A validation of ergonomic criteria for the evaluation of human‐computer interfaces

This article presents the results of an experiment designed to validate a set of ergonomic criteria for the evaluation of human‐computer interfaces. Criteria definitions that were designed in a previous study, were tested in a concept‐identification task. Twenty‐four subjects (12 human factors specialists and 12 nonspecialists) were asked to identify the criterion, within a set of 18 elementary criteria, that was violated for each of 36 usability problems. The results show no difference between groups either in terms of performance times or correct identifications. The mean percentage of correct identifications was 59.85%. This result calls for the refinement of some definitions. A detailed examination of the data and an analysis of confusion matrices permits the identification of categories of well‐defined criteria and categories of criteria that would benefit from improvements in their definitions. These results seem to support the feasibility of an evaluation method based on explicitely defined criteria.     

Multi‐linguality in networking services: The MAITS project

The paper discuss the needs of users for multi‐language support in current networking services. The framework of a four‐level model for language processing for the provision of multi‐lingual support in networking services is presented. In addition, project MAITS, which is funded by the CEC under the Framework program and which is trying to provide solutions for smooth and friendly transparent language processing, based on the four level model, is briefly described. The current results of the project which enable a character sets conversion engine to provide the correct display of documents prepared in different languages to user client/browse, which lack the capability to negotiate the language and character sets content, are presented.     

Multi‐year circumpolar assessment of the area burnt in boreal ecosystems using SPOT‐VEGETATION

The Russian Academy of Sciences' Space Research Institute has developed a new burnt area mapping method and a five‐year database to estimate biomass burning in the Earth's entire boreal region. The mapping method involved SPOT‐VEGETATION time‐series data analysis to detect inter‐annual vegetation changes combined with MODIS hot‐spot data to distinguish fire‐related changes from other types of disturbances. The burnt area database actually covers the boreal biome for the period 2000–2004 with 1 km spatial resolution and 10‐day time frequency, while an automatic data processing chain allows this database to be updated continuously. The accuracy assessment involved comparison with Landsat‐ETM+ derived burnt area estimates for Northern Eurasia and ground data for Canada. This Letter describes the satellite sensor data processing method and the results of the accuracy assessment of the burnt area database and provides burnt area statistics for the boreal region countries.     

DEM‐optical‐radar data integration for palaeohydrological mapping in the northern Darfur,Sudan: implication for groundwater exploration

North‐western Sudan, as a part of the eastern Sahara, is among the driest places on earth. However, the region underwent drastic climatic changes through the alternation of dry and wet conditions in the past. During humid phases, when the rain was plentiful over a prolonged time period, the surface was veined by rivers and dotted by large lakes. The new Shuttle Radar Topography Mission data (SRTM ～90 m) revealed a large endorheic drainage basin, which is centred by a large terminal palaeolake, in the northern Darfur State. The use of GIS methods allowed the delineation of the drainage basin and its associated palaeorivers. The SRTM data along with the Landsat (ETM+) and Radarsat‐1 images corroborate the presence of segments of palaeoshorelines associated with the palaeolake highstands. These constitute a convincing argument of the long‐term existence of a possible pre‐Holocene large water body in the region in the past. The remains of the highest palaeoshoreline have a constant altitude of 573±3 m asl. At its maximum extent, the mega Lake occupied an area of about 30 750 km² (the same size as the Great Bear Lake, Canada's largest lake), which would have contained approximately 2530 km³ of water. This, ancestral lake, which we named the Northern Darfur Megalake (ND Megalake), represents indisputable evidence of the past pluvial conditions in the eastern Sahara. The discovered palaeoshorelines will have significant consequences for improving our knowledge of continental climate change and regional palaeohydorology, and should be taken into consideration in studies of past human habitation in the region. Much of the water carried by the Northern Darfur palaeorivers and the ND Megalake would have percolated into the underlying rocks feeding the Nubian Sandston aquifer. These findings show that the used approach of space‐data integration can help significantly in the groundwater exploration efforts in the Darfur region, where freshwater access is essential for refugee survival, and can be successfully adopted in other parts of Sudan and arid lands in general.     

River bed identification for check‐dam engineering using SPOT‐5 image in the HongShiMao watershed of the Loess Plateau,China

The Loess Plateau located in the upper and middle reaches of the Yellow River is the most serious soil erosion region in China. Check‐dams (also known as silt trappers) have been demonstrated to be an effective soil and water conservation measure in the region and a traditional workflow for check‐dam planning and engineering is time‐consuming and cannot meet the requirement of efficiently locating optimal check‐dam sites. Fine resolution satellite imagery and analysis can play a key role in screening and determining special river bed segments that can be candidates for check‐dam sites. In this research, HongShiMao watershed of the Loess Plateau was selected as our case study area. Based on a detailed analysis of spectral characteristics of a fused SPOT‐5 imagery for dominant land covers and geomorphological features of a constructed digital elevation model, the river bed of key channels within the watershed was automatically identified. Then we selected four check‐dam sites on the river bed and four orientations of a check‐dam site to explore locational and directional profiles. Such profile information is most useful for locating optimal check‐dam sites in a cost‐effective manner and reducing associated expenditures surrounding check‐dam constructions. This remote sensing application demonstrates the latest spatial information technologies such as fine resolution satellite imagery and 3D geospatial visualisation hold promises for changing traditional workflows and advancing scientific decision making of environmental conservation projects.     

Modelling,identification and control of sugar evaporation – theoretical design and experimental evaluation

This paper discusses the problem of controlling a multiple-stage industrial evaporator in a sugar factory. The control objectives are: syrup should have a sucrose concentration of 72%, the evaporator should produce the required amount of steam, and the steam consumption should be as low as possible. Achieving these objectives is difficult, due to the following plant features: strong disturbances, large time delays and many constraints. The control problem is solved by developing a physical model which is used as benchmark; then, a parametric identification is performed to obtain a control model. Finally, a successful real-time application of a multivariable GPC controller is presented.     

Developing knowledge‐based decision support systems in public sector administration: A case study in the treasury department,ministry of finance,Malaysia

Since its introduction in the early 1970s the Decision Support System (DSS) concept has attracted a lot of attention from academics as well as users from business organizations. The literature abounds with accounts of systems that are claimed to have used the concept. The common characteristics of most of these systems are that they rely heavily on the use of quantitative models. In ill‐structured and higher level decision making quantitative models are used in conjunction with the qualitative models; in these cases a different approach and method in DSS development needs to be adopted. The objectives of this paper are twofold: to give a brief overview of the concept of DSS and Knowledge‐Based Systems and to describe the approach adopted and experience gained in conceptual analysis and modelling of the decision making process in an attempt to develop a Knowledge‐Based Decision Support System for Public Sector Management.     

M-learning in review： Technology, standard and evaluation

Nowadays E-learning as a form of learning depending on networks and computer devices has been expanding by leaps and bounds. As a special kind of E-learning, M-learning （mobile learning） aims at the use of mobile devices anywhere at anytime by anybody. In this paper, the technologies to develop a M-learning system are deeply analyzed according to the layer model at first. Then, from the view of application, the standardization in M-learning is researched in order to accelerate the development and popularization of M-learning. Finally, quality estimation of M-learning system is discussed from the view of QoE （quality of experiences）. The experience form end-user is the sole effective norm to judge the result of M-learning technology. It is no doubt that technologies, standardization and evaluation will play very important parts in the course of M-leaming development.     

The assessment of leaf water content using leaf reflectance ratios in the visible,near‐, and short‐wave‐infrared

The common features of spectral reflectance from vegetation foliage upon leaf dehydration are decreasing water absorption troughs in the near‐infrared (NIR) and short‐wave‐infrared (SWIR). We studied which leaf water index in the NIR and SWIR is most suitable for the assessment of leaf water content and the detection of leaf dehydration from the laboratory standpoint. We also examined the influence of the thickness of leaves upon leaf water indices. All leaf water content indices examined exhibited basic correlations with the relative water content (RWC) of leaves, while the R ₁₃₀₀/R ₁₄₅₀ leaf water index also demonstrated a high signal strength and low variability (R ²>0.94). All examined leaf reflectance ratios could also be correlated with leaf thickness. The thickness of leaves, however, was not independent of leaf RWC but appeared to decrease substantially as a result of leaf dehydration.     

Small‐footprint,waveform‐resolving lidar estimation of submerged and sub‐canopy topography in coastal environments

The experimental advanced airborne research lidar (EAARL) is an airborne lidar instrument designed to map near‐shore submerged topography and adjacent land elevations simultaneously. This study evaluated data acquired by the EAARL system in February 2003 and March 2004 along the margins of Tampa Bay, Florida, USA, to map bare‐earth elevations under a variety of vegetation types and submerged topography in shallow, turbid water conditions. A spatial filtering algorithm, known as the iterative random consensus filter (IRCF), was used to extract ground elevations from a point cloud of processed last‐surface EAARL returns. Filtered data were compared with acoustic and field measurements acquired in shallow submerged (0–2.5 m water depth) and sub‐canopy environments. Root mean square elevation errors (RMSEs) ranged from 10–14 cm for submerged topography to 16–20 cm for sub‐canopy topography under a variety of vegetation communities. The effect of lidar sampling angles and global positioning system (GPS) satellite configuration on accuracy was investigated. Results show high RMSEs for data acquired during periods of poor satellite configuration and at large sampling angles along the edges of the lidar scan. The results presented in this study confirm the cross‐environment capability of a green‐wavelength, waveform‐resolving lidar system, making it an ideal tool for mapping coastal environments.     

Comparison of SeaWiFS,MODIS‐Terra and MODIS‐Aqua in the Southern Ocean

The surface chlorophyll‐a concentrations measured by SeaWiFS, MODIS‐Terra and MODIS‐Aqua are compared in the Southern Ocean in summer 2003. The radiometers generally agree within their estimated accuracy. Residual discrepancies could be reduced by regional calibrations of the bio‐optical algorithms.     

The development,validation, and application of a science curriculum delivery evaluation questionnaire for francophone‐minority settings

Abstract

The study described in this paper examines the procedures used in the identification of the broad and complex factors influencing science curriculum delivery in francophone‐minority settings where the teaching of science is the responsibility of non‐specialist science teachers. Furthermore, it describes the processes involved in the development and validation of an evaluation instrument, the Science Delivery Evaluation Instrument for Francophone‐minority Settings (SDEIFMS), used to identify factors influencing science program delivery. The study begins by exploring the themes generated from several qualitative studies pertaining to the phenomenon of science delivery in francophone‐minority settings in Saskatchewan and Manitoba. Subsequent to this, quantitative procedures used to develop and validate the SDEIFMS are presented. Finally, practical applications of the SDEIFMS as a part of an ongoing CRYSTAL initiative are also discussed.     

Outliers, inliers and the generalized least trimmed squares estimator in system identification

The least trimmed squares estimator (LTS) is a well known robust estinaator in terms of protecting the estimatefrom the outliers. Its high computational complexity is however a problem in practice. We show that the LTS estimate can be obtained by a simple algorithm with the complexity O( N In N) for large N, where N is the number of measurements. We also showthat though the LTS is robust in terms of the outliers, it is sensitive to the inliers. The concept of the inliers is introduced. Moreover, the Generalized Least Trimmed Squares estimator (GLTS) together with its solution are presented that reduces the effect of both the outliers and the inliers.     

Performance, interdependence and coordination in business‐to‐business electronic commerce and supply chain management

After discovering the inadequacy of traditional relationships across the value‐chain, many organizations today are establishing new forms of interorganizational systems with their suppliers and customers in an effort to improve total channel performance. Electronic commerce linkages are being created between independent organizations in multiple industries, including manufacturing, financial services, transportation, and retailing. Efforts to improve channel efficiency using business‐to‐business electronic commerce systems generally require increased interdependence and expanded coordination between independent firms to capture the potential benefits enabled by tighter interorganizational integration of operations. Participating firms can gain dramatic benefits from establishing electronic linkage only when the system is used to increase interdependence and to expand coordination between firms involved in the new interorganizational relationship. Drawing on theoretical and empirical research on electronic communications and inter‐firm designs, we develop and test a model for the relationship between performance, interdependence and coordination of firms involved in interorganizational relations within the US grocery channel. The research design includes qualitative case study analysis and quantitative survey data analysis to validate the key case study findings. Both qualitative and quantitative findings indicate that channel performance, interdependence, and coordination are closely related for firms in interorganizational relationships. This revised version was published online in July 2006 with corrections to the Cover Date.     

Land use studies in drylands: an evaluation of object‐oriented classification of very high resolution panchromatic imagery

Object‐oriented classification approaches offer an alternative to per‐pixel methods for assessment of land use and land cover. Combining object‐oriented approaches with very high resolution imagery may provide enhanced possibilities for applications requiring land use and land cover data. The aim of this study is to evaluate the application of object‐oriented classification of panchromatic very high resolution data in African drylands, where sizes and shapes of fields are varied, and intercropping practised, which might lead to difficulties in image segmentation. The results show that region‐based segmentation is sensitive to the proportion of spectral and shape information and the best results were gained when the segmentation was based on predominately spectral information. The accuracy (Kappa value of 0.6) for the object‐oriented classification was significantly higher than that for per‐pixel classification. However, both the segmentation and the classification were time‐consuming based on a trial and error process.     

Eco‐environmental evaluation with remote sensing in the middle and upper areas of the Yellow River drainage basin

Based on remote sensing data and investigations, this paper focuses mainly on a general evaluation of environmental quality in the middle‐upper areas of the Yellow River region using GIS technology, Arc/Info, and ArcView. In this paper, the upper areas of the Yellow River regions are divided into three parts: the north‐east Qinghai‐Tibet Plateau ecosystem areas, the Erdos Plateau‐Hetao Plain ecosystem areas, and the Loess‐Plateau ecosystem areas. The study analyses the current environmental situation and the overall environmental quality in each ecosystem area and determines the law of distribution of environmental quality in the three areas. Finally, the paper provides some suggestions to improve the ecological environment in each area, in the hope of yielding a scientific foundation based on planning ecological environment protection in the Yellow River basin.     

Teaching of a computer literacy course in South Africa: A case study using traditional and co‐operative learning

Abstract

The Department of Informatics at the University of Pretoria in South Africa has been involved in a research project funded by the Foundation for Research and Development (FRD) since 1996. The main focus of this project is to establish computer‐supported co‐operative learning centres in various rural communities. The case study described in this paper discusses a part of this project that was undertaken during 1998. The paper outlines the computer literacy course where co‐operative learning and traditional learning methods were used. A discussion about co‐operative learning and traditional learning, with specific reference to the implementation of the two methods at SEIDET, is presented. An outline of the research results based on a questionnaire completed by the teachers who took part in the case study, is given. Although most of the teachers preferred the traditional and known method of teaching that was used for the MsExcel part of the course, they indicated that they have learnt more using the co‐operative learning method.     

Estimation of chlorophyll‐a concentration in Lake Tai,China using in situ hyperspectral data

Reflectance spectra of water in Lake Tai of East China were measured at 28 monitoring stations with an ASD FieldSpec spectroradiometer at an interval of 1.58 nm over five days in each month from June to August of 2004. Water samples collected at these stations were analyzed in the laboratory to determine chlorophyll‐a (chl‐a) concentration. Twenty‐eight spectral reflectance curves were standardized and correlated with chl‐a concentration. Examination of these curves reveals a peak reflectance at 719 nm. Chl‐a concentration level in the Lake was most closely correlated with the reflectance near 700 nm. If regressed against the reflectance at the wavelength of 667 nm (R ₆₆₇), chl‐a concentration was not accurately estimated at R ² = 0.494. Accuracy of estimation was improved to R ² = 0.817 using the maximum reflectance. A higher accuracy of 0.837 was achieved using the peak reflectance at 719 nm (R ₇₁₉) because it does not drift with the level of chl‐a concentration. The highest accuracy of estimation was achieved at R ² = 0.868 using R ₇₁₉/R ₆₆₇.     

Comments on: “Continuous time model identification from sampled data: implementation and performance evaluation”, Garnier,Mensler and Richard (2003)

This note extends the discussion of the above paper with respect to the finite time integration method of data preparation for continuous time system identification of linear systems.