squares (FCLS) and FCLS with Total Variation (FCLS-TV) are applied. We use five simulated datasets contaminated by various noise levels. Three datasets cover two spectral scenarios with different endmembers. A univariate and a bivariate analysis are carried out on CWV and AOD. The other two datasets are used to analyze the effect of surface albedo. The analysis identifies trends in performance degradation caused by the gradual shift in parameter values from their true value. The maximum achievable performance depends upon spectral characteristics of the datasets, noise level, and surface albedo. As expected, under noisy conditions FCLS-TV performs better than FCLS. Our research opens new perspectives for applications where estimation of reflectance is so far considered to be deterministic

Ecotoxicological assessment of the effect of some new organic-mineral fertilizers on Eisenia foetida earthworms

Ecotoxicity tests provide a direct measure of the bioavailability of toxicants and help to establish linkages between site contamination and adverse ecological effects. There are more current laboratory test methods outlined, but it is very important the major advantages/disadvantages of each of them. The present paper uses as research methodology the OECD Guideline for testing of chemicals no. 207 which meets the most criteria expected for ecotoxicological testing. Earthworms Eisenia foetida (Savigny, 1826) had been exposed for 14 days to a geometrical series range of concentrations of the test substances (organic-mineral fertilizers L-200-Hum and SH-120). The performed study showed that the fertilizer L-200-Hum determined lower earthworm mortality comparing to SH-120 for all tested concentration levels and the fertilizer L-200-Hum positively influenced the earthworm rate of biomass accumulation. DL 50 it was established to be the concentration 4 g for the SH-120 fertilizer at the end of the test (14 days)

Influența calitǎții job-ului asupra creșterii performanțelor în activitatea de cercetare

Among the professional factors that influence performance in the research-development-innovation (RDI) activities are: quality of occupation, organization and management in RDI activity, professional development and organization resources. This article analyzes the influence of job quality in increasing the performance in RDI activities. The analysis was structured on three categories of factors that depend on the quality of employment, the quality of work and the professional development. The professional factors that have a great influence on performance (the average above 3.50) and that are linked to the quality of work are: salary level, flexibility of work schedule, work autonomy, job stability, individual work development program, and specialization stages