Prof. S.H. von Solms

M. Ing. / Change management is a crucial component in the daily activities inherent within the civil engineering industry, which if used effectively, can mitigate the impact of project scope changes and be beneficial to the life cycle of the a project. Project scope changes regularly occur during the construction phase of civil engineering projects, and normally result in severe disruptions. Although scope changes during the implementation phase are avoided where possible, their existence is a practical reality. These changes can be managed by a Change Management System (CMS) that can minimize the impact of these changes. This dissertation investigates different change management systems, which are used by major companies to mitigate the impact of project scope changes. Case studies on change management systems are provided, and the advantages and disadvantages of these systems are discussed. These change management systems were used as a reference axis for a newly proposed project scope change management system, namely the Proactive Change Management Database System (PACMDS). The PACMDS was developed by the author, to minimize the impact of scope changes in civil projects. In a survey done to establish whether the PACMDS would be effective in mitigating project scope changes, it was found that the PACMDS would assist in managing project scope changes effectively.

Increased production and use of multimedia data has led to the development of a more advanced Database Management System (DBMS), like an Object Relational Database Management System (ORDBMS). These advanced databases are necessitated by the complexity in structure and the functionality required by multimedia data. Unfortunately, no suitable benchmarks exist with which to test the performance of databases when handling multimedia data. This thesis describes the design of a benchmark to measure the performance of basic functionality found in multimedia databases. The benchmark, called MORD (Multimedia Object Relational Databases), targets Oracle, a well known commercial Object Relational Database Management System (ORDBMS) that can handle multimedia data. Although MORD targets Oracle, it can easily be applied to other Multimedia Database Management System (MMDBMS) as a result of a design that stressed its portability, and simplicity. MORD consists of a database schema, test data, and code to simulate representative queries on multimedia databases. A number of experiments are described that validate MORD and ensure its correct design and that its objectives are met. A by-product of these experiments is an initial understanding of the performance of multimedia databases. The experiments show that with multimedia data the buffer cache should be at least large enough to hold the largest dataset, a bigger block size improves the performance, and turning off logging and caching for bulk loading improves the performance. MORD can be used to compare different ORDBMS or to assist in the configuration of a specific database.

Moving objects database systems are the most challenging sub-category among Spatio-Temporal database systems. A database system that updates in real-time the location information of GPS-equipped moving vehicles has to meet even stricter requirements. Currently existing data storage models and indexing mechanisms work well only when the number of moving objects in the system is relatively small. This dissertation research aimed at the real-time tracking and history retrieval of massive numbers of vehicles moving on road networks. A total solution has been provided for the real-time update of the vehicles’ location and motion information, range queries on current and history data, and prediction of vehicles’ movement in the near future. To achieve these goals, a new approach called Segmented Time Associated to Partitioned Space (STAPS) was first proposed in this dissertation for building and manipulating the indexing structures for moving objects databases. Applying the STAPS approach, an indexing structure of associating a time interval tree to each road segment was developed for real-time database systems of vehicles moving on road networks. The indexing structure uses affordable storage to support real-time data updates and efficient query processing. The data update and query processing performance it provides is consistent without restrictions such as a time window or assuming linear moving trajectories. An application system design based on distributed system architecture with centralized organization was developed to maximally support the proposed data and indexing structures. The suggested system architecture is highly scalable and flexible. Finally, based on a real-world application model of vehicles moving in region-wide, main issues on the implementation of such a system were addressed.

The increasing number of devices owned by a single user makes it increasingly difficult to access, organise and visualise personal information (PI), i.e. documents and media, across these devices. The primary method that is currently used to organise and visualise PI is the hierarchical folder structure, which is a familiar and widely used means to manage PI. However, this hierarchy does not effectively support personal information management (PIM) across multiple devices. Current solutions, such as the Personal Information Dashboard and Stuff I’ve Seen, do not support PIM across multiple devices. Alternative PIM tools, such as Dropbox and TeamViewer, attempt to provide a means of accessing PI across multiple devices, but these solutions also suffer from several limitations. The aim of this research was to investigate to what extent enhanced information visualisation (IV) techniques could be used to support accessing PI across multiple devices. An interview study was conducted to identify how PI is currently managed across multiple devices. This interview study further motivated the need for a tool to support visualising PI across multiple devices and identified requirements for such an IV tool. Several suitable IV techniques were selected and enhanced to support PIM across multiple devices. These techniques comprised an Overview using a nested circles layout, a Tag Cloud and a Partition Layout, which used a novel set-based technique. A prototype, called MyPSI, was designed and implemented incorporating these enhanced IV techniques. The requirements and design of the MyPSI prototype were validated using a conceptual walkthrough. The design of the MyPSI prototype was initially implemented for a desktop or laptop device with mouse-based interaction. A sample personal space of information (PSI) was used to evaluate the prototype in a controlled user study. The user study was used to identify any usability problems with the MyPSI prototype. The results were highly positive and the participants agreed that such a tool could be useful in future. No major problems were identified with the prototype. The MyPSI prototype was then implemented on a mobile device, specifically an Android tablet device, using a similar design, but supporting touch-based interaction. Users were allowed to upload their own PSI using Dropbox, which was visualised by the MyPSI prototype. A field study was conducted following the Multi-dimensional In-depth Long-term Case Studies approach specifically designed for IV evaluation. The field study was conducted over a two-week period, evaluating both the desktop and mobile versions of the MyPSI prototype. Both versions received positive results, but the desktop version was slightly preferred over the mobile version, mainly due to familiarity and problems experienced with the mobile implementation. Design recommendations were derived to inform future designs of IV tools to support accessing PI across multiple devices. This research has shown that IV techniques can be enhanced to effectively support accessing PI across multiple devices. Future work will involve customising the MyPSI prototype for mobile phones and supporting additional platforms.

The aim of this diploma thesis is a detail description of current possibilities and ways of storing open data. It focuses on tools and database systems used for storing linked open data as well as on the selection of such systems for subsequent analysis and comparison. The practical part of the thesis then focuses on the comparison of selected systems based on a selected use case. This thesis introduces the fundamental terms and concepts concerning linked open data. Besides that, various approaches and formats for storing linked open data (namely file ori-ented approaches and database approaches) are analyzed. . The thesis also focuses on the RDF format and database systems. Ten triplestore database solutions (solutions for storing data in the RDF format) are introduced and described briefly. Out of these, three are cho-sen for a detailed analysis by which they are compared with one another and with a rela-tional database system. The core of the detail analysis lies in performance benchmarks. Ex-isting performance oriented benchmarks of triplestore systems are described and analyzed. In addition to that, the thesis introduces a newly developed benchmark as a collection of database queries. The benchmark is then used for the performance testing. The following systems have been tested: Apache Jena TDB/Fuseki, OpenLink Virtuoso, Oracle Spatial and Graph a Microsoft SQL Server. The main contribution of this thesis consists in a comprehensive presentation of current possibilities of storing linked open data.

The Teradata database system is specially designed for data warehousing environment. This thesis explores the use of Teradata in this environment and describes its characteristics and potential areas for optimization. The theoretical part is tended to be a user study material and it shows the main principles Teradata system operation and describes factors significantly affecting system performance. Following sections are based on previously acquired information which is used for analysis and optimization in several areas of described environment.

This thesis involves the financial analysis of spanish companies with an emphasis on their evaluation according to selected sectors and autonomous regions. For the purpose of the evaluation the indicators of profitability, turnover, liquidity and indebtedness are used. The autonomous regions are firstly evaluated from the point of view of the revenues of the individual sectors as part of the total turnover for the region. These practical parts are supplemented by the general but also economic characteristics of Spain. The conclusion reached following the evaluation of the individual indicators is that the most sucessful sectors are "DC -- Manufacture of leather and leather products", "DK -- Manufacture of machinery and equipment n.e.c." and "DL -- Manufacture of electrical and optical equipment". In contrast the sectors "A -- Agricultural, hunting and forestry" and "B -- Fishing" were the least sucessful. In addition it was found, that in general, the greatest share of the revenues of the autonomous regions were in the sectors "F -- Construction", "DA -- Manufacture of food products, beverages and tobacco" and "DJ -- Manufacture of basic metals and fabricated metal products". In contrast the sectors of "B --fishing" and "CA -- Mining and quarrying of energy producing materials" contribute the least in terms of revenues. The greatest absolute revenue values are achieved in the autonomous region of Madrid, followed by the regions of Cataluňa and País Vasco. In contrast the Extremadura region had the lowest revenues.

Nowadays the importance of disposing of some information system still grows - organizations are more and more dependent on these systems, because they consider it to be storage of their valuable data. So they are still trying to improve those systems. Their importance grows even in the area of small business. These small businessmen appre-ciate improving situation of affordability of software solutions which they can use for supporting their business. Custom made or customized solutions which could be still developed are very appreciated. This diploma thesis deals with customization of MMSP methodics (Methodics for Small Software Projects) in FileMaker software. FileMaker is a computer program developed for creating individual information systems focusing on personal or business matters. FileMaker contains starting solutions which can be used right after installation the software (invoicing, project planning etc.). But it does not contain guidelines or any methodics which can be used during devel-opment of an individual system. In this thesis, I have edited the MMSP methodics and delivered new steps in order to support development in FileMaker software. The main benefit of this thesis is the customization of the MMSP methodics for using it during projects which deal with FileMaker software or similar during creation of a new system. This custom-ized methodics can be used as a supplement of the MMSP.

Millennial students make up a large portion of undergraduate students attending colleges and universities, and they have a variety of online resources available to them to complete academically related information searches, primarily Web based and library-based online information retrieval systems. The content, ease of use, and required search techniques are different between the two information retrieval systems. Students often prefer searching the Web, but in doing so often miss higher quality materials that may be available only through their library. Furthermore, each system uses different information retrieval algorithms for producing results, so proficiency in one search system may not transfer to another. Web based information retrieval systems are unable to search and retrieve many resources available in libraries and other proprietary information retrieval systems, often referred to as the Invisible Web. These are resources that are not available to the general public and are password protected (from anyone not considered to be an affiliated user of that particular organization). These resources are often licensed to libraries by third party vendors or publishers and include fee-based access to content. Therefore, many millennial students may not be accessing many scholarly resources available to them if they were to use Web based information retrieval systems. Investigation of how millennial students approach searches for the same topic in both systems was conducted. The goal was to build upon theory of why students search using various techniques, why they often choose the Web for their searches, and what can be done to improve library online information retrieval systems. Mixed qualitative methods of data gathering were used to elicit this information. The investigation showed that millennial undergraduate students lacked detailed search strategies, and often used the same search techniques regardless of system or subject. Students displayed greater familiarity and ease of use with Web based IR systems than online library IR systems. Results illustrated suggestions for search design enhancements to library online information retrieval systems such as better natural language searching and easier linking to full text articles. Design enhancements based on millennial search strategies should encourage students to use library-based information retrieval systems more often.