Web Development

The Web of Data is an open environment consisting of a great number of large inter-linked RDF datasets from various do-mains. In this environment, organizations and companies adopt the Linked Data practices utilizing Semantic Web (SW) tech-nologies, in order to publish their data and offer SPARQL endpoints (i.e., SPARQL-based search services). On the other hand, the dominant standard for information exchange in the Web today is XML. Additionally, many international standards (e.g., Dublin Core, MPEG-7, METS, TEI, IEEE LOM) in several domains (e.g., Digital Libraries, GIS, Multimedia, e-Learning) have been expressed in XML Schema. The aforementioned have led to an increasing emphasis on XML data, accessed using the XQuery query language. The SW and XML worlds and their developed infrastructures are based on different data models, semantics and query languages. Thus, it is crucial to develop interoperability mechanisms that allow the Web of Data users to access XML datasets, using SPARQL, from their own working environments. It is unrealistic to expect that all the existing legacy data (e.g., Relational, XML, etc.) will be transformed into SW data. Therefore, publishing legacy data as Linked Data and providing SPARQL endpoints over them has become a major research challenge. In this direction, we introduce the SPARQL2XQuery Framework which creates an interoperable environment, where SPARQL queries are automatically translated to XQuery queries, in order to access XML data across the Web. The SPARQL2XQuery Framework provides a mapping model for the expression of OWL–RDF/S to XML Schema mappings as well as a method for SPARQL to XQuery translation. To this end, our Framework supports both manual and automatic mapping specification between ontologies and XML Schemas. In the automatic mapping specification scenario, the SPARQL2XQuery exploits the XS2OWL component which transforms XML Sche-mas into OWL ontologies. Finally, extensive experiments have been conducted in order to evaluate the schema transfor-mation, mapping generation, query translation and query evaluation efficiency, using both real and synthetic datasets.

Data exploration and visualization systems are of great importance in the Big Data era, in which the volume and
heterogeneity of available information make it difficult for humans to manually explore and analyse data. Most traditional systems
operate in an offline way, limited to accessing preprocessed (static) sets of data. They also restrict themselves to dealing
with small dataset sizes, which can be easily handled with conventional techniques. However, the Big Data era has realized the
availability of a great amount and variety of big datasets that are dynamic in nature; most of them offer API or query endpoints
for online access, or the data is received in a stream fashion. Therefore, modern systems must address the challenge of on-the-fly
scalable visualizations over large dynamic sets of data, offering efficient exploration techniques, as well as mechanisms for
information abstraction and summarization. Further, they must take into account different user-defined exploration scenarios
and user preferences. In this work, we present a generic model for personalized multilevel exploration and analysis over large
dynamic sets of numeric and temporal data. Our model is built on top of a lightweight tree-based structure which can be efficiently
constructed on-the-fly for a given set of data. This tree structure aggregates input objects into a hierarchical multiscale
model. We define two versions of this structure, that adopt different data organization approaches, well-suited to exploration and
analysis context. In the proposed structure, statistical computations can be efficiently performed on-the-fly. Considering different
exploration scenarios over large datasets, the proposed model enables efficient multilevel exploration, offering incremental construction
and prefetching via user interaction, and dynamic adaptation of the hierarchies based on user preferences. A thorough
theoretical analysis is presented, illustrating the efficiency of the proposed model. The proposed model is realized in a web-based
prototype tool, called SynopsViz that offers multilevel visual exploration and analysis over Linked Data datasets. Finally, we
provide a performance evaluation and a empirical user study employing real datasets.

In Lake Krankesjön, southern Sweden, sago pondweed (Potamogeton pectinatus L.) and a stonewort (Chara tomentosa L.) expanded spatially during the second half of the 1980's after more than a decade of phytoplankton blooms and sparse submerged vegetation. During ...

Public sector bodies are increasingly relying on the Internet. On this channel, indispensable information is transmitted to the public and a wide range of services is already available. Therefore, the usability, accessibility, and the security of these websites are very important. Accessibility is particularly crucial for persons with disabilities. The accessibility of public service websites is regulated by a number of laws; among others, the directive "on the accessibility of the websites and mobile applications of public sector bodies" adopted by the European Parliament in 2016. This obliges all European Union member states to make all public sector websites and mobile applications accessible by 23 September 2021. In practice, this means that websites must fulfil the level AA recommendations in WCAG 2.1. In our study, a website assessment method is developed by comparing different analytical tools. With this method, we analysed how Hungarian websites of public sector bodies fulfil the requirements of the directive. We have also investigated how well they comply with usability and security guidelines. The results showed that none of the 25 websites of the examined Hungarian public sector bodies could completely fulfil the recommendations of the Web Content Accessibility Guidelines (WCAG) and that half of the websites had only the lowest level of compliance in usability tests. From the security point of view, almost half of the websites use outdated server versions and programming language, which is very critical. We have proposed several suggestions to address the major problems , so website developers and administrators can improve the accessibility, usability, and security aspects of these websites.

We describe a survey of Web developers in which we collected over 300 responses from individuals with widely varying levels of experience and training. This survey continues our studies of informal Web developers, loosely defined as those who develop Web sites but have not been trained as programmers. They are a growing segment of end user programmers, but very little is known about them, and this survey was aimed at helping to characterize this population. In this paper we report on survey questions probing Web ...

Web sites are increasingly adapted towards their users by a variety of dynamic techniques, providing improved personalization for the individual. In this paper we discuss various possible approaches from a museological as well as a technical point of view. A number of Web sites, some produced by museums and some in other fields such as e-commerce or Internet based information services, will be considered as case studies. All use personalization techniques in ways that could be beneficial also for the cultural sector. Other possible applications such as audio guides or interactive devices will also be considered, especially with respect to how this technique could help in the personalization of museum Web sites. Currently most museums lag well behind the state of the art with respect to on-line personalization. Perhaps this paper will inspire some museums to add personalization facilities to their Web sites the next time they undertake major updates.

Keywords: Personalization, customization, adaptivity, adaptability, museums, Web sites.

I want freedom for the full expression on my personality.
- Mahatma Gandhi (1869-1948)

Introduction Web sites are developed by a wide variety of companies from small one or two person operations to large corporations with entire teams and departments devoted to web development work. Many of the smaller companies have no usability professionals to help with the design of their sites; many of the companies don't even realize they should have usability professionals assess their sites Often, budget constraints prohibit hiring a usability professional. Furthermore, the time line for development may not allow for usability testing and iterative design. Traditional usability methods are expensive, time consuming, and many require professional usability engineers. The environment in which web sites are designed cannot easily support these constraints. Our approach assumes that evaluation of web sites must be rapid, remote, and as automated as possible. In this paper, we'll discuss three software tools and two techniques that we have developed to facilitate q

The challenge of developing more usable Web applications has motivated the appearance of a number of techniques, methods and tools to address Web usability issues. Although there are many proposals for supporting the development of usable Web applications, many developers are not aware of them and many organizations do not properly apply them. This paper reports on a systematic review of the use of usability evaluation methods in Web development. The objective of the review is to investigate what usability evaluation methods have been employed by researchers to evaluate Web artifacts and how they were employed. A total of 51 research papers have been reviewed from an initial set of 410 papers. The results show that 45% of the papers reviewed reported the use of evaluation methods specifically crafted for the Web and that the most employed method is user testing. In addition, the results of the review have identified several research gaps. Specifically, 80% of the evaluations are still performed at the implementation phase of Web applications development and 47% of the papers did not present any validation of the usability evaluation method(s) employed.

End-users who are nonprogrammers create web applications by using advanced web development tools. However, these tools are not supported by any methodological process which produces that web applications are of low quality. This paper presents an approach to bring web engineering principles to the end-user community. We complement the web engineering method OOWS with tools that allow end-users to develop web applications by: (1) describing web applications in terms of the end-users’ knowledge about the application domain, (2) automatically obtaining a web application prototype by means of the OOWS code generation strategy, and (3) personalizing the web application look and feel by simply selecting a design template. To achieve this, an ontology-based strategy is introduced to support end-users throughout the web application development. We also introduce a strategy that allows us to define domain-independent presentation templates.

After more than a decade of web developments and some deafening fiascos, it has become clear that it is not possible to face the development of large scale web systems without following a systematic and well-defined process to guarantee quality, measurability, ...

Web engineering, an emerging new discipline, advocates a process and a systematic approach to development of high quality Web based systems. In contrast the commercial practice still remains ad-hoc. Although the Web based systems has become increasingly complex, the development process is still un-engineered. "There are very few standard methods for the Web developers to use. Hence, there is a strong need to understand and undertake Web engineering ". (Y. Deshpande and M. Gaedke, 2005) This paper is a result of our extensive survey of literature, our work and interaction with developers. This paper gives an introductory overview on Web engineering, it assesses similarities and differences between development of traditional software and Web based systems, and reviews some of the ongoing work in this area. We discuss the need for development of process model for Web based applications (WBA). such as is available far conventional software, with an overview of our work on development of such a process framework (R. Ahmad, et al, 2005). This paper also attempts to highlight the areas that need further study.

This paper focuses on the evaluation of quality perceptions from users of an electronic government website. As government organizations have begun to enhance transparency, communicate and interact with citizens via the Web, developing appropriate online services has demanded heightened understanding of the requirements of users and appropriate tailoring of solutions. The site examined in the paper enables the online submission of self-assessed tax returns in the UK. Survey data collected via the eQual ...