Visualising user–website interaction: description and evaluation of a teaching method

This paper presents a teaching method applied in a usability research course that is part of a bachelor degree programme at the Academy of Fine Arts in Katowice. The method employs visualisation techniques of the user–website interaction, a design practice popular in other fields, but less often used in usability studies. The theoretical background of the data visualisation method, as well as examples of its use in research, are presented and discussed in this paper. In addition to presenting the method, the paper evaluates and analyses how students have responded to it. Using the technology acceptance model, we identified the perceived usability of the method as the main factor influencing students’ behavioural intention to use it in the future.

     

CANDE: a versatile soil—structure design and analysis computer program

This paper introduces CANDE, a new computer program for the structural design, analysis, and evaluation of buried culverts or other soil—structure interaction problems. Structures composed of corrugated steel, corrugated aluminium, reinforced concrete, and structural plastic may be designed and/or analysed for incremented soil loading and live loading. Both the soil mass and structure are incorporated into an incremental, static, plane-strain formulation and solved by a chosen solution level. There are three solution levels corresponding to successive increases in analytical power. Level 1 is a closed form elasticity solution, whereas levels 2 and 3 are based on the finite element method. Level 2 employs a completely automated finite element mesh generation scheme suitable for most culvert installations, thus no special knowledge of finite element mesh construction is required for this level. Level 3 applies to an arbitrary soil—structure configuration, but requires a user-defined finite element mesh topology. The solution level concept permits the user to choose a degree of rigour and cost commensurate with the worth of a particular project and confidence in input parameters.Analytical modelling features include incremental construction, nonlinear soil models, structural models for ductile yielding and cracking, and special interface models for frictional sliding, debonding and rebonding.Example applications demonstrate the results of: frictional interfaces between culvert and soil, comparing predicted and experimental data, and investigating parameters of long-span soil structures.     

Design and evaluation of MagnetViz—a graph visualization tool

MagnetViz was designed for the interactive manipulation of force-directed graph layouts, allowing the user to obtain visualizations based on the graph topology and/or the attributes of its nodes and edges. The user can introduce virtual magnets anywhere in the graph and these can be set to attract nodes and edges that fulfill user-defined criteria. When a magnet is placed, the force-directed nature of the layout forces it to reorganize itself in order to reflect the changes in the balance of forces, consequently changing the visualization into one that is more semantically relevant to the user. This paper describes MagnetViz’s concepts, illustrating them with examples and a case study based on a usage scenario. We also describe how the MagnetViz has evolved since its original version and present the evaluation of its latest version. This evaluation consists of two user studies aiming at assessing generated layout quality and how well the concepts can be apprehended and employed, and a task taxonomy assessment focusing on establishing which graph visualization tasks the technique is able to handle.     

Single-mode—multimode—single-mode and lossy mode resonance-based devices: a comparative study for sensing applications

In this work, a thin-film consisting of 15 bilayers (estimated thickness: 210 nm) of titanium (IV) oxide and poly(sodium 4-styrenesulfonate) is simultaneously deposited onto two optical fiber structures: a single-mode—multimode—single-mode (SMS) device and a lossy mode resonance (LMR)-based device. The performance of both structures, as refractometers and relative humidity sensors, is studied and compared. In both cases, the sensitivity of the LMR-based device (955 nm/RIU and 3.54 nm/RH %, respectively) highly improves the one of the SMS (142 nm/RIU and 0.3 nm/RH %). These facts can be taken into account when developing sensors based on either SMS or LMR technologies.     

Assimilating satellite imagery and visible–near infrared spectroscopy to model and map soil loss by water erosion in Australia

Soil loss causes environmental degradation and reduces agricultural productivity over large areas of the world. Here, we use the latest earth observation data and soil visible–near infrared (vis–NIR) spectroscopy to estimate the factors of the Revised Universal Soil Loss Equation (RUSLE) and to model soil loss by water erosion in Australia. We estimate rainfall erosivity (R) using the Tropical Rainfall Measuring Mission (TRMM); slope length and steepness (L and S) using a 3-arcsec Shuttle Radar Topography Mission (SRTM) digital elevation model; cover management (C) and control practice (P) using the national dynamic land cover dataset (DLCD) of Australia derived from the moderate-resolution imaging spectroradiometer (MODIS); and soil erodibility (K) using vis–NIR estimates of the contents of sand, silt, clay and organic carbon in Australian soil. We model K using a machine-learning algorithm with environmental predictors selected to best capture the factors that influence erodibility and produced a digital map of K. We use the derived RUSLE factors to estimate soil loss at 1-km resolution across the whole of Australia. We found that the potential gross average soil loss by water erosion in Australian is 1.86 t ha⁻¹ y⁻¹ (95% confidence intervals of 1.78 and 1.93 t ha⁻¹ y⁻¹), equivalent to a total of 1242 × 10⁶ tonnes of soil lost annually (95% confidence intervals of 1195 and 1293 t × 10⁶ y⁻¹). Our estimates of erosion are generally smaller than previous continental estimates using the RUSLE, but particularly in croplands, which might indicate that soil conservation practices effectively reduced erosion in Australia. However we also identify localized regions with large erosion in northern Australia and northeastern Queensland. Erosion in these areas carries sediments laden with nitrogen, phosphorus and pollutants from agricultural production into the sea, negatively affecting marine ecosystems. We used the best available data and our results provide better estimates compared to previous assessments. Our approach will be valuable for other large, sparsely sampled areas of the world where assessments of soil erosion are needed.     

Accuracy,robustness and behavior of the STICS soil–crop model for plant,water and nitrogen outputs: Evaluation over a wide range of agro-environmental conditions in France

Soil–crop models are increasingly used as predictive tools to assess yield and environmental impacts of agriculture in a growing diversity of contexts. They are however seldom evaluated at a given time over a wide domain of use. We tested here the performances of the STICS model (v8.2.2) with its standard set of parameters over a dataset covering 15 crops and a wide range of agropedoclimatic conditions in France. Model results showed a good overall accuracy, with little bias. Relative RMSE was larger for soil nitrate (49%) than for plant biomass (35%) and nitrogen (33%) and smallest for soil water (10%). Trends induced by contrasted environmental conditions and management practices were well reproduced. Finally, limited dependency of model errors on crops or environments indicated a satisfactory robustness. Such performances make STICS a valuable tool for studying the effects of changes in agro-ecosystems over the domain explored.     

WEC-C: a distributed,deterministic catchment model — theory,formulation and testing

WEC-C is a distributed, deterministic, catchment-scale water flow and solute transport model containing a number of innovations not present in comparable models. For example, it allows for the imposition of catchment topological changes resulting from land uses such as surface mining. In addition, it features preferential vertical flow in the vadose zone modelled using a dual continuum approach. Numerically, it differs from many existing models in that it employs a direct linkage between the vertical and lateral solvers of its split-solver scheme and, due to its use of explicit solvers, is stable regardless of the form of the soil moisture characteristic curves. The WEC-C model framework is a rectangular grid of uniform cell size in the lateral plane combined with a system of soil layers, of variable thickness, in the vertical direction. Within this structure, the governing equations for flow and transport are discretised and solved. All parameters are defined locally in each computational cell so that all available data on catchment variability can be incorporated directly into the model. This paper describes the formulation of WEC-C, which is based on operator splitting with first-order accurate solvers for both the vertical and lateral flow and transport models. WEC-C was subjected to four stringent, synthetic tests designed to evaluate its accuracy by comparison with available analytical and numerical solutions. These showed that there were scale issues associated with the model, and that induced numeric dispersion of solutes could be significant. Nonetheless, it is suggested that WEC-C is still useful as a distributed catchment model.     

IPES—a program system for inorganic properties estimation and evaluation

An overview is given for the Inorganic Properties Estimation and evaluation System, IPES. The system is developed to provide comprehensive data of inorganic property services and assist in evaluating relevant data. The important features of IPES are to intelligently deal with the problems concerned and provide flexible and effective execution modes for the user.     

Selecting the best statistical distribution—a comment and a suggestion on multi-criterion evaluation

An interesting new approach for selecting a distribution to describe the observed data has been presented in a paper recently published in Computers and Industrial Engineering. While appreciating the new contribution of the paper, we highlight an important difficulty with their method and suggest that data envelopment analysis (DEA) could be advantageously used to improve the multi-criterion evaluation.     

Information search and paid results — proposition and test of a hierarchy-of-effect model

Search engines stand as the first entry point to internet resources for 70% of users. The results page is therefore an appealing place for advertising in the form of sponsored links also called paid results. Yet little academic knowledge has been developed to understand users’ perceptions and behaviors toward sponsored links. In particular it is of foremost importance to delineate factors that influence click intention and behavior. This paper proposes a hierarchy-of-effects model in order to understand surfers’ click on sponsored links. An empirical study is conducted over 349 participants confronted to three different Search Engine Result Pages (SERP) representing three search situations. Results indicate a significant relationship between attitude toward sponsored links and behavioral intention. In addition, past satisfaction is found to significantly predict click behavior. The contribution of this study for both researchers and practitioners is discussed.     

Location-based services deployment and demand: a roadmap model

The advancements in mobile, wireless and positioning technologies have enabled applications and services such as route guiding and emergency call-out assistance. These and other similar services have become known as ‘location-based services’ (LBS). The literature on LBS development and deployment addresses technological issues (for example, usability and integration) and issues related to LBS implementation—including LBS business models, adoption and customer concerns and requirements. In the study presented here LBS development and deployment were investigated from a case study perspective and the LBS landscape is explored and analyzed. The study finds that while the regulatory environment has played a critical role as a success factor in the markets investigated some of innovative business approaches may have been equally important as customer demand generators. Economies on the road to deploying LBS should therefore focus on creating a supportive environment encouraging the development of services, which meet the identified needs and requirements of the target customer market.     

3D-line clipping algorithms — a comparative study

Some well-known line-polyhedron intersection methods are summed up and new accelerating modifications presented. Results of comparison of known and newly developed methods are included. New methods use the fact that each line can be described as the intersection of two planes.     

Accessibility,usability, and security evaluation of universities’ prospective student web pages: a comparative study of Europe,North America,and Oceania

Universal Access in the Information Society - Universities' prospective student web pages aim to disseminate information about their academic and social opportunities to their stakeholders;...     

SCUT-COUCH2009—a comprehensive online unconstrained Chinese handwriting database and benchmark evaluation

A comprehensive online unconstrained Chinese handwriting dataset, SCUT-COUCH2009, is introduced in this paper. As a revision of SCUT-COUCH2008 [1], the SCUT-COUCH2009 database consists of more datasets with larger vocabularies and more writers. The database is built to facilitate the research of unconstrained online Chinese handwriting recognition. It is comprehensive in the sense that it consists of 11 datasets of different vocabularies, named GB1, GB2, TradGB1, Big5, Pinyin, Letters, Digit, Symbol, Word8888, Word17366 and Word44208. In particular, the SCUT-COUCH2009 database contains handwritten samples of 6,763 single Chinese characters in the GB2312-80 standard, 5,401 traditional Chinese characters of the Big5 standard, 1,384 traditional Chinese characters corresponding to the level 1 characters of the GB2312-80 standard, 8,888 frequently used Chinese words, 17,366 daily-used Chinese words, 44,208 complete words from the Fourth Edition of “The Contemporary Chinese Dictionary”, 2,010 Pinyin and 184 daily-used symbols. The samples were collected using PDAs (Personal Digit Assistant) and smart phones with touch screens and were contributed by more than 190 persons. The total number of character samples is over 3.6 million. The SCUT-COUCH2009 database is the first publicly available large vocabulary online Chinese handwriting database containing multi-type character/word samples. We report some evaluation results on the database using state-of-the-art recognizers for benchmarking.     

Evaluation of user interfaces: EVADIS II— a comprehensive evaluation approach

Abstract

As a result of the importance of the usability approach in system development and the EC's ‘Directive concerning the minimum safety and health requirements for VDT workers’ (EWG 1990), there is an accepted need for practical evaluation methods for user interfaces. The usability approach and the EC Directive are not restricted to user interface design, as they include the design of appropriate hardware and software, as well as organization, job, and task design. Therefore system designers are faced with many, often conflicting, requirements and need to address the question, ‘How can usability requirements comprehensively be considered and evaluated in system development?’ Customers buying hardware and software and introducing them into their organization ask, (How can I select easy-to-use hardware and software?’ Both designers and customers need an evaluation procedure that covers all the organizational, user, hard- and software requirements. The evaluation method, EVADIS.II, we present in this paper overcomes characteristic deficiencies of previous evaluation methods. In particular, it takes the tasks, the user, and the organizational context into consideration during the evaluation process, and provides computer support for the use of the evaluation procedure.     

End-to-end transmission of scalable video contents: performance evaluation over EvalSVC—a new open-source evaluation platform

Multimedia Tools and Applications - Scalable Video Coding (SVC) is the latest extension of the famous Advance Video Coding (AVC) standard. Scalability is important and useful because it is...