Refine
Year of publication
Document Type
- Master's Thesis (208) (remove)
Has Fulltext
- yes (208)
Is part of the Bibliography
- no (208)
Keywords
- IT-Sicherheit (10)
- E-Learning (7)
- Maschinelles Lernen (7)
- Deep learning (6)
- Internet der Dinge (5)
- Künstliche Intelligenz (5)
- Marketing (5)
- Social Media (5)
- Computersicherheit (4)
- Internet of Things (4)
Institute
- Fakultät Medien und Informationswesen (M+I) (bis 21.04.2021) (57)
- Fakultät Medien (M) (ab 22.04.2021) (55)
- Fakultät Maschinenbau und Verfahrenstechnik (M+V) (40)
- Fakultät Elektrotechnik, Medizintechnik und Informatik (EMI) (ab 04/2019) (34)
- Fakultät Wirtschaft (W) (15)
- Fakultät Elektrotechnik und Informationstechnik (E+I) (bis 03/2019) (13)
- ivESK - Institut für verlässliche Embedded Systems und Kommunikationselektronik (5)
- INES - Institut für nachhaltige Energiesysteme (4)
- IDEeP - Institute for Digital Engineering and Production (ab 12.10.2022) (1)
- IUAS - Institute for Unmanned Aerial Systems (1)
Open Access
- Closed Access (101)
- Closed (75)
- Open Access (32)
- Diamond (6)
AI-based Ground Penetrating Radar Signal Processing for Thickness Estimation of Subsurface Layers
(2023)
This thesis focuses on the estimation of subsurface layer thickness using Ground Penetrating Radar (GPR) A-scan and B-scan data through the application of neural networks. The objective is to develop accurate models capable of estimating the thickness of up to two subsurface layers.
Two different approaches are explored for processing the A-scan data. In the first approach, A-scans are compressed using Principal Component Analysis (PCA), and a regression feedforward neural network is employed to estimate the layers’ thicknesses. The second approach utilizes a regression one-dimensional Convolutional Neural Network (1-D CNN) for the same purpose. Comparative analysis reveals that the second approach yields superior results in terms of accuracy.
Subsequently, the proposed 1-D CNN architecture is adapted and evaluated for Step Frequency Continuous Wave (SFCW) radar, expanding its applicability to this type of radar system. The effectiveness of the proposed network in estimating subsurface layer thickness for SFCW radar is demonstrated.
Furthermore, the thesis investigates the utilization of GPR B-scan images as input data for subsurface layer thickness estimation. A regression CNN is employed for this purpose, although the results achieved are not as promising as those obtained with the 1-D CNN using A-scan data. This disparity is attributed to the limited availability of B-scan data, as B-scan generation is a resource-intensive process.
Much of the research in the field of audio-based machine learning has focused on recreating human speech via feature extraction and imitation, known as deepfakes. The current state of affairs has prompted a look into other areas, such as the recognition of recording devices, and potentially speakers, by only analysing sound files. Segregation and feature extraction are at the core of this approach.
This research focuses on determining whether a recorded sound can reveal the recording device with which it was captured. Each specific microphone manufacturer and model, among other characteristics and imperfections, can have subtle but compounding effects on the results, whether it be differences in noise, or the recording tempo and sensitivity of the microphone while recording. By studying these slight perturbations, it was found to be possible to distinguish between microphones based on the sounds they recorded.
After the recording, pre-processing, and feature extraction phases we completed, the prepared data was fed into several different machine learning algorithms, with results ranging from 70% to 100% accuracy, showing Multi-Layer Perceptron and Logistic Regression to be the most effective for this type of task.
This was further extended to be able to tell the difference between two microphones of the same make and model. Achieving the identification of identical models of a microphone suggests that the small deviations in their manufacturing process are enough of a factor to uniquely distinguish them and potentially target individuals using them. This however does not take into account any form of compression applied to the sound files, as that may alter or degrade some or most of the distinguishing features that are necessary for this experiment.
Building on top of prior research in the area, such as by Das et al. in in which different acoustic features were explored and assessed on their ability to be used to uniquely fingerprint smartphones, more concrete results along with the methodology by which they were achieved are published in this project’s publicly accessible code repository.
Estimation and projecting total steel industry production costs from 2019 to 2030 for Germany
(2023)
This thesis analyses the total production cost of the German steel industry from 2019 to 2022, as well as a projection of the German steel industry's total production cost until 2030. The research separates the costs of steel production into their primary components, such as raw materials, energy, CO2 cost, capital expenses and operating expenses. The cost of steel production is determined separately for primary steelmaking with the blast furnace and basic oxygen furnace (BF-BOF) and secondary steelmaking with the electric arc furnace (EAF).
The analysis indicates that, following the COVID-19 disaster and the fuel crisis, the overall cost of producing steel in Germany has progressively risen over the previous few years, reaching its peak in the first half of 2022. In addition, there are considerable disparities between the production costs of primary and secondary steelmaking processes, with primary steelmaking generally being more expensive.
In this analysis, the total cost of production for the German steel industry in the year 2030 has been estimated by taking into account historical trends as well as other predictions that are currently available.
This thesis provides overall insights on the economics of the German steel sector. By giving thorough information on production costs and changes over time, this research can assist guide crucial future investment decisions in this essential industry. To ensure long-term success, our findings emphasize the significance of investing in more sustainable and ecologically friendly steel production processes.
Truth is the first causality of war”, is a very often used statement. What rather intrigues the mind is what causes the causality of truth. If one dives deeper, one may also wonder why is this so-called truth the first target in a war. Who all see the truth before it dies. These questions rarely get answered as the media and general public tends to focus more on the human and economic losses in a war or war like situation. What many fail to realize is that these truthful pieces of information are critical to how a situation further develops. One correct information may change the course of the whole war saving millions and one mis-information may do the opposite.
Since its inception, some studies have been conducted to propose and develop new applications for OSINT in various fields. In addition to OSINT, Artificial Intelligence is a worldwide trend that is being used in conjunction witThe question here is, what is this information. Who transmits this and how? What is the source. Although, there has been an extensive use of the information provided by the secret services of any nation, which have come handy to many, another kind of information system is using the one that is publicly available, but in different pieces. This kind of information may come from people posting on social media, some publicly available records and much more. The key part in this publicly available information is that these are just pieces of information available across the globe from various different sources. This could be seen as small pieces of a puzzle that need to be put together to see the bigger picture. This is where OSINT comes in place.
h other areas (AI). AI is the branch of computer science that is in charge of developing intelligent systems. In terms of contribution, this work presents a 9-step systematic literature review as well as consolidated data to support future OSINT studies. It was possible to understand where the greatest concentration of publications was, which countries and continents developed the most research, and the characteristics of these publications using this information. What are the trends for the next OSINT with AI studies? What AI subfields are used with OSINT? What are the most popular keywords, and how do they relate to others over time?A timeline describing the application of OSINT is also provided. It was also clear how OSINT was used in conjunction with AI to solve problems in various areas with varying objectives. Private investigators and journalists are no longer the primary users of open-source intelligence gathering and analysis (OSINT) techniques. Approximately 80-90 percent of data analysed by intelligence agencies is now derived from publicly available sources. Furthermore, the massive expansion of the internet, particularly social media platforms, has made OSINT more accessible to civilians who simply want to trawl the Web for information on a specific individual, organisation, or product. The General Data Protection Regulation (GDPR) of the European Union was implemented in the United Kingdom in May 2018 through the new Data Protection Act, with the goal of protecting personal data from unauthorised collection, storage, and exploitation. This document presents a preliminary review of the literature on GDPR-related work.
The reviewed literature is divided into six sections: ’What is OSINT?’, ’What are the risks?’ and benefits of OSINT?’, ’What is the rationale for data protection legislation?’, ’What are the current legislative frameworks in the UK and Europe?’, ’What is the potential impact of the GDPR on OSINT?’, and ’Have the views of civilian and commercial stakeholders been sought and why is this important?’. Because OSINT tools and techniques are available to anyone, they have the unique ability to be used to hold power accountable. As a result, it is critical that new data protection legislation does not impede civilian OSINT capabilities.
In this paper we see how OSINT has played an important role in the wars across the globe in the past. We also see how OSINT is used in our everyday life. We also gain insights on how OSINT is playing a role in the current war going on between Russia and Ukraine. Furthermore, we look into some of these OSINT tools and how they work. We also consider a use case where OSINT is used as an anti terrorism tool. At the end, we also see how OSINT has evolved over the years, and what we can expect in the future as to what OSINT may look like.
Cloud computing is a combination of technologies, including grid computing and distributed computing, that use the Internet as a network for service delivery. Organizations can select the price and service models that best accommodate their demands and financial restrictions. Cloud service providers choose the pricing model for their cloud services, taking the size, usage, user, infrastructure, and service size into account. Thus, cloud computing’s economic and business advantages are driving firms to shift more applications to the cloud, boosting future development. It enlarges the possibilities of current IT systems.
Over the past several years, the ”cloud computing” industry has exploded in popularity, going from a promising business concept to one of the fastest expanding areas of the IT sector. Most enterprises are hosting or installing web services in a cloud architecture for management simplicity and improved availability. Virtual environments are applied to accomplish multi-tenancy in the cloud. A vulnerability in a cloud computing environment poses a direct threat to the users’ privacy and security. In our digital age, the user has many identities. At all levels, access rights and digital identities must be regulated and controlled.
Identity and access management(IAM) are the process of managing identities and regulating access privileges. It is considered as a front-line soldier of IT security. It is the goal of identity and access management systems to protect an organization’s assets by limiting access to just those who need it and in the appropriate cases. It is required for all businesses with thousands of users and is the best practice for ensuring user access control. It identifies, authenticates, and authorizes people to access an organization’s resources. This, in turn, enhances access management efficiency. Authentication, authorization, data protection, and accountability are just a few of the areas in which cloud-based web services have security issues. These features come under identity and access management.
The implementation of identity and access management(IAM) is essential for any business. It’s becoming more and more business-centric, so we need more than technical know-how to succeed. Organizations may save money on identity management and, more crucially, become much nimbler in their support of new business initiatives if they have developed sophisticated IAM capabilities. We used these features of identity and access management to validate the robustness of the cloud computing environment with a comparison of traditional identity and access management.
Go ist eine 2009 veröffentlichte Programmiersprache mit einem statischen Typsystem. Seit Version 1.18 sind auch Generics ein Teil der Sprache. Deren Übersetzung wurde im de facto Standard-Compiler mittels Monomorphisierung umgesetzt. Diese bringt neben einigen Vorteilen auch Nachteile mit sich. Aus diesem Grund beschäftigt sich diese Arbeit mit einer alternativen Übersetzungsstrategie für Generics in Go und implementiert diese in einem neuen Compiler für Featherweight Generic Go, einem Subset von Go. Zum Schluss steht damit ein nahezu funktionierender Compiler, welcher schließlich Racket-Code ausgibt. Eine Evaluierung der Performanz der Übersetzungsstrategie ist allerdings noch ausstehend.
Für Unternehmen ist es zunehmend von Interesse, durch Social-Media-Kommunikation nicht nur die Aufmerksamkeit der Zielgruppe zu wecken, sondern mit der aufmerksamkeitsstarken Ansprache die Wahrnehmung ihrer Marke und das marktbezogene Verhalten zu beeinflussen. Humorvolle Appelle sind in diesem Zusammenhang zur gängigen Werbepraxis geworden und finden auf Social Media in der direkten Interaktion zwischen Marken und ihrer Zielgruppe statt. Mit der vorliegenden Arbeit wird humorvoll-schlagfertige Unternehmenskommunikation auf Social Media untersucht. Das Ziel war es, die Wirkungszusammenhänge zwischen derartiger Kommunikation, deren Bewertung, dem Markenimage, der Markenauthentizität und den Handlungsabsichten besser zu verstehen. Die Erkenntnisse über diese Zusammenhänge können sowohl der weiteren Erforschung als auch künftigen Marketingentscheidungen dienen.
Im Zuge dessen wurden die theoretischen Hintergründe moderner Markenkommunikation sowie der Konzepte Humor und Schlagfertigkeit ausgearbeitet. Der empirische Teil der Arbeit besteht aus der Konzipierung, Durchführung, Analyse und Ergebnisdiskussion einer quantitativen Studie. Zu den zentralen Ergebnissen zählt, dass sich der Grad an Humor und an Schlagfertigkeit darauf auswirkt, wie sehr die Kommunikation gefällt. Wenn diese gut gefällt, stärkt das wiederum das Markenimage. Auch die wahrgenommene Markenauthentizität bestimmt das Markenimage und wird selbst vor allem durch den Grad der Schlagfertigkeit bestimmt. Das Markenimage beeinflusst die Weiterleitungsabsicht der Kommunikation (virale Effekte) und die Kaufabsicht. Dabei unterscheidet sich humorvoll-schlagfertige Unternehmenskommunikation von neutraler Vergleichskommunikation hinsichtlich der Weiterleitungsabsicht signifikant.
Ziel der vorliegenden Arbeit ist das netzdienliche Betreiben einer Wärmepumpe. Um diese Netzdienlichkeit zu erreichen, wird ein modellprädiktiver Regler entwickelt und implementiert, dessen Ziel es ist die Stromkosten einer Wärmepumpe zu senken. Dazu werden die Variablen Stromkosten und ein simulierter Heizbetrieb betrachtet.
Die Entwicklung eines modellprädiktiven Reglers setzt zunächst eine Modellierung der Komponenten des Heizsystems voraus. Ebenfalls muss eine Kostenfunktion formuliert werden, die es zu minimieren gilt. In einem Optimierungsproblem werden die Modelle als Randbedingungen und die Kostenfunktion als Zielfunktion der Optimierung formuliert. Dazu müssen gewisse Vereinfachungen getroffen werden, um das Optimierungsproblem zuverlässig und ohne enormen Rechenaufwand in einer Regelungsschleife lösen zu können.
Nun wird das Optimierungsproblem mit externen Modulen verknüpft, die eine Kommunikation mit der realen Wärmepumpen, Strompreisprognosen und Wettervorhersagen ermöglichen. Der dabei entwickelte Algorithmus wird auf einem Raspberry Pi Einplatinencomputer gespeichert und dort in einem regelmäßigen Zeitintervall von 15 Minuten ausgeführt, um den Betrieb der Wärmepumpe zu regeln.
Schließlich wird der modellprädiktive Regler in Betrieb genommen. Anschließend kann der modellprädiktive Betrieb mit dem konventionellen Betrieb verglichen werden. Aus dem Vergleich wird deutlich, dass eine modellprädiktive Regelung tatsächlich die Netzdienlichkeit einer Wärmepumpe verbessern kann. Andererseits werden auch die Entwicklungspotentiale identifiziert.
The current thesis conducts the study on the integration of digitalization techniques aimed at improving energy supply efficiency in off-grid energy systems. The primary objective is to fortify the security of energy supply in remote areas, particularly in instances of adverse weather conditions, unanticipated changes in load and fluctuations in the performance of renewable energy systems. This objective is to be achieved through the implementation of a smart load management strategy in stand-alone photovoltaic systems (SAPVS). This strategy involves deployment of forecasting algorithms on an edge device that operates with limited processing resources in an environment characterized for the lack of internet connection. The edge device is designed to interact with a smart home gateway that prioritizes, and schedules smart appliances based on the forecasted state of charge (SOC) in the 36-hours ahead of the SAPVS operation (the implementation of the loads schedule deployed on the Home Assistant device is out of the scope of the tasks implemented for this project).
The edge device, developed using a Raspberry Pi 3B+, was specifically intended for being implemented along with a SAPVS, in remote areas such as health stations in Africa and tropical islands, providing communities with a reliable source of electrical energy. The deployment of the strategy was carried out in four phases. The first phase involved the implementation of an Extraction-Transformation-Load (ETL) pipeline, where data was gathered from various heterogeneous hardware sources of an implemented test system that served as the enabler and testbench of this research, this test stand is composed of power electronics components such as an inverter, a MPPT solar charge controller, a smart meter, and a BOS LiFePo4 battery prototype. In the transformation stage, a data model was developed to identify the most critical parameters of the energy system, and to eliminate outliers and null values. In the load stage, a local SQL database was established for saving and structuring the data gathered and to ensure high-quality data with defined units and casting.
The second phase involved data analysis to identify the relevant features and potential exogenous variables for the forecasting model to implement. In the third phase, an Auto Regressive Moving Average (ARMA) model with two selected exogenous variables was implemented to forecast the AC load consumption profile for the 36- hours ahead of the off-grid system operation. The final phase involved the information exchange with the Home Assistant device, by transferring to it from the edge device the battery SOC present value and the predicted 36-hour ahead AC load profile information for prioritization and scheduling of loads; this through an MQTT interface.
The outcome of the experiment was a successful deployment of a data engineering and data forecasting approach that enabled data quality strategy implementation, local database storage, and forecasting algorithms on a processing and internet-constrained edge device. The interface with a home assistant implementation resulted in the successful execution of smart load management endeavors in an off-grid system, thereby enhancing the energy security of supply and contributing to the advancement of data-driven strategies in the rural electrification sector.
This thesis emphasizes the significance of digitalization strategies in smart SAPVS and highlights the potential of edge computing solutions in achieving seamless energy management in smart homes.
Die rasante Digitalisierung verändert die Hochschule Offenburg nachhaltig. Jedes Semester entstehen zahlreiche akademische Arbeiten und Prüfungsdaten, die von hoher Bedeutung für die Qualitätssicherung und den Bildungsprozess sind. Bisher fehlte jedoch eine effiziente Lösung zur Archivierung dieser Daten. Meine Masterarbeit präsentiert ein neues Archivierungskonzept, das eine zentrale, digitale Plattform schafft. Diese ermöglicht es Lehrenden und Studierenden, leicht auf ihre Daten zuzugreifen, sei es für Projektarbeiten, Seminarleistungen oder Prüfungen. Ich stelle nicht nur das Konzept vor, sondern auch die Umsetzung eines Prototyps auf Intrexx, einer Low-Code-Entwicklungsplattform. Mein Ziel ist es, ein Handbuch für zukünftige Entwickler zu hinterlassen, um zur digitalen Transformation der Hochschule beizutragen und die Bildungsprozesse zu optimieren.