The 100 most recently published documents
Abstract
In this paper, we shed light on shared hosting services’ security and trust implications and measure their attack surfaces. To do so, we analyzed 30 shared hosters and found that all of them might leak relevant information, which could be abused unnoticed. An adversary could use this attack surface to covertly extract data from various third parties registered with a shared hoster. Furthermore, we found that most hosters suffer from vulnerabilities that can be used by an internal attacker (i.e., someone using the service) to compromise other hosted services or the entire system.
Abstract
For years, researchers have been analyzing mobile Android apps to investigate diverse properties such as software engineering practices, business models, security, privacy, or usability, as well as differences between marketplaces. While similar studies on iOS have been limited, recent work has started to analyze and compare Android apps with those for iOS. To obtain the most representative analysis results across platforms, the ideal approach is to compare their characteristics and behavior for the same set of apps, e. g., to study a set of apps for iOS and their respective counterparts for Android. Previous work has only attempted to identify and evaluate such cross-platform apps to a limited degree, mostly comparing sets of apps independently drawn from app stores, manually matching small sets of apps, or relying on brittle matches based on app and developer names. This results in (1) comparing apps whose behavior and properties significantly differ, (2) limited scalability, and (3) the risk of matching only a small fraction of apps.
In this work, we propose a novel approach to create an extensive dataset of cross-platform apps for the iOS and Android ecosystems. We describe an analysis pipeline for discovering, retrieving, and matching apps from the Apple App Store and Google Play Store that we used to create a set of 3,322 cross-platform apps out of 10,000 popular apps for iOS and Android, respectively. We evaluate existing and new approaches for cross-platform app matching against a set of reference pairs that we obtained from Google's data migration service. We identify a combination of seven features from app store metadata and the apps themselves to match iOS and Android apps with high confidence (95.82 %). Compared to previous attempts that identified 14 % of apps as cross-platform, we are able to match 34 % of apps in our dataset. To foster future research in the cross-platform analysis of mobile apps, we make our pipeline available to the community.
Abstract
This paper challenges the conventional assumption in cybersecurity that users act as rational actors. Despite numerous technical solutions, awareness campaigns, and organizational strategies aimed at bolstering cybersecurity, these often overlook the prevalence of non-rational user behavior. Our study, involving a survey of 208 participants, empirically demonstrates this aspect. We found that a significant portion of users (55.3%) would accept a substantial risk (35%) to click on a potentially malicious link or attachment. This propensity increases to 61% when users are led to believe there is a 65% chance of facing no adverse consequences. To address this irrationality, we explored the efficacy of nudging mechanisms within email systems. Our qualitative user study revealed that incorporating a simple colored nudge in the email intably enhance the ability of users to discern malicious emails, improving decision-making accuracy by an average of 10%.
Blood vessel formation relies on biochemical and mechanical signals, particularly during sprouting angiogenesis when endothelial tip cells (TCs) guide sprouting through filopodia formation. The contribution of BMP receptors in defining tip-cell characteristics is poorly understood. Our study combines genetic, biochemical, and molecular methods together with 3D traction force microscopy, which reveals an essential role of BMPR2 for actin-driven filopodia formation and mechanical properties of endothelial cells (ECs). Targeting of Bmpr2 reduced sprouting angiogenesis in zebrafish and BMPR2-deficient human ECs formed fewer filopodia, affecting cell migration and actomyosin localization. Spheroid assays revealed a reduced sprouting of BMPR2-deficient ECs in fibrin gels. Even more strikingly, in mosaic spheroids, BMPR2-deficient ECs failed to acquire tip-cell positions. Yet, 3D traction force microscopy revealed that these distinct cell behaviors of BMPR2-deficient tip cells cannot be explained by differences in force-induced matrix deformations, even though these cells adopted distinct cone-shaped morphologies. Notably, BMPR2 positively regulates local CDC42 activity at the plasma membrane to promote filopodia formation. Our findings reveal that BMPR2 functions as a nexus integrating biochemical and biomechanical processes crucial for TCs during angiogenesis.
The study introduces flexible and scalable manufacturing approach for electrodes utilizing boron-doped silicon as conductive support for iridium nanoparticles, addressing the challenges of cost and scarcity associated with noble catalysts for oxygen evolution reaction (OER). Colloidal Ir nanoparticles are synthesized via pulsed-laser ablation (≈4–7 nm) and decorated on B-doped Si (≈100 nm) through electrostatic adsorption. Titanium substrates are ultrasonically sprayed with Si:B – Ir and Ir nanoparticles with very low iridium loading of 12 wt.%. Crystalline Ir phases (Ir(111), Ir(200)) are observed and known to enhance the OER mechanism. Additionally, atom probe tomography confirms that the Si support particles contained 0.03-0.5 at.% of boron throughout the entire particle, while electrical permittivity and through-plane measurements reveal a positive impact of B-doped Si on the electrical conductivity of the nanocatalysts and of the ultralow-loaded catalyst coated Ti substrates (0.12 mgIr cm−2), respectively. Rotating disk electrode results show pronounced oxidation peaks for decorated Ir nanoparticles. The Si:B-Ir 4 nm catalyst exhibits the highest turnover frequency (2.62 s−1) and a competitive electrochemical surface area (25 m2 gIr−1) compared to Si:B-Ir 7 nm (0.96 s−1; 37.5 m2 gIr−1) and Ir black (0.24 s−1; 5 m2 gIr−1). The overall analysis of the parameters highlights a performant catalytic efficiency, through balancing activity and reaction kinetics effectively.
Abstract
Considering the significant health risks posed by hard chrome plating during its application, thermally sprayed Cr3C2-NiCr cermet coatings represent a suitable alternative. Incorporating hexagonal boron nitride (hBN) as a dry lubricant into the feedstock powder can further enhance wear resistance and thermal conductivity, crucial for preventing premature failure caused by inadequate lubrication. In this study, the mass fraction of hBN was varied between 0 and 15 wt.% to assess its influence on the tribological performance of the coatings using pin-on-disk tests. The coating’s hardness was measured via the Vickers method, and its cracking tendency at the coating/substrate interface was evaluated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to analyze the microstructure and phase composition, while thermal diffusivity was determined using the laser flash method. The findings revealed that the inclusion of hBN, at concentrations of up to 10 wt.%, leads to an improvement in thermal diffusivity and a reduction in the coefficient of friction. However, exceeding this threshold leads to a decrease in hardness and increased crack formation tendency, highlighting the trade-off between frictional and mechanical properties.
Abstract
The feed-in of electricity from renewable energies, such as wind or solar power, fluctuates based on weather conditions. This unpredictability due to volatile feed-in can lead to sudden changes in energy generation so that solutions ensuring grid stability need to be implemented. The cooling sector offers the opportunity to create flexibilities for such balancing, with this study focusing on the thermal flexibilities that can be provided by cooling applications. Various cooling-demand profiles are investigated with respect to their load profile and their impact on flexibility is analysed. In addition to the cooling demand, scenarios of different storage dimensions are considered. As a result, it shows that an increasing base-load level and increasing operating-load duration have a negative effect on flexibility, while an increasing full-load duration is beneficial for flexibility. Storage size also has a strong impact as higher storage capacity and storage performance indicate higher flexibility, whereas above a certain size they only provide little added value.
Abstract
This research focuses on the significant role of Corporate Social Responsibility (CSR) in shaping employees’ behavior towards the reduction of food waste in the hospitality industry that has been under scrutiny for its environmental impact. The study aimed at understanding how CSR, coupled with employees’ moral attitudes, admiration for their organization, and climate change awareness influences sustainable practices by realizing the complex interplay between company initiatives and personal psychology. The participants were staff members who worked in several hotels in China where there were active CSR programs. Using established scales, we collected 422 valid responses over three waves to strengthen our data collection process. Empirically, it was found that CSR directly influenced food-waste-reduction behavior. Additionally, it was discovered that this relationship was mediated by moral attitudes and employee admiration as well as moderated by awareness of climate change. The findings have substantial theoretical implications regarding the interaction between emotional and cognitive factors within the CSR framework to influence behavior among employees. This paves the way for creating well-rounded strategies that appeal to staff and encourage sustainability in the hotel business. While focused on China’s hospitality industry, this research creates room for future studies in other places around the world using various methods. The conclusions drawn underline the critical role of CSR in promoting environmental sustainability in the hospitality industry, providing a pathway for organizations to engage employees in meaningful and impactful sustainability initiatives.
Abstract
Seed treatment is a powerful technique for adding beneficial ingredients to plants during the seed preparation process. Biopolymers as drying agents and delivery systems in seed treatments were investigated for their biocompatibility with blastospores of the nematophagous fungus Pochonia chlamydosporia. To produce a novel seed treatment for the cover crop Phacelia tanacetifolia, xanthan gum TG and gellan gum were the most promising biopolymers in combination with potato starch and bentonite. The seed treatment process as well as the drying process were specially designed to be scalable, which make it suitable for applying the developed seed treatment in agriculture. Application of gellan gum in seed treatments led to 6.3% ± 1.6% of vital blastospores per seed compared to 3.8% ± 0.3% of vital blastospores when applying xanthan gum. Storage tests for seed treatments with 0.5% gellan gum indicated a higher stability at 4 °C compared to storage at 21 °C. After 42 days of storage at 4 °C, 54.1% ± 15.1% of the applied blastospores were viable compared to 0.3% ± 0.8% at 21 °C. This novel seed treatment application with P. chlamydosporia blastospores includes the seed treatment procedure, drying process, and storage tests and can easily be upscaled for application in agriculture.
Abstract:
Virtual Machine Introspection (VMI) is a powerful technology used to detect and analyze malicious software inside Virtual Machines (VMs) from outside. Asynchronously accessing the VM ’s memory can be insufficient for efficiently monitoring what is happening inside of a VM. Active VMI introduces breakpoints to intercept VM execution at relevant points. Especially for frequently visited breakpoints, and even more so for production systems, it is crucial to keep their performance overhead as low as possible. In this paper, we provide a systematization of existing VMI breakpoint implementation variants, propose workloads to quantify the different performance penalties of breakpoints, and implement them in the benchmarking application bpbench. We used this benchmark to measure that, on an Intel Core i5 7300U, SmartVMI’s breakpoints take around 81 μs to handle, and keeping the breakpoint invisible costs an additional 21 μs per read access. The availability of bpbench facilitates the comparison of disparate breakpoint mechanisms and their performance optimization with immediate feedback.
Fake News, PR-Skandal, Mainstream-Presse – diese Schlagworte kennzeichnen vor allem eines: den Vertrauensverlust der Öffentlichkeit in die Berichterstattung von Medien und Unternehmen. In einem nahezu unentwirrbaren Kommunikationsdschungel aus Medien, Internetportalen und sozialen Plattformen wird es nicht nur für Laien immer schwieriger, verlässliche und unseriöse Kommunikation voneinander zu unterscheiden.
So steigt die Anzahl derer, die professioneller Kommunikation mit Misstrauen begegnen und in ihr vor allem Einflussnahme oder gar Manipulation sehen. Aus den Augen gerät dabei oft, dass Deutschland über eines der freiheitlichsten und vielfältigsten Mediensysteme der Welt verfügt.
Das Buch diskutiert die Grenzen zwischen Manipulation und Kommunikation on- wie offline und zeigt, wie man schlampige und seriöse Meinungsmacher unterscheidet, welche Rolle Fakten spielen und wie Medien und Unternehmen dazu beitragen können, dass Glaubwürdigkeit in der medialen Debatte wieder einen Stellenwert bekommt.
Focusing on the implementation of the Smart Specialisation Strategy (S3), the chapter examines the development of cluster policies in the Ruhr Metropolis as a post-industrial region. The chapter traces the historical development of the Ruhr Area from its industrial peak in the 20th century to its slow transformation into a post-industrial landscape characterised by high urban density, new knowledge-based clusters and a persistent structural lack of effective regional cooperation. The analysis shows the conceptual shift from traditional cluster policies to the S3 approach, introduced by the European Union in 2014. The Smart Specialisation Strategy calls for a focus on comparative regional strengths and the involvement of a wide range of stakeholders in the identification of clusters for sustainable economic growth. The chapter also discusses the challenges and milestones in developing a coherent and effective Smart Specialisation Strategy, emphasising the need for inter-municipal cooperation and a new multi-level approach to regional governance. Using the case of the Ruhr Metropolis, the chapter highlights the opportunities and constraints of S3 policies to revitalise post-industrial regions by promoting innovation and adapting to global economic trends in cluster development, thus showing a way forward for other regions with similar structural challenges.
Abstract
Filter lists are used by various users, tools, and researchers to identify tracking technologies on the Web. These lists are created and maintained by dedicated communities. Aside from popular blocking lists (e.g., EasyList), the communities create region-specific blocklists that account for trackers and ads that are only common in these regions. The lists aim to keep the size of a general blocklist minimal while protecting users against region-specific trackers.
In this paper, we perform a large-scale Web measurement study
to understand how different region-specific filter lists (e.g., a blocklist specifically designed for French users) protect users when visiting websites. We define three privacy scenarios to understand when and how users benefit from these regional lists and what effect they have in practice. The results show that although the lists differ significantly, the number of rules they contain is unrelated to the number of blocked requests. We find that the lists’ overall efficacy varies notably. Filter lists also do not meet the expectation that they increase user protection in the regions for which they were designed. Finally, we show that the majority of the rules on the lists were not used in our experiment and that only a fraction of the rules would provide comparable protection for users.
This study contributes to the literature by analysing the joint association of managerial overconfidence, certainty, narcissism, and the Big Five personality traits with debt ratios in the institutional setting of the German two-tier system. Moreover, it provides insights into how corporate governance quality moderates the effects of personality. The analysis relied on the chief executive officers’ (CEOs’) speeches at annual general meetings (AGMs) that were voluntarily disseminated, a novel data source. Managers’ personality traits were measured using software-aided content analysis, and their impact on the debt ratio was analysed using panel regressions. Consistent with previous studies, the debt ratios of German issuers are significantly and positively related to the proxies of managerial certainty and narcissism. However, their model inclusion contributes only marginally to explanatory power. Conversely, the coefficients of the proxies for the Big Five personality traits remained statistically non-significant. Moreover, a significantly negative relationship between debt ratios and the interaction term between a proxy for corporate governance quality and managerial certainty is observed that corresponds to the risk-mitigating impact of corporate governance.
Motorisches Lernen
(2024)
In diesem Kapitel geben wir einen Überblick über unterschiedliche Forschungstraditionen im Bereich des motorischen Lernens, indem wir motorisches Lernen auf unterschiedlichen Zeitskalen betrachten: Sensomotorische Adaptation beschreibt motorisches Lernen auf der kürzesten Zeitskala. Fertigkeitserwerb bezieht sich auf den länger andauernden Erwerb eines neuen Bewegungsablaufs. Fitness oder evolutionäres motorisches Lernen thematisiert angeborene Verhaltensweisen, die sich im Laufe der Stammesgeschichte als nützlich erwiesen haben, und wird der Vollständigkeit halber am Ende des Kapitels kurz umrissen.
Senior police officers' tactical gaze control and visual attention improve with an individual video-based police firearms training. To validate the efficacy of said intervention training, a previous experiment was systematically replicated with a sample of N = 52 second-year police cadets. Participants were randomly assigned to the intervention training that focused on situational awareness, tactical gaze control, and visual attention, or an active control training that addressed traditional marksmanship skills. In a pre- and post-test, they had to engage in dynamic shoot/don't shoot video scenarios in an indoor firing range. Overall, the previous findings were replicated: Baseline levels of performance were elevated, yet the intervention group significantly improved their response time and time until the first hit. False positive decision-making cannot be reported at all; false negatives were marginal in the pre-test and eliminated after training. Further, the outcomes of the previous sample of senior officers and the present sample of cadets are compared and lead to the conclusion that the presented approach is a valuable extension of current training standards for both senior police officers and police cadets.
Action-imagery-practice refers to the repetitive use of action imagery to improve subsequent performance leading to partially different representation types than action-execution-practice (AEP). This study explored the representation types in kinesthetic action-imagery-practice (K-AIP) and visual action-imagery-practice (V-AIP) in a serial reaction time task using the crossed hand transfer paradigm. 169 participants (age M ± SD = 25.2 ± 3.9) were randomly assigned to AEP, K-AIP, V-AIP, or control-practice (CP), practicing with uncrossed hands on ten consecutive days. Tests involved the same sequence, a mirror sequence, a shifted sequence, and a shifted mirror sequence, each with uncrossed and crossed hands. With crossed hands, sequence-specific transfer effects indicated only little evidence for effector-independent representations in late stages of learning in AEP and V-AIP. Performance in the same sequence with uncrossed hands indicated the acquisition of stimulus-response location associated effector-dependent sequence-specific representations in AEP, K-AIP and V-AIP, but not in CP. These visual-spatial effector-dependent representations were stronger after AEP than after AIP. Overall, no important differences between both AIP groups were observed, and both groups reported similar focus on kinesthesis and vision, suggesting that irrespective of the instructions, rather than focusing on one single modality, AIP always involves a combination of both modalities - vision and kinesthesis - that promote motor learning.
Abstract
Earthquakes, fire, and floods often cause structural collapses of buildings. However, the inspection of such damaged buildings poses a high risk for emergency forces or is even impossible. We present three recently selected missions of the Robotics Task Force of the German Rescue Robotics Center (DRZ), where both ground and aerial robots were used to explore destroyed buildings. We describe and reflect the missions as well as the lessons learned that have resulted from them. To make robots from research laboratories fit for real operations, realistic outdoor and indoor test environments were set up at the DRZ and used for tests in regular exercises by researchers and emergency forces. On the basis of this experience, the robots and their control software were significantly improved. Furthermore, expert teams of
researchers and first responders were formed, each with realistic assessments of the operational and practical suitability of robotic systems.
Integrity Assessment of Electron-Beam-Welded Joints of Additively Manufactured AlSi10Mg Components
(2023)
Abstract
Laser-based powder bed fusion of metals (PBF-LB/M) is found to be a promising
processing method for the fabrication of components with no limits of complexity
by adding layers upon layers of material. However, drawbacks such as pro-
ductivity and dimension limitations adversely affect the employment of com-
ponents processed by additive manufacturing (AM) in envisaged applications.
This brings welding and joining techniques into play to integrate AM metal parts
into larger assemblies. In the present study, electron beam welding is used to join
the AlSi10Mg specimens, fabricated via two different manufacturing processes,
that is, PBF-LB/M and casting. The main focus is to study the quasistatic and
fatigue behavior of similar and dissimilar welded joints in different combinations,
namely AM–AM, AM–cast, and cast–cast, alongside thorough microstructure
analysis, to investigate the correlation between the microscopic and macroscopic
properties. Dissimilar welded joints demonstrate inferior material strength. This
fact can be attributed to the inherent coarse microstructure of the cast material.
Although similar welded joints of AM components suffer from high porosity in
the weld zone, they are characterized by a better fatigue life, which can be
attributed to the equiaxed eutectic microstructure in the welded area.
Abstract
Discussions about the environmental impacts of production and consumption are fuelling interest in strategies to transform industrial regions. While economic geography and regional development research extensively cover sustainable innovation and green regional development, innovation diffusion, demand-side aspects, and market emergence are often neglected. This paper illustrates how an enhanced valuation perspective that integrates materiality more directly helps to assess dynamic social processes of valuation in the case of low-carbon, resource efficient solutions. Through a path tracing approach, the paper assesses how two industrial by-products, slag sand and fly ash, evolved into highly valued secondary resources in Germany's Ruhr. Regional availability, market devices, and institutional work influence different dimensions of market valuation in waste-to-value processes. Insights on different phases of the development provide hint on how to organise and foster regional circular solutions. Findings may inform research and policy to advance emerging green industries, market creation for sustainable resources, and industrial decarbonisation, where the materiality of technologies and resources plays a key role.
Anchoring challenges through citizen participation in regional challenge-based innovation policies
(2024)
Abstract
This study focuses on citizen participation as a co-productive and knowledge-intensive process in innovation policies concerned with regionally anchoring grand challenges. We apply a process-tracing approach and analyse citizen participation in two regional challenge-based innovation policies in the Ruhr, Germany. Local sensemaking, problem ownership, iterations and knowledge co-production are discussed as key mechanisms in the anchoring process. The results reveal the importance of a collective dimension in interpreting the local problem setting of a challenge achieved by reaching out to numerous citizens and how local, corrective and actionable knowledge facilitate the regional challenge anchoring. The policy formulation phase required the highest level of knowledge co-produced with citizens, followed by the implementation phase.
Abstract
There is an ongoing process that greenhouse gas emissions of transport will be incorporated in the European Emissions Trading System. The cap-and-trade approach will result in substantial price increases for fossil fuels which will affect affordability of the transport systems. Within this paper the regressive effect on car-owning households is described in different area categories of the urban and rural region in Germany. Equal-per-household redistribution of the carbon revenue could reverse the regressive effect into a progressive effect. However, there is substantial variation within the different economic status groups leaving notable shares of households with a very low economic status without a positive net transfer. This share will be lowest in the metropolises of the urban region and highest in small-sized cities/village areas of the urban and rural region. Particularly in the latter area categories, these households may need temporary mobility allowances due to limited abatement options. Despite the environmental bonus, electric car-owning households still belong to groups of higher economic status, and public transport supply is limited, particularly in the small-sized cities/village areas of the urban and rural region.
Abstract
In this work, we develop an approach for the level set based topology optimization of millable 3D structures. We focus on the 3-axis machining with realistic formed milling tools. The basis of the method lies in the identification of surface areas that cannot be reached by a given milling tool during optimization. For this purpose, we present an interpolation method that identifies these areas by an interpolation of the level set function along the outer contours of realistic milling tools, considering available machining directions. To minimize inaccessible surfaces, we define a potential field whose values decrease linearly into the outer normal direction of the structure. The inaccessible boundaries are pushed outward by minimizing their respective potential and therefore become accessible. Manufacturability is integrated into the optimization problem as an explicit constraint.
Abstract
Purpose
We aim to investigate the integration of augmented reality (AR) within the context of increasingly complex surgical procedures and instrument handling toward the transition to smart operating rooms (OR). In contrast to cumbersome paper-based surgical instrument manuals still used in the OR, we wish to provide surgical staff with an AR head-mounted display that provides in-situ visualization and guidance throughout the assembly process of surgical instruments. Our requirement analysis supports the development and provides guidelines for its transfer into surgical practice.
Methods
A three-phase user-centered design approach was applied with online interviews, an observational study, and a workshop with two focus groups with scrub nurses, circulating nurses, surgeons, manufacturers, clinic IT staff, and members of the sterilization department. The requirement analysis was based on key criteria for usability. The data were analyzed via structured content analysis.
Results
We identified twelve main problems with the current use of paper manuals. Major issues included sterile users’ inability to directly handle non-sterile manuals, missing details, and excessive text information, potentially delaying procedure performance. Major requirements for AR-driven guidance fall into the categories of design, practicability, control, and integration into the current workflow. Additionally, further recommendations for technical development could be obtained.
Conclusion
In conclusion, our insights have outlined a comprehensive spectrum of requirements that are essential for the successful implementation of an AI- and AR-driven guidance for assembling surgical instruments. The consistently appreciative evaluation by stakeholders underscores the profound potential of AR and AI technology as valuable assistance and guidance.
Abstract
Additive manufacturing (AM) has gained considerable interest due to its ability to produce lightweight parts with hierarchical microstructures. However, the current constraints on the build chamber size in powder-bed fusion type AM processes limit its industrial application. A hybrid welded joint, consisting of an AM-processed and a conventionally manufactured part, can be employed to produce larger components. Due to the varying processing conditions, these hybrid welded joints contain a wide range of microstructural heterogeneities, which influences the mechanical properties of the joint. Using a numerical model to predict the mechanical behavior of welded joints by considering the microstructural variations is essential for the safe and reliable implementation of hybrid welded joints. This study aims to predict the local tensile behavior of each region of a hybrid friction-stir welded joint of AlSi10Mg produced by laser-based powder bed fusion and casting using a microstructure-sensitive model as well as the global tensile behavior by considering the properties of each region using a joint macroscopic model. The results from this modeling approach agree well with the experimental results. Therefore, this method can predict the mechanical behavior of hybrid welded joints and can establish the structure–property relationship in each weld region.
This paper discusses the transformative potential of 6G technology and the tactile Internet in reshaping participatory healthcare models while architecturing these digital healthcare systems with security and resiliency by design. As healthcare continues to advance towards more inclusive and patient-centered approaches, the role of emerging technologies like mobile health, 6G, and the Internet will become increasingly significant in facilitating these interactions while ensuring the security and privacy of patient data. Furthermore, the organizations providing healthcare to patients must ensure compliance with different regulations, which are also focusing more and more on cybersecurity issues.
This article analyses the early years of the history of the Bundesbank from a history of economic thought perspective. The study uses the example of Bernhard Benning, who headed the Economics Department of the Reichs-Kredit-Gesellschaft, one of the major banks owned by the German Reich during the National Socialist era. After the war Benning was appointed a member of the board of directors of the Deutsche Bundesbank for twenty-two years. As a student of Adolf Weber and his Munich school of economics, Benning's views were shaped by classical liberal rather than ordoliberal ideas. His legitimacy in postwar Germany stemmed from his public opposition to war financing and warnings about inflation during the Donner-Benning Debate of 1942–43. In this tradition, the early Bundesbank was Weberian rather than ordoliberal, so, for instance, fixed exchange rates were favored, and a strong business and investment perspective was adopted.
Experiencing relational devaluation at work through social stressors has been linked to various detrimental outcomes. In the current study, we investigate the role of hardiness and mindfulness as personal resources which help employees to effectively cope with such stressors and thereby prevent burnout.
We focus on trait mindfulness as the innate capacity of paying and maintaining attention to present-moment experiences with an open and nonjudgmental attitude. It has been shown to promote concentration and well-being and to facilitate decision making; it is often seen as an important resource for overcoming challenges in everyday work life.
Hardiness also constitutes a personality profile of dispositional resilience that describes how people deal with stressful events and includes the core aspects of challenge (conviction that challenges offer opportunities), engagement (actively tackling tasks and challenges) and a sense of control (conviction of influence over one's own life circumstances). People with high hardiness show better health and higher job satisfaction and performance.
We build our hypothesis according to the extended version of the Job Demands–Resources model, which states that personal resources protect employees from burnout, because they shape employees’ perceptions of and reactions towards their work environment. In a similar vein, stress theory suggests that personal resources mitigate burnout through lower stress appraisals, greater use of adaptive coping, and flexibility in matching coping to appraisals.
We measured social stressors at work with the scale developed by Frese et al and further asked participants to work on the Maslach Burnout Inventory, the Mindful Attention and Awareness Scale and the short version of the Revised Norwegian Dispositional Resilience (Hardiness) Scale. Our cross-sectional study was based on a sample of N = 174 employees from a broad range of organizations and job types.
Statistical Analyses revealed significant negative correlations of both personal resources with reported symptoms of burnout and the perception of social stressors as well. However, in line with prior research, they indeed did not attenuate the relationship between social stressors and emotional exhaustion at work. Theoretical and practical implications as well as limitations and avenues for future research are discussed.
Naming chemical compounds systematically is a complex task governed by a set of rules established by the International Union of Pure and Applied Chemistry (IUPAC). These rules are universal and widely accepted by chemists worldwide, but their complexity makes it challenging for individuals to consistently apply them accurately. A translation method can be employed to address this challenge. Accurate translation of chemical compounds from SMILES notation into their corresponding IUPAC names is crucial, as it can significantly streamline the laborious process of naming chemical structures. Here, we present STOUT (SMILES-TO-IUPAC-name translator) V2, which addresses this challenge by introducing a transformer-based model that translates string representations of chemical structures into IUPAC names. Trained on a dataset of nearly 1 billion SMILES strings and their corresponding IUPAC names, STOUT V2 demonstrates exceptional accuracy in generating IUPAC names, even for complex chemical structures. The model’s ability to capture intricate patterns and relationships within chemical structures enables it to generate precise and standardised IUPAC names. While established deterministic algorithms remain the gold standard for systematic chemical naming, our work, enabled by access to OpenEye’s Lexichem software through an academic license, demonstrates the potential of neural approaches to complement existing tools in chemical nomenclature.
The precision of yield calculation of modern design and simulation software for photovoltaic systems strongly rely, beside the accuracy of the specified module and inverter data, on the quality of the weather data. Since data from weather stations is not available for most locations world-wide this data is calculated by using modern interpolation methods. Beside this, simulation software typically uses historical weather data. In this work the mismatch of yield simulation results based on proprietary data, meaning interpolated or also called synthetical data, and data coming from a weather station in proximity to the installation is evaluated. The simulated data sets are compared to measurement data as obtained by the inverter output and hence give a profound understanding how interpolated data may influence the simulation results. The outcome shows that the quality of the yield simulation, if compared to the measurement data, is increased by a factor of up to four if on-site weather data is used as input for the simulation. The largest source of deviation is irradiation, which varies up to 10% if synthetical and measured irradiation on-site is compared. The second largest sources for simulation mismatches are power calculation and module temperature correction.
Einsatz hardwaregestützter Virtualisierungstechnologien in der Malwareanalyse und Angriffserkennung
(2021)
Diese Arbeit ist das Ergebnis einer Recherche in den technischen Themengebieten hardwaregestützten Systemvirtualisierung, Virtual-Machine-Introspection (VMI) und VM-Erkennungsmechanismen sowie deren Abwehr. Dabei liegt der Fokus auf dem Einsatz dieser Technologien in der Malwareanalyse oder der Angriffserkennung im Kontext einer EDR-Sensorik. Es werden die grundlegenden Konzepte und Begriffe Systemvirtualisierung eingeführt, erklärt und zu verwandten Gebieten abgegrenzt. Der Weg über die Erweiterung bestehender Schutz-Konzepte moderner CPUs und Betriebssysteme wird beschrieben hin zu Befehlssatzerweiterungen, welche die Hypervisor-Software bei der Bildung der Abstraktionsebenen unterstützen. Dabei wird die Verwendung der Virtualisierungserweiterungen VT-x und AMD-V für die IA32/AMD64-ISA erklärt einschließlich verschiedener Methoden zur Virtualisierung des Paging-Systems. Ein besonderer Fokus liegt dabei auf dem „Second Level Address Translation“-Konzept (SLAT). Neben der Betrachtung der PC-Prozessoren wird auch die Virtualisierungsfunktionalitäten der ARMv8-Architektur erläutert und deren Verwendung beispielhaft beschrieben. Im Kontext der Malwareanalyse und Angriffserkennung ist es besonders relevant, dass Virtualisierungs- und Analyseumgebungen nicht erkannt werden können. Es werden verschiedene Erkennungsansätze und Verfahren diese abzuwehren beschrieben. Um Malware unbemerkt analysieren zu können bietet sich die Analyse über den Hypervisor mittels Virtual-Machine-Introspection (VMI) an. Diese wird erklärt, deren Schwierigkeiten bezüglich des Semantic-Gaps benannt und Möglichkeiten aufgezeigt, diesen Problemen zu begegnen. Zudem werden einige wichtige VMI-Bibliotheken und Verfahren beschrieben. Abschließend werden noch zwei recht unterschiedliche Beispiellösungen kurz betrachtet. Diese sind Drakvuf als Beispiel für eine Malwareanalyse-Sandbox auf Basis von VMI und SimpleVisor, ein minimaler Modell-Hypervisor, der das Hyperjacking-Prinzip verwendet.
Introduction: Drawing tasks are an elementary component of psychological assessment in the evaluation of mental health. With the rise of digitalization not only in psychology but healthcare in general, digital drawing tools (dDTs) have also been developed for this purpose. This scoping review aims at summarizing the state of the art of dDTs available to assess mental health conditions in people above preschool age. Methods: PubMed, PsycInfo, PsycArticles, CINAHL, and Psychology and Behavioral Sciences Collection were searched for dDTs from 2000 onwards. The focus was on dDTs, which not only evaluate the final drawing, but also process data. Results: After applying the search and selection strategy, a total of 37 articles, comprising unique dDTs, remained for data extraction. Around 75 % of these articles were published after 2014 and most of them target adults (86.5 %). In addition, dDTs were mainly used in two areas: tremor detection and assessment of cognitive states, utilizing, for example, the Spiral Drawing Test and the Clock Drawing Test. Conclusion: Early detection of mental diseases is an increasingly important field in healthcare. Through the integration of digital and art based solutions, this area could expand into an interdisciplinary science. This review shows that the first steps in this direction have already been taken and that the possibilities for further research, e.g., on the optimized application of dDTs, are still open.
When organizing intercultural and interdisciplinary Project-Based Learning (PBL) activities across Higher Education Institutions (HEIs), the organizational and resource implications, along with the associated financial challenges, soon become crucial. Even promising approaches may not take off as a simple ‘return on investment’ view and funding decision may not fully address their various impacts on students, staff, institutions and society.
This paper explores the experiences within a distributed interdisciplinary project-based learning program run from 2020 to 2023 and involving more than 150 students from four continents learning 21st century skills by collaborating over one semester to address real-world problems faced by clients in partner countries. While the primary goal of this distributed interdisciplinary and intercultural project-based learning program was to offer students a truly Global Intercultural Project Experience (GIPE), this paper explores its broader impact. We found that the program significantly influenced both the academic and administrative staff at all partner universities. Furthermore, we examine the program's effect on the participating institutions themselves over the four-year period. Our conclusion is that the invaluable benefits of such interdisciplinary project-based learning extend well beyond financial metrics. They include enhanced student learning experiences, strengthened cooperation and mutual learning between academics and administrative staff, improved institutional reputation, and positive societal impact.
Thus, we worked hard to convince both our university management and the world's largest funding organisation for the international exchange of students and researchers to grant financial support for another 3-year period in 2025 to 2027 during which the GIPE concept will be further developed and a permanent organizational structure shall be established based on an extended network of partner institutions and sponsors around the world.
Unleashing Personalized Education Using Large Language Models in Online Collaborative Settings
(2024)
The Artificial Intelligence community has long pursued personalized education. Over the past decades, efforts have ranged from automated advisors to Intelligent Tutoring Systems, all aimed at tailoring learning experiences to students' individual needs and interests. Unfortunately, many of these endeavors remained largely theoretical or proposed solutions challenging to implement in real-world scenarios. However, we are now in the era of Large Language Models (LLMs) like ChatGPT, Mistral, or Claude, which exhibit promising capabilities with significant potential to impact personalized education. For instance, ChatGPT 4 can assist students in using the Socratic method in their learning process. Despite the immense possibilities these technologies offer, limited significant results are showcasing the impact of LLMs in educational settings. Therefore, this paper aims to present tools and strategies based on LLMs to address personalized education within online collaborative learning settings. To do so, we propose RAGs (Retrieval-Augmented Generation) agents that could be added to online collaborative learning platforms: a) the Oracle agent, capable of answering questions related to topics and materials uploaded to the platform.; b) the Summary agent, which can summarize and present content based on students' profiles.; c) the Socratic agent, guiding students in learning topics through close interaction.; d) the Forum agent, analyzing students' forum posts to identify challenging topics and suggest ways to overcome difficulties or foster peer collaboration.; e) the Assessment agent, presenting personalized challenges based on students' needs. f) the Proactive agent, analyzing student activity and suggesting learning paths as needed. Importantly, each RAG agent can leverage historical student data to personalize the learning experience effectively. To assess the effectiveness of this personalized approach, we plan to evaluate the use of RAGs in online collaborative learning platforms compared to previous online learning courses conducted in previous years.
This paper discusses the experiences of a distributed interdisciplinary project-based learning program for students across continents. For the years 2020 until 2023, we received seed-funding for four annual projects to engage students from Germany (Europe), Namibia (Africa), Indonesia (Asia), and Peru (Latin-America) to collaborate over one semester on interdisciplinary projects contributing to the solution of some real-life client’s problems in the partner countries. During this period, more than 150 students embarked on these projects with 116 of them being selected for a scholarship for an international mobility. With the guidance and support by academics from all partner universities, the students success-fully completed each project expressing deep appreciation for the learning opportunities while over¬coming challenges of working across widespread time zones, different cultures, changing requirements, and various technical difficulties.
While the primary aim of this distributed interdisciplinary and intercultural project-based learning program was to provide students with a truly Global Intercultural Project Experience (GIPE), in this paper we investigate on its impact in a broader sense as it was observed that this program also had a significant impact on both academic and administrative staff at all partner universities. Finally, we also reveal the impact of this four-year-program on the participating institutions themselves and conclude that the invaluable returns of such interdisciplinary project-based learning extend far beyond financial metrics. It encompasses enhanced student learning experiences, strengthened cooperation and mutual learning between academics and administrative staff, as well as institutional reputation, and societal impact.
The emergence of digital technologies over the past two decades has brought about changes that threaten the very existence of german media companies. The journalistic business model is losing sales, and the decline in print circulations is making it successively difficult to earn money with journalistic products. Therefore, german media companies have been investing in business models that have no relation to journalism to generate growth for years – with success. Considering this development, it is astonishing from a purely economic perspective that media groups, which are increasingly developing into technology companies, are still clinging to the ailing journalistic business model at all. To examine their motives to do so, this study poses the following research question: "Why do media companies still invest in journalistic products today?" To answer it, the researcher conducted interviews with highlevel employees from media companies as part of a qualitative study. Analysis of the data revealed that media companies continue to invest in journalism mainly because they benefit economically from the brands their journalistic products represent. Other reasons like serving as a pillar of the democratic constitution or to help shape public discourse seem to be less important.
The question of the optimal design of financial systems, whether more bank-based or more market-based, has a long history. Four phases of the discussion can be distinguished: Before World War I, in the rivalry between Germany and England, the debate begins. Across the spectrum, from the liberal Adolf Weber to the Marxist Rudolf Hilferding and the eclectic Joseph Schumpeter, comparisons were made, and the heterogenous authors arrived at similar assessments. During the Cold War, in contrast to the Soviet-Russian model, Alexander Gerschenkron’s depiction with the advantages of backwardness became influential. After the 1990s and in line with the Varieties of Capitalism approach, the discussion led by Ross Levine resulted in a consensus where different financial systems were embedded in their broader institutional context. The current discussion attempts to prove the superiority of capital markets, pointing to the American system as example.
The question of the optimal design of financial systems, whether more bank-based or more market-based, has a long history. Four phases of the discussion can be distinguished: Before World War I, in the rivalry between Germany and England, the debate begins. Across the spectrum, from the liberal Adolf Weber to the Marxist Rudolf Hilferding and the eclectic Joseph Schumpeter, comparisons were made, and the heterogenous authors arrived at similar assessments. During the Cold War, in contrast to the Soviet-Russian model, Alexander Gerschenkron’s depiction with the advantages of backwardness became influential. After the 1990s and in line with the Varieties of Capitalism approach, the discussion led by Ross Levine resulted in a consensus where different financial systems were embedded in their broader institutional context. The current discussion attempts to prove the superiority of capital markets, pointing to the American system as example.
The European Sustainable Finance regulation is primarily focused on capital markets, requiring companies to disclose extensive data. However, these regulations pose challenges for German SMEs, which rely heavily on bank financing. A survey showed that 60% of SMEs invest in sustainability, but external financing remains limited. The EU's approach may need adjustments, such as creating a voluntary sustainability reporting standard for SMEs and developing a streamlined approach for green loans.
The European Sustainable Finance regulation is primarily focused on capital markets, requiring companies to disclose extensive data. However, these regulations pose challenges for German SMEs, which rely heavily on bank financing. A survey showed that 60% of SMEs invest in sustainability, but external financing remains limited. The EU's approach may need adjustments, such as creating a voluntary sustainability reporting standard for SMEs and developing a streamlined approach for green loans.
This study presents the correlation between electrolyte pH, surface morphology, chemical speciation and electro-catalytic oxygen evolution activity of additive-free electrodeposited NiFe catalysts for application in anion exchange membrane water electrolysis. Spherical morphologies were identified at pH 0, shifting towards honey-combed structures at pH 4 with increasing surface area, especially at pH 3. Further, the electrolyte pH was found to influence the NiFe composition and electro-catalytic activity. Enhanced OER activity was noted at pH 2 with overpotentials of 214 mV at 10 mA cm−2 and 267 mV at 100 mA cm−2. The results reveal that the electrolyte pH is a parameter not only influencing the morphology but also tailoring the surface area, Fe oxide and Fe hydroxide composition and consequently the catalytic activity. Further, the outcomes highlight the electrolyte pH as a key process parameter that should be adjusted according to the application, and may substitute the addition of electrolyte-additives, proposing a simpler method for improving catalyst electrodeposition.
This Paper explores how emergent technologies such as 6G and tactile Internet can potentially enhance cognitive, personal informatics (CPI) in participatory healthcare, promoting patient-centered healthcare models through high-speed, reliable communication networks. It highlights the transition to improved patient engagement and better health outcomes facilitated by these technologies, underscoring the importance of ultra-reliable, low-latency communications (URLLC) and realizing the tactile Internet’s potential in healthcare. This innovation could dramatically transform telemedicine and mobile health (mHealth) by enabling remote healthcare delivery while providing a better understanding of the inner workings of the patient. While generating many advantages, these developments have disadvantages and risks. Therefore, this study addresses the critical security and privacy concerns related to the digital transformation of healthcare. Our work focuses on the challenges of managing and understanding cognitive data within the CPI and the potential threats from analyzing such data. It proposed a comprehensive analysis of potential vulnerabilities and cyber threats, emphasizing the need for robust security frameworks designed with resilience in mind to protect sensitive cognitive data. We present scenarios for reward and punishment systems and their impacts on users. In conclusion, we outline a vision for the future of secure, resilient, and patient-centric digital healthcare systems that leverage 6G and the tactile Internet to enhance the CPI. We offer policy recommendations and strategic directions for stakeholders to create a secure, empowering environment for patients to manage their cognitive health information.
§ 12a KAG NRW
(2024)
Steckbriefe zur Energiewende
(2024)
In dem Bericht werden insbesondere auf Daten der Bundesnetzagentur (2022) basierende Steckbriefe sämtlicher bei der simulatorischen Behandlung der generellen Leistungsverhält-nisse in einem der geplanten Energiewende unterworfenen Energieversorgungssystem darge stellt. Die Steckbriefe umfassen die auftretenden Leistungsverläufe der Versorgung aus Photovoltaik, Windkraft, Biomasse usw. und des Verbrauchs mit Stromdirektverbrauchern, Wärmepumpen und Elektro-Fahrzeugen. Für den Verbrauch werden zwei Lastvarianten angegeben. Elektrolyseure sind in beiden Varianten nicht berücksichtigt, da sie trotz ihrer hohen Verluste dem Bereich der Wasserstoffspeicherung zugeordnet werden. Ebenso werden Wasserstoff-Kraftwerke weder dem Bereich der Erzeuger oder, aufgrund ihrer hohen Verluste, der Verbraucher zugeordnet; diese sind ebenfalls dem Bereich der Wasserstoffspeicherung zuzuordnen.
Die Leistungsverläufe werden ergänzt durch „Heatmaps“, mit deren Hilfe sich die Leistungsverläufe in vorteilhafter Weise tages- und stundenweise auflösen lassen. Im Gegensatz zur normalen Darstellung der Leistungsverläufe, aus denen sich saisonale Leistungsgänge und Leistungswerte sehr gut ablesen lassen, lassen sich aus diesen Heatmaps auch Tagesgänge aufgrund menschlicher Verhaltensweisen ermitteln. Statistiken zur Verteilung der Leistungswerte und Tabellen mit den wichtigsten Eckwerten der entsprechenden EE-Erzeuger und Verbraucher vervollständigen die Steckbriefe. In Einzelfällen werden noch Zusatzerläuterungen gegeben, ohne die sich die entsprechenden Steckbriefe unvollständig wären.
Insgesamt ergibt sich, dass der Stromverbrauch ab 2045 saisonal enorm ausgeprägte Maxima und Minima aufweist, die erheblich von den Maxima und Minima des heutigen Stromverbrauchs abweichen. Dies ist das Resultat des Stromverbrauchs aus Wärmepumpen und Elektro-Fahr-zeugen. Die Verbrauchsmaxima können dabei Werte von etwa 170 GW erreichen, was im Gegensatz zu heutigen Maxima von weniger als 90 GW als bemerkenswert bezeichnet werden muss.
In jedem Fall wird ein steuerbarer Backup-Kraftwerkspark benötigt, dessen kontinuierliche Verfügbarkeit während eines Tages größer wie 2 Stunden sein muss. Er muss gezielt zur Morgenzeit, typischerweise zwischen 05:00 und 07:00, mit Leistungshüben von 20 GW/h eingeschaltet und abends, typischerweise zwischen 18:00 und 20:00, mit Lastabwürfen von über 22 GW/h gezielt wieder abgeschaltet werden können. Grund hierfür ist der Wechsel menschlicher Tagesaktivität auf Nachtpassivität und umgekehrt, was sich im täglichen Strombedarf widerspiegelt.
Deutschlands Stromversorgung soll im Jahr 2045 gemäß aktueller Planung (z.B. EEG 2023) aus-schließlich mit Hilfe sog. erneuerbarer Energien geschehen. Hierzu gehören Wind- und Solar-kraft und in erheblichst geringerem Maße Biomasse- und Laufwasserkraft.
Bekannt ist, dass die Energiezufuhr aus diesen Energiequellen überwiegend volatil und daher inkompatibel mit dem Strombedarf der Verbraucher ist. Ohne weitere Maßnahmen käme es ständig zu Über- oder Unterversorgungssituationen mit der Folge dauerhafter Blackouts.
Während eine Überversorgung im einfachsten Fall mit dem rechtzeitigen, wenn auch unwirtschaftlichen Abschalten der entsprechenden Energieversorger sehr gut beherrschbar ist – andere Maßnahmen sind die Speicherung der überschüssigen Energie oder deren Export, sofern es das Ausland zulässt –, ist die Darstellung der Versorgungssicherheit im Falle einer Unterversorgung, also die Vermeidung ewiger Blackouts, nur mit Hilfe zusätzlicher aktiv steuerbarer Energiequellen darstellbar. In Frage kommen hierfür nach heutiger Diskussionslage Gas- bzw. H2-Kraftwerke, virtuelle und reale Batterie-Kraftwerke, sowie Pumpspeicher-Kraftwerke und Stromimporte. Für den Import muss das Ausland für Deutschland regelbare Kraftwerke vorhalten, die stets dann mit erster Priorität bereitstehen müssen, wenn Deutschland in eine Unterversorgungslage gerät. Diese Möglichkeit erscheint dem Berichter eher spekulativ als gesichert. Die Verwendung deutscher Kernkraftwerke wird heutzutage aus politischen Gründen negiert, während gleichzeitig und widersinnigerweise der Import ausländischen Kernkraftstroms billigend in Kauf genommen wird.
Anlass der Studie ist das im Juli 2024 vom Bundesministerium für Wirtschaft und Klimaschutz BMWK herausgegebene „Strommarktdesign der Zukunft : Optionen für ein sicheres, bezahlbares und nachhaltiges Stromsystem“ [BMWK 2024]. Das Strommarktdesign solle einen Paradigmenwechsel im Strommarkt herbeiführen. Eingeführt werden soll ein Kapazitätsmarkt, eine Art systemische Grundgebühr, zur Finanzierung unwirtschaftlicher Investitionen in künftig nur wenig auslastbare Kraftwerke. Zudem sollen die Stromverbraucher als Regelkomponente in einer zukünftig volatilen Stromversorgung eingesetzt werden. Die Motivation hierzu soll mit Hilfe dynamischer Stromtarife gelingen. Vorliegende Studie befasst sich insbesondere mit der potentiellen Wirkung dynamischer Strom-preise auf den Stromverbrauch. Hierzu wird das Einsparpotenzial bei Nutzung dieser Stromtarife untersucht. Empirische Befunde aus Deutschland und Schweden unterfüttern und erweitern diese Untersuchung mit Blick auf die erhoffte Beeinflussbarkeit des künftigen, den politischen Energiewende-Planungen unterworfenen Stromversorgungssystems.
Die Untersuchungsergebnisse werden wie folgt interpretiert:
• In „Smart-Grids“ können dynamische Stromtarife das Verbraucherverhalten bei einem Einsparpotential von 10 bis 15% begrenzt beeinflussen.
• Der Einfluss beschränkt sich auf lokale Stromversorgungsnetze.
• Der Stromverbrauch wird in dem Sinne vergleichmäßigt, dass tageweise auftretende Lastspitzen und Lasttäler sich durch Lastverschiebungen ausgeglichener darstellen. Die Differenz der beiden Tagesextremwerte könnte um bis zu 20% sinken.
• Der jährliche Stromverbrauch wird hierdurch nicht wahrnehmbar beeinflusst. Der qualitative Verlauf des Lastgangs ebenso wenig.
• Die Vergleichmäßigung ist in dem Sinne netzdienlich, dass nur unzureichend ausgebaute Ortsnetze durch die künftige zunehmende Beanspruchung durch Elektromobilität und Wärmepumpen nicht überbeansprucht werden bzw. dass deren sowieso notwendiger Ausbau in etwas reduzierter Weise ausgeführt werden kann.
• Die grundlegenden Probleme bzw. Herausforderungen des geplant volatilen Gesamtstromversorgungssystems lassen sich durch Einsatz der Stromverbraucher als system-dienliches Regelglied nicht lösen. Dazu ist ihre Wirkung im Vergleich zur über das Jahr gemittelten Last zu gering. Der gewünschte Ausgleich sollte besser mit Hilfe geeigneter Speicher statt mit humanen Ressourcen als Regelglied gelöst werden.
Prinzipiell kann die geplante Flexibilisierung des Strommarktes als eine gut vermittelbare und von den Stromkunden nur schlecht zu erkennende Form der Energierationierung durch Preismechanismen gesehen werden. Energierationierungen signalisieren oft strukturelle Probleme im Energiesektor eines Landes. Die Frage, ob der vom BMWK vorgeschlagene Paradigmenwechsel bereits in diese Richtung zielt, darf zusammen mit den derzeit immer offener und häufiger zutage tretenden, bisher noch verkraftbaren Dysfunktionalitäten der derzeitigen Stromversorgung durchaus in Betracht gezogen werden.
Diese Arbeit bietet einen Überblick über das Thema der ereignisbasierten Systemüberwachung von Windows-PCs. Die frühe Erkennung von Angriffen und der Ausführung von Schadsoftware auf Windows-Clients bedingt Sensor-Technologien, die Systemereignisse erkennen und protokollieren. Anhand bestimmter Ereignisse oder komplexerer Ereignismuster können illegitime Vorgänge auf Computersystemen erkannt werden. Der Fokus dieser Arbeit liegt darauf einen detaillierten Überblick über diese ereignisbasierte Sensorik für Windows-Endpunkte zu geben, die Systemereignisse erkennt und Ereignis-Objekte mit beschreibenden Attributen liefert. Im Gegensatz dazu wird die Interpretation der bereitgestellten Ereignisdaten und der Musterabgleich in dieser Arbeit nicht behandelt. Zu Beginn werden dafür die elementaren Aspekte und Begriffe einer solchen Sensor-Technologie allgemein erklärt. Dabei werden einige charakterisierende Grundeigenschaften erläutert, anhand derer solche Senor-Verfahren eingeordnet werden können. Zudem wird auf Basis durchgeführter Messungen eine Abschätzung bezüglich der Auftrittsfrequenzen verschiedener Systemereignisse geliefert. Im Hauptteil werden die zwei ereignisbasierten Monitoring-Systeme Event-Tracing-for-Windows (ETW) und Sysmon vorgestellt. Die Funktionalität, Architektur und interne Funktionsweise der beiden Systeme wird detailliert erläutert. Zudem werden ihre charakterisierenden Basiseigenschaften herausgearbeitet, um Stärken und Schwächen zu erkennen. Der ETW-basierte Sensor und SIGMA-Regelscanner Nextron Aurora, der Sysmon-ähnliche Ereignisdaten bereitstellt, wird ebenfalls behandelt.
Verwaltungsprozessrecht
(2024)
Reducing Automotive Cooling System Complexity through an Adaptive Biomimetic Air Control Valve
(2024)
Future automotive mobility is predominantly electric. Compared to existing systems, the requirements of subsystems change. Air flow for cooling components is needed predominantly when the car is in rest (i.e., charging) or at slow speeds. So far, actively driven fans consuming power and generating noise are used in this case. Here we propose a passive adaptive system allowing for convection-driven cooling. The developed system is a highly adaptive flat valve derived from the bordered pit. It was developed through an iterative design process including simulations, both structural and thermodynamic. In hardwoods and conifers, bordered pits enable the challenging transport of vertical fluids by locally limiting damage. Depending on the structure, these can close at sudden pressure changes and take the function of valves.
The result of the biomimetic abstraction process is a system-integrative, low-profile valve that is cheap to produce, long-lasting, lightweight, maintenance-free, and noise-free. It allows for the passive switching of air flow generation at the heat exchanger of the cooling between natural convection or an active airstream without the need for complex sensing and control systems. The geometric and material design factors allow for the simple tuning of the valve to the desired switching conditions during the design process.
In recent decades, batch hot-dip galvanized (HDG) steel has proven itself in practical applications due to the good corrosion resistance of its components. Despite the importance of the mechanical-load-bearing capacity of these coatings, the wear behavior has, so far, only been investigated very sporadically and not systematically, so a quantification of the wear behavior and statements on the mechanisms are vague. Therefore, two body wear tests with bonded abrasive grain were carried out. Varying the friction rolls, load, and total number of cycles, the wear behavior was investigated. The mass loss and the layer thickness reduction were measured at different intervals. After the test, the microstructure in the cross- section and the hardness according to Vickers (0.01 HV) were evaluated. The results showed that the wear behavior of HDG coatings against abrasive loads can be characterized with the selected test conditions. Initially, the applied load removed the soft η-phase. As the total number of cycles increases, the η- and ζ-phases deform plastically, resulting in a lower mass reduction compared to that expected from the measured layer thickness. The characteristic structure of a batch HDG coating with hard intermetallic Zn-Fe phases and an outer pure zinc phase has demonstrated effective resistance to abrasion.
Brazing is a joining process that involves melting a filler metal and flowing it into the joint between two closely fitting parts. While brazing is primarily used for joining metals, it can also be adapted for certain coating deposition applications. The present study investigates the microstructure and corrosion behavior and sliding wear resistance of WC (Tungsten Carbide)-CoCr-Ni reinforced Co-based composite coatings deposited onto the surface of AISI 904L stainless steel using a vacuum brazing method. The primary objective of this experimental work was to evaluate the influence of WC-based particles added to the microstructure and the properties of the brazed Co composite coating. The focus was on enhancing the sliding wear resistance of the coatings while ensuring that their corrosion resistance in chloride media was not adversely affected. The morphology and microstructure of the composite coatings were investigated using scanning electron microscopy (SEM) and phase identification by X-ray diffraction (XRD). The SEM analysis revealed in the coating the presence of intermetallic compounds and carbides, which increase the hardness of the material. The sliding wear resistance was assessed using the pin-on-disk method, and the corrosion properties were determined using electrochemical measurements. The results obtained showed that as the WC particle ratio in the Co-based composite coating increased, the mechanical properties improved, the alloy became harder, and the tribological properties were improved. The evaluation of the electrochemical tests revealed no significant alterations of the manufactured composite in comparison with the Co-based alloys. In all cases, the corrosion behavior was better compared with that of the stainless-steel substrate.
Dimensional accuracy and mechanical properties of components printed by fused deposition modeling (FDM) are influenced by several process parameters. In this paper, the authors targeted the effect of the printing scenario and the PLA (polylactic acid) color on parts’ quality. Three scenarios were analyzed: individually printing, simultaneously printing of three, respective five specimens of natural (transparent), red, grey, and black PLA. The temperature variations of successive deposited layers were recorded for the black PLA. The dimensional accuracy of tensile specimens was evaluated, tensile tests were performed, and the results were correlated with the mesostructure of the prints. The effect of the independent variables on the measured parameters was analyzed by ANOVA. The experiments revealed differences for the same printing scenario regarding cross-section area (up to 5.71%) and tensile strength (up to 10.45%) determined by the material color. The number of specimens printed simultaneously and the position of the pecimens on the build plate were found to influence too, but less than the color. Thus, increasing from one to five the number of specimens printed at a time altered both the dimensional accuracy (up to 3.93% increase of the cross-section area) and the tensile strength (up to 3.63% reduction).
Random Forest Classification of Cognitive Impairment Using Digital Tree Drawing Test (dTDT) Data
(2024)
Early detection and diagnosis of dementia is a major challenge for medical research and practice. Hence, in the last decade, digital drawing tests became popular, showing sometimes even better performance than their paper-and-pencil versions. Combined with machine learning algorithms, these tests are used to differentiate between healthy people and people with mild cognitive impairment (MCI) or early Alzheimer’s disease (eAD), commonly using data from the Clock Drawing Test (CDT). In this investigation, a Random Forest Classification (RF) algorithm is trained on digital Tree Drawing Test (dTDT) data, containing socio-medical information and process data of 86 healthy people, 97 people with MCI, and 74 people with eAD. The results indicate that the binary classification works well for homogeneous groups, as demonstrated by a sensitivity of 0.85 and a specificity of 0.9 (AUC of 0.94). In contrast, the performance of both binary and multiclass classification degrades for groups with het erogeneous characteristics, which is reflected in a sensitivity of 0.91 and 0.29 and a specificity of 0.44 and 0.36 (AUC of 0.74 and 0.65), respectively. Nevertheless, as the early detection of cognitive impairment becomes increasingly important in healthcare, the results could be useful for models that aim for automatic identification
Coating efficiency and quality can be significantly improved by carefully optimizing the coating parameters. Particularly in the flame spray method, the oxygen/fuel ratio, which is classified
as oxidizing flame stoichiometry (excess oxygen) and reduces flame stoichiometry (excess acetylene), and spray distance are the most critical factors, as they correlate significantly with coating porosity and corrosion performance. Hence, understanding the effects of these parameters is essential to further minimize the porosity, improving the corrosion performance of thermally sprayed coatings. In this work, a NiWCrBSi alloy coating was deposited via the oxyacetylene flame spray/Flexicord-wire (FS/FC) method. The effect of the flame oxygen/fuel ratio and spray distance on the microstructure properties and corrosion behavior of the coatings was investigated. Afterwards, the microstructure, phases’ compositions, spray distance, and corrosion performance were studied. The equivalent circuit
model was proposed, and the corrosion mechanism was discussed. The obtained results highlight that the oxygen-to-fuel ratio is a promising solution for the further application of flame spray/Flexicordwire (FS/FC) cermet coatings in hostile environments. Depending on the flame’s oxygen/fuel ratio,
careful selection of the flame stoichiometry provides low porosity and high corrosion performance.
Naming chemical compounds systematically is a complex task governed by a set of rules established by the International Union of Pure and Applied Chemistry (IUPAC). These rules are universal and widely accepted by chemists worldwide, but their complexity makes it challenging for individuals to consistently apply them accurately. A translation method can be employed to address this challenge. Accurate translation of chemical compounds from SMILES notation into their corresponding IUPAC names is crucial, as it can significantly streamline the laborious process of naming chemical structures. Here, we present STOUT (SMILES-TO-IUPAC-name translator) V2.0, which addresses this challenge by introducing a transformer-based model that translates string representations of chemical structures into IUPAC names. Trained on a dataset of nearly 1 billion SMILES strings and their corresponding IUPAC names, STOUT V2.0 demonstrates exceptional accuracy in generating IUPAC names, even for complex chemical structures. The model's ability to capture intricate patterns and relationships within chemical structures enables it to generate precise and standardised IUPAC names. Deterministic algorithms for systematically naming chemical structures have been available for many years. Also, this work has only been possible through an academic license for OpenEye’s Lexichem software.
An automated pipeline for comprehensive calculation of intermolecular interaction energies based on molecular force-fields using the Tinker molecular modelling package is presented. Starting with non-optimized chemically intuitive monomer structures, the pipeline allows the approximation of global minimum energy monomers and dimers, configuration sampling for various monomer–monomer distances, estimation of coordination numbers by molecular dynamics simulations, and the evaluation of differential pair interaction energies. The latter are used to derive Flory–Huggins parameters and isotropic particle–particle repulsions for Dissipative Particle Dynamics (DPD). The computational results for force fields MM3, MMFF94, OPLS-AA and AMOEBA09 are analyzed with Density Functional Theory (DFT) calculations and DPD simulations for a mixture of the non-ionic polyoxyethylene alkyl ether surfactant C10E4 with water to demonstrate the usefulness of the approach.
Since high costs restrict the wide-range implementation of green hydrogen production capacities based on proton exchange membrane water electrolysis (PEMWE), efforts on cost reduced components need to be made. Beside the necessary noble metal catalyst, the membrane material is a main cost driver. In this work, a novel glass fibre reinforced PFSA/ssPS composite membrane is investigated as an alternative to widely used Nafion®. These membranes are processed into membrane-electrode-assemblies (MEAs) in conjunction with catalyst-coated substrates, prepared via electrochemical catalyst deposition. This approach is promising to reduce costs due to less expensive raw materials and due to increasing catalyst utilization by graded catalyst layers. Characterisation of the components and entire MEAs was performed ex-situ as well as in-situ via PEMWE operation.
Die Anwendung des "FullControll GCode Designer" vereinfacht den 3D-Druckprozess, indem er die 3D-Modellierung und den Einsatz eines Slicer-Programms überspringt und stattdessen direkt den G-Code erstellt. Die vorgefertigte Excel-Anwendung ermöglicht es, Objekte durch Angabe der Start- und Zielkoordinaten effizient Linie für Linie mit minimalem Eingabeaufwand zu programmieren, wobei verschiedene Druckparameter angepasst werden können, um unterschiedliche Effekte zu erzielen. In diesem Werk werden die Möglichkeiten und Grenzen des Designers erarbeitet.
Maximilian Steinbeis: Die verwundbare Demokratie – Strategien gegen die populistische Übernahme
(2024)
Geldschöpfung und Geldpolitik im Euroraum: Inwieweit ist Geldpolitik zugleich Strukturpolitik?
(2024)
Johann Friedrich Pfeiffer on Adam Smith: An Early Reception of Adam Smith in the German States
(2024)
Different from the usual portrayal that it was not until the turn of the nineteenth century that Adam Smith’s work became influential, the extensive commentary by Johann Friedrich Pfeiffer shows an immediate effect on German economic discourse. Pfeiffer, who lived from 1717 until 1787, was as a late and liberal cameralist. Pfeiffer was a prolific writer and well-known scholar during his lifetime. He lived so close to 1789 that his works were only briefly received, and he was not able to leave a lasting legacy on cameralist thought, which withered after the French Revolution. The significance of Smith was recognized by Pfeiffer, placing Smith above most of his German-speaking contemporaries. Both Pfeiffer and Smith addressed many similar topics and Pfeiffer expresses his agreement with large parts of Smith’s Wealth of Nations. However, Pfeiffer criticizes Smith because of Smith’s general support of free trade and his idealistic concept of a system of natural liberty. Pfeiffer, in contrast, was much more in favor of state interventions, given the lack of knowledge and irrational behavior of humans. While their political points of view differ, there are many theoretical similarities between them.
Die steigende Zahl an Unternehmen, die nach der Corporate Sustainability Reporting Directive berichtspflichtig werden, müssen in ihrer Nachhaltigkeitsberichterstattung neben der eigenen Geschäftstätigkeit auch die Wertschöpfungskette abbilden. Damit werden auch nicht direkt berichtspflichtige Unternehmen häufig zur Weitergabe von Nachhaltigkeitsinformationen aufgefordert. Um eine Vereinheitlichung der Informationsanforderungen zu erreichen, hat die EFRAG einen Standardentwurf entwickelt und zur Konsultation gestellt (VSME-Standard). Dieser Beitrag stellt den VSME-Standardentwurf kurz in Grundzügen vor und geht anschließend auf Forderungen und Rückmeldungen, die im Rahmen der Konsultation ent-standen sind, ein.
The energy transition towards renewable energies for the overall energy supply (electricity, heat, mobility, etc.) is already well advanced and the further expansion is planned. The volatility of renewable energies is being addressed by the hydrogen technology. However, there is still a need for optimization of the cost-efficient reconversion of stored energy in the form of hydrogen, e.g. in applications for decarbonization of the power grid or of the mobility sector. For instance, the cost of an automotive low-temperature polymer electrolyte membrane fuel cell (PEMFC) must be lowered by reducing the platinum loading and the lifetime must be further improved to achieve the competitiveness of this technology.
The aim of the present thesis was to develop membrane electrode assemblies (MEAs) with ultra-low platinum loading, high performance and increased lifetime for the use in PEMFCs. They are fabricated by an innovative MEA preparation process based on the pulse electrodeposition of platinum (Pt) using carbon nanofibers (CNFs) as a catalyst support with enhanced resistance to carbon oxidation reaction.
The design of the MEA preparation process and the development of ultra-low Pt-loaded anodes and cathodes was the starting point of this thesis. It was found that the Pt/CNF catalyst used on the anode side had better characteristics than a commercial Pt/C catalyst, since the same power output of 0.525 W cm-2 was obtained with 10 .....
Um CO2-frei, mit erneuerbaren Technologien, Energie umzuwandeln, zu speichern und Wasserstoff zu produzieren, bedarf es einer Technologie, welche zu hoher Leistungsdichte, Flexibilität und Effizienz fähig ist. Die Polymerelektrolytmembran-(PEM) Wasser-Elektrolyse besitzt das Potential alle diese Attribute in sich zu vereinen, weswegen sie eine Schlüsseltechnologie bei dem Umstieg auf erneuerbare Energien darstellt. Die aktuellen hohen Beladungen der Elektroden mit Katalysatormaterial für die Sauerstoffentwicklungsreaktion (OER) wie Iridium und die bisher noch ungenügend erforschten Alterungsmechanismen dieser über eine längere Nutzdauer, sind bisher die größten Herausforderungen für die großflächige industrielle Nutzung dieser Systeme. Mit diesem Hintergrund stellt sich diese Arbeit der Herausforderung die untersuchten PEM-Anoden mit reduzierter Beladung, hinsichtlich ihrer Stabilität und Alterungsmechanismen zu charakterisieren und den ersten Schritt in Richtung eines Degradationsprotokolls zu machen, um solche Elektroden künftig zu untersuchen. In der vorgegangenen Arbeit, aus welcher die hier untersuchten Proben stammen, wurden Elektroden hergestellt, indem auf ein Titansubstrat eine Supportschicht mit unterstöchiometrischem Titanoxid eingesintert wurde, auf welchem wiederum das Iridium galvanisch gepulst abgeschieden wurde. Die Beladung mit Katalysatormaterial war hier geringer als der der Stand der Technik, doch die katalytische Aktivität wurde durch die optimierte Elektrodenarchitektur erhöht. In dieser Arbeit wurden die Elektroden einem elektrochemischen Degradationsprotokoll unterzogen, welches sich aus Cyclovoltametrie (CV) gefolgt von Chronopotentiometrie (CP) und Chronoamperometrie, mit wechselnden Potentialen, zusammensetzt. Der dabei verwendete Elektrolyt wurde ebenfalls durch Filtration und Titration auf Zerfallsprodukte der Elektroden hin untersucht. Nach erfolgter Degradation wurden die Elektroden auf topografische Änderungen, mittels Rasterelektronenmikroskop (REM), Änderungen der Kristallinität, mittels Röntgendiffraktometrie (XRD) und Änderungen der Elementenkonzentration durch Röntgenfluoreszenzspektroskopie (XRF) hin untersucht.
Diese Arbeit befasst sich mit der Entwicklung einer Titanträgerlage, die anschließend als Supportstruktur für den Anodenkatalysator eines PEM-Elektrolyseurs genutzt werden soll, sowie mit der Parametrisierung der hierfür genutzten Lasersinteranlage.
Dafür wird 1 mg cm-2 unterstöchiometrisches Titanoxid (TiOx) auf eine poröse Titantransportschicht gesprüht und anschließend mit einem gepulsten Laser in Argonatmosphäre gesintert, um beide Materialien zu verbinden und die Oberfläche gezielt verändern zu können. Da die benötigte Menge des unterstöchiometrischen TiOx-Pulvers nicht abschätzbar war, wurden die Arbeiten mit kommerziell verfügbarem Titandioxid-(TiOx) Pulver durchgeführt.
Im ersten Schritt wurde ein bestehender Sprühprozess optimiert. Der Fokus lag dabei auf einem gleichmäßigen Sprühergebnis und dem reproduzierbaren Erreichen einer vorgegebenen Beladung. Die Optimierung wurde auf Titanblech und auf porösen Titansubstraten durchgeführt.
Anschließend wurde das verwendetet Lasersystem, das einen luftgekühlten Neodymdotierten Yttrium-Aluminium-Granat (Nd:YAG)-Festkörperlaser mit einer Wellenlänge von 355 nm nutzt, parametrisiert. Das Erreichen der Bearbeitungsschwelle und die maximalen Spotgrößen bei verschiedenen Diodenströmen wurden untersucht. Anschließend wurde die Frequenz erhöht, dies führte zu geringeren Einzelpulsenergien und daher zu neuen Bearbeitungsschwellen bei den unterschiedlichen Diodenströmen. Die Variierung des Vorschubs führt zu einer Änderung der eingebrachten Energie pro Fläche und wirkt sich direkt auf die Sinterdauer aus. Als letztes wurde der Einfluss des Linienabstandes untersucht. Wenn der Linienabstand unterhalb des Wertes gehalten wird, ab dem eine streifenfreie Oberfläche entsteht, wirkt die Verkleinerung des Linienabstandes wie die Verringerung des Vorschubs.
Um grünen Wasserstoff effizient als Energieträger nutzen zu können, ist die Entwicklung von haltbaren und aktiven Katalysatorschichten für Brennstoffzellen und Elektrolyseuren von äußerster Wichtigkeit. Eine große Herausforderung ist, dass konventionelle C/Pt-Katalysatoren eine starke Korrosionsreaktion durchlaufen und mit hohen Kosten verknüpft sind. Weswegen alternative Kohlenstoffträger wie Kohlenstoffnanofaser-Materialien entwickelt wurden, welche eine längere Haltbarkeit aufweisen können. In dieser Arbeit wurde die Aufbringung von Pt- und Ir-Nanopartikeln auf gesponnene Kohlenstoffnanofaser-Vliese untersucht. Es wurden erstmals in einer Flüssigkeit laserablatierte Pt-Nanoartikel mit einem PAN-Vlies versponnen oder in einem zweiten Syntheseverfahren auf ein Vlies aufgesprüht. Diese Methoden wurden mit der gepulsten galvanischen Abscheidung von Pt auf einem PAN-Vlies verglichen. Die Vliese wurden bezüglich ihres Graphitisierungsgrades, ihrer Partikelverteilung und ihrer Beständigkeit untersucht, einschließlich des Einflusses der Karbonisierungstemperatur. Die Raman- und XRF-Messungen ergaben eine Erhöhung des Graphitisierungsgrades und eine Abnahme der PAN-Reste mit dem Anstieg der Karbonisierungstemperatur. Elektrochemische Messungen und REM-Aufnahmen bestätigten die erfolgreiche Synthese von langzeitstabilen CNF-Vliesen mit einer hohen massenspezifischen aktiven Platinoberfläche und einer guten Nanopartikelverteilung. Diese Ergebnisse tragen zur Entwicklung von ökologischen und ökonomischen Katalysatorschichten bei.
Ni-based alloys are among the materials of choice in developing high-quality coatings for ambient and high temperature applications that require protection against intense wear and corrosion. The current study aims to develop and characterize NiCrBSi coatings with high wear resistance and improved adhesion to the substrate. Starting with nickel-based feedstock powders, thermally sprayed coatings were initially fabricated. Prior to deposition, the powders were characterized in terms of microstructure, particle size, chemical composition, flowability, and density. For comparison, three types of powders with different chemical compositions and characteristics were deposited onto a 1.7227 tempered steel substrate using oxyacetylene flame spraying, and subsequently, the coatings were inductively remelted. Ball-on-disc sliding wear testing was chosen to investigate the tribological properties of both the as-sprayed and induction-remelted coatings. The results reveal that, in the case of as-sprayed coatings, the main wear mechanisms were abrasive, independent of powder chemical composition, and correlated with intense wear losses due to the poor intersplat cohesion typical of flame-sprayed coatings. The remelting treatment improved the performance of the coatings in terms of wear compared to that of the as-sprayed ones, and the density and lower porosity achieved during the induction post-treatment had a significant positive role in this behavior.
Without proper post-processing (often using flame, furnace, laser remelting, and induction) or reinforcements’ addition, Ni-based flame-sprayed coatings generally manifest moderate adhesion to the substrate, high porosity, unmelted particles, undesirable oxides, or weak wear resistance and mechanical properties. The current research aimed to investigate the addition of ZrO2 as reinforcement to the self-fluxing alloy coatings. Mechanically mixed NiCrBSi-ZrO2 powders were thermally sprayed onto an industrially relevant high-grade steel. After thermal spraying, the samples were differently post-processed with a flame gun and with a vacuum furnace, respectively. Scanning electron microscopy showed a porosity reduction for the vacuum-heat-treated samples compared to that of the flame-post-processed ones. X-ray diffraction measurements showed differences in the main peaks of the patterns for the thermal processed samples compared to the as-sprayed ones, these having a direct influence on the mechanical behavior of the coatings. Although a slight microhardness decrease was observed in the case of vacuum-remelted samples, the overall low porosity and the phase differences helped the coating to perform better during wear-resistance testing, realized using a ball-on-disk arrangement, compared to the as-sprayed reference samples.
Among the FDM process variables, one of the less addressed in previous research is the filament color. Moreover, if not explicitly targeted, the filament color is usually not even mentioned.
Aiming to point out if, and to what extent, the color of the PLA filaments influences the dimensional precision and the mechanical strength of FDM prints, the authors of the present research carried out experiments on tensile specimens. The variable parameters were the layer height (0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm) and the material color (natural, black, red, grey). The experimental results clearly showed that the filament color is an influential factor for the dimensional accuracy as well as for the tensile strength of the FDM printed PLA parts. Moreover, the two way ANOVA test performed revealed that the strongest effect on the tensile strength was exerted by the PLA color (2 = 97.3%), followed by the layer height (2 = 85.5%) and the interaction between the PLA color and the layer height (2 = 80.0%). Under the same printing conditions, the best dimensional accuracy was ensured by the black PLA (0.17% width deviations, respectively 5.48% height deviations), whilst the grey PLA showed the highest ultimate tensile strength values (between 57.10 MPa and 59.82 MPa).
