000 Allgemeines, Informatik, Informationswissenschaft
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Surrogate-based optimization, nature-inspired metaheuristics, and hybrid combinations have become state of the art in algorithm design for solving real-world optimization problems. Still, it is difficult for practitioners to get an overview that explains their advantages in comparison to a large number of available methods in the scope of optimization. Available taxonomies lack the embedding of current approaches in the larger context of this broad field. This article presents a taxonomy of the field, which explores and matches algorithm strategies by extracting similarities and differences in their search strategies. A particular focus lies on algorithms using surrogates, nature-inspired designs, and those created by automatic algorithm generation. The extracted features of algorithms, their main concepts, and search operators, allow us to create a set of classification indicators to distinguish between a small number of classes. The features allow a deeper understanding of components of the search strategies and further indicate the close connections between the different algorithm designs. We present intuitive analogies to explain the basic principles of the search algorithms, particularly useful for novices in this research field. Furthermore, this taxonomy allows recommendations for the applicability of the corresponding algorithms.
Ground tire rubber (GTR) is a product obtained by grinding worn tire treads before retreading them or via the cryogenic or ambient temperature milling of end-of-life tires (ELTs). The aim of this study is to evaluate if calcium carbonate can be substituted by GTR and, if so, to what extent. Different types of ground tire rubber are incorporated in an EPDM (ethylene–propylene–diene–rubber) model compound as partial or complete substitutes of calcium carbonate. The raw compounds and the vulcanizates are characterized to identify the limits. In general, it is apparent that increasing amounts of GTR and larger particles degrade the mechanical properties. The GTR also influences the vulcanization kinetics by reducing the scorch time up to 50% and vulcanization time up to nearly 80%. This is significant for production processes. The compounds with one-third substitution with the smaller-particle-size GTR show mostly similar or even better properties than the reference.
Academic search systems aid users in finding information covering specific topics of scientific interest and have evolved from early catalog-based library systems to modern web-scale systems. However, evaluating the performance of the underlying retrieval approaches remains a challenge. An increasing amount of requirements for producing accurate retrieval results have to be considered, e.g., close integration of the system’s users. Due to these requirements, small to mid-size academic search systems cannot evaluate their retrieval system in-house. Evaluation infrastructures for shared tasks alleviate this situation. They allow researchers to experiment with retrieval approaches in specific search and recommendation scenarios without building their own infrastructure. In this paper, we elaborate on the benefits and shortcomings of four state-of-the-art evaluation infrastructures on search and recommendation tasks concerning the following requirements: support for online and offline evaluations, domain specificity of shared tasks, and reproducibility of experiments and results. In addition, we introduce an evaluation infrastructure concept design aiming at reducing the shortcomings in shared tasks for search and recommender systems.
This paper introduces CAAI, a novel cognitive architecture for artificial intelligence in cyber-physical production systems. The goal of the architecture is to reduce the implementation effort for the usage of artificial intelligence algorithms. The core of the CAAI is a cognitive module that processes the user’s declarative goals, selects suitable models and algorithms, and creates a configuration for the execution of a processing pipeline on a big data platform. Constant observation and evaluation against performance criteria assess the performance of pipelines for many and different use cases. Based on these evaluations, the pipelines are automatically adapted if necessary. The modular design with well-defined interfaces enables the reusability and extensibility of pipeline components. A big data platform implements this modular design supported by technologies such as Docker, Kubernetes, and Kafka for virtualization and orchestration of the individual components and their communication. The implementation of the architecture is evaluated using a real-world use case. The prototypic implementation is accessible on GitHub and contains a demonstration.
In recent years there have been numerous technical innovations such as CGM systems or insulin pumps that have made life easier for people with type 1 diabetes. However, this also means that more and more information is available. The aim of the present study is to find out more about the daily handling of information. The following research question was asked: What information do people with type 1 diabetes use? To answer this research question, a quantitative online survey of people with type 1 diabetes was conducted by Prof. Dr. Matthias Fank at the Technical University of Cologne. The online survey mainly consisted of 25 closed questions, which were asked on a scale from 0 to 10. The responses of 1,025 people who are at least 18 years old were included in the evaluation. The most important information for type 1 diabetics is the "current value". 67.5% have this on Place 1 placed. Current glucose levels are provided by CGM systems used by 94.2% of people with type 1 diabetes. Quarterly visits to the diabetologist are important and provide important information. 30.8% “completely” agree with this statement on a scale from 0 to 10. Only 2.2% of people with type 1 diabetes are satisfied with their current diabetes management apps. There is a desire for a manufacturer-independent app. The strongest agreement with a value of 10 was chosen by almost a quarter (24.6%) of the people with type 1 diabetes. The study provides an insight into diabetes therapy and shows the need for action.
Educational institutions have increasing needs for professional digital communication. When selecting suitable communication tools, there is a need for appropriate information as a basis for decision-making. Messenger communication in particular is strongly integrated into people's private everyday lives. While needs for extensive data-secure communication in educational contexts are increasing, there is a lack of concepts for data-protected and privacy-preserving support of educational processes through software (Karaboga et al 2014; Digitalcourage e.V. n.d.) , as well as for mandatory training for professionals (Zorn, Tillmann, and Kaminski 2014; Imort and Niesyto 2014), and reliable information for viable software alternatives. This paper outlines the specific requirements of educational institutions when selecting suitable software, using messenger communication as an example. From these requirements, criteria for needed information are presented as a basis for software selection decisions in three categories: data protection/privacy, accessibility/low-barrier, practicability. Since no criteria and good practice suggestions were available so far, a study was conducted to elicit the characteristics of potentially suitable messenger software. To this end, the necessary criteria for the three categories mentioned were first defined and then German and well-known international messengers were tested for data protection criteria. Based on the results for conformity with the EU's General Data Protection Regulation (GDPR) as an inclusion criterion, the messengers in question were subjected to a practical test. In the process, additional practicality criteria were developed, in part iteratively.
In addition to institution-internal messengers, six services were identified among the freely available provider-dependent messengers that can be used in a GDPR-compliant manner, at least for users over the age of 16. At the time of publication, this leaves only five: Threema, Wire, SID, Ginlo, Chiffry. Furthermore, provider-independent messenger systems that adhere to the international standard protocol for the exchange of chat messages (XMPP) appear to be a viable option for educational institutions. In-house or commissioned server hosting would then be possible and a corresponding agreement for commissioned data processing can be concluded with an IT service provider.
The decisions to use "Wire" and "Threema Work" in the IDiT project context are explained and justified. The context was vocational training for prospective office management clerks at vocational schools and vocational training centers. Although the underlying considerations are tailored to the project context (application in the Berufsförderungswerk Köln), they can be generalized.
A test tool for Langton's ant-based algorithms is created. Among other things, it can create test files for the NIST-Statistical-Test-Suite. The test tool is used to investigate the invertibility, ring formation and randomness of 7 created models which are extensions of Langton’s ant. The models are examined to possibly use them as pseudo-random generator (PRG) or block cipher. All models use memories which are based on tori. This property is central, because this is how rings are formed in the first place and in addition the behavior of all models at the physical boundaries of the memory is clearly defined in this way. The different models have special properties which are also investigated. These include variable color sets, discrete convolution, multidimensionality, and the use of multiple ants, which are arranged fractal hierarchically and influence each other. The extensions convolution, multidimensional scalable and multidimensional scalable fractal ant colony are presented here for the first time. It is shown that well-chosen color sets and high-dimensional tori are particularly well suited as a basis for Langton's ant based PRGs. In addition, it is shown that a block cipher can be generated on this basis.
This bachelor thesis deals with framework-agnostic design systems in the environment of micro frontends. The properties of micro frontends and design systems are developed individually, to finally get combined. Important disciplines of this research are in particular cybernetics and system thinking, whereby further properties in the relationships between the stakeholders and the design system are highlighted and defined. In addition, based on the highlighted properties, a practically oriented evaluation is prepared, which demonstratively verifies how framework-agnostic design systems can be realized using Svelte and Tailwind CSS. The insights gained from this work can be used for further considerations in other works within the domain, or similar domains. In particular the cybernetic view of systematic design offers potential for further investigations.
This thesis proposes four different Augmented Reality (AR) display techniques that can overcome the problem of uncertain tracking errors. Where most other papers focus on limiting the amount of error that a user tracking system generates, this paper pro-poses visualizations that limit their impact instead. For this, four different display techniques have been developed and evaluated using criteria found in related literate. Two of the four proposed solutions consistently ranked better within these criteria. The first, Bending Words, uses a mix between spatially registered information and turn instructions to achieve that result. The second, WIM, mostly relies on context infor-mation of the building instead.
Sensors can monitor physical attributes and record multimodal data in order to provide feedback. The application calligraphy trainer, exploits these affordances in the context of handwriting learning. It records the expert’s handwriting performance to compute an expert model. The application then uses the expert model to provide guidance and feedback to the learners.
However, new learners can be overwhelmed by the feedback as handwriting learning is a tedious task. This paper presents the pilot study done with the calligraphy trainer to evaluate the mental effort induced by various types of feedback provided by the application. Ten participants, five in the control group and five in the treatment group, who were Ph.D. students in the technology-enhanced learning domain, took part in the study. The participants used the application to learn three characters from the Devanagari script. The results show higher mental effort in the treatment group when all types of feedback are provided simultaneously. The mental efforts for individual feedback were similar to the control group. In conclusion, the feedback provided by the calligraphy trainer does not impose high mental effort and, therefore, the design considerations of the calligraphy trainer can be insightful for multimodal feedback designers.
With Google’s Flutter framework continuing to grow in popularity for companies and developers alike, the need for an understanding of how to utilize the framework in a large-scale context has become more relevant than ever. The purpose of this thesis is to document the crucial steps most development teams using Flutter in a large-scale application will face. Additionally, a fully documented, large-scale reference application was generated so that other developers may use it as an aid when creating their own Flutter projects on a similar scale. Multiple steps were taken to ensure that optimal solutions were chosen for each aspect of the development process. For each of those aspects, a wide range of possible solutions were explored, compared and analysed. Finally, one of the possible solutions was chosen based on a wide range of scientific papers and community-generated sources. Additionally, an interview with an expert in the field was conducted to further validate those decisions. After the application was fully implemented, ten crucial aspects of the development process were identified. Those ten aspects are now explained in detail in this thesis. Ultimately, the knowledge provided by this thesis can act as a map for peers using Flutter in a large-scale context and help them overcome the crossroads they will most likely come to face.
Digital competences are describing a set of skills, which are necessary to use digital devices and tools with an adequate degree of self-determination. With the ubiquitous digitization of our lives and our society it is important for every citizen to have digital competences. Therefor, it is necessary to educate those competences in schools. As one cannot assume teachers to have enough digital competences to well educate the children of todays classes, this master thesis tries to find out: How to shape the process of teaching digital competences to adolescents in German schools, focusing on including multiple parties from diverse backgrounds into the process? At first, the current situation of teaching digital competences in German schools is analyzed by means of a literature review. After the identification of the challenges within the German system, international best practices are examined. Therefor, four countries, which have reached high scores in the International Computer and Information Literacy Study are selected. Australia, the Czech Republic, Denmark and the Republic of Korea are compared and possible chances for Germany identified. As the next step, expert interviews with divers parties, which have direct or indirect relation to the German education system, are held. The goal of the interviews is to generate ideas on how to support the education system by external help. At the end of the thesis the recommended approach of Motivating External People is presented. Several measures, such as teaching or mentoring students in a guest lecturer model; providing IT support for the hard- and software of the schools or creating Open Educational Resources as education material for the teachers are presented and possible third parties are named. As it is not possible to support the education system from the outside without education system internal persons, it is presented, what needs to change within the system to get the approach working. Therefor, not a complex and system changing approach is presented, but a combined top-down and bottom-up process to motivate external people to support.
Web browsers use HTTP caches to reduce the amount of data to be transferred over the network and allow Web pages to load faster. Content such as scripts, images, and style sheets, which are static most of the time or shared across multiple websites, are stored and loaded locally when recurring requests ask for cached resources. This behaviour can be exploited if the cache is based on a naive implementation. This paper summarises possible attacks on the browser cache and shows through extensive experiments that even modern web browsers still do not provide enough safeguards to protect their users. Moreover, the available built-in as well as addable cache controls offer rather limited functionality in terms of protection and ease of use. Due to the volatile and inhomogeneous APIs for controlling the cache in modern browsers, the development of enhanced user-centric cache controls remains -until further notice- in the hands of browser manufacturers.
Online services such as social networks, online shops, and search engines deliver different content to users depending on their location, browsing history, or client device. Since these services have a major influence on opinion forming, understanding their behavior from a social science perspective is of greatest importance. In addition, technical aspects of services such as security or privacy are becoming more and more relevant for users, providers, and researchers. Due to the lack of essential data sets, automatic black box testing of online services is currently the only way for researchers to investigate these services in a methodical and reproducible manner. However, automatic black box testing of online services is difficult since many of them try to detect and block automated requests to prevent bots from accessing them.
In this paper, we introduce a testing tool that allows researchers to create and automatically run experiments for exploratory studies of online services. The testing tool performs programmed user interactions in such a manner that it can hardly be distinguished from a human user. To evaluate our tool, we conducted - among other things - a large-scale research study on Risk-based Authentication (RBA), which required human-like behavior from the client. We were able to circumvent the bot detection of the investigated online services with the experiments. As this demonstrates the potential of the presented testing tool, it remains to the responsibility of its users to balance the conflicting interests between researchers and service providers as well as to check whether their research programs remain undetected.
REST became the go to approach when it comes to large scale distributed systems on, or outside the World Wide Web. This paper aims to give a brief overview of what REST is and what its main draws and benefits are. Secondly, I will showcase the implementation of REST using HTTP and why this approach became as popular as it is today. Based on my research I concluded that REST’s advantages in scalability, coupling, performance and its seamless integration with HTTP enabled it to rightfully overtake classic RPC based approaches.
Risk-based authentication (RBA) is an adaptive security measure to strengthen password-based authentication. RBA monitors additional implicit features during password entry such as device or geolocation information, and requests additional authentication factors if a certain risk level is detected. RBA is recommended by the NIST digital identity guidelines, is used by several large online services, and offers protection against security risks such as password database leaks, credential stuffing, insecure passwords and large-scale guessing attacks. Despite its relevance, the procedures used by RBA-instrumented online services are currently not disclosed. Consequently, there is little scientific research about RBA, slowing down progress and deeper understanding, making it harder for end users to understand the security provided by the services they use and trust, and hindering the widespread adoption of RBA.
In this paper, with a series of studies on eight popular online services, we (i) analyze which features and combinations/classifiers are used and are useful in practical instances, (ii) develop a framework and a methodology to measure RBA in the wild, and (iii) survey and discuss the differences in the user interface for RBA. Following this, our work provides a first deeper understanding of practical RBA deployments and helps fostering further research in this direction.
Observational studies and clinical trials have become increasingly important over recent years and play an essential role in advancing medical knowledge. In today’s world of clinical research, it is not possible to imagine trials without the founda-tion of a well-established it-infrastructure. Electronic capture and usage of data is pervasive.
In practice, medical progress requires the ability to integrate data from different systems. An essential factor in enabling different actors, such as institutions and hospitals, to have their systems exchange structured data and make use of the information is the interoperability of the data and systems.
FHIR (Fast Healthcare Interoperable Resources) is a free and easily customizable HL7 platform standard, based on 30 years of experience of HL7. It is focused on providing health-related information and defines a set of capabilities used in the health care process.
This thesis will provide a conceptual approach for working with FHIR, as well as concrete approaches for working with FHIR profiles and for customizing the standard for particular use cases. It will be carried out in cooperation with the Medical Systems R&D, which is a service provider within the University Hospital of Cologne.
The guiding request approach will focus on the evaluation of requirements for clini-cal trials and how clinical research protocols can be represented in an interoperable and machine-parsable format using FHIR.
Blogging has established itself as an important and influential part of the
modern online media. At the dawn of the blogosphere people were publishing
their diaries and life journals. Nowadays, some bloggers operate blogs that are
hardly any different from online newspapers and magazines. On the one hand
professional blogging is broadly accepted in the society, but on the other hand
it is poorly understood. The purpose of this explorative study is to broaden
the understanding of blogging as a professional activity. In particular, this
study explores the aspects of professional blogging and the interplay between
credibility, authenticity and monetisation in blogs.
To understand blogging as a professional activity an extensive literature
research is conducted. First, main concepts of blogging as a social activity
are discussed. Then, the changes that come together with the transformation
of a social activity into a professional activity of blogging are discussed. To
look at the activity of blogging from an unusual perspective, a comprehensive
qualitative survey is conducted with blog readers. The survey examines
not only readers’ perception of blogging as a professional activity, but also
motivations for reading blogs and attitude to monetising practices and labelling
of monetised content in blogs. Information received from the survey is used to
draw some conclusions about the state of the art of blogging as a professional
activity, and challenges and opportunities blogging industry faces nowadays.
Since the development of eGovernment systems is gaining worldwide momentum, the European Union is constantly increasing its efforts to induce the development of eGovernment systems in its member states. The currently running strategy is the ’eGovernment Action Plan 2016-2020’, which understands itself as a catalyst for developments in the member states.
Despite these ongoing efforts by the European Union regarding eGovernment, stud- ies are repeatedly revealing that the quality and acceptance by the citizens of dig- ital public services are varying heavily within the EU. Being based on the same political guidelines provided by the EU, the national strategies implemented the core principles to different degrees. These different implementation rates, analyzed for Germany, the United Kingdom and Estonia, supplement the holistic analysis of the eGovernment policies, applications and usage in each member state. This gets proven by the connection of this indicator with related studies in the field of eGov- ernment applications and usage within the European Union.
The aim of this thesis is, on the one hand, to quantify differences in the implementa- tion of the ’eGovernment Action Plan 2016-2020’ into national policies in Germany, the UK and Estonia and, on the other hand, establish this indicator as a valuable asset for evaluating and monitoring the eGovernment efforts by the EU member states.
This thesis is aimed for finding a solution for non-gaming application of Virtual Reality technology in data visualization and analysis. Starting by reconstructing the concept of Virtual Reality, the paper then describes the principles, concepts and techniques of designing a Virtual Reality application. In the last part of the thesis, a detailed description of how a prototype implemented is presented to provide a preview of how data visualization and analysis and Virtual Reality technology can be combined together in order to enable users to perceive and comprehend data in a possibly better way.
Intelligent use of energy is one of the keys to success for an energy revolution. To meet this challenge, smart meters are suitable tools because INTELLIGENT use of energy means not only to use efficiency technology, but also to determine load shifting potentials and use them accordingly. Especially farms with high power consumption are becoming increasingly concerned about reducing energy costs due to rising energy prices and need a systematic analysis of their operational energy flow. To find solutions for farms, the NaRoTec e.V., the TH Köln, and the Machinery Ring Höxter-Warburg have joined forces with partners and launched the project "Intelligent Energy in Agriculture", which is funded by the state of NRW. The aim of the project is to be able to give individual advice recommendations for energy optimization of agricultural holdings. This will be achieved inter alia through an operational energy audit and current measurements in different operating ranges. To achieve this, smart meters were installed in selected energy-intensive dairy and pig farms. As part of the project, the installed smart meter information about the consumption of various plants and their components were analyzed, regularities and adaptability in loading history identified, and the energy efficiency of the equipment and systems used verified (especially pumps, ventilators, feeding systems). Then recommendations were formulated to shift electricity-intensive processes to times with low electricity costs and high intrinsic power production. The resulting findings will be used as the basis for intelligent energy management in the further course of the project. Overall, efficiency streamlining measures in the field of ventilation and lighting systems, flexible dry feeding systems by decoupling power purchase and consumption, as well as energy savings and related CO2 savings were determined.
Intelligent use of energy is one of the keys to success for an energy revolution. To meet this challenge, smart meters are suitable tools because INTELLIGENT use of energy means not only to use efficiency technology, but also to determine load shifting potentials and use them accordingly. Especially farms with high power consumption are becoming increasingly concerned about reducing energy costs due to rising energy prices and need a systematic analysis of their operational energy flow. To find solutions for farms, the NaRoTec e.V., the TH Köln, and the Machinery Ring Höxter-Warburg have joined forces with partners and launched the project "Intelligent Energy in Agriculture", which is funded by the state of NRW in Germany. The aim of the project is to be able to give individual advice recommendations for energy optimization of agricultural holdings. This will be achieved inter alia through an operational energy audit and current measurements in different operating ranges. To achieve this, smart meters were installed in selected energy-intensive dairy and pig farms.
As part of the project, the installed smart meter information of one of the dairy Farms is used to optimize the energy consumption of the farm and increase the degree of self-sufficiency. A good way to achieve this is by taking a closer look at the cooling process of the produced milk since it is one of the most energy consuming processes on a dairy farm. In addition an installation of an ice cooling system instead of a direct cooling system enables the possibility to store self-produced energy in the form of ice and use it later on when it is needed to cool the milk. This flattens the usual energy peaks throughout the day and increases the degree of self-sufficiency. To ensure a sufficient amount of self-produced energy with solar power plants of various sizes were designed. The different sizes of the power plants are defined by the use of the gathered smart meter data is used to cover different electric loads in addition to the ice water cooling system. Afterwards the different simulated models are compared to find the best balance between energy production, investment cost and a high degree of self-sufficiency. First results show that using an ice cooling system in combination with a solar power plant improvement the degree of self-sufficiency by up to 7.8 %.
Due to the present developments of the Internet and its technical components, the skills of the web experts have to be more and more complex and specific. The Internet experts in the creative field are located distributedly around the whole world. As a result, many companies have problems to find the needed experts on site and are dependent on creative cooperations and virtual teams with the help of technical tools. The virtual working place is an important issue, particularly in modern times and the market offers more and more cooperation systems for exactly this purpose: Creative cooperation in distributed working situations. This thesis examines the approaches of creative cooperation and cooperation technologies with an analysis about existing cooperation systems with a creative context. It spans a wide range of tools. On the one hand, there are approaches which offer only straightforward solutions for single design tasks. On the other hand, there are providers which recognised the great need of creative cooperation systems and working at full speed to extend their systems. The examined areas of this work lead to a design process oriented approach with flexible frames and enough space for the creative development of every single user. The cooperation in a creative context stays in the foreground and is the base for future approaches for the web design sector.
The topic for the thesis originated from the CAP4ACCESS project run by the European Commission and its partners, which deals towards the sensiti-zation of people and development of tools for awareness about people with movement disabilities. The explorative analysis is never ending and to explore and find interest-ing patterns and the results is a tedious task. Therefore, a scientific approach was very important. To start with, familiarizing the domain and the data sources were done. Thereafter, selection of methodology for data analysis was done which resulted in the use of CRISP-DM methodology. The data sources are the source of blood to the analysis methodology, and as there were two sources of data that is MICROM and OSM Wheelchair History(OWH), it was important to integrate them together to extract relevant datasets. Therefore a functional and technically impure data warehouse was created, from which the datasets are extracted and analysed.The next task was to select appropriate tools for analysis. This task was very important as the data set although was not big data but con-tained a large number of rows. After careful analysis, Apache spark and its machine learning library were utilized for building and testing supervised models. DataFrame API for Python, Pandas, the machine learning library Sci-kit learn provided unsupervised algorithms for analysis, the association rule analysis was performed using WEKA. Tableau[21] and Matplotlib[24] provide attractive visualizations for representation and analysis.
An empirical evaluation of using the Swift language as the underlying technology of RESTful APIs
(2016)
The purpose of the current thesis is to determine the appropriateness of using the Swift language as the underlying technology for the development of RESTful APIs in a Linux environment. The current paper describes the process of designing, implementing and testing individual RESTful API components based on Node.js, PHP, Python and Swift and seeks to determine whether Swift is a viable alternative.
The thesis begins by defining a methodology for implementing and testing individual RESTful API components based on Node.js, PHP, Python and Swift. It then proceeds to detail the implementation and testing processes, following with an analytic discussion regarding the advantages and drawbacks of using the Swift language as the underlying technology for RESTful APIs and server-side Linux-based applications in general.
Based on the implementation process and on the results of the previously mentioned evaluation phase, it can be stated that the Swift language is not yet ready to be used in a production environment. However, its rapid evolution and potential for surpassing its competitors in the foreseeable future make it an ideal candidate for implementing RESTful APIs to be used in development environments.
This thesis focuses on the identification of influential users, also known as key opinion leaders, within the social network Instagram. Instagram is a very popular platform to share images with the option to categorise the images by certain tags. It is possible to collect public data from Instagram via the open API of the platform.
This thesis presents a concept to create an automated crawler for this API and col- lect data into a database in order to apply algorithms from graph theory to identify opinion leaders afterwards. The sample topic for this thesis has been veganfood and all associated posts from Instagram have been crawled.
After the user data has been crawled a graph has been created to do further research with common social network analysis tools. The graph contained a total set of more than 26,000 nodes.
To identify opinion leaders from this graph, five di↵erent metrics have been applied, in particular PageRank, Betweenness centrality, Closeness Centrality, Degree and Eigen- vector centrality. After applying the di↵erent algorithms the results have been eval- uated and additionally an marketing expert with focus on social media analysed the results.
This project was able to figured out that it is possible to find opinion leaders by using the PageRank algorithm and that those opinion leaders have a very good value of en- gagement. This indicates that they show a high interaction with other users on their posts. In conclusion the additional research options are discussed to provide a future outlook.
This paper is grounded in the emerging field of web science and shall contribute to its further classification and demarcation by illustrating the current state of »web-native research methods«. It builds upon an initial arraying work of Richard Rogers, who coined the term »Digital Methods« for research with methods that were »born« in the web, and illustrated and organized them in his eponymous book in 2013. This paper attempts to develop a more appropriate illustration of the Digital Methods by following the web’s very own, hypertextual, network-like nature, in particular by construing an ontological representation on the base of the Web Ontology Language (OWL). By virtue of decomposing the book into granular information units and their subsequent reassembly into OWL entities, immediate access to the entire knowledge domain can be provided, and coherencies, interrelations and distinctions between concepts become apparent. The ontology’s structure was induced narrowly along the provided examples of research projects and subsequently clustered in topic groups, of which the three most important ones were (a) the Digital Methods as an arraying space of web-native methodology, (b) a collection of concrete applications of these Digital Methods in research projects, and (c) a hierarchical scheme of traditional sciences with a distinct interest in answering research questions with help of Digital Methods. Subsequently, the ontology was evaluated in three general dimensions: Deriving user stories and scenarios provided means to validate the utilization quality; the accuracy and reliability of the resulting structure was validated with help of a control group of web-native research projects; and process control instruments served as a validator for the ontology’s correctness. Despite the ontology itself, this paper also resulted in a first interpretation of the produced information: Statements about research practise in social science, politics and philosophy were as possible as findings about commonly applied varieties of methods. Concluding, the present paper proposes a process of ontology engineering, an evaluation of the ontology’s value, and an interpretation of the ontology’s content.