Modelling dynamic web data

We introduce Xd¼, a peer-to-peer model for reasoning about the dynamic behaviour of web data. It is based on an idealised model of semistructured data, and an extension of the ¼-calculus with process mobility and with operations for interacting with data. Our model can be used to reason about behaviour found in, for example, dynamic web page programming, applet interaction, and service orchestration. We study behavioural equivalences for Xd¼, motivated by examples

Bioaccumulation modelling and sensitivity analysis for discovering key players in contaminated food webs: the case study of PCBs in the Adriatic Sea

Modelling bioaccumulation processes at the food web level is the main step to analyse the effects of pollutants at the global ecosystem level. A crucial question is understanding which species play a key role in the trophic transfer of contaminants to disclose the contribution of feeding linkages and the importance of trophic dependencies in bioaccumulation dynamics. In this work we present a computational framework to model the bioaccumulation of organic chemicals in aquatic food webs, and to discover key species in polluted ecosystems. As a result, we reconstruct the first PCBs bioaccumulation model of the Adriatic food web, estimated after an extensive review of published concentration data. We define a novel index aimed to identify the key species in contaminated networks, Sensitivity Centrality, and based on sensitivity analysis. The index is computed from a dynamic ODE model parametrised from the estimated PCBs bioaccumulation model and compared with a set of established trophic indices of centrality. Results evidence the occurrence of PCBs biomagnification in the Adriatic food web, and highlight the dependence of bioaccumulation on trophic dynamics and external factors like fishing activity. We demonstrate the effectiveness of the introduced Sensitivity Centrality in identifying the set of species with the highest impact on the total contaminant flows and on the efficiency of contaminant transport within the food web

Generating dynamic higher-order Markov models in web usage mining

Markov models have been widely used for modelling users’ web navigation behaviour. In previous work we have presented a dynamic clustering-based Markov model that accurately represents second-order transition probabilities given by a collection of navigation sessions. Herein, we propose a generalisation of the method that takes into account higher-order conditional probabilities. The method makes use of the state cloning concept together with a clustering technique to separate the navigation paths that reveal differences in the conditional probabilities. We report on experiments conducted with three real world data sets. The results show that some pages require a long history to understand the users choice of link, while others require only a short history. We also show that the number of additional states induced by the method can be controlled through a probability threshold parameter

Developing Data Extraction and Dynamic Data Visualization (Styling) Modules for Web GIS Risk Assessment System (WGRAS)

Interactive web-GIS tools play an important role in determining disaster risk assessment which ultimately result in reduction of unexpected damages, cost and saves millions of lives. Disaster management practitioners largely benefited information at their disposal about location where possible incidents are eminent, anticipate the impact and project possible outcomes to help mitigate and organize proper response. It is also important to note that, accurate and timely information is critical for coherent coordination in response to disasters. All the above can be achieved through proper data collection combined with computer assisted modelling, analysis, production and timely dissemination of spatial information. This Master’s thesis aims to extend features of Web GIS for Risk Assessment (WGRAS) project conducted at the Department of Physical Geography and Ecosystem Science at Lund University. The work includes development of tools for geospatial data acquisition and extraction from freely available external open non-commercial sources and dynamic, user-oriented map Visualization allowing user-defined symbolization and coloring resulting flexible visual portrayal of geospatial data in the web environment. In this regard, solutions are driven based upon open source, open data and implementation strictly complies with open web standard protocols and web services. As a result, WGRAS is furnished with easy and user driven raw geo-spatial data extracts for an area of interest from OpenStreetMap (OSM). Thus, data is automatically stored for later use for different spatial modelling and analysis. The second most important contribution of this thesis is the feature developed to solve visualization of geographic information through a map server where maps are generated with a pre-defined style that limits user’s visual needs. Visualization module enables dynamic definition of style (symbolization and coloring) data which assist non-GIS expert to produce instant and meaningful presentation of maps to the end user. Overall, the work in this practical thesis adds value to disaster management and analysis in terms of easy provision of data and enabling clear dissection of disaster prone areas using effective visualization mechanism.Interactive web-GIS tools play an important role in determining disaster risk assessment which ultimately result in reduction of unexpected damages, cost and saves millions of lives. Disaster management practitioners largely benefited information at their disposal about location where possible incidents are eminent, anticipate the impact and project possible outcomes to help mitigate and organized response. It is also important to note that, accurate and timely information is critical for coherent coordination in response to disasters. This can be achieved through proper data collection combined with computer assisted modelling, analysis, production and timely dissemination of spatial information. This Master’s thesis aims to extend features of Web GIS for Risk Assessment (WGRAS) project conducted at the Department of Physical Geography and Ecosystem Science at Lund University. Modules are developed to enable easy integration of geospatial data extraction from freely available sources which are open to use and non-commercial. Implementation is facilitated with intuitive user interface which allows extracts for an area by location name(s) or area defined by two latitude and two longitude values. The other major contribution of the study focuses on visualization of geographic information in the web environment. Currently, map servers use pre-defined styling mechanism which virtually doesn’t satisfy user’s visual needs. This module enable dynamic and user-oriented map visualization allowing non-GIS experts to define (symbolization and colouring) and produce instant and meaningful presentation of maps to the end user. As recommendation, visualization of geographic data in the web environment should further be examined, especially the map servers in use should integrate powerful and meaningful dynamic styling on top existing pre-defined style. In conclusion, this thesis adds value for disaster management and analysis in terms of easy provision of geographic data and enabling clear dissection of disaster prone areas using effective visualization mechanism

What effect does web-based information sources have on dynamic capabilities, and furthermore performance, in service firms compared to manufacturing firms?

This article examines the effect web-based information sources have on dynamic capabilities, and furthermore performance, in service and manufacturing firms. To our knowledge, there are no studies that address a comparison between service and manufacturing firms inside the aforementioned research area. Previous research points to several differences in the aforementioned firm types, which underlines the importance of a comparison between service and manufacturing firms regarding this topic. The research question of the thesis is therefore: “What effect does web-based information sources have on dynamic capabilities, and furthermore performance, in service firms compared to manufacturing firms”. We have made a research model that makes the foundation of our approach to this study. The study is a quantitative study, where we utilize a questionnaire to approach managers and board members of service and manufacturing firms. Additionally, it is a correlation study, which is based on a deducting strategy, with testing of hypotheses. We used the data analysis program AMOS 23, using structural equation modelling (SEM) to analyze the gathered data material from the questionnaire. The result of the study shows that the effect web-based information sources have on the dynamic capabilities sensing, seizing, and reconfiguring, and furthermore performance, is just as strong, and in most cases more so, in manufacturing firms in comparison to service firms

What effect does web-based information sources have on dynamic capabilities, and furthermore performance, in service firms compared to manufacturing firms?

This article examines the effect web-based information sources have on dynamic capabilities, and furthermore performance, in service and manufacturing firms. To our knowledge, there are no studies that address a comparison between service and manufacturing firms inside the aforementioned research area. Previous research points to several differences in the aforementioned firm types, which underlines the importance of a comparison between service and manufacturing firms regarding this topic. The research question of the thesis is therefore: “What effect does web-based information sources have on dynamic capabilities, and furthermore performance, in service firms compared to manufacturing firms”. We have made a research model that makes the foundation of our approach to this study. The study is a quantitative study, where we utilize a questionnaire to approach managers and board members of service and manufacturing firms. Additionally, it is a correlation study, which is based on a deducting strategy, with testing of hypotheses. We used the data analysis program AMOS 23, using structural equation modelling (SEM) to analyze the gathered data material from the questionnaire. The result of the study shows that the effect web-based information sources have on the dynamic capabilities sensing, seizing, and reconfiguring, and furthermore performance, is just as strong, and in most cases more so, in manufacturing firms in comparison to service firms

Data Modeling of Physical-Mechanical Processes in Nanoconcrete with the Ensemble of Pores

This paper assesses the strength of nano concrete and methods of strengthening it by adding nanoparticles. Since concrete structures are exposed to the environment and external influences, there is a need to enhance resistance to destruction. Modelling of behaviour and the nature of changes in indicators of chemical shrinkage and destructive load is performed. Data analysis is executed based on the data of ordinary portland cement pastes and cement-fly ash pastes. The results are compared with admixtures to these materials of three nanomaterials: nanolimestone, nanosilica, and nanoclay. The percentage ratio for compressive strength for materials is established. The data processing and visualization of the results are presented using an interactive web page using dynamic mathematical calculations of approximation and interpolation based on the entered data. The data is processed using modern open-source libraries and stored in the database. The work aims to develop a methodological approach for modelling physico-mechanical processes in nano concrete, considering nanoparticles and an ensemble of pores

CSynth: An Interactive Modelling and Visualisation Tool for 3D Chromatin Structure

Motivation The 3D structure of chromatin in the nucleus is important for gene expression and regulation. Chromosome conformation capture techniques, such as Hi-C, generate large amounts of data showing interaction points on the genome but these are hard to interpret using standard tools. Results We have developed CSynth, an interactive 3D genome browser and real-time chromatin restraint-based modeller to visualise models of any chromosome conformation capture (3C) data. Unlike other modelling systems CSynth allows dynamic interaction with the modelling parameters to allow experimentation and effects on the model. It also allows comparison of models generated from data in different tissues / cell states and the results of third-party 3D modelling outputs. In addition, we include an option to view and manipulate these complicated structures using Virtual Reality (VR) so scientists can immerse themselves in the models for further understanding. This VR component has also proven to be a valuable teaching and public engagement tool. Availability CSynth is web based and available to use at https://csynth.org

Modelling data intensive web sites with OntoWeaver

This paper illustrates the OntoWeaver modelling approach, which relies on a set of comprehensive site ontologies to model all aspects of data intensive web sites and thus offers high level support for the design and development of data-intensive web sites. In particular, the OntoWeaver site ontologies comprise two components: a site view ontology and a presentation ontology. The site view ontology provides meta-models to allow for the composition of sophisticated site views, which allow end users to navigate and manipulate the underlying domain databases. The presentation ontology abstracts the look and feel for site views and makes it possible for the visual appearance and layout to be specified at a high level of abstractio